gh-83754: Use the Py_TYPE() macro (#120599)

Don't access directly PyObject.ob_type, but use the Py_TYPE() macro
instead.

Author: vstinner

Include/cpython/longintrepr.h

@@ -120,7 +120,7 @@ PyAPI_FUNC(PyLongObject*) _PyLong_FromDigits(
 
 static inline int
 _PyLong_IsCompact(const PyLongObject* op) {
-    assert(PyType_HasFeature((op)->ob_base.ob_type, Py_TPFLAGS_LONG_SUBCLASS));
+    assert(PyType_HasFeature(Py_TYPE(op), Py_TPFLAGS_LONG_SUBCLASS));
     return op->long_value.lv_tag < (2 << _PyLong_NON_SIZE_BITS);
 }
 
@@ -130,7 +130,7 @@ static inline Py_ssize_t
 _PyLong_CompactValue(const PyLongObject *op)
 {
     Py_ssize_t sign;
-    assert(PyType_HasFeature((op)->ob_base.ob_type, Py_TPFLAGS_LONG_SUBCLASS));
+    assert(PyType_HasFeature(Py_TYPE(op), Py_TPFLAGS_LONG_SUBCLASS));
     assert(PyUnstable_Long_IsCompact(op));
     sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);
     return sign * (Py_ssize_t)op->long_value.ob_digit[0];

Include/object.h

@@ -261,8 +261,8 @@ PyAPI_DATA(PyTypeObject) PyBool_Type;
 
 // bpo-39573: The Py_SET_SIZE() function must be used to set an object size.
 static inline Py_ssize_t Py_SIZE(PyObject *ob) {
-    assert(ob->ob_type != &PyLong_Type);
-    assert(ob->ob_type != &PyBool_Type);
+    assert(Py_TYPE(ob) != &PyLong_Type);
+    assert(Py_TYPE(ob) != &PyBool_Type);
     return  _PyVarObject_CAST(ob)->ob_size;
 }
 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 < 0x030b0000
@@ -289,8 +289,8 @@ static inline void Py_SET_TYPE(PyObject *ob, PyTypeObject *type) {
 #endif
 
 static inline void Py_SET_SIZE(PyVarObject *ob, Py_ssize_t size) {
-    assert(ob->ob_base.ob_type != &PyLong_Type);
-    assert(ob->ob_base.ob_type != &PyBool_Type);
+    assert(Py_TYPE(_PyObject_CAST(ob)) != &PyLong_Type);
+    assert(Py_TYPE(_PyObject_CAST(ob)) != &PyBool_Type);
 #ifdef Py_GIL_DISABLED
     _Py_atomic_store_ssize_relaxed(&ob->ob_size, size);
 #else

Modules/_datetimemodule.c

@@ -3090,7 +3090,7 @@ static PyDateTime_Delta *
 look_up_delta(int days, int seconds, int microseconds, PyTypeObject *type)
 {
     if (days == 0 && seconds == 0 && microseconds == 0
-            && type == zero_delta.ob_base.ob_type)
+            && type == Py_TYPE(&zero_delta))
     {
         return &zero_delta;
     }

Objects/dictobject.c

@@ -2389,7 +2389,7 @@ PyObject *
 _PyDict_GetItemWithError(PyObject *dp, PyObject *kv)
 {
     assert(PyUnicode_CheckExact(kv));
-    Py_hash_t hash = kv->ob_type->tp_hash(kv);
+    Py_hash_t hash = Py_TYPE(kv)->tp_hash(kv);
     if (hash == -1) {
         return NULL;
     }

Python/gc.c

@@ -2083,7 +2083,7 @@ PyVarObject *
 _PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems)
 {
     const size_t basicsize = _PyObject_VAR_SIZE(Py_TYPE(op), nitems);
-    const size_t presize = _PyType_PreHeaderSize(((PyObject *)op)->ob_type);
+    const size_t presize = _PyType_PreHeaderSize(Py_TYPE(op));
     _PyObject_ASSERT((PyObject *)op, !_PyObject_GC_IS_TRACKED(op));
     if (basicsize > (size_t)PY_SSIZE_T_MAX - presize) {
         return (PyVarObject *)PyErr_NoMemory();
@@ -2101,15 +2101,15 @@ _PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems)
 void
 PyObject_GC_Del(void *op)
 {
-    size_t presize = _PyType_PreHeaderSize(((PyObject *)op)->ob_type);
+    size_t presize = _PyType_PreHeaderSize(Py_TYPE(op));
     PyGC_Head *g = AS_GC(op);
     if (_PyObject_GC_IS_TRACKED(op)) {
         gc_list_remove(g);
 #ifdef Py_DEBUG
         PyObject *exc = PyErr_GetRaisedException();
         if (PyErr_WarnExplicitFormat(PyExc_ResourceWarning, "gc", 0,
                                      "gc", NULL, "Object of type %s is not untracked before destruction",
-                                     ((PyObject*)op)->ob_type->tp_name)) {
+                                     Py_TYPE(op)->tp_name)) {
             PyErr_WriteUnraisable(NULL);
         }
         PyErr_SetRaisedException(exc);

Python/specialize.c

@@ -637,7 +637,7 @@ specialize_module_load_attr(
 ) {
     _PyAttrCache *cache = (_PyAttrCache *)(instr + 1);
     PyModuleObject *m = (PyModuleObject *)owner;
-    assert((owner->ob_type->tp_flags & Py_TPFLAGS_MANAGED_DICT) == 0);
+    assert((Py_TYPE(owner)->tp_flags & Py_TPFLAGS_MANAGED_DICT) == 0);
     PyDictObject *dict = (PyDictObject *)m->md_dict;
     if (dict == NULL) {
         SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_NO_DICT);