bpo-39573: Add Py_SET_REFCNT() function (GH-18389)

Add a Py_SET_REFCNT() function to set the reference counter of an
object.

3 files changed, 8 insertions, 7 deletions

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 49cfd574d5..da329b4fba 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -51,7 +51,7 @@ PyModuleDef_Init(struct PyModuleDef* def)
          return NULL;
     if (def->m_base.m_index == 0) {
         max_module_number++;
-        Py_REFCNT(def) = 1;
+        Py_SET_REFCNT(def, 1);
         Py_TYPE(def) = &PyModuleDef_Type;
         def->m_base.m_index = max_module_number;
     }
diff --git a/Objects/object.c b/Objects/object.c
index f9682fe5b1..aca20e8d09 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -213,7 +213,7 @@ PyObject_CallFinalizerFromDealloc(PyObject *self)
     }
 
     /* Temporarily resurrect the object. */
-    Py_REFCNT(self) = 1;
+    Py_SET_REFCNT(self, 1);
 
     PyObject_CallFinalizer(self);
 
@@ -223,7 +223,8 @@ PyObject_CallFinalizerFromDealloc(PyObject *self)
 
     /* Undo the temporary resurrection; can't use DECREF here, it would
      * cause a recursive call. */
-    if (--Py_REFCNT(self) == 0) {
+    Py_SET_REFCNT(self, Py_REFCNT(self) - 1);
+    if (Py_REFCNT(self) == 0) {
         return 0;         /* this is the normal path out */
     }
 
@@ -231,7 +232,7 @@ PyObject_CallFinalizerFromDealloc(PyObject *self)
      * never happened. */
     Py_ssize_t refcnt = Py_REFCNT(self);
     _Py_NewReference(self);
-    Py_REFCNT(self) = refcnt;
+    Py_SET_REFCNT(self, refcnt);
 
     _PyObject_ASSERT(self,
                      (!PyType_IS_GC(Py_TYPE(self))
@@ -1818,7 +1819,7 @@ _Py_NewReference(PyObject *op)
 #ifdef Py_REF_DEBUG
     _Py_RefTotal++;
 #endif
-    Py_REFCNT(op) = 1;
+    Py_SET_REFCNT(op, 1);
 #ifdef Py_TRACE_REFS
     _Py_AddToAllObjects(op, 1);
 #endif
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 7c8bc06252..fa48ee1ac7 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1903,7 +1903,7 @@ unicode_dealloc(PyObject *unicode)
 
     case SSTATE_INTERNED_MORTAL:
         /* revive dead object temporarily for DelItem */
-        Py_REFCNT(unicode) = 3;
+        Py_SET_REFCNT(unicode, 3);
         if (PyDict_DelItem(interned, unicode) != 0) {
             _PyErr_WriteUnraisableMsg("deletion of interned string failed",
                                       NULL);
@@ -15367,7 +15367,7 @@ PyUnicode_InternInPlace(PyObject **p)
     }
     /* The two references in interned are not counted by refcnt.
        The deallocator will take care of this */
-    Py_REFCNT(s) -= 2;
+    Py_SET_REFCNT(s, Py_REFCNT(s) - 2);
     _PyUnicode_STATE(s).interned = SSTATE_INTERNED_MORTAL;
 }