bpo-32571: Avoid raising unneeded AttributeError and silencing it in C code (GH-5222)

Add two new private APIs: _PyObject_LookupAttr() and _PyObject_LookupAttrId()

1 files changed, 9 insertions, 12 deletions

diff --git a/Objects/genobject.c b/Objects/genobject.c
index 0a34c1f..7baffa7 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -352,13 +352,11 @@ gen_close_iter(PyObject *yf)
             return -1;
     }
     else {
-        PyObject *meth = _PyObject_GetAttrId(yf, &PyId_close);
-        if (meth == NULL) {
-            if (!PyErr_ExceptionMatches(PyExc_AttributeError))
-                PyErr_WriteUnraisable(yf);
-            PyErr_Clear();
+        PyObject *meth;
+        if (_PyObject_LookupAttrId(yf, &PyId_close, &meth) < 0) {
+            PyErr_WriteUnraisable(yf);
         }
-        else {
+        if (meth) {
             retval = _PyObject_CallNoArg(meth);
             Py_DECREF(meth);
             if (retval == NULL)
@@ -471,13 +469,12 @@ _gen_throw(PyGenObject *gen, int close_on_genexit,
             gen->gi_running = 0;
         } else {
             /* `yf` is an iterator or a coroutine-like object. */
-            PyObject *meth = _PyObject_GetAttrId(yf, &PyId_throw);
+            PyObject *meth;
+            if (_PyObject_LookupAttrId(yf, &PyId_throw, &meth) < 0) {
+                Py_DECREF(yf);
+                return NULL;
+            }
             if (meth == NULL) {
-                if (!PyErr_ExceptionMatches(PyExc_AttributeError)) {
-                    Py_DECREF(yf);
-                    return NULL;
-                }
-                PyErr_Clear();
                 Py_DECREF(yf);
                 goto throw_here;
             }