python, hg: tow outside the environment.

they've served us well, and can ride off into the sunset.

1 files changed, 0 insertions, 1390 deletions

diff --git a/sys/src/cmd/python/Modules/gcmodule.c b/sys/src/cmd/python/Modules/gcmodule.c
deleted file mode 100644
index 6c5011cab..000000000
--- a/sys/src/cmd/python/Modules/gcmodule.c
+++ /dev/null
@@ -1,1390 +0,0 @@
-/*
-
-  Reference Cycle Garbage Collection
-  ==================================
-
-  Neil Schemenauer <nas@arctrix.com>
-
-  Based on a post on the python-dev list.  Ideas from Guido van Rossum,
-  Eric Tiedemann, and various others.
-
-  http://www.arctrix.com/nas/python/gc/
-  http://www.python.org/pipermail/python-dev/2000-March/003869.html
-  http://www.python.org/pipermail/python-dev/2000-March/004010.html
-  http://www.python.org/pipermail/python-dev/2000-March/004022.html
-
-  For a highlevel view of the collection process, read the collect
-  function.
-
-*/
-
-#include "Python.h"
-
-/* Get an object's GC head */
-#define AS_GC(o) ((PyGC_Head *)(o)-1)
-
-/* Get the object given the GC head */
-#define FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1))
-
-/*** Global GC state ***/
-
-struct gc_generation {
-	PyGC_Head head;
-	int threshold; /* collection threshold */
-	int count; /* count of allocations or collections of younger
-		      generations */
-};
-
-#define NUM_GENERATIONS 3
-#define GEN_HEAD(n) (&generations[n].head)
-
-/* linked lists of container objects */
-static struct gc_generation generations[NUM_GENERATIONS] = {
-	/* PyGC_Head,				threshold,	count */
-	{{{GEN_HEAD(0), GEN_HEAD(0), 0}},	700,		0},
-	{{{GEN_HEAD(1), GEN_HEAD(1), 0}},	10,		0},
-	{{{GEN_HEAD(2), GEN_HEAD(2), 0}},	10,		0},
-};
-
-PyGC_Head *_PyGC_generation0 = GEN_HEAD(0);
-
-static int enabled = 1; /* automatic collection enabled? */
-
-/* true if we are currently running the collector */
-static int collecting = 0;
-
-/* list of uncollectable objects */
-static PyObject *garbage = NULL;
-
-/* Python string to use if unhandled exception occurs */
-static PyObject *gc_str = NULL;
-
-/* Python string used to look for __del__ attribute. */
-static PyObject *delstr = NULL;
-
-/* set for debugging information */
-#define DEBUG_STATS		(1<<0) /* print collection statistics */
-#define DEBUG_COLLECTABLE	(1<<1) /* print collectable objects */
-#define DEBUG_UNCOLLECTABLE	(1<<2) /* print uncollectable objects */
-#define DEBUG_INSTANCES		(1<<3) /* print instances */
-#define DEBUG_OBJECTS		(1<<4) /* print other objects */
-#define DEBUG_SAVEALL		(1<<5) /* save all garbage in gc.garbage */
-#define DEBUG_LEAK		DEBUG_COLLECTABLE | \
-				DEBUG_UNCOLLECTABLE | \
-				DEBUG_INSTANCES | \
-				DEBUG_OBJECTS | \
-				DEBUG_SAVEALL
-static int debug;
-static PyObject *tmod = NULL;
-
-/*--------------------------------------------------------------------------
-gc_refs values.
-
-Between collections, every gc'ed object has one of two gc_refs values:
-
-GC_UNTRACKED
-    The initial state; objects returned by PyObject_GC_Malloc are in this
-    state.  The object doesn't live in any generation list, and its
-    tp_traverse slot must not be called.
-
-GC_REACHABLE
-    The object lives in some generation list, and its tp_traverse is safe to
-    call.  An object transitions to GC_REACHABLE when PyObject_GC_Track
-    is called.
-
-During a collection, gc_refs can temporarily take on other states:
-
->= 0
-    At the start of a collection, update_refs() copies the true refcount
-    to gc_refs, for each object in the generation being collected.
-    subtract_refs() then adjusts gc_refs so that it equals the number of
-    times an object is referenced directly from outside the generation
-    being collected.
-    gc_refs remains >= 0 throughout these steps.
-
-GC_TENTATIVELY_UNREACHABLE
-    move_unreachable() then moves objects not reachable (whether directly or
-    indirectly) from outside the generation into an "unreachable" set.
-    Objects that are found to be reachable have gc_refs set to GC_REACHABLE
-    again.  Objects that are found to be unreachable have gc_refs set to
-    GC_TENTATIVELY_UNREACHABLE.  It's "tentatively" because the pass doing
-    this can't be sure until it ends, and GC_TENTATIVELY_UNREACHABLE may
-    transition back to GC_REACHABLE.
-
-    Only objects with GC_TENTATIVELY_UNREACHABLE still set are candidates
-    for collection.  If it's decided not to collect such an object (e.g.,
-    it has a __del__ method), its gc_refs is restored to GC_REACHABLE again.
-----------------------------------------------------------------------------
-*/
-#define GC_UNTRACKED			_PyGC_REFS_UNTRACKED
-#define GC_REACHABLE			_PyGC_REFS_REACHABLE
-#define GC_TENTATIVELY_UNREACHABLE	_PyGC_REFS_TENTATIVELY_UNREACHABLE
-
-#define IS_TRACKED(o) ((AS_GC(o))->gc.gc_refs != GC_UNTRACKED)
-#define IS_REACHABLE(o) ((AS_GC(o))->gc.gc_refs == GC_REACHABLE)
-#define IS_TENTATIVELY_UNREACHABLE(o) ( \
-	(AS_GC(o))->gc.gc_refs == GC_TENTATIVELY_UNREACHABLE)
-
-/*** list functions ***/
-
-static void
-gc_list_init(PyGC_Head *list)
-{
-	list->gc.gc_prev = list;
-	list->gc.gc_next = list;
-}
-
-static int
-gc_list_is_empty(PyGC_Head *list)
-{
-	return (list->gc.gc_next == list);
-}
-
-#if 0
-/* This became unused after gc_list_move() was introduced. */
-/* Append `node` to `list`. */
-static void
-gc_list_append(PyGC_Head *node, PyGC_Head *list)
-{
-	node->gc.gc_next = list;
-	node->gc.gc_prev = list->gc.gc_prev;
-	node->gc.gc_prev->gc.gc_next = node;
-	list->gc.gc_prev = node;
-}
-#endif
-
-/* Remove `node` from the gc list it's currently in. */
-static void
-gc_list_remove(PyGC_Head *node)
-{
-	node->gc.gc_prev->gc.gc_next = node->gc.gc_next;
-	node->gc.gc_next->gc.gc_prev = node->gc.gc_prev;
-	node->gc.gc_next = NULL; /* object is not currently tracked */
-}
-
-/* Move `node` from the gc list it's currently in (which is not explicitly
- * named here) to the end of `list`.  This is semantically the same as
- * gc_list_remove(node) followed by gc_list_append(node, list).
