gh-108511: Add C API functions which do not silently ignore errors (GH-109025)

Add the following functions:

* PyObject_HasAttrWithError()
* PyObject_HasAttrStringWithError()
* PyMapping_HasKeyWithError()
* PyMapping_HasKeyStringWithError()

Doc/c-api/mapping.rst

@@ -76,6 +76,24 @@ See also :c:func:`PyObject_GetItem`, :c:func:`PyObject_SetItem` and
    rather than a :c:expr:`PyObject*`.
 
 
+.. c:function:: int PyMapping_HasKeyWithError(PyObject *o, PyObject *key)
+
+   Return ``1`` if the mapping object has the key *key* and ``0`` otherwise.
+   This is equivalent to the Python expression ``key in o``.
+   On failure, return ``-1``.
+
+   .. versionadded:: 3.13
+
+
+.. c:function:: int PyMapping_HasKeyStringWithError(PyObject *o, const char *key)
+
+   This is the same as :c:func:`PyMapping_HasKeyWithError`, but *key* is
+   specified as a :c:expr:`const char*` UTF-8 encoded bytes string,
+   rather than a :c:expr:`PyObject*`.
+
+   .. versionadded:: 3.13
+
+
 .. c:function:: int PyMapping_HasKey(PyObject *o, PyObject *key)
 
    Return ``1`` if the mapping object has the key *key* and ``0`` otherwise.
@@ -86,8 +104,8 @@ See also :c:func:`PyObject_GetItem`, :c:func:`PyObject_SetItem` and
 
       Exceptions which occur when this calls :meth:`~object.__getitem__`
       method are silently ignored.
-      For proper error handling, use :c:func:`PyMapping_GetOptionalItem` or
-      :c:func:`PyObject_GetItem()` instead.
+      For proper error handling, use :c:func:`PyMapping_HasKeyWithError`,
+      :c:func:`PyMapping_GetOptionalItem` or :c:func:`PyObject_GetItem()` instead.
 
 
 .. c:function:: int PyMapping_HasKeyString(PyObject *o, const char *key)
@@ -101,7 +119,8 @@ See also :c:func:`PyObject_GetItem`, :c:func:`PyObject_SetItem` and
       Exceptions that occur when this calls :meth:`~object.__getitem__`
       method or while creating the temporary :class:`str`
       object are silently ignored.
-      For proper error handling, use :c:func:`PyMapping_GetOptionalItemString` or
+      For proper error handling, use :c:func:`PyMapping_HasKeyStringWithError`,
+      :c:func:`PyMapping_GetOptionalItemString` or
       :c:func:`PyMapping_GetItemString` instead.
 
 

Doc/c-api/object.rst

@@ -27,6 +27,24 @@ Object Protocol
    instead of the :func:`repr`.
 
 
+.. c:function:: int PyObject_HasAttrWithError(PyObject *o, const char *attr_name)
+
+   Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise.
+   This is equivalent to the Python expression ``hasattr(o, attr_name)``.
+   On failure, return ``-1``.
+
+   .. versionadded:: 3.13
+
+
+.. c:function:: int PyObject_HasAttrStringWithError(PyObject *o, const char *attr_name)
+
+   This is the same as :c:func:`PyObject_HasAttrWithError`, but *attr_name* is
+   specified as a :c:expr:`const char*` UTF-8 encoded bytes string,
+   rather than a :c:expr:`PyObject*`.
+
+   .. versionadded:: 3.13
+
+
 .. c:function:: int PyObject_HasAttr(PyObject *o, PyObject *attr_name)
 
    Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise.  This
@@ -37,8 +55,8 @@ Object Protocol
 
       Exceptions that occur when this calls :meth:`~object.__getattr__` and
       :meth:`~object.__getattribute__` methods are silently ignored.
-      For proper error handling, use :c:func:`PyObject_GetOptionalAttr` or
-      :c:func:`PyObject_GetAttr` instead.
+      For proper error handling, use :c:func:`PyObject_HasAttrWithError`,
+      :c:func:`PyObject_GetOptionalAttr` or :c:func:`PyObject_GetAttr` instead.
 
