From 407b9ba71fa323516587d688f994fd9a8c6df15e Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Sat, 4 Apr 2020 23:49:26 +0200
Subject: [PATCH] bpo-40170: Remove PyIndex_Check() macro

Always declare PyIndex_Check() as an opaque function to hide
implementation details: remove PyIndex_Check() macro. The macro
accessed directly the PyTypeObject.tp_as_number member.
---
 Include/cpython/abstract.h                                  | 6 ------
 .../next/C API/2020-04-04-23-51-59.bpo-40170.uXQ701.rst     | 3 +++
 Objects/abstract.c                                          | 6 +++---
 3 files changed, 6 insertions(+), 9 deletions(-)
 create mode 100644 Misc/NEWS.d/next/C API/2020-04-04-23-51-59.bpo-40170.uXQ701.rst

diff --git a/Include/cpython/abstract.h b/Include/cpython/abstract.h
index 9d23c8c11be577..38e0689a1ec0b5 100644
--- a/Include/cpython/abstract.h
+++ b/Include/cpython/abstract.h
@@ -337,12 +337,6 @@ PyAPI_FUNC(void) PyBuffer_Release(Py_buffer *view);
     (Py_TYPE(obj)->tp_iternext != NULL && \
      Py_TYPE(obj)->tp_iternext != &_PyObject_NextNotImplemented)
 
-/* === Number Protocol ================================================== */
-
-#define PyIndex_Check(obj)                              \
-    (Py_TYPE(obj)->tp_as_number != NULL &&            \
-     Py_TYPE(obj)->tp_as_number->nb_index != NULL)
-
 /* === Sequence protocol ================================================ */
 
 /* Assume tp_as_sequence and sq_item exist and that 'i' does not
diff --git a/Misc/NEWS.d/next/C API/2020-04-04-23-51-59.bpo-40170.uXQ701.rst b/Misc/NEWS.d/next/C API/2020-04-04-23-51-59.bpo-40170.uXQ701.rst
new file mode 100644
index 00000000000000..22bdc74904f41c
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2020-04-04-23-51-59.bpo-40170.uXQ701.rst	
@@ -0,0 +1,3 @@
+Always declare :c:func:`PyIndex_Check` as an opaque function to hide
+implementation details: remove ``PyIndex_Check()`` macro. The macro accessed
+directly the :c:member:`PyTypeObject.tp_as_number` member.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 02e4ad70718cd9..ca692cd6d3f016 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1291,15 +1291,15 @@ PyNumber_Absolute(PyObject *o)
     return type_error("bad operand type for abs(): '%.200s'", o);
 }
 
-#undef PyIndex_Check
 
 int
 PyIndex_Check(PyObject *obj)
 {
-    return Py_TYPE(obj)->tp_as_number != NULL &&
-           Py_TYPE(obj)->tp_as_number->nb_index != NULL;
+    PyNumberMethods *tp_as_number = Py_TYPE(obj)->tp_as_number;
+    return (tp_as_number != NULL && tp_as_number->nb_index != NULL);
 }
 
+
 /* Return a Python int from the object item.
    Raise TypeError if the result is not an int
    or if the object cannot be interpreted as an index.