- */
-static void
-gc_list_move(PyGC_Head *node, PyGC_Head *list)
-{
-	PyGC_Head *new_prev;
-	PyGC_Head *current_prev = node->gc.gc_prev;
-	PyGC_Head *current_next = node->gc.gc_next;
-	/* Unlink from current list. */
-	current_prev->gc.gc_next = current_next;
-	current_next->gc.gc_prev = current_prev;
-	/* Relink at end of new list. */
-	new_prev = node->gc.gc_prev = list->gc.gc_prev;
-	new_prev->gc.gc_next = list->gc.gc_prev = node;
-	node->gc.gc_next = list;
-}
-
-/* append list `from` onto list `to`; `from` becomes an empty list */
-static void
-gc_list_merge(PyGC_Head *from, PyGC_Head *to)
-{
-	PyGC_Head *tail;
-	assert(from != to);
-	if (!gc_list_is_empty(from)) {
-		tail = to->gc.gc_prev;
-		tail->gc.gc_next = from->gc.gc_next;
-		tail->gc.gc_next->gc.gc_prev = tail;
-		to->gc.gc_prev = from->gc.gc_prev;
-		to->gc.gc_prev->gc.gc_next = to;
-	}
-	gc_list_init(from);
-}
-
-static Py_ssize_t
-gc_list_size(PyGC_Head *list)
-{
-	PyGC_Head *gc;
-	Py_ssize_t n = 0;
-	for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) {
-		n++;
-	}
-	return n;
-}
-
-/* Append objects in a GC list to a Python list.
- * Return 0 if all OK, < 0 if error (out of memory for list).
- */
-static int
-append_objects(PyObject *py_list, PyGC_Head *gc_list)
-{
-	PyGC_Head *gc;
-	for (gc = gc_list->gc.gc_next; gc != gc_list; gc = gc->gc.gc_next) {
-		PyObject *op = FROM_GC(gc);
-		if (op != py_list) {
-			if (PyList_Append(py_list, op)) {
-				return -1; /* exception */
-			}
-		}
-	}
-	return 0;
-}
-
-/*** end of list stuff ***/
-
-
-/* Set all gc_refs = ob_refcnt.  After this, gc_refs is > 0 for all objects
- * in containers, and is GC_REACHABLE for all tracked gc objects not in
- * containers.
- */
-static void
-update_refs(PyGC_Head *containers)
-{
-	PyGC_Head *gc = containers->gc.gc_next;
-	for (; gc != containers; gc = gc->gc.gc_next) {
-		assert(gc->gc.gc_refs == GC_REACHABLE);
-		gc->gc.gc_refs = FROM_GC(gc)->ob_refcnt;
-		/* Python's cyclic gc should never see an incoming refcount
-		 * of 0:  if something decref'ed to 0, it should have been
-		 * deallocated immediately at that time.
-		 * Possible cause (if the assert triggers):  a tp_dealloc
-		 * routine left a gc-aware object tracked during its teardown
-		 * phase, and did something-- or allowed something to happen --
-		 * that called back into Python.  gc can trigger then, and may
-		 * see the still-tracked dying object.  Before this assert
-		 * was added, such mistakes went on to allow gc to try to
-		 * delete the object again.  In a debug build, that caused
-		 * a mysterious segfault, when _Py_ForgetReference tried
-		 * to remove the object from the doubly-linked list of all
-		 * objects a second time.  In a release build, an actual
-		 * double deallocation occurred, which leads to corruption
-		 * of the allocator's internal bookkeeping pointers.  That's
-		 * so serious that maybe this should be a release-build
-		 * check instead of an assert?
-		 */
-		assert(gc->gc.gc_refs != 0);
-	}
-}
-
-/* A traversal callback for subtract_refs. */
-static int
-visit_decref(PyObject *op, void *data)
-{
-        assert(op != NULL);
-	if (PyObject_IS_GC(op)) {
-		PyGC_Head *gc = AS_GC(op);
-		/* We're only interested in gc_refs for objects in the
-		 * generation being collected, which can be recognized
-		 * because only they have positive gc_refs.
-		 */
-		assert(gc->gc.gc_refs != 0); /* else refcount was too small */
-		if (gc->gc.gc_refs > 0)
-			gc->gc.gc_refs--;
-	}
-	return 0;
-}
-
-/* Subtract internal references from gc_refs.  After this, gc_refs is >= 0
- * for all objects in containers, and is GC_REACHABLE for all tracked gc
- * objects not in containers.  The ones with gc_refs > 0 are directly
- * reachable from outside containers, and so can't be collected.
- */
-static void
-subtract_refs(PyGC_Head *containers)
-{
-	traverseproc traverse;
-	PyGC_Head *gc = containers->gc.gc_next;
-	for (; gc != containers; gc=gc->gc.gc_next) {
-		traverse = FROM_GC(gc)->ob_type->tp_traverse;
-		(void) traverse(FROM_GC(gc),
-			       (visitproc)visit_decref,
-			       NULL);
-	}
-}
-
-/* A traversal callback for move_unreachable. */
-static int
-visit_reachable(PyObject *op, PyGC_Head *reachable)
-{
-	if (PyObject_IS_GC(op)) {
-		PyGC_Head *gc = AS_GC(op);
-		const Py_ssize_t gc_refs = gc->gc.gc_refs;
-
-		if (gc_refs == 0) {
-			/* This is in move_unreachable's 'young' list, but
-			 * the traversal hasn't yet gotten to it.  All
-			 * we need to do is tell move_unreachable that it's
-			 * reachable.
-			 */
-			gc->gc.gc_refs = 1;
-		}
-		else if (gc_refs == GC_TENTATIVELY_UNREACHABLE) {
-			/* This had gc_refs = 0 when move_unreachable got
-			 * to it, but turns out it's reachable after all.
-			 * Move it back to move_unreachable's 'young' list,
-			 * and move_unreachable will eventually get to it
-			 * again.