 
 .. c:function:: int PyObject_HasAttrString(PyObject *o, const char *attr_name)
@@ -52,7 +70,8 @@ Object Protocol
       Exceptions that occur when this calls :meth:`~object.__getattr__` and
       :meth:`~object.__getattribute__` methods or while creating the temporary
       :class:`str` object are silently ignored.
-      For proper error handling, use :c:func:`PyObject_GetOptionalAttrString`
+      For proper error handling, use :c:func:`PyObject_HasAttrStringWithError`,
+      :c:func:`PyObject_GetOptionalAttrString`
       or :c:func:`PyObject_GetAttrString` instead.
 
 

Doc/data/stable_abi.dat

@@ -377,6 +377,8 @@ function,PyMapping_GetOptionalItem,3.13,,
 function,PyMapping_GetOptionalItemString,3.13,,
 function,PyMapping_HasKey,3.2,,
 function,PyMapping_HasKeyString,3.2,,
+function,PyMapping_HasKeyStringWithError,3.13,,
+function,PyMapping_HasKeyWithError,3.13,,
 function,PyMapping_Items,3.2,,
 function,PyMapping_Keys,3.2,,
 function,PyMapping_Length,3.2,,
@@ -523,6 +525,8 @@ function,PyObject_GetOptionalAttrString,3.13,,
 function,PyObject_GetTypeData,3.12,,
 function,PyObject_HasAttr,3.2,,
 function,PyObject_HasAttrString,3.2,,
+function,PyObject_HasAttrStringWithError,3.13,,
+function,PyObject_HasAttrWithError,3.13,,
 function,PyObject_Hash,3.2,,
 function,PyObject_HashNotImplemented,3.2,,
 function,PyObject_Init,3.2,,

Doc/whatsnew/3.13.rst

@@ -926,6 +926,18 @@ New Features
   be treated as a failure.
   (Contributed by Serhiy Storchaka in :gh:`106307`.)
 
+* Add fixed variants of functions which silently ignore errors:
+
+  - :c:func:`PyObject_HasAttrWithError` replaces :c:func:`PyObject_HasAttr`.
+  - :c:func:`PyObject_HasAttrStringWithError` replaces :c:func:`PyObject_HasAttrString`.
+  - :c:func:`PyMapping_HasKeyWithError` replaces :c:func:`PyMapping_HasKey`.
+  - :c:func:`PyMapping_HasKeyStringWithError` replaces :c:func:`PyMapping_HasKeyString`.
+
+  New functions return not only ``1`` for true and ``0`` for false, but also
+  ``-1`` for error.
+
+  (Contributed by Serhiy Storchaka in :gh:`108511`.)
+
 * If Python is built in :ref:`debug mode <debug-build>` or :option:`with
   assertions <--with-assertions>`, :c:func:`PyTuple_SET_ITEM` and
   :c:func:`PyList_SET_ITEM` now check the index argument with an assertion.

Include/abstract.h

@@ -50,6 +50,25 @@ extern "C" {
 
    This function always succeeds. */
 
+
+/* Implemented elsewhere:
+
+   int PyObject_HasAttrStringWithError(PyObject *o, const char *attr_name);
+
+   Returns 1 if object 'o' has the attribute attr_name, and 0 otherwise.
+   This is equivalent to the Python expression: hasattr(o,attr_name).
+   Returns -1 on failure. */
+
+
+/* Implemented elsewhere:
+
+   int PyObject_HasAttrWithError(PyObject *o, PyObject *attr_name);
+
+   Returns 1 if o has the attribute attr_name, and 0 otherwise.
+   This is equivalent to the Python expression: hasattr(o,attr_name).
+   Returns -1 on failure. */
+
+
 /* Implemented elsewhere:
 
    PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name);
@@ -821,6 +840,18 @@ PyAPI_FUNC(int) PyMapping_HasKeyString(PyObject *o, const char *key);
    This function always succeeds. */
 PyAPI_FUNC(int) PyMapping_HasKey(PyObject *o, PyObject *key);
 
