bpo-36974: Make tp_call=PyVectorcall_Call work for inherited types (GH-13699)
When inheriting a heap subclass from a vectorcall class that sets
`.tp_call=PyVectorcall_Call` (as recommended in PEP 590), the subclass does
not inherit `_Py_TPFLAGS_HAVE_VECTORCALL`, and thus `PyVectorcall_Call` does
not work for it.
This attempts to solve the issue by:
* always inheriting `tp_vectorcall_offset` unless `tp_call` is overridden
in the subclass
* inheriting _Py_TPFLAGS_HAVE_VECTORCALL for static types, unless `tp_call`
is overridden
* making `PyVectorcall_Call` ignore `_Py_TPFLAGS_HAVE_VECTORCALL`
This means it'll be ever more important to only call `PyVectorcall_Call`
on classes that support vectorcall. In `PyVectorcall_Call`'s intended role
as `tp_call` filler, that's not a problem.
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index fabc821..88bda05 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -515,9 +515,10 @@
def test_vectorcall(self):
# Test a bunch of different ways to call objects:
- # 1. normal call
- # 2. vectorcall using _PyObject_Vectorcall()
- # 3. vectorcall using PyVectorcall_Call()
+ # 1. vectorcall using PyVectorcall_Call()
+ # (only for objects that support vectorcall directly)
+ # 2. normal call
+ # 3. vectorcall using _PyObject_Vectorcall()
# 4. call as bound method
# 5. call using functools.partial
@@ -543,18 +544,37 @@
for (func, args, kwargs, expected) in calls:
with self.subTest(str(func)):
+ if not kwargs:
+ self.assertEqual(expected, pyvectorcall_call(func, args))
+ self.assertEqual(expected, pyvectorcall_call(func, args, kwargs))
+
+ # Add derived classes (which do not support vectorcall directly,
+ # but do support all other ways of calling).
+
+ class MethodDescriptorHeap(_testcapi.MethodDescriptorBase):
+ pass
+
+ class MethodDescriptorOverridden(_testcapi.MethodDescriptorBase):
+ def __call__(self, n):
+ return 'new'
+
+ calls += [
+ (MethodDescriptorHeap(), (0,), {}, True),
+ (MethodDescriptorOverridden(), (0,), {}, 'new'),
+ ]
+
+ for (func, args, kwargs, expected) in calls:
+ with self.subTest(str(func)):
args1 = args[1:]
meth = MethodType(func, args[0])
wrapped = partial(func)
if not kwargs:
self.assertEqual(expected, func(*args))
self.assertEqual(expected, pyobject_vectorcall(func, args, None))
- self.assertEqual(expected, pyvectorcall_call(func, args))
self.assertEqual(expected, meth(*args1))
self.assertEqual(expected, wrapped(*args))
self.assertEqual(expected, func(*args, **kwargs))
self.assertEqual(expected, vectorcall(func, args, kwargs))
- self.assertEqual(expected, pyvectorcall_call(func, args, kwargs))
self.assertEqual(expected, meth(*args1, **kwargs))
self.assertEqual(expected, wrapped(*args, **kwargs))
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index bf20e81..eed34c9 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -5854,7 +5854,7 @@
static PyObject *
MethodDescriptor_new(PyTypeObject* type, PyObject* args, PyObject *kw)
{
- MethodDescriptorObject *op = PyObject_New(MethodDescriptorObject, type);
+ MethodDescriptorObject *op = type->tp_alloc(type, 0);
op->vectorcall = MethodDescriptor_vectorcall;
return (PyObject *)op;
}
diff --git a/Objects/call.c b/Objects/call.c
index c0d1456..578e1b3 100644
--- a/Objects/call.c
+++ b/Objects/call.c
@@ -173,12 +173,22 @@
PyObject *
PyVectorcall_Call(PyObject *callable, PyObject *tuple, PyObject *kwargs)
{
- vectorcallfunc func = _PyVectorcall_Function(callable);
+ /* get vectorcallfunc as in _PyVectorcall_Function, but without
+ * the _Py_TPFLAGS_HAVE_VECTORCALL check */
+ Py_ssize_t offset = Py_TYPE(callable)->tp_vectorcall_offset;
+ if ((offset <= 0) || (!Py_TYPE(callable)->tp_call)) {
+ PyErr_Format(PyExc_TypeError, "'%.200s' object does not support vectorcall",
+ Py_TYPE(callable)->tp_name);
+ return NULL;
+ }
+ vectorcallfunc func = *(vectorcallfunc *)(((char *)callable) + offset);
if (func == NULL) {
PyErr_Format(PyExc_TypeError, "'%.200s' object does not support vectorcall",
Py_TYPE(callable)->tp_name);
return NULL;
}
+
+ /* Convert arguments & call */
PyObject *const *args;
Py_ssize_t nargs = PyTuple_GET_SIZE(tuple);
PyObject *kwnames;
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index b6d925c..76e06aa 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -5145,17 +5145,21 @@
}
COPYSLOT(tp_repr);
/* tp_hash see tp_richcompare */
- COPYSLOT(tp_call);
- /* Inherit tp_vectorcall_offset and _Py_TPFLAGS_HAVE_VECTORCALL if tp_call
- * was inherited, but only for extension types */
- if ((base->tp_flags & _Py_TPFLAGS_HAVE_VECTORCALL) &&
- !(type->tp_flags & _Py_TPFLAGS_HAVE_VECTORCALL) &&
- !(type->tp_flags & Py_TPFLAGS_HEAPTYPE) &&
- base->tp_call &&
- type->tp_call == base->tp_call)
{
- type->tp_vectorcall_offset = base->tp_vectorcall_offset;
- type->tp_flags |= _Py_TPFLAGS_HAVE_VECTORCALL;
+ /* Inherit tp_vectorcall_offset only if tp_call is not overridden */
+ if (!type->tp_call) {
+ COPYSLOT(tp_vectorcall_offset);
+ }
+ /* Inherit_Py_TPFLAGS_HAVE_VECTORCALL for non-heap types
+ * if tp_call is not overridden */
+ if (!type->tp_call &&
+ (base->tp_flags & _Py_TPFLAGS_HAVE_VECTORCALL) &&
+ !(type->tp_flags & _Py_TPFLAGS_HAVE_VECTORCALL) &&
+ !(type->tp_flags & Py_TPFLAGS_HEAPTYPE))
+ {
+ type->tp_flags |= _Py_TPFLAGS_HAVE_VECTORCALL;
+ }
+ COPYSLOT(tp_call);
}
COPYSLOT(tp_str);
{