-			 */
-			gc_list_move(gc, reachable);
-			gc->gc.gc_refs = 1;
-		}
-		/* Else there's nothing to do.
-		 * If gc_refs > 0, it must be in move_unreachable's 'young'
-		 * list, and move_unreachable will eventually get to it.
-		 * If gc_refs == GC_REACHABLE, it's either in some other
-		 * generation so we don't care about it, or move_unreachable
-		 * already dealt with it.
-		 * If gc_refs == GC_UNTRACKED, it must be ignored.
-		 */
-		 else {
-		 	assert(gc_refs > 0
-		 	       || gc_refs == GC_REACHABLE
-		 	       || gc_refs == GC_UNTRACKED);
-		 }
-	}
-	return 0;
-}
-
-/* Move the unreachable objects from young to unreachable.  After this,
- * all objects in young have gc_refs = GC_REACHABLE, and all objects in
- * unreachable have gc_refs = GC_TENTATIVELY_UNREACHABLE.  All tracked
- * gc objects not in young or unreachable still have gc_refs = GC_REACHABLE.
- * All objects in young after this are directly or indirectly reachable
- * from outside the original young; and all objects in unreachable are
- * not.
- */
-static void
-move_unreachable(PyGC_Head *young, PyGC_Head *unreachable)
-{
-	PyGC_Head *gc = young->gc.gc_next;
-
-	/* Invariants:  all objects "to the left" of us in young have gc_refs
-	 * = GC_REACHABLE, and are indeed reachable (directly or indirectly)
-	 * from outside the young list as it was at entry.  All other objects
-	 * from the original young "to the left" of us are in unreachable now,
-	 * and have gc_refs = GC_TENTATIVELY_UNREACHABLE.  All objects to the
-	 * left of us in 'young' now have been scanned, and no objects here
-	 * or to the right have been scanned yet.
-	 */
-
-	while (gc != young) {
-		PyGC_Head *next;
-
-		if (gc->gc.gc_refs) {
-                        /* gc is definitely reachable from outside the
-                         * original 'young'.  Mark it as such, and traverse
-                         * its pointers to find any other objects that may
-                         * be directly reachable from it.  Note that the
-                         * call to tp_traverse may append objects to young,
-                         * so we have to wait until it returns to determine
-                         * the next object to visit.
-                         */
-                        PyObject *op = FROM_GC(gc);
-                        traverseproc traverse = op->ob_type->tp_traverse;
-                        assert(gc->gc.gc_refs > 0);
-                        gc->gc.gc_refs = GC_REACHABLE;
-                        (void) traverse(op,
-                                        (visitproc)visit_reachable,
-                                        (void *)young);
-                        next = gc->gc.gc_next;
-		}
-		else {
-			/* This *may* be unreachable.  To make progress,
-			 * assume it is.  gc isn't directly reachable from
-			 * any object we've already traversed, but may be
-			 * reachable from an object we haven't gotten to yet.
-			 * visit_reachable will eventually move gc back into
-			 * young if that's so, and we'll see it again.
-			 */
-			next = gc->gc.gc_next;
-			gc_list_move(gc, unreachable);
-			gc->gc.gc_refs = GC_TENTATIVELY_UNREACHABLE;
-		}
-		gc = next;
-	}
-}
-
-/* Return true if object has a finalization method.
- * CAUTION:  An instance of an old-style class has to be checked for a
- *__del__ method, and earlier versions of this used to call PyObject_HasAttr,
- * which in turn could call the class's __getattr__ hook (if any).  That
- * could invoke arbitrary Python code, mutating the object graph in arbitrary
- * ways, and that was the source of some excruciatingly subtle bugs.
- */
-static int
-has_finalizer(PyObject *op)
-{
-	if (PyInstance_Check(op)) {
-		assert(delstr != NULL);
-		return _PyInstance_Lookup(op, delstr) != NULL;
-	}
-	else if (PyType_HasFeature(op->ob_type, Py_TPFLAGS_HEAPTYPE))
-		return op->ob_type->tp_del != NULL;
-	else if (PyGen_CheckExact(op))
-		return PyGen_NeedsFinalizing((PyGenObject *)op);
-	else
-		return 0;
-}
-
-/* Move the objects in unreachable with __del__ methods into `finalizers`.
- * Objects moved into `finalizers` have gc_refs set to GC_REACHABLE; the
- * objects remaining in unreachable are left at GC_TENTATIVELY_UNREACHABLE.
- */
-static void
-move_finalizers(PyGC_Head *unreachable, PyGC_Head *finalizers)
-{
-	PyGC_Head *gc;
-	PyGC_Head *next;
-
-	/* March over unreachable.  Move objects with finalizers into
-	 * `finalizers`.
-	 */
-	for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) {
-		PyObject *op = FROM_GC(gc);
-
-		assert(IS_TENTATIVELY_UNREACHABLE(op));
-		next = gc->gc.gc_next;
-
-		if (has_finalizer(op)) {
-			gc_list_move(gc, finalizers);
-			gc->gc.gc_refs = GC_REACHABLE;
-		}
-	}
-}
-
-/* A traversal callback for move_finalizer_reachable. */
-static int
-visit_move(PyObject *op, PyGC_Head *tolist)
-{
-	if (PyObject_IS_GC(op)) {
-		if (IS_TENTATIVELY_UNREACHABLE(op)) {
-			PyGC_Head *gc = AS_GC(op);
-			gc_list_move(gc, tolist);
-			gc->gc.gc_refs = GC_REACHABLE;
-		}
-	}
-	return 0;
-}
-
-/* Move objects that are reachable from finalizers, from the unreachable set
- * into finalizers set.
- */
-static void
-move_finalizer_reachable(PyGC_Head *finalizers)
-{
-	traverseproc traverse;
-	PyGC_Head *gc = finalizers->gc.gc_next;
-	for (; gc != finalizers; gc = gc->gc.gc_next) {
-		/* Note that the finalizers list may grow during this. */
-		traverse = FROM_GC(gc)->ob_type->tp_traverse;
-		(void) traverse(FROM_GC(gc),
-				(visitproc)visit_move,
-				(void *)finalizers);
-	}
-}
-
-/* Clear all weakrefs to unreachable objects, and if such a weakref has a
- * callback, invoke it if necessary.  Note that it's possible for such
- * weakrefs to be outside the unreachable set -- indeed, those are precisely
- * the weakrefs whose callbacks must be invoked.  See gc_weakref.txt for
- * overview & some details.  Some weakrefs with callbacks may be reclaimed
- * directly by this routine; the number reclaimed is the return value.  Other
- * weakrefs with callbacks may be moved into the `old` generation.  Objects
- * moved into `old` have gc_refs set to GC_REACHABLE; the objects remaining in
- * unreachable are left at GC_TENTATIVELY_UNREACHABLE.  When this returns,
- * no object in `unreachable` is weakly referenced anymore.