+/* Return 1 if the mapping object has the key 'key', and 0 otherwise.
+   This is equivalent to the Python expression: key in o.
+   On failure, return -1. */
+
+PyAPI_FUNC(int) PyMapping_HasKeyWithError(PyObject *o, PyObject *key);
+
+/* Return 1 if the mapping object has the key 'key', and 0 otherwise.
+   This is equivalent to the Python expression: key in o.
+   On failure, return -1. */
+
+PyAPI_FUNC(int) PyMapping_HasKeyStringWithError(PyObject *o, const char *key);
+
 /* On success, return a list or tuple of the keys in mapping object 'o'.
    On failure, return NULL. */
 PyAPI_FUNC(PyObject *) PyMapping_Keys(PyObject *o);

Include/object.h

@@ -394,6 +394,10 @@ PyAPI_FUNC(int) PyObject_GetOptionalAttrString(PyObject *, const char *, PyObjec
 PyAPI_FUNC(int) PyObject_SetAttr(PyObject *, PyObject *, PyObject *);
 PyAPI_FUNC(int) PyObject_DelAttr(PyObject *v, PyObject *name);
 PyAPI_FUNC(int) PyObject_HasAttr(PyObject *, PyObject *);
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030d0000
+PyAPI_FUNC(int) PyObject_HasAttrWithError(PyObject *, PyObject *);
+PyAPI_FUNC(int) PyObject_HasAttrStringWithError(PyObject *, const char *);
+#endif
 PyAPI_FUNC(PyObject *) PyObject_SelfIter(PyObject *);
 PyAPI_FUNC(PyObject *) PyObject_GenericGetAttr(PyObject *, PyObject *);
 PyAPI_FUNC(int) PyObject_GenericSetAttr(PyObject *, PyObject *, PyObject *);

Lib/test/test_capi/test_abstract.py

@@ -129,6 +129,34 @@ class CAPITest(unittest.TestCase):
         # CRASHES hasattrstring(obj, NULL)
         # CRASHES hasattrstring(NULL, b'a')
 
+    def test_object_hasattrwitherror(self):
+        xhasattr = _testcapi.object_hasattrwitherror
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        self.assertTrue(xhasattr(obj, 'a'))
+        self.assertFalse(xhasattr(obj, 'b'))
+        self.assertTrue(xhasattr(obj, '\U0001f40d'))
+
+        self.assertRaises(RuntimeError, xhasattr, obj, 'evil')
+        self.assertRaises(TypeError, xhasattr, obj, 1)
+        # CRASHES xhasattr(obj, NULL)
+        # CRASHES xhasattr(NULL, 'a')
+
+    def test_object_hasattrstringwitherror(self):
+        hasattrstring = _testcapi.object_hasattrstringwitherror
+        obj = TestObject()
+        obj.a = 1
+        setattr(obj, '\U0001f40d', 2)
+        self.assertTrue(hasattrstring(obj, b'a'))
+        self.assertFalse(hasattrstring(obj, b'b'))
+        self.assertTrue(hasattrstring(obj, '\U0001f40d'.encode()))
+
+        self.assertRaises(RuntimeError, hasattrstring, obj, b'evil')
+        self.assertRaises(UnicodeDecodeError, hasattrstring, obj, b'\xff')
+        # CRASHES hasattrstring(obj, NULL)
+        # CRASHES hasattrstring(NULL, b'a')
+
     def test_object_setattr(self):
         xsetattr = _testcapi.object_setattr
         obj = TestObject()
@@ -339,6 +367,44 @@ class CAPITest(unittest.TestCase):
         self.assertFalse(haskeystring([], b'a'))
         self.assertFalse(haskeystring(NULL, b'a'))
 
