Use ALIGNOF_MAX_ALIGN_T

Author: encukou

Modules/_testcapi/heaptype_relative.c

@@ -280,13 +280,7 @@ _PyTestCapi_Init_HeaptypeRelative(PyObject *m) {
         return -1;
     }
 
-#ifdef __alignof_is_defined
-    // C11
-    PyModule_AddIntConstant(m, "alignof_max_align_t", alignof(max_align_t));
-#else
-    // if alignof and max_align_t is unavailable, skip the alignment tests
-    PyModule_AddIntConstant(m, "alignof_max_align_t", 1);
-#endif
+    PyModule_AddIntConstant(m, "alignof_max_align_t", ALIGNOF_MAX_ALIGN_T);
 
     return 0;
 }

Objects/typeobject.c

@@ -3553,22 +3553,9 @@ static const PySlot_Offset pyslot_offsets[] = {
 /* Align up to the nearest multiple of alignof(max_align_t)
  * (like _Py_ALIGN_UP, but for a size rather than pointer)
  */
-#if __alignof_is_defined
-    // C11
-    #define MAX_ALIGN alignof(max_align_t)
-#else
-    // workaround for MSVC
-    typedef union {
-        intmax_t x;
-        long double y;
-        void *z;
-        void (*f)();
-    } _max_align_t_wannabe;
-    #define MAX_ALIGN _Alignof(_max_align_t_wannabe)
-#endif
 static Py_ssize_t
 _align_up(Py_ssize_t size) {
-    return (size + MAX_ALIGN - 1) & ~(MAX_ALIGN - 1);
+    return (size + ALIGNOF_MAX_ALIGN_T - 1) & ~(ALIGNOF_MAX_ALIGN_T - 1);
 }
 
 /* Given a PyType_FromMetaclass `bases` argument (NULL, type, or tuple of