- */
-static int
-handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
-{
-	PyGC_Head *gc;
-	PyObject *op;		/* generally FROM_GC(gc) */
-	PyWeakReference *wr;	/* generally a cast of op */
-	PyGC_Head wrcb_to_call;	/* weakrefs with callbacks to call */
-	PyGC_Head *next;
-	int num_freed = 0;
-
-	gc_list_init(&wrcb_to_call);
-
-	/* Clear all weakrefs to the objects in unreachable.  If such a weakref
-	 * also has a callback, move it into `wrcb_to_call` if the callback
-	 * needs to be invoked.  Note that we cannot invoke any callbacks until
-	 * all weakrefs to unreachable objects are cleared, lest the callback
-	 * resurrect an unreachable object via a still-active weakref.  We
-	 * make another pass over wrcb_to_call, invoking callbacks, after this
-	 * pass completes.
-	 */
-	for (gc = unreachable->gc.gc_next; gc != unreachable; gc = next) {
-		PyWeakReference **wrlist;
-
-		op = FROM_GC(gc);
-		assert(IS_TENTATIVELY_UNREACHABLE(op));
-		next = gc->gc.gc_next;
-
-		if (! PyType_SUPPORTS_WEAKREFS(op->ob_type))
-			continue;
-
-		/* It supports weakrefs.  Does it have any? */
-		wrlist = (PyWeakReference **)
-			     		PyObject_GET_WEAKREFS_LISTPTR(op);
-
-		/* `op` may have some weakrefs.  March over the list, clear
-		 * all the weakrefs, and move the weakrefs with callbacks
-		 * that must be called into wrcb_to_call.
-		 */
-		for (wr = *wrlist; wr != NULL; wr = *wrlist) {
-			PyGC_Head *wrasgc;	/* AS_GC(wr) */
-
-			/* _PyWeakref_ClearRef clears the weakref but leaves
-			 * the callback pointer intact.  Obscure:  it also
-			 * changes *wrlist.
-			 */
-			assert(wr->wr_object == op);
-			_PyWeakref_ClearRef(wr);
-			assert(wr->wr_object == Py_None);
-			if (wr->wr_callback == NULL)
-				continue;	/* no callback */
-
-	/* Headache time.  `op` is going away, and is weakly referenced by
-	 * `wr`, which has a callback.  Should the callback be invoked?  If wr
-	 * is also trash, no:
-	 *
-	 * 1. There's no need to call it.  The object and the weakref are
-	 *    both going away, so it's legitimate to pretend the weakref is
-	 *    going away first.  The user has to ensure a weakref outlives its
-	 *    referent if they want a guarantee that the wr callback will get
-	 *    invoked.
-	 *
-	 * 2. It may be catastrophic to call it.  If the callback is also in
-	 *    cyclic trash (CT), then although the CT is unreachable from
-	 *    outside the current generation, CT may be reachable from the
-	 *    callback.  Then the callback could resurrect insane objects.
-	 *
-	 * Since the callback is never needed and may be unsafe in this case,
-	 * wr is simply left in the unreachable set.  Note that because we
-	 * already called _PyWeakref_ClearRef(wr), its callback will never
-	 * trigger.
-	 *
-	 * OTOH, if wr isn't part of CT, we should invoke the callback:  the
-	 * weakref outlived the trash.  Note that since wr isn't CT in this
-	 * case, its callback can't be CT either -- wr acted as an external
-	 * root to this generation, and therefore its callback did too.  So
-	 * nothing in CT is reachable from the callback either, so it's hard
-	 * to imagine how calling it later could create a problem for us.  wr
-	 * is moved to wrcb_to_call in this case.
-	 */
-	 		if (IS_TENTATIVELY_UNREACHABLE(wr))
-	 			continue;
-			assert(IS_REACHABLE(wr));
-
-			/* Create a new reference so that wr can't go away
-			 * before we can process it again.
-			 */
-			Py_INCREF(wr);
-
-			/* Move wr to wrcb_to_call, for the next pass. */
-			wrasgc = AS_GC(wr);
-			assert(wrasgc != next); /* wrasgc is reachable, but
-			                           next isn't, so they can't
-			                           be the same */
-			gc_list_move(wrasgc, &wrcb_to_call);
-		}
-	}
-
-	/* Invoke the callbacks we decided to honor.  It's safe to invoke them
-	 * because they can't reference unreachable objects.
-	 */
-	while (! gc_list_is_empty(&wrcb_to_call)) {
-		PyObject *temp;
-		PyObject *callback;
-
-		gc = wrcb_to_call.gc.gc_next;
-		op = FROM_GC(gc);
-		assert(IS_REACHABLE(op));
-		assert(PyWeakref_Check(op));
-		wr = (PyWeakReference *)op;
-		callback = wr->wr_callback;
-		assert(callback != NULL);
-
-		/* copy-paste of weakrefobject.c's handle_callback() */
-		temp = PyObject_CallFunctionObjArgs(callback, wr, NULL);
-		if (temp == NULL)
-			PyErr_WriteUnraisable(callback);
-		else
-			Py_DECREF(temp);
-
-		/* Give up the reference we created in the first pass.  When
-		 * op's refcount hits 0 (which it may or may not do right now),
-		 * op's tp_dealloc will decref op->wr_callback too.  Note
-		 * that the refcount probably will hit 0 now, and because this
-		 * weakref was reachable to begin with, gc didn't already
-		 * add it to its count of freed objects.  Example:  a reachable
-		 * weak value dict maps some key to this reachable weakref.
-		 * The callback removes this key->weakref mapping from the
-		 * dict, leaving no other references to the weakref (excepting
-		 * ours).