+    def test_mapping_haskeywitherror(self):
+        haskey = _testcapi.mapping_haskeywitherror
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertTrue(haskey(dct, 'a'))
+        self.assertFalse(haskey(dct, 'b'))
+        self.assertTrue(haskey(dct, '\U0001f40d'))
+
+        dct2 = ProxyGetItem(dct)
+        self.assertTrue(haskey(dct2, 'a'))
+        self.assertFalse(haskey(dct2, 'b'))
+
+        self.assertTrue(haskey(['a', 'b', 'c'], 1))
+
+        self.assertRaises(TypeError, haskey, 42, 'a')
+        self.assertRaises(TypeError, haskey, {}, [])  # unhashable
+        self.assertRaises(IndexError, haskey, [], 1)
+        self.assertRaises(TypeError, haskey, [], 'a')
+
+        # CRASHES haskey({}, NULL))
+        # CRASHES haskey(NULL, 'a'))
+
+    def test_mapping_haskeystringwitherror(self):
+        haskeystring = _testcapi.mapping_haskeystringwitherror
+        dct = {'a': 1, '\U0001f40d': 2}
+        self.assertTrue(haskeystring(dct, b'a'))
+        self.assertFalse(haskeystring(dct, b'b'))
+        self.assertTrue(haskeystring(dct, '\U0001f40d'.encode()))
+
+        dct2 = ProxyGetItem(dct)
+        self.assertTrue(haskeystring(dct2, b'a'))
+        self.assertFalse(haskeystring(dct2, b'b'))
+
+        self.assertRaises(TypeError, haskeystring, 42, b'a')
+        self.assertRaises(UnicodeDecodeError, haskeystring, {}, b'\xff')
+        self.assertRaises(SystemError, haskeystring, {}, NULL)
+        self.assertRaises(TypeError, haskeystring, [], b'a')
+        # CRASHES haskeystring(NULL, b'a')
+
     def test_object_setitem(self):
         setitem = _testcapi.object_setitem
         dct = {}

Lib/test/test_stable_abi_ctypes.py

@@ -405,6 +405,8 @@ SYMBOL_NAMES = (
     "PyMapping_GetOptionalItemString",
     "PyMapping_HasKey",
     "PyMapping_HasKeyString",
+    "PyMapping_HasKeyStringWithError",
+    "PyMapping_HasKeyWithError",
     "PyMapping_Items",
     "PyMapping_Keys",
     "PyMapping_Length",
@@ -542,6 +544,8 @@ SYMBOL_NAMES = (
     "PyObject_GetTypeData",
     "PyObject_HasAttr",
     "PyObject_HasAttrString",
+    "PyObject_HasAttrStringWithError",
+    "PyObject_HasAttrWithError",
     "PyObject_Hash",
     "PyObject_HashNotImplemented",
     "PyObject_Init",

Misc/NEWS.d/next/C API/2023-09-01-16-28-09.gh-issue-108511.gg-QDG.rst

@@ -0,0 +1,4 @@
+Add functions :c:func:`PyObject_HasAttrWithError`,
+:c:func:`PyObject_HasAttrStringWithError`,
+:c:func:`PyMapping_HasKeyWithError` and
+:c:func:`PyMapping_HasKeyStringWithError`.

Misc/stable_abi.toml

@@ -2452,3 +2452,11 @@
     added = '3.13'
 [function.PyLong_AsInt]
     added = '3.13'
+[function.PyObject_HasAttrWithError]
+    added = '3.13'
+[function.PyObject_HasAttrStringWithError]
+    added = '3.13'
+[function.PyMapping_HasKeyWithError]
+    added = '3.13'
+[function.PyMapping_HasKeyStringWithError]
+    added = '3.13'

Modules/_ctypes/stgdict.c

@@ -386,11 +386,11 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
     if (fields == NULL)
         return 0;
 
-    if (PyObject_GetOptionalAttr(type, &_Py_ID(_swappedbytes_), &tmp) < 0) {
+    int rc = PyObject_HasAttrWithError(type, &_Py_ID(_swappedbytes_));
+    if (rc < 0) {
         return -1;
     }
-    if (tmp) {
-        Py_DECREF(tmp);
+    if (rc) {
         big_endian = !PY_BIG_ENDIAN;
     }
     else {

Modules/_elementtree.c

@@ -3532,12 +3532,11 @@ expat_start_doctype_handler(XMLParserObject *self,
                                            sysid_obj, NULL);
         Py_XDECREF(res);
     }
-    else if (PyObject_GetOptionalAttr((PyObject *)self, st->str_doctype, &res) > 0) {
+    else if (PyObject_HasAttrWithError((PyObject *)self, st->str_doctype) > 0) {
         (void)PyErr_WarnEx(PyExc_RuntimeWarning,
                 "The doctype() method of XMLParser is ignored.  "
                 "Define doctype() method on the TreeBuilder target.",
                 1);
-        Py_DECREF(res);
     }
 
