Revert "bpo-40170: PyType_HasFeature() now always calls PyType_GetFla…

…gs() (GH-19378)" (GH-21390) This partially reverts commit 45ec5b9.
python · Jul 8, 2020 · b26a0db · b26a0db
1 parent aebc049
commit b26a0db
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/Include/object.h b/Include/object.h
@@ -637,8 +637,16 @@ times.
 
 
 static inline int
-PyType_HasFeature(PyTypeObject *type, unsigned long feature) {
- return ((PyType_GetFlags(type) & feature) != 0);
+PyType_HasFeature(PyTypeObject *type, unsigned long feature)
+{
+ unsigned long flags;
+#ifdef Py_LIMITED_API
+ // PyTypeObject is opaque in the limited C API
+ flags = PyType_GetFlags(type);
+#else
+ flags = type->tp_flags;
+#endif
+ return ((flags & feature) != 0);
 }
 
 #define PyType_FastSubclass(type, flag) PyType_HasFeature(type, flag)

diff --git a/Misc/NEWS.d/next/C API/2020-07-08-10-14-52.bpo-40170.N6Qx1i.rst b/Misc/NEWS.d/next/C API/2020-07-08-10-14-52.bpo-40170.N6Qx1i.rst
@@ -0,0 +1,4 @@
+Revert :c:func:`PyType_HasFeature` change: it reads again directly the
+:c:member:`PyTypeObject.tp_flags` member when the limited C API is not used,
+rather than always calling :c:func:`PyType_GetFlags` which hides implementation
+details.