-		 */
-		Py_DECREF(op);
-		if (wrcb_to_call.gc.gc_next == gc) {
-			/* object is still alive -- move it */
-			gc_list_move(gc, old);
-		}
-		else
-			++num_freed;
-	}
-
-	return num_freed;
-}
-
-static void
-debug_instance(char *msg, PyInstanceObject *inst)
-{
-	char *cname;
-	/* simple version of instance_repr */
-	PyObject *classname = inst->in_class->cl_name;
-	if (classname != NULL && PyString_Check(classname))
-		cname = PyString_AsString(classname);
-	else
-		cname = "?";
-	PySys_WriteStderr("gc: %.100s <%.100s instance at %p>\n",
-			  msg, cname, inst);
-}
-
-static void
-debug_cycle(char *msg, PyObject *op)
-{
-	if ((debug & DEBUG_INSTANCES) && PyInstance_Check(op)) {
-		debug_instance(msg, (PyInstanceObject *)op);
-	}
-	else if (debug & DEBUG_OBJECTS) {
-		PySys_WriteStderr("gc: %.100s <%.100s %p>\n",
-				  msg, op->ob_type->tp_name, op);
-	}
-}
-
-/* Handle uncollectable garbage (cycles with finalizers, and stuff reachable
- * only from such cycles).
- * If DEBUG_SAVEALL, all objects in finalizers are appended to the module
- * garbage list (a Python list), else only the objects in finalizers with
- * __del__ methods are appended to garbage.  All objects in finalizers are
- * merged into the old list regardless.
- * Returns 0 if all OK, <0 on error (out of memory to grow the garbage list).
- * The finalizers list is made empty on a successful return.
- */
-static int
-handle_finalizers(PyGC_Head *finalizers, PyGC_Head *old)
-{
-	PyGC_Head *gc = finalizers->gc.gc_next;
-
-	if (garbage == NULL) {
-		garbage = PyList_New(0);
-		if (garbage == NULL)
-			Py_FatalError("gc couldn't create gc.garbage list");
-	}
-	for (; gc != finalizers; gc = gc->gc.gc_next) {
-		PyObject *op = FROM_GC(gc);
-
-		if ((debug & DEBUG_SAVEALL) || has_finalizer(op)) {
-			if (PyList_Append(garbage, op) < 0)
-				return -1;
-		}
-	}
-
-	gc_list_merge(finalizers, old);
-	return 0;
-}
-
-/* Break reference cycles by clearing the containers involved.	This is
- * tricky business as the lists can be changing and we don't know which
- * objects may be freed.  It is possible I screwed something up here.
- */
-static void
-delete_garbage(PyGC_Head *collectable, PyGC_Head *old)
-{
-	inquiry clear;
-
-	while (!gc_list_is_empty(collectable)) {
-		PyGC_Head *gc = collectable->gc.gc_next;
-		PyObject *op = FROM_GC(gc);
-
-		assert(IS_TENTATIVELY_UNREACHABLE(op));
-		if (debug & DEBUG_SAVEALL) {
-			PyList_Append(garbage, op);
-		}
-		else {
-			if ((clear = op->ob_type->tp_clear) != NULL) {
-				Py_INCREF(op);
-				clear(op);
-				Py_DECREF(op);
-			}
-		}
-		if (collectable->gc.gc_next == gc) {
-			/* object is still alive, move it, it may die later */
-			gc_list_move(gc, old);
-			gc->gc.gc_refs = GC_REACHABLE;
-		}
-	}
-}
-
-/* This is the main function.  Read this to understand how the
- * collection process works. */
-static Py_ssize_t
-collect(int generation)
-{
-	int i;
-	Py_ssize_t m = 0; /* # objects collected */
-	Py_ssize_t n = 0; /* # unreachable objects that couldn't be collected */
-	PyGC_Head *young; /* the generation we are examining */
-	PyGC_Head *old; /* next older generation */
-	PyGC_Head unreachable; /* non-problematic unreachable trash */
-	PyGC_Head finalizers;  /* objects with, & reachable from, __del__ */
-	PyGC_Head *gc;
-	double t1 = 0.0;
-
-	if (delstr == NULL) {
-		delstr = PyString_InternFromString("__del__");
-		if (delstr == NULL)
-			Py_FatalError("gc couldn't allocate \"__del__\"");
-	}
-
-	if (debug & DEBUG_STATS) {
-		if (tmod != NULL) {
-			PyObject *f = PyObject_CallMethod(tmod, "time", NULL);
-			if (f == NULL) {
-				PyErr_Clear();
-			}
-			else {
-				t1 = PyFloat_AsDouble(f);
-				Py_DECREF(f);
-			}
-		}
-		PySys_WriteStderr("gc: collecting generation %d...\n",
-				  generation);
-		PySys_WriteStderr("gc: objects in each generation:");
-		for (i = 0; i < NUM_GENERATIONS; i++)
-			PySys_WriteStderr(" %" PY_FORMAT_SIZE_T "d",
-					  gc_list_size(GEN_HEAD(i)));
-		PySys_WriteStderr("\n");
-	}
-
-	/* update collection and allocation counters */
-	if (generation+1 < NUM_GENERATIONS)
-		generations[generation+1].count += 1;
-	for (i = 0; i <= generation; i++)
-		generations[i].count = 0;
-
-	/* merge younger generations with one we are currently collecting */
-	for (i = 0; i < generation; i++) {
-		gc_list_merge(GEN_HEAD(i), GEN_HEAD(generation));
-	}
-
-	/* handy references */
-	young = GEN_HEAD(generation);
-	if (generation < NUM_GENERATIONS-1)
-		old = GEN_HEAD(generation+1);
-	else
-		old = young;
-
-	/* Using ob_refcnt and gc_refs, calculate which objects in the
-	 * container set are reachable from outside the set (i.e., have a
-	 * refcount greater than 0 when all the references within the
-	 * set are taken into account).
-	 */
-	update_refs(young);
-	subtract_refs(young);
-
-	/* Leave everything reachable from outside young in young, and move
-	 * everything else (in young) to unreachable.
-	 * NOTE:  This used to move the reachable objects into a reachable
-	 * set instead.  But most things usually turn out to be reachable,
-	 * so it's more efficient to move the unreachable things.
-	 */
-	gc_list_init(&unreachable);
-	move_unreachable(young, &unreachable);
-
-	/* Move reachable objects to next generation. */
-	if (young != old)
-		gc_list_merge(young, old);
-
-	/* All objects in unreachable are trash, but objects reachable from
-	 * finalizers can't safely be deleted.  Python programmers should take
-	 * care not to create such things.  For Python, finalizers means
-	 * instance objects with __del__ methods.  Weakrefs with callbacks
-	 * can also call arbitrary Python code but they will be dealt with by
-	 * handle_weakrefs().
- 	 */
-	gc_list_init(&finalizers);
-	move_finalizers(&unreachable, &finalizers);
-	/* finalizers contains the unreachable objects with a finalizer;
-	 * unreachable objects reachable *from* those are also uncollectable,
-	 * and we move those into the finalizers list too.