     Py_DECREF(doctype_name_obj);

Modules/_io/iobase.c

@@ -148,13 +148,9 @@ _io__IOBase_truncate_impl(PyObject *self, PyTypeObject *cls,
 static int
 iobase_is_closed(PyObject *self)
 {
-    PyObject *res;
-    int ret;
     /* This gets the derived attribute, which is *not* __IOBase_closed
        in most cases! */
-    ret = PyObject_GetOptionalAttr(self, &_Py_ID(__IOBase_closed), &res);
-    Py_XDECREF(res);
-    return ret;
+    return PyObject_HasAttrWithError(self, &_Py_ID(__IOBase_closed));
 }
 
 /* Flush and close methods */

Modules/_io/textio.c

@@ -1223,11 +1223,10 @@ _io_TextIOWrapper___init___impl(textio *self, PyObject *buffer,
         goto error;
     self->seekable = self->telling = r;
 
-    r = PyObject_GetOptionalAttr(buffer, &_Py_ID(read1), &res);
+    r = PyObject_HasAttrWithError(buffer, &_Py_ID(read1));
     if (r < 0) {
         goto error;
     }
-    Py_XDECREF(res);
     self->has_read1 = r;
 
     self->encoding_start_of_stream = 0;

Modules/_pickle.c

@@ -5799,14 +5799,13 @@ instantiate(PyObject *cls, PyObject *args)
        into a newly created tuple. */
     assert(PyTuple_Check(args));
     if (!PyTuple_GET_SIZE(args) && PyType_Check(cls)) {
-        PyObject *func;
-        if (PyObject_GetOptionalAttr(cls, &_Py_ID(__getinitargs__), &func) < 0) {
+        int rc = PyObject_HasAttrWithError(cls, &_Py_ID(__getinitargs__));
+        if (rc < 0) {
             return NULL;
         }
-        if (func == NULL) {
+        if (!rc) {
             return PyObject_CallMethodOneArg(cls, &_Py_ID(__new__), cls);
         }
-        Py_DECREF(func);
     }
     return PyObject_CallObject(cls, args);
 }

Modules/_testcapi/abstract.c

@@ -105,6 +105,31 @@ object_hasattrstring(PyObject *self, PyObject *args)
     return PyLong_FromLong(PyObject_HasAttrString(obj, attr_name));
 }
 
+static PyObject *
+object_hasattrwitherror(PyObject *self, PyObject *args)
+{
+    PyObject *obj, *attr_name;
+    if (!PyArg_ParseTuple(args, "OO", &obj, &attr_name)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    NULLABLE(attr_name);
+    RETURN_INT(PyObject_HasAttrWithError(obj, attr_name));
+}
+
+static PyObject *
+object_hasattrstringwitherror(PyObject *self, PyObject *args)
+{
+    PyObject *obj;
+    const char *attr_name;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &obj, &attr_name, &size)) {
+        return NULL;
+    }
+    NULLABLE(obj);
+    RETURN_INT(PyObject_HasAttrStringWithError(obj, attr_name));
+}
+
 static PyObject *
 object_setattr(PyObject *self, PyObject *args)
 {
@@ -280,6 +305,31 @@ mapping_haskeystring(PyObject *self, PyObject *args)
     return PyLong_FromLong(PyMapping_HasKeyString(mapping, key));
 }
 
