bpo-38787: C API for module state access from extension methods (PEP 573) (GH-19936)
Module C state is now accessible from C-defined heap type methods (PEP 573).
Patch by Marcel Plch and Petr Viktorin.
Co-authored-by: Marcel Plch <mplch@redhat.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Objects/methodobject.c b/Objects/methodobject.c
index 20eba6f..5659f21 100644
--- a/Objects/methodobject.c
+++ b/Objects/methodobject.c
@@ -10,12 +10,16 @@
/* undefine macro trampoline to PyCFunction_NewEx */
#undef PyCFunction_New
+/* undefine macro trampoline to PyCMethod_New */
+#undef PyCFunction_NewEx
/* Forward declarations */
static PyObject * cfunction_vectorcall_FASTCALL(
PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames);
static PyObject * cfunction_vectorcall_FASTCALL_KEYWORDS(
PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames);
+static PyObject * cfunction_vectorcall_FASTCALL_KEYWORDS_METHOD(
+ PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames);
static PyObject * cfunction_vectorcall_NOARGS(
PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames);
static PyObject * cfunction_vectorcall_O(
@@ -33,9 +37,16 @@
PyObject *
PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
{
+ return PyCMethod_New(ml, self, module, NULL);
+}
+
+PyObject *
+PyCMethod_New(PyMethodDef *ml, PyObject *self, PyObject *module, PyTypeObject *cls)
+{
/* Figure out correct vectorcall function to use */
vectorcallfunc vectorcall;
- switch (ml->ml_flags & (METH_VARARGS | METH_FASTCALL | METH_NOARGS | METH_O | METH_KEYWORDS))
+ switch (ml->ml_flags & (METH_VARARGS | METH_FASTCALL | METH_NOARGS |
+ METH_O | METH_KEYWORDS | METH_METHOD))
{
case METH_VARARGS:
case METH_VARARGS | METH_KEYWORDS:
@@ -55,17 +66,44 @@
case METH_O:
vectorcall = cfunction_vectorcall_O;
break;
+ case METH_METHOD | METH_FASTCALL | METH_KEYWORDS:
+ vectorcall = cfunction_vectorcall_FASTCALL_KEYWORDS_METHOD;
+ break;
default:
PyErr_Format(PyExc_SystemError,
"%s() method: bad call flags", ml->ml_name);
return NULL;
}
- PyCFunctionObject *op =
- PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);
- if (op == NULL) {
- return NULL;
+ PyCFunctionObject *op = NULL;
+
+ if (ml->ml_flags & METH_METHOD) {
+ if (!cls) {
+ PyErr_SetString(PyExc_SystemError,
+ "attempting to create PyCMethod with a METH_METHOD "
+ "flag but no class");
+ return NULL;
+ }
+ PyCMethodObject *om = PyObject_GC_New(PyCMethodObject, &PyCMethod_Type);
+ if (om == NULL) {
+ return NULL;
+ }
+ Py_INCREF(cls);
+ om->mm_class = cls;
+ op = (PyCFunctionObject *)om;
+ } else {
+ if (cls) {
+ PyErr_SetString(PyExc_SystemError,
+ "attempting to create PyCFunction with class "
+ "but no METH_METHOD flag");
+ return NULL;
+ }
+ op = PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);
+ if (op == NULL) {
+ return NULL;
+ }
}
+
op->m_weakreflist = NULL;
op->m_ml = ml;
Py_XINCREF(self);
@@ -107,6 +145,16 @@
return PyCFunction_GET_FLAGS(op);
}
+PyTypeObject *
+PyCMethod_GetClass(PyObject *op)
+{
+ if (!PyCFunction_Check(op)) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+ return PyCFunction_GET_CLASS(op);
+}
+
/* Methods (the standard built-in methods, that is) */
static void
@@ -118,6 +166,7 @@
}
Py_XDECREF(m->m_self);
Py_XDECREF(m->m_module);
+ Py_XDECREF(PyCFunction_GET_CLASS(m));
PyObject_GC_Del(m);
}
@@ -196,6 +245,7 @@
{
Py_VISIT(m->m_self);
Py_VISIT(m->m_module);
+ Py_VISIT(PyCFunction_GET_CLASS(m));
return 0;
}
@@ -314,6 +364,13 @@
0, /* tp_dict */
};
+PyTypeObject PyCMethod_Type = {
+ PyVarObject_HEAD_INIT(&PyType_Type, 0)
+ .tp_name = "builtin_method",
+ .tp_basicsize = sizeof(PyCMethodObject),
+ .tp_base = &PyCFunction_Type,
+};
+
/* Vectorcall functions for each of the PyCFunction calling conventions,
* except for METH_VARARGS (possibly combined with METH_KEYWORDS) which
* doesn't use vectorcall.
@@ -386,6 +443,22 @@
}
static PyObject *
+cfunction_vectorcall_FASTCALL_KEYWORDS_METHOD(
+ PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames)
+{
+ PyThreadState *tstate = _PyThreadState_GET();
+ PyTypeObject *cls = PyCFunction_GET_CLASS(func);
+ Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
+ PyCMethod meth = (PyCMethod)cfunction_enter_call(tstate, func);
+ if (meth == NULL) {
+ return NULL;
+ }
+ PyObject *result = meth(PyCFunction_GET_SELF(func), cls, args, nargs, kwnames);
+ _Py_LeaveRecursiveCall(tstate);
+ return result;
+}
+
+static PyObject *
cfunction_vectorcall_NOARGS(
PyObject *func, PyObject *const *args, size_t nargsf, PyObject *kwnames)
{