bpo-42747: Remove Py_TPFLAGS_HAVE_AM_SEND and make Py_TPFLAGS_HAVE_VERSION_TAG no-op (GH-27260) (GH-27306)
* Remove code that checks Py_TPFLAGS_HAVE_VERSION_TAG
The field is always present in the type struct, as explained
in the added comment.
* Remove Py_TPFLAGS_HAVE_AM_SEND
The flag is not needed, and since it was added in 3.10 it can be removed now.
(cherry picked from commit a4760cc32d9e5dac7be262e9736eb30502cd7be3)
Co-authored-by: Petr Viktorin <encukou@gmail.com>diff --git a/Include/object.h b/Include/object.h
index 109f535..9e6a8f4 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -368,18 +368,12 @@ given type object has a specified feature.
/* Objects behave like an unbound method */
#define Py_TPFLAGS_METHOD_DESCRIPTOR (1UL << 17)
-/* Objects support type attribute cache */
-#define Py_TPFLAGS_HAVE_VERSION_TAG (1UL << 18)
+/* Object has up-to-date type attribute cache */
#define Py_TPFLAGS_VALID_VERSION_TAG (1UL << 19)
/* Type is abstract and cannot be instantiated */
#define Py_TPFLAGS_IS_ABSTRACT (1UL << 20)
-#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030A0000
-/* Type has am_send entry in tp_as_async slot */
-#define Py_TPFLAGS_HAVE_AM_SEND (1UL << 21)
-#endif
-
// This undocumented flag gives certain built-ins their unique pattern-matching
// behavior, which allows a single positional subpattern to match against the
// subject itself (rather than a mapped attribute on it):
@@ -397,19 +391,23 @@ given type object has a specified feature.
#define Py_TPFLAGS_DEFAULT ( \
Py_TPFLAGS_HAVE_STACKLESS_EXTENSION | \
- Py_TPFLAGS_HAVE_VERSION_TAG | \
0)
-/* NOTE: The following flags reuse lower bits (removed as part of the
+/* NOTE: Some of the following flags reuse lower bits (removed as part of the
* Python 3.0 transition). */
-/* The following flag is kept for compatibility. Starting with 3.8,
- * binary compatibility of C extensions across feature releases of
- * Python is not supported anymore, except when using the stable ABI.
+/* The following flags are kept for compatibility; in previous
+ * versions they indicated presence of newer tp_* fields on the
+ * type struct.
+ * Starting with 3.8, binary compatibility of C extensions across
+ * feature releases of Python is not supported anymore (except when
+ * using the stable ABI, in which all classes are created dynamically,
+ * using the interpreter's memory layout.)
+ * Note that older extensions using the stable ABI set these flags,
+ * so the bits must not be repurposed.
*/
-
-/* Type structure has tp_finalize member (3.4) */
#define Py_TPFLAGS_HAVE_FINALIZE (1UL << 0)
+#define Py_TPFLAGS_HAVE_VERSION_TAG (1UL << 18)
/*