[Python-checkins] bpo-43977: Use tp_flags for collection matching (GH-25723)
markshannon
webhook-mailer at python.org
Fri Apr 30 04:50:37 EDT 2021
https://github.com/python/cpython/commit/069e81ab3da46c441335ca762c4333b7bd91861d
commit: 069e81ab3da46c441335ca762c4333b7bd91861d
branch: master
author: Mark Shannon <mark at hotpy.org>
committer: markshannon <mark at hotpy.org>
date: 2021-04-30T09:50:28+01:00
summary:
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.
files:
A Misc/NEWS.d/next/Core and Builtins/2021-04-29-17-40-25.bpo-43977.FrQhge.rst
M Include/internal/pycore_interp.h
M Include/object.h
M Lib/_collections_abc.py
M Modules/_abc.c
M Modules/_collectionsmodule.c
M Modules/arraymodule.c
M Objects/descrobject.c
M Objects/dictobject.c
M Objects/listobject.c
M Objects/memoryobject.c
M Objects/rangeobject.c
M Objects/tupleobject.c
M Objects/typeobject.c
M Python/ceval.c
M Python/pystate.c
diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 11d31da382958..bfd082b588256 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -247,10 +247,6 @@ struct _is {
// importlib module
PyObject *importlib;
- // Kept handy for pattern matching:
- PyObject *map_abc; // _collections_abc.Mapping
- PyObject *seq_abc; // _collections_abc.Sequence
-
/* Used in Modules/_threadmodule.c. */
long num_threads;
/* Support for runtime thread stack size tuning.
diff --git a/Include/object.h b/Include/object.h
index d8476f9213760..cffe72cda869f 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -320,6 +320,13 @@ Code can use PyType_HasFeature(type_ob, flag_value) to test whether the
given type object has a specified feature.
*/
+#ifndef Py_LIMITED_API
+/* Set if instances of the type object are treated as sequences for pattern matching */
+#define Py_TPFLAGS_SEQUENCE (1 << 5)
+/* Set if instances of the type object are treated as mappings for pattern matching */
+#define Py_TPFLAGS_MAPPING (1 << 6)
+#endif
+
/* Set if the type object is immutable: type attributes cannot be set nor deleted */
#define Py_TPFLAGS_IMMUTABLETYPE (1UL << 8)
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py
index dddf8a23ff985..d92b848e9436f 100644
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -793,7 +793,6 @@ def __isub__(self, it):
### MAPPINGS ###
-
class Mapping(Collection):
"""A Mapping is a generic container for associating key/value
pairs.
@@ -804,6 +803,9 @@ class Mapping(Collection):
__slots__ = ()
+ # Tell ABCMeta.__new__ that this class should have TPFLAGS_MAPPING set.
+ __abc_tpflags__ = 1 << 6 # Py_TPFLAGS_MAPPING
+
@abstractmethod
def __getitem__(self, key):
raise KeyError
@@ -842,7 +844,6 @@ def __eq__(self, other):
__reversed__ = None
-
Mapping.register(mappingproxy)
@@ -1011,7 +1012,6 @@ def setdefault(self, key, default=None):
### SEQUENCES ###
-
class Sequence(Reversible, Collection):
"""All the operations on a read-only sequence.
@@ -1021,6 +1021,9 @@ class Sequence(Reversible, Collection):
__slots__ = ()
+ # Tell ABCMeta.__new__ that this class should have TPFLAGS_SEQUENCE set.
