bpo-43977: Use tp_flags for collection matching (GH-25723)
* Add Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING, add to all relevant standard builtin classes.
* Set relevant flags on collections.abc.Sequence and Mapping.
* Use flags in MATCH_SEQUENCE and MATCH_MAPPING opcodes.
* Inherit Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING.
* Add NEWS
* Remove interpreter-state map_abc and seq_abc fields.
diff --git a/Python/ceval.c b/Python/ceval.c
index 326930b..866c57a 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -3889,76 +3889,20 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
}
case TARGET(MATCH_MAPPING): {
- // PUSH(isinstance(TOS, _collections_abc.Mapping))
PyObject *subject = TOP();
- // Fast path for dicts:
- if (PyDict_Check(subject)) {
- Py_INCREF(Py_True);
- PUSH(Py_True);
- DISPATCH();
- }
- // Lazily import _collections_abc.Mapping, and keep it handy on the
- // PyInterpreterState struct (it gets cleaned up at exit):
- PyInterpreterState *interp = PyInterpreterState_Get();
- if (interp->map_abc == NULL) {
- PyObject *abc = PyImport_ImportModule("_collections_abc");
- if (abc == NULL) {
- goto error;
- }
- interp->map_abc = PyObject_GetAttrString(abc, "Mapping");
- if (interp->map_abc == NULL) {
- goto error;
- }
- }
- int match = PyObject_IsInstance(subject, interp->map_abc);
- if (match < 0) {
- goto error;
- }
- PUSH(PyBool_FromLong(match));
+ int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_MAPPING;
+ PyObject *res = match ? Py_True : Py_False;
+ Py_INCREF(res);
+ PUSH(res);
DISPATCH();
}
case TARGET(MATCH_SEQUENCE): {
- // PUSH(not isinstance(TOS, (bytearray, bytes, str))
- // and isinstance(TOS, _collections_abc.Sequence))
PyObject *subject = TOP();
- // Fast path for lists and tuples:
- if (PyType_FastSubclass(Py_TYPE(subject),
- Py_TPFLAGS_LIST_SUBCLASS |
- Py_TPFLAGS_TUPLE_SUBCLASS))
- {
- Py_INCREF(Py_True);
- PUSH(Py_True);
- DISPATCH();
- }
- // Bail on some possible Sequences that we intentionally exclude:
- if (PyType_FastSubclass(Py_TYPE(subject),
- Py_TPFLAGS_BYTES_SUBCLASS |
- Py_TPFLAGS_UNICODE_SUBCLASS) ||
- PyByteArray_Check(subject))
- {
- Py_INCREF(Py_False);
- PUSH(Py_False);
- DISPATCH();
- }
- // Lazily import _collections_abc.Sequence, and keep it handy on the
- // PyInterpreterState struct (it gets cleaned up at exit):
- PyInterpreterState *interp = PyInterpreterState_Get();
- if (interp->seq_abc == NULL) {
- PyObject *abc = PyImport_ImportModule("_collections_abc");
- if (abc == NULL) {
- goto error;
- }
- interp->seq_abc = PyObject_GetAttrString(abc, "Sequence");
- if (interp->seq_abc == NULL) {
- goto error;
- }
- }
- int match = PyObject_IsInstance(subject, interp->seq_abc);
- if (match < 0) {
- goto error;
- }
- PUSH(PyBool_FromLong(match));
+ int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_SEQUENCE;
+ PyObject *res = match ? Py_True : Py_False;
+ Py_INCREF(res);
+ PUSH(res);
DISPATCH();
}
diff --git a/Python/pystate.c b/Python/pystate.c
index 81bcf68..aeebd6f 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -308,8 +308,6 @@ interpreter_clear(PyInterpreterState *interp, PyThreadState *tstate)
Py_CLEAR(interp->importlib);
Py_CLEAR(interp->import_func);
Py_CLEAR(interp->dict);
- Py_CLEAR(interp->map_abc);
- Py_CLEAR(interp->seq_abc);
#ifdef HAVE_FORK
Py_CLEAR(interp->before_forkers);
Py_CLEAR(interp->after_forkers_parent);