bpo-40170: PyObject_NEW() becomes an alias to PyObject_New() (GH-19379)

The PyObject_NEW() macro becomes an alias to the PyObject_New()
macro, and the PyObject_NEW_VAR() macro becomes an alias to the
PyObject_NewVar() macro, to hide implementation details. They no
longer access directly the PyTypeObject.tp_basicsize member.

Exclude _PyObject_SIZE() and _PyObject_VAR_SIZE() macros from
the limited C API.

Replace PyObject_NEW() with PyObject_New() and replace
PyObject_NEW_VAR() with PyObject_NewVar().

3 files changed, 7 insertions, 6 deletions

diff --git a/Objects/capsule.c b/Objects/capsule.c
index 599893a..ed24cc1 100644
--- a/Objects/capsule.c
+++ b/Objects/capsule.c
@@ -50,7 +50,7 @@ PyCapsule_New(void *pointer, const char *name, PyCapsule_Destructor destructor)
         return NULL;
     }
 
-    capsule = PyObject_NEW(PyCapsule, &PyCapsule_Type);
+    capsule = PyObject_New(PyCapsule, &PyCapsule_Type);
     if (capsule == NULL) {
         return NULL;
     }
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index fd64393..1820d8c 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -219,7 +219,7 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
             cell2arg = NULL;
         }
     }
-    co = PyObject_NEW(PyCodeObject, &PyCode_Type);
+    co = PyObject_New(PyCodeObject, &PyCode_Type);
     if (co == NULL) {
         if (cell2arg)
             PyMem_FREE(cell2arg);
diff --git a/Objects/object.c b/Objects/object.c
index 05241e8..069afc0 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -161,11 +161,12 @@ PyObject_InitVar(PyVarObject *op, PyTypeObject *tp, Py_ssize_t size)
 PyObject *
 _PyObject_New(PyTypeObject *tp)
 {
-    PyObject *op;
-    op = (PyObject *) PyObject_MALLOC(_PyObject_SIZE(tp));
-    if (op == NULL)
+    PyObject *op = (PyObject *) PyObject_MALLOC(_PyObject_SIZE(tp));
+    if (op == NULL) {
         return PyErr_NoMemory();
-    return PyObject_INIT(op, tp);
+    }
+    PyObject_INIT(op, tp);
+    return op;
 }
 
 PyVarObject *