Add _PyObject_GetWeakRefsHead().

Author: ericsnowcurrently

Include/cpython/object.h

@@ -422,9 +422,6 @@ PyAPI_FUNC(int) _PyObject_CheckConsistency(
     int check_content);
 
 
-Py_ssize_t _PyObject_GetWeakRefCount(PyObject *op);
-
-
 /* Trashcan mechanism, thanks to Christian Tismer.
 
 When deallocating a container object, it's possible to trigger an unbounded

Include/cpython/weakrefobject.h

@@ -54,3 +54,7 @@ static inline PyObject* PyWeakref_GET_OBJECT(PyObject *ref_obj) {
     return Py_None;
 }
 #define PyWeakref_GET_OBJECT(ref) PyWeakref_GET_OBJECT(_PyObject_CAST(ref))
+
+
+PyWeakReference * _PyObject_GetWeakRefsHead(PyObject *op);
+Py_ssize_t _PyObject_GetWeakRefCount(PyObject *op);

Modules/_weakref.c

@@ -1,10 +1,6 @@
 #include "Python.h"
-#include "pycore_object.h"   // _PyObject_GET_WEAKREFS_LISTPTR
 
 
-#define GET_WEAKREFS_LISTPTR(o) \
-        ((PyWeakReference **) _PyObject_GET_WEAKREFS_LISTPTR(o))
-
 /*[clinic input]
 module _weakref
 [clinic start generated code]*/
@@ -86,11 +82,9 @@ _weakref_getweakrefs(PyObject *module, PyObject *object)
 
     Py_ssize_t count = _PyObject_GetWeakRefCount(object);
     if (count > 0) {
-        PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);
-
         result = PyList_New(count);
         if (result != NULL) {
-            PyWeakReference *current = *list;
+            PyWeakReference *current = _PyObject_GetWeakRefsHead(object);
             Py_ssize_t i;
             for (i = 0; i < count; ++i) {
                 PyList_SET_ITEM(result, i, (PyObject *) current);

Objects/weakrefobject.c

@@ -947,6 +947,12 @@ PyObject_GET_WEAKREFS_LISTPTR(PyObject *op)
     return _PyObject_GET_WEAKREFS_LISTPTR(op);
 }
 
+PyWeakReference *
+_PyObject_GetWeakRefsHead(PyObject *op)
+{
+    return (PyWeakReference *)(*_PyObject_GET_WEAKREFS_LISTPTR(op));
+}
+
 Py_ssize_t
 _PyObject_GetWeakRefCount(PyObject *op)
 {