Make sure all redefined locals are written back to stack

Author: markshannon

Include/internal/pycore_freelist.h

@@ -51,6 +51,7 @@ _Py_freelists_GET(void)
 static inline int
 _PyFreeList_Push(struct _Py_freelist *fl, void *obj, Py_ssize_t maxsize)
 {
+    assert((((uintptr_t)obj) & 3) == 0);
     if (fl->size < maxsize && fl->size >= 0) {
         FT_ATOMIC_STORE_PTR_RELAXED(*(void **)obj, fl->freelist);
         fl->freelist = obj;
@@ -74,6 +75,7 @@ static inline void *
 _PyFreeList_PopNoStats(struct _Py_freelist *fl)
 {
     void *obj = fl->freelist;
+    assert((((uintptr_t)obj) & 3) == 0);
     if (obj != NULL) {
         assert(fl->size > 0);
         fl->freelist = *(void **)obj;

Include/internal/pycore_stackref.h

@@ -598,7 +598,7 @@ PyStackRef_Borrow(_PyStackRef ref)
 #endif
 
 extern PyObject *
-_Py_StackRef_BoxAndReturnObject(_PyStackRef ref);
+_Py_StackRef_BoxInt(_PyStackRef ref);
 
 static inline PyObject *
 PyStackRef_AsPyObjectSteal(_PyStackRef ref)
@@ -607,7 +607,7 @@ PyStackRef_AsPyObjectSteal(_PyStackRef ref)
         return BITS_TO_PTR(ref);
     }
     else if (PyStackRef_IsTaggedInt(ref)) {
-        return _Py_StackRef_BoxAndReturnObject(ref);
+        return _Py_StackRef_BoxInt(ref);
     }
     else {
         return Py_NewRef(BITS_TO_PTR_MASKED(ref));
@@ -818,8 +818,9 @@ static inline PyObject *
 PyStackRef_AsPyObjectBorrowed(_PyStackRef *ptr)
 {
     if (PyStackRef_IsTaggedInt(*ptr)) {
-        PyObject *res = _Py_StackRef_BoxAndReturnObject(*ptr);
+        PyObject *res = _Py_StackRef_BoxInt(*ptr);
         *ptr = _PyStackRef_FromPyObjectStealUnchecked(res);
+        assert(Py_REFCNT(res) > 0);
         return res;
     }
     PyObject *cleared = ((PyObject *)(ptr->bits & (~Py_TAG_BITS)));
@@ -840,7 +841,7 @@ static inline PyObject *
 PyStackRef_AsPyObjectNew(_PyStackRef ref)
 {
     if (PyStackRef_IsTaggedInt(ref)) {
-        return _Py_StackRef_BoxAndReturnObject(ref);
+        return _Py_StackRef_BoxInt(ref);
     }
     return Py_NewRef(PyStackRef_AsPyObjectBorrowNonInt(ref));
 

Objects/object.c

@@ -1935,7 +1935,7 @@ _PyObject_GenericSetAttrWithDict(PyObject *obj, PyObject *name,
     _PyThreadState_PushCStackRef(tstate, &cref);
 
     _PyType_LookupStackRefAndVersion(tp, name, &cref.ref);
-    descr = PyStackRef_AsPyObjectBorrowNonInt(cref.ref);
+    descr = PyStackRef_AsPyObjectBorrowed(&cref.ref);
 
     if (descr != NULL) {
         f = Py_TYPE(descr)->tp_descr_set;