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gh-106303: Use _PyObject_LookupAttr() instead of PyObject_GetAttr() #106304

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Merged
merged 2 commits into from
Jul 9, 2023
Merged

gh-106303: Use _PyObject_LookupAttr() instead of PyObject_GetAttr() #106304

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ba5ae85
gh-106303: Use _PyObject_LookupAttr() instead of PyObject_GetAttr()
serhiy-storchaka Jul 1, 2023
9e25f55
Update Objects/funcobject.c
serhiy-storchaka Jul 1, 2023
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1 change: 1 addition & 0 deletions Include/internal/pycore_global_objects_fini_generated.h
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1 change: 1 addition & 0 deletions Include/internal/pycore_global_strings.h
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Original file line number Diff line number Diff line change
Expand Up @@ -157,6 +157,7 @@ struct _Py_global_strings {
STRUCT_FOR_ID(__lshift__)
STRUCT_FOR_ID(__lt__)
STRUCT_FOR_ID(__main__)
STRUCT_FOR_ID(__match_args__)
STRUCT_FOR_ID(__matmul__)
STRUCT_FOR_ID(__missing__)
STRUCT_FOR_ID(__mod__)
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1 change: 1 addition & 0 deletions Include/internal/pycore_runtime_init_generated.h
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3 changes: 3 additions & 0 deletions Include/internal/pycore_unicodeobject_generated.h
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15 changes: 5 additions & 10 deletions Objects/funcobject.c
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Original file line number Diff line number Diff line change
Expand Up @@ -942,17 +942,12 @@ PyTypeObject PyFunction_Type = {
static int
functools_copy_attr(PyObject *wrapper, PyObject *wrapped, PyObject *name)
{
PyObject *value = PyObject_GetAttr(wrapped, name);
if (value == NULL) {
if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
PyErr_Clear();
return 0;
}
return -1;
PyObject *value;
int res = _PyObject_LookupAttr(wrapped, name, &value);
if (value != NULL) {
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How about adding an assert before reassignment?

assert(res > 0);

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This was not necessary in many other cases where a similar idiom is used.

res = PyObject_SetAttr(wrapper, name, value);
Py_DECREF(value);
}

int res = PyObject_SetAttr(wrapper, name, value);
Py_DECREF(value);
return res;
}

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16 changes: 6 additions & 10 deletions Python/ceval.c
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Expand Up @@ -418,10 +418,8 @@ match_class_attr(PyThreadState *tstate, PyObject *subject, PyObject *type,
}
return NULL;
}
PyObject *attr = PyObject_GetAttr(subject, name);
if (attr == NULL && _PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
_PyErr_Clear(tstate);
}
PyObject *attr;
(void)_PyObject_LookupAttr(subject, name, &attr);
return attr;
}

Expand Down Expand Up @@ -456,7 +454,9 @@ match_class(PyThreadState *tstate, PyObject *subject, PyObject *type,
// First, the positional subpatterns:
if (nargs) {
int match_self = 0;
match_args = PyObject_GetAttrString(type, "__match_args__");
if (_PyObject_LookupAttr(type, &_Py_ID(__match_args__), &match_args) < 0) {
goto fail;
}
if (match_args) {
if (!PyTuple_CheckExact(match_args)) {
const char *e = "%s.__match_args__ must be a tuple (got %s)";
Expand All @@ -466,8 +466,7 @@ match_class(PyThreadState *tstate, PyObject *subject, PyObject *type,
goto fail;
}
}
else if (_PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
_PyErr_Clear(tstate);
else {
// _Py_TPFLAGS_MATCH_SELF is only acknowledged if the type does not
// define __match_args__. This is natural behavior for subclasses:
// it's as if __match_args__ is some "magic" value that is lost as
Expand All @@ -476,9 +475,6 @@ match_class(PyThreadState *tstate, PyObject *subject, PyObject *type,
match_self = PyType_HasFeature((PyTypeObject*)type,
_Py_TPFLAGS_MATCH_SELF);
}
else {
goto fail;
}
assert(PyTuple_CheckExact(match_args));
Py_ssize_t allowed = match_self ? 1 : PyTuple_GET_SIZE(match_args);
if (allowed < nargs) {
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