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

It simplifies and speed up the code.

1 files changed, 6 insertions, 10 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 1b8650a..da11355 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -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;
 }
 
@@ -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)";
@@ -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
@@ -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) {