-	 */
-	move_finalizer_reachable(&finalizers);
-
-	/* Collect statistics on collectable objects found and print
-	 * debugging information.
-	 */
-	for (gc = unreachable.gc.gc_next; gc != &unreachable;
-			gc = gc->gc.gc_next) {
-		m++;
-		if (debug & DEBUG_COLLECTABLE) {
-			debug_cycle("collectable", FROM_GC(gc));
-		}
-		if (tmod != NULL && (debug & DEBUG_STATS)) {
-			PyObject *f = PyObject_CallMethod(tmod, "time", NULL);
-			if (f == NULL) {
-				PyErr_Clear();
-			}
-			else {
-				t1 = PyFloat_AsDouble(f)-t1;
-				Py_DECREF(f);
-				PySys_WriteStderr("gc: %.4fs elapsed.\n", t1);
-			}
-		}
-	}
-
-	/* Clear weakrefs and invoke callbacks as necessary. */
-	m += handle_weakrefs(&unreachable, old);
-
-	/* Call tp_clear on objects in the unreachable set.  This will cause
-	 * the reference cycles to be broken.  It may also cause some objects
-	 * in finalizers to be freed.
-	 */
-	delete_garbage(&unreachable, old);
-
-	/* Collect statistics on uncollectable objects found and print
-	 * debugging information. */
-	for (gc = finalizers.gc.gc_next;
-	     gc != &finalizers;
-	     gc = gc->gc.gc_next) {
-		n++;
-		if (debug & DEBUG_UNCOLLECTABLE)
-			debug_cycle("uncollectable", FROM_GC(gc));
-	}
-	if (debug & DEBUG_STATS) {
-		if (m == 0 && n == 0)
-			PySys_WriteStderr("gc: done.\n");
-		else
-			PySys_WriteStderr(
-			    "gc: done, "
-			    "%" PY_FORMAT_SIZE_T "d unreachable, "
-			    "%" PY_FORMAT_SIZE_T "d uncollectable.\n",
-			    n+m, n);
-	}
-
-	/* Append instances in the uncollectable set to a Python
-	 * reachable list of garbage.  The programmer has to deal with
-	 * this if they insist on creating this type of structure.
-	 */
-	(void)handle_finalizers(&finalizers, old);
-
-	if (PyErr_Occurred()) {
-		if (gc_str == NULL)
-			gc_str = PyString_FromString("garbage collection");
-		PyErr_WriteUnraisable(gc_str);
-		Py_FatalError("unexpected exception during garbage collection");
-	}
-	return n+m;
-}
-
-static Py_ssize_t
-collect_generations(void)
-{
-	int i;
-	Py_ssize_t n = 0;
-
-	/* Find the oldest generation (higest numbered) where the count
-	 * exceeds the threshold.  Objects in the that generation and
-	 * generations younger than it will be collected. */
-	for (i = NUM_GENERATIONS-1; i >= 0; i--) {
-		if (generations[i].count > generations[i].threshold) {
-			n = collect(i);
-			break;
-		}
-	}
-	return n;
-}
-
-PyDoc_STRVAR(gc_enable__doc__,
-"enable() -> None\n"
-"\n"
-"Enable automatic garbage collection.\n");
-
-static PyObject *
-gc_enable(PyObject *self, PyObject *noargs)
-{
-	enabled = 1;
-	Py_INCREF(Py_None);
-	return Py_None;
-}
-
-PyDoc_STRVAR(gc_disable__doc__,
-"disable() -> None\n"
-"\n"
-"Disable automatic garbage collection.\n");
-
-static PyObject *
-gc_disable(PyObject *self, PyObject *noargs)
-{
-	enabled = 0;
-	Py_INCREF(Py_None);
-	return Py_None;
-}
-
-PyDoc_STRVAR(gc_isenabled__doc__,
-"isenabled() -> status\n"
-"\n"
-"Returns true if automatic garbage collection is enabled.\n");
-
-static PyObject *
-gc_isenabled(PyObject *self, PyObject *noargs)
-{
-	return PyBool_FromLong((long)enabled);
-}
-
-PyDoc_STRVAR(gc_collect__doc__,
-"collect([generation]) -> n\n"
-"\n"
-"With no arguments, run a full collection.  The optional argument\n"
-"may be an integer specifying which generation to collect.  A ValueError\n"
-"is raised if the generation number is invalid.\n\n"
-"The number of unreachable objects is returned.\n");
-
-static PyObject *
-gc_collect(PyObject *self, PyObject *args, PyObject *kws)
-{
-	static char *keywords[] = {"generation", NULL};
-	int genarg = NUM_GENERATIONS - 1;
-	Py_ssize_t n;
-
-	if (!PyArg_ParseTupleAndKeywords(args, kws, "|i", keywords, &genarg))
-		return NULL;
-
-	else if (genarg < 0 || genarg >= NUM_GENERATIONS) {
-		PyErr_SetString(PyExc_ValueError, "invalid generation");
-		return NULL;
-	}
-
-	if (collecting)
-		n = 0; /* already collecting, don't do anything */
-	else {
-		collecting = 1;
-		n = collect(genarg);
-		collecting = 0;
-	}
-
-	return PyInt_FromSsize_t(n);
-}
-
-PyDoc_STRVAR(gc_set_debug__doc__,
-"set_debug(flags) -> None\n"
-"\n"
-"Set the garbage collection debugging flags. Debugging information is\n"
-"written to sys.stderr.\n"
-"\n"
-"flags is an integer and can have the following bits turned on:\n"
-"\n"
-"  DEBUG_STATS - Print statistics during collection.\n"
-"  DEBUG_COLLECTABLE - Print collectable objects found.\n"
-"  DEBUG_UNCOLLECTABLE - Print unreachable but uncollectable objects found.\n"
-"  DEBUG_INSTANCES - Print instance objects.\n"
-"  DEBUG_OBJECTS - Print objects other than instances.\n"
-"  DEBUG_SAVEALL - Save objects to gc.garbage rather than freeing them.\n"
-"  DEBUG_LEAK - Debug leaking programs (everything but STATS).\n");
-
-static PyObject *
-gc_set_debug(PyObject *self, PyObject *args)
-{
-	if (!PyArg_ParseTuple(args, "i:set_debug", &debug))
-		return NULL;
-
-	Py_INCREF(Py_None);
-	return Py_None;
-}
-
-PyDoc_STRVAR(gc_get_debug__doc__,
-"get_debug() -> flags\n"
-"\n"
-"Get the garbage collection debugging flags.\n");
-
-static PyObject *
-gc_get_debug(PyObject *self, PyObject *noargs)
-{
-	return Py_BuildValue("i", debug);
-}
-
-PyDoc_STRVAR(gc_set_thresh__doc__,
-"set_threshold(threshold0, [threshold1, threshold2]) -> None\n"
-"\n"
-"Sets the collection thresholds.  Setting threshold0 to zero disables\n"
-"collection.\n");
-
-static PyObject *
-gc_set_thresh(PyObject *self, PyObject *args)
-{
-	int i;
-	if (!PyArg_ParseTuple(args, "i|ii:set_threshold",
-			      &generations[0].threshold,
-			      &generations[1].threshold,
-			      &generations[2].threshold))
-		return NULL;
-	for (i = 2; i < NUM_GENERATIONS; i++) {
- 		/* generations higher than 2 get the same threshold */
-		generations[i].threshold = generations[2].threshold;
-	}
-
-	Py_INCREF(Py_None);
-	return Py_None;
-}
-
-PyDoc_STRVAR(gc_get_thresh__doc__,
-"get_threshold() -> (threshold0, threshold1, threshold2)\n"
-"\n"
-"Return the current collection thresholds\n");
-
-static PyObject *
-gc_get_thresh(PyObject *self, PyObject *noargs)
-{
-	return Py_BuildValue("(iii)",
-			     generations[0].threshold,
-			     generations[1].threshold,
-			     generations[2].threshold);
-}
-
-PyDoc_STRVAR(gc_get_count__doc__,
-"get_count() -> (count0, count1, count2)\n"
-"\n"
-"Return the current collection counts\n");
-
-static PyObject *
-gc_get_count(PyObject *self, PyObject *noargs)
-{
-	return Py_BuildValue("(iii)",
-			     generations[0].count,
-			     generations[1].count,
-			     generations[2].count);
-}
-
-static int
-referrersvisit(PyObject* obj, PyObject *objs)
-{
-	Py_ssize_t i;
-	for (i = 0; i < PyTuple_GET_SIZE(objs); i++)
-		if (PyTuple_GET_ITEM(objs, i) == obj)
-			return 1;
-	return 0;
-}
-
-static int
-gc_referrers_for(PyObject *objs, PyGC_Head *list, PyObject *resultlist)
-{
-	PyGC_Head *gc;
-	PyObject *obj;
-	traverseproc traverse;
-	for (gc = list->gc.gc_next; gc != list; gc = gc->gc.gc_next) {
-		obj = FROM_GC(gc);
-		traverse = obj->ob_type->tp_traverse;
-		if (obj == objs || obj == resultlist)
-			continue;
-		if (traverse(obj, (visitproc)referrersvisit, objs)) {
-			if (PyList_Append(resultlist, obj) < 0)
-				return 0; /* error */
-		}
-	}
-	return 1; /* no error */
-}
-
-PyDoc_STRVAR(gc_get_referrers__doc__,
-"get_referrers(*objs) -> list\n\
-Return the list of objects that directly refer to any of objs.");
-
-static PyObject *
-gc_get_referrers(PyObject *self, PyObject *args)
-{
-	int i;
-	PyObject *result = PyList_New(0);
-	if (!result) return NULL;
-
-	for (i = 0; i < NUM_GENERATIONS; i++) {
-		if (!(gc_referrers_for(args, GEN_HEAD(i), result))) {
-			Py_DECREF(result);
-			return NULL;
-		}
-	}
-	return result;
-}
-
-/* Append obj to list; return true if error (out of memory), false if OK. */
-static int
-referentsvisit(PyObject *obj, PyObject *list)
-{
-	return PyList_Append(list, obj) < 0;
-}
-
-PyDoc_STRVAR(gc_get_referents__doc__,
-"get_referents(*objs) -> list\n\
-Return the list of objects that are directly referred to by objs.");
-
-static PyObject *
-gc_get_referents(PyObject *self, PyObject *args)
-{
-	Py_ssize_t i;
-	PyObject *result = PyList_New(0);
-
-	if (result == NULL)
-		return NULL;
-
-	for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
-		traverseproc traverse;
-		PyObject *obj = PyTuple_GET_ITEM(args, i);
-
-		if (! PyObject_IS_GC(obj))
-			continue;
-		traverse = obj->ob_type->tp_traverse;
-		if (! traverse)
-			continue;
-		if (traverse(obj, (visitproc)referentsvisit, result)) {
-			Py_DECREF(result);
-			return NULL;
-		}
-	}
-	return result;
-}
-
-PyDoc_STRVAR(gc_get_objects__doc__,
-"get_objects() -> [...]\n"
-"\n"
-"Return a list of objects tracked by the collector (excluding the list\n"
-"returned).\n");
-
-static PyObject *
-gc_get_objects(PyObject *self, PyObject *noargs)
-{
-	int i;
-	PyObject* result;
-
-	result = PyList_New(0);
-	if (result == NULL)
-		return NULL;
-	for (i = 0; i < NUM_GENERATIONS; i++) {
-		if (append_objects(result, GEN_HEAD(i))) {
-			Py_DECREF(result);
-			return NULL;
-		}
-	}
-	return result;
-}
-
-
-PyDoc_STRVAR(gc__doc__,
-"This module provides access to the garbage collector for reference cycles.\n"
-"\n"
-"enable() -- Enable automatic garbage collection.\n"
-"disable() -- Disable automatic garbage collection.\n"
-"isenabled() -- Returns true if automatic collection is enabled.\n"
-"collect() -- Do a full collection right now.\n"
-"get_count() -- Return the current collection counts.\n"
-"set_debug() -- Set debugging flags.\n"
-"get_debug() -- Get debugging flags.\n"
-"set_threshold() -- Set the collection thresholds.\n"
-"get_threshold() -- Return the current the collection thresholds.\n"
-"get_objects() -- Return a list of all objects tracked by the collector.\n"
-"get_referrers() -- Return the list of objects that refer to an object.\n"
-"get_referents() -- Return the list of objects that an object refers to.\n");
-
-static PyMethodDef GcMethods[] = {
-	{"enable",	   gc_enable,	  METH_NOARGS,  gc_enable__doc__},
-	{"disable",	   gc_disable,	  METH_NOARGS,  gc_disable__doc__},
-	{"isenabled",	   gc_isenabled,  METH_NOARGS,  gc_isenabled__doc__},
-	{"set_debug",	   gc_set_debug,  METH_VARARGS, gc_set_debug__doc__},
-	{"get_debug",	   gc_get_debug,  METH_NOARGS,  gc_get_debug__doc__},
-	{"get_count",	   gc_get_count,  METH_NOARGS,  gc_get_count__doc__},
-	{"set_threshold",  gc_set_thresh, METH_VARARGS, gc_set_thresh__doc__},
-	{"get_threshold",  gc_get_thresh, METH_NOARGS,  gc_get_thresh__doc__},
-	{"collect",	   (PyCFunction)gc_collect,
-         	METH_VARARGS | METH_KEYWORDS,           gc_collect__doc__},
-	{"get_objects",    gc_get_objects,METH_NOARGS,  gc_get_objects__doc__},
-	{"get_referrers",  gc_get_referrers, METH_VARARGS,
-		gc_get_referrers__doc__},
-	{"get_referents",  gc_get_referents, METH_VARARGS,
-		gc_get_referents__doc__},
-	{NULL,	NULL}		/* Sentinel */
-};
-
-PyMODINIT_FUNC
-initgc(void)
-{
-	PyObject *m;
-
-	m = Py_InitModule4("gc",
-			      GcMethods,
-			      gc__doc__,
-			      NULL,
-			      PYTHON_API_VERSION);
-	if (m == NULL)
-		return;
-
-	if (garbage == NULL) {
-		garbage = PyList_New(0);
-		if (garbage == NULL)
-			return;
-	}
-	Py_INCREF(garbage);
-	if (PyModule_AddObject(m, "garbage", garbage) < 0)
-		return;
-
-	/* Importing can't be done in collect() because collect()
-	 * can be called via PyGC_Collect() in Py_Finalize().
-	 * This wouldn't be a problem, except that <initialized> is
-	 * reset to 0 before calling collect which trips up
-	 * the import and triggers an assertion.
-	 */
-	if (tmod == NULL) {
-		tmod = PyImport_ImportModule("time");
-		if (tmod == NULL)
-			PyErr_Clear();
-	}
-
-#define ADD_INT(NAME) if (PyModule_AddIntConstant(m, #NAME, NAME) < 0) return
-	ADD_INT(DEBUG_STATS);
-	ADD_INT(DEBUG_COLLECTABLE);
-	ADD_INT(DEBUG_UNCOLLECTABLE);
-	ADD_INT(DEBUG_INSTANCES);
-	ADD_INT(DEBUG_OBJECTS);
-	ADD_INT(DEBUG_SAVEALL);
-	ADD_INT(DEBUG_LEAK);
-#undef ADD_INT
-}
-
-/* API to invoke gc.collect() from C */
-Py_ssize_t
-PyGC_Collect(void)
-{
-	Py_ssize_t n;
-
-	if (collecting)
-		n = 0; /* already collecting, don't do anything */
-	else {
-		collecting = 1;
-		n = collect(NUM_GENERATIONS - 1);
-		collecting = 0;
-	}
-
-	return n;
-}
-
-/* for debugging */
-void
-_PyGC_Dump(PyGC_Head *g)
-{
-	_PyObject_Dump(FROM_GC(g));
-}
-
-/* extension modules might be compiled with GC support so these
-   functions must always be available */
-
-#undef PyObject_GC_Track
-#undef PyObject_GC_UnTrack
-#undef PyObject_GC_Del
-#undef _PyObject_GC_Malloc
-
-void
-PyObject_GC_Track(void *op)
-{
-	_PyObject_GC_TRACK(op);
-}
-
-/* for binary compatibility with 2.2 */
-void
-_PyObject_GC_Track(PyObject *op)
-{
-    PyObject_GC_Track(op);
-}
-
-void
-PyObject_GC_UnTrack(void *op)
-{
-	/* Obscure:  the Py_TRASHCAN mechanism requires that we be able to
-	 * call PyObject_GC_UnTrack twice on an object.
-	 */
-	if (IS_TRACKED(op))
-		_PyObject_GC_UNTRACK(op);
-}
-
-/* for binary compatibility with 2.2 */
-void
-_PyObject_GC_UnTrack(PyObject *op)
-{
-    PyObject_GC_UnTrack(op);
-}
-
-PyObject *
-_PyObject_GC_Malloc(size_t basicsize)
-{
-	PyObject *op;
-	PyGC_Head *g = (PyGC_Head *)PyObject_MALLOC(
-                sizeof(PyGC_Head) + basicsize);
-	if (g == NULL)
-		return PyErr_NoMemory();
-	g->gc.gc_refs = GC_UNTRACKED;
-	generations[0].count++; /* number of allocated GC objects */
- 	if (generations[0].count > generations[0].threshold &&
- 	    enabled &&
- 	    generations[0].threshold &&
- 	    !collecting &&
- 	    !PyErr_Occurred()) {
-		collecting = 1;
-		collect_generations();
-		collecting = 0;
-	}
-	op = FROM_GC(g);
-	return op;
-}
-
-PyObject *
-_PyObject_GC_New(PyTypeObject *tp)
-{
-	PyObject *op = _PyObject_GC_Malloc(_PyObject_SIZE(tp));
-	if (op != NULL)
-		op = PyObject_INIT(op, tp);
-	return op;
-}
-
-PyVarObject *
-_PyObject_GC_NewVar(PyTypeObject *tp, Py_ssize_t nitems)
-{
-	const size_t size = _PyObject_VAR_SIZE(tp, nitems);
-	PyVarObject *op = (PyVarObject *) _PyObject_GC_Malloc(size);
-	if (op != NULL)
-		op = PyObject_INIT_VAR(op, tp, nitems);
-	return op;
-}
-
-PyVarObject *
-_PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems)
-{
-	const size_t basicsize = _PyObject_VAR_SIZE(op->ob_type, nitems);
-	PyGC_Head *g = AS_GC(op);
-	g = (PyGC_Head *)PyObject_REALLOC(g,  sizeof(PyGC_Head) + basicsize);
-	if (g == NULL)
-		return (PyVarObject *)PyErr_NoMemory();
-	op = (PyVarObject *) FROM_GC(g);
-	op->ob_size = nitems;
-	return op;
-}
-
-void
-PyObject_GC_Del(void *op)
-{
-	PyGC_Head *g = AS_GC(op);
-	if (IS_TRACKED(op))
-		gc_list_remove(g);
-	if (generations[0].count > 0) {
-		generations[0].count--;
-	}
-	PyObject_FREE(g);
-}
-
-/* for binary compatibility with 2.2 */
-#undef _PyObject_GC_Del
-void
-_PyObject_GC_Del(PyObject *op)
-{
-    PyObject_GC_Del(op);
-}