+ __abc_tpflags__ = 1 << 5 # Py_TPFLAGS_SEQUENCE
+
@abstractmethod
def __getitem__(self, index):
raise IndexError
@@ -1072,7 +1075,6 @@ def count(self, value):
'S.count(value) -> integer -- return number of occurrences of value'
return sum(1 for v in self if v is value or v == value)
-
Sequence.register(tuple)
Sequence.register(str)
Sequence.register(range)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-04-29-17-40-25.bpo-43977.FrQhge.rst b/Misc/NEWS.d/next/Core and Builtins/2021-04-29-17-40-25.bpo-43977.FrQhge.rst
new file mode 100644
index 0000000000000..038d7390852ba
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-04-29-17-40-25.bpo-43977.FrQhge.rst
@@ -0,0 +1,2 @@
+Use :c:member:`~PyTypeObject.tp_flags` on the class object to determine if the subject is a sequence
+or mapping when pattern matching. Avoids the need to import :mod:`collections.abc` when pattern matching.
diff --git a/Modules/_abc.c b/Modules/_abc.c
index 0ddc2abeee1e0..39261dd3cd579 100644
--- a/Modules/_abc.c
+++ b/Modules/_abc.c
@@ -15,6 +15,7 @@ PyDoc_STRVAR(_abc__doc__,
_Py_IDENTIFIER(__abstractmethods__);
_Py_IDENTIFIER(__class__);
_Py_IDENTIFIER(__dict__);
+_Py_IDENTIFIER(__abc_tpflags__);
_Py_IDENTIFIER(__bases__);
_Py_IDENTIFIER(_abc_impl);
_Py_IDENTIFIER(__subclasscheck__);
@@ -417,6 +418,8 @@ compute_abstract_methods(PyObject *self)
return ret;
}
+#define COLLECTION_FLAGS (Py_TPFLAGS_SEQUENCE | Py_TPFLAGS_MAPPING)
+
/*[clinic input]
_abc._abc_init
@@ -446,6 +449,31 @@ _abc__abc_init(PyObject *module, PyObject *self)
return NULL;
}
Py_DECREF(data);
+ /* If __abc_tpflags__ & COLLECTION_FLAGS is set, then set the corresponding bit(s)
+ * in the new class.
+ * Used by collections.abc.Sequence and collections.abc.Mapping to indicate
+ * their special status w.r.t. pattern matching. */
+ if (PyType_Check(self)) {
+ PyTypeObject *cls = (PyTypeObject *)self;
+ PyObject *flags = _PyDict_GetItemIdWithError(cls->tp_dict, &PyId___abc_tpflags__);
+ if (flags == NULL) {
+ if (PyErr_Occurred()) {
+ return NULL;
+ }
+ }
+ else {
+ if (PyLong_CheckExact(flags)) {
+ long val = PyLong_AsLong(flags);
+ if (val == -1 && PyErr_Occurred()) {
+ return NULL;
+ }
+ ((PyTypeObject *)self)->tp_flags |= (val & COLLECTION_FLAGS);
+ }
+ if (_PyDict_DelItemId(cls->tp_dict, &PyId___abc_tpflags__) < 0) {
+ return NULL;
+ }
+ }
+ }
Py_RETURN_NONE;
}
@@ -499,6 +527,11 @@ _abc__abc_register_impl(PyObject *module, PyObject *self, PyObject *subclass)
/* Invalidate negative cache */
get_abc_state(module)->abc_invalidation_counter++;
+ if (PyType_Check(subclass) && PyType_Check(self) &&
+ !PyType_HasFeature((PyTypeObject *)subclass, Py_TPFLAGS_IMMUTABLETYPE))
+ {
+ ((PyTypeObject *)subclass)->tp_flags |= (((PyTypeObject *)self)->tp_flags & COLLECTION_FLAGS);
+ }
Py_INCREF(subclass);
return subclass;
}
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 8b01a7fad01a2..9c8701af904ab 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -1662,7 +1662,8 @@ static PyTypeObject deque_type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
+ Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_SEQUENCE,
/* tp_flags */
deque_doc, /* tp_doc */
(traverseproc)deque_traverse, /* tp_traverse */
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index 367621fd03b88..d65c1449eb38e 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -2848,7 +2848,8 @@ static PyType_Spec array_spec = {
.name = "array.array",
.basicsize = sizeof(arrayobject),
.flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
- Py_TPFLAGS_IMMUTABLETYPE),