+static PyObject *
+mapping_haskeywitherror(PyObject *self, PyObject *args)
+{
+    PyObject *mapping, *key;
+    if (!PyArg_ParseTuple(args, "OO", &mapping, &key)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    NULLABLE(key);
+    RETURN_INT(PyMapping_HasKeyWithError(mapping, key));
+}
+
+static PyObject *
+mapping_haskeystringwitherror(PyObject *self, PyObject *args)
+{
+    PyObject *mapping;
+    const char *key;
+    Py_ssize_t size;
+    if (!PyArg_ParseTuple(args, "Oz#", &mapping, &key, &size)) {
+        return NULL;
+    }
+    NULLABLE(mapping);
+    RETURN_INT(PyMapping_HasKeyStringWithError(mapping, key));
+}
+
 static PyObject *
 object_setitem(PyObject *self, PyObject *args)
 {
@@ -568,6 +618,8 @@ static PyMethodDef test_methods[] = {
     {"object_getoptionalattrstring", object_getoptionalattrstring, METH_VARARGS},
     {"object_hasattr", object_hasattr, METH_VARARGS},
     {"object_hasattrstring", object_hasattrstring, METH_VARARGS},
+    {"object_hasattrwitherror", object_hasattrwitherror, METH_VARARGS},
+    {"object_hasattrstringwitherror", object_hasattrstringwitherror, METH_VARARGS},
     {"object_setattr", object_setattr, METH_VARARGS},
     {"object_setattrstring", object_setattrstring, METH_VARARGS},
     {"object_delattr", object_delattr, METH_VARARGS},
@@ -582,6 +634,8 @@ static PyMethodDef test_methods[] = {
     {"mapping_getoptionalitemstring", mapping_getoptionalitemstring, METH_VARARGS},
     {"mapping_haskey", mapping_haskey, METH_VARARGS},
     {"mapping_haskeystring", mapping_haskeystring, METH_VARARGS},
+    {"mapping_haskeywitherror", mapping_haskeywitherror, METH_VARARGS},
+    {"mapping_haskeystringwitherror", mapping_haskeystringwitherror, METH_VARARGS},
     {"object_setitem", object_setitem, METH_VARARGS},
     {"mapping_setitemstring", mapping_setitemstring, METH_VARARGS},
     {"object_delitem", object_delitem, METH_VARARGS},

Modules/_xxinterpchannelsmodule.c

@@ -123,7 +123,7 @@ get_module_from_type(PyTypeObject *cls)
 static PyObject *
 add_new_exception(PyObject *mod, const char *name, PyObject *base)
 {
-    assert(!PyObject_HasAttrString(mod, name));
+    assert(!PyObject_HasAttrStringWithError(mod, name));
     PyObject *exctype = PyErr_NewException(name, base, NULL);
     if (exctype == NULL) {
         return NULL;

Modules/_xxsubinterpretersmodule.c

@@ -41,7 +41,7 @@ _get_current_interp(void)
 static PyObject *
 add_new_exception(PyObject *mod, const char *name, PyObject *base)
 {
-    assert(!PyObject_HasAttrString(mod, name));
+    assert(!PyObject_HasAttrStringWithError(mod, name));
     PyObject *exctype = PyErr_NewException(name, base, NULL);
     if (exctype == NULL) {
         return NULL;

Objects/abstract.c

@@ -2426,6 +2426,24 @@ PyMapping_SetItemString(PyObject *o, const char *key, PyObject *value)
     return r;
 }
 
+int
+PyMapping_HasKeyStringWithError(PyObject *obj, const char *key)
+{
+    PyObject *res;
+    int rc = PyMapping_GetOptionalItemString(obj, key, &res);
+    Py_XDECREF(res);
+    return rc;
+}
+
+int
+PyMapping_HasKeyWithError(PyObject *obj, PyObject *key)
+{
+    PyObject *res;
+    int rc = PyMapping_GetOptionalItem(obj, key, &res);
+    Py_XDECREF(res);
+    return rc;
+}
+
 int
 PyMapping_HasKeyString(PyObject *o, const char *key)
 {

Objects/dictobject.c

@@ -2688,12 +2688,11 @@ dict_update_arg(PyObject *self, PyObject *arg)
     if (PyDict_CheckExact(arg)) {
         return PyDict_Merge(self, arg, 1);
     }
-    PyObject *func;
-    if (PyObject_GetOptionalAttr(arg, &_Py_ID(keys), &func) < 0) {
+    int has_keys = PyObject_HasAttrWithError(arg, &_Py_ID(keys));
+    if (has_keys < 0) {
         return -1;
     }
-    if (func != NULL) {
-        Py_DECREF(func);
+    if (has_keys) {
         return PyDict_Merge(self, arg, 1);
     }
     return PyDict_MergeFromSeq2(self, arg, 1);

Objects/genericaliasobject.c

@@ -55,8 +55,7 @@ ga_repr_item(_PyUnicodeWriter *writer, PyObject *p)
     PyObject *qualname = NULL;
     PyObject *module = NULL;
     PyObject *r = NULL;
-    PyObject *tmp;
-    int err;
+    int rc;
 
     if (p == Py_Ellipsis) {
         // The Ellipsis object
@@ -64,19 +63,14 @@ ga_repr_item(_PyUnicodeWriter *writer, PyObject *p)
         goto done;
     }
 
-    if (PyObject_GetOptionalAttr(p, &_Py_ID(__origin__), &tmp) < 0) {
-        goto done;
-    }
-    if (tmp != NULL) {
-        Py_DECREF(tmp);
-        if (PyObject_GetOptionalAttr(p, &_Py_ID(__args__), &tmp) < 0) {
-            goto done;
-        }
-        if (tmp != NULL) {
-            Py_DECREF(tmp);
+    if ((rc = PyObject_HasAttrWithError(p, &_Py_ID(__origin__))) > 0 &&
+        (rc = PyObject_HasAttrWithError(p, &_Py_ID(__args__))) > 0)
+    {
         // It looks like a GenericAlias
         goto use_repr;
     }
+    if (rc < 0) {
+        goto done;
     }
 
     if (PyObject_GetOptionalAttr(p, &_Py_ID(__qualname__), &qualname) < 0) {
@@ -113,13 +107,13 @@ done:
     Py_XDECREF(module);
     if (r == NULL) {
         // error if any of the above PyObject_Repr/PyUnicode_From* fail
-        err = -1;
+        rc = -1;
     }
     else {
-        err = _PyUnicodeWriter_WriteStr(writer, r);
+        rc = _PyUnicodeWriter_WriteStr(writer, r);
         Py_DECREF(r);
     }
-    return err;
+    return rc;
 }
 
 static int
@@ -253,18 +247,17 @@ _Py_make_parameters(PyObject *args)
     Py_ssize_t iparam = 0;
     for (Py_ssize_t iarg = 0; iarg < nargs; iarg++) {
         PyObject *t = PyTuple_GET_ITEM(args, iarg);
-        PyObject *subst;
         // We don't want __parameters__ descriptor of a bare Python class.
         if (PyType_Check(t)) {
             continue;
         }
-        if (PyObject_GetOptionalAttr(t, &_Py_ID(__typing_subst__), &subst) < 0) {
+        int rc = PyObject_HasAttrWithError(t, &_Py_ID(__typing_subst__));
+        if (rc < 0) {
             Py_DECREF(parameters);
             return NULL;
         }
-        if (subst) {
+        if (rc) {
             iparam += tuple_add(parameters, iparam, t);
-            Py_DECREF(subst);
         }
         else {
             PyObject *subparams;

Objects/object.c

@@ -911,26 +911,24 @@ PyObject_GetAttrString(PyObject *v, const char *name)
 }
 
 int
-PyObject_HasAttrString(PyObject *v, const char *name)
+PyObject_HasAttrStringWithError(PyObject *obj, const char *name)
 {
-    if (Py_TYPE(v)->tp_getattr != NULL) {
-        PyObject *res = (*Py_TYPE(v)->tp_getattr)(v, (char*)name);
-        if (res != NULL) {
-            Py_DECREF(res);
-            return 1;
-        }
-        PyErr_Clear();
-        return 0;
-    }
+    PyObject *res;
+    int rc = PyObject_GetOptionalAttrString(obj, name, &res);
+    Py_XDECREF(res);
+    return rc;
+}
 
-    PyObject *attr_name = PyUnicode_FromString(name);
-    if (attr_name == NULL) {
+
+int
+PyObject_HasAttrString(PyObject *obj, const char *name)
+{
+    int rc = PyObject_HasAttrStringWithError(obj, name);
+    if (rc < 0) {
         PyErr_Clear();
         return 0;
     }
-    int ok = PyObject_HasAttr(v, attr_name);
-    Py_DECREF(attr_