+ Py_TPFLAGS_IMMUTABLETYPE |
+ Py_TPFLAGS_SEQUENCE),
.slots = array_slots,
};
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index dd41620b9a9ee..57a9607d10c31 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1852,7 +1852,8 @@ PyTypeObject PyDictProxy_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+ Py_TPFLAGS_MAPPING, /* tp_flags */
0, /* tp_doc */
mappingproxy_traverse, /* tp_traverse */
0, /* tp_clear */
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 0aeee7011e844..9e2c12229df80 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -3553,7 +3553,7 @@ PyTypeObject PyDict_Type = {
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_BASETYPE | Py_TPFLAGS_DICT_SUBCLASS |
- _Py_TPFLAGS_MATCH_SELF, /* tp_flags */
+ _Py_TPFLAGS_MATCH_SELF | Py_TPFLAGS_MAPPING, /* tp_flags */
dictionary_doc, /* tp_doc */
dict_traverse, /* tp_traverse */
dict_tp_clear, /* tp_clear */
diff --git a/Objects/listobject.c b/Objects/listobject.c
index e7987a6d352bf..6eb7dce759cf8 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -3053,7 +3053,7 @@ PyTypeObject PyList_Type = {
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_BASETYPE | Py_TPFLAGS_LIST_SUBCLASS |
- _Py_TPFLAGS_MATCH_SELF, /* tp_flags */
+ _Py_TPFLAGS_MATCH_SELF | Py_TPFLAGS_SEQUENCE, /* tp_flags */
list___init____doc__, /* tp_doc */
(traverseproc)list_traverse, /* tp_traverse */
(inquiry)_list_clear, /* tp_clear */
diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index d328f4d40b7a4..913d358062219 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -3287,7 +3287,8 @@ PyTypeObject PyMemoryView_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
&memory_as_buffer, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+ Py_TPFLAGS_SEQUENCE, /* tp_flags */
memoryview__doc__, /* tp_doc */
(traverseproc)memory_traverse, /* tp_traverse */
(inquiry)memory_clear, /* tp_clear */
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index 530426c8ac904..3e05707b1cee6 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -735,7 +735,7 @@ PyTypeObject PyRange_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_SEQUENCE, /* tp_flags */
range_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 89c393ccc5fbc..6b1ab740121e8 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -918,7 +918,7 @@ PyTypeObject PyTuple_Type = {
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_BASETYPE | Py_TPFLAGS_TUPLE_SUBCLASS |
- _Py_TPFLAGS_MATCH_SELF, /* tp_flags */
+ _Py_TPFLAGS_MATCH_SELF | Py_TPFLAGS_SEQUENCE, /* tp_flags */
tuple_new__doc__, /* tp_doc */
(traverseproc)tupletraverse, /* tp_traverse */
0, /* tp_clear */
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index ac4dc1da4411d..19d619fada0e9 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -5717,10 +5717,15 @@ inherit_special(PyTypeObject *type, PyTypeObject *base)
else if (PyType_IsSubtype(base, &PyDict_Type)) {
type->tp_flags |= Py_TPFLAGS_DICT_SUBCLASS;
}
-
if (PyType_HasFeature(base, _Py_TPFLAGS_MATCH_SELF)) {
type->tp_flags |= _Py_TPFLAGS_MATCH_SELF;
}
+ if (PyType_HasFeature(base, Py_TPFLAGS_SEQUENCE)) {
+ type->tp_flags |= Py_TPFLAGS_SEQUENCE;
+ }
+ if (PyType_HasFeature(base, Py_TPFLAGS_MAPPING)) {
+ type->tp_flags |= Py_TPFLAGS_MAPPING;
+ }
}
static int
diff --git a/Python/ceval.c b/Python/ceval.c
index 326930b706c43..866c57afdbf9d 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 81bcf68219a0e..aeebd6f61c6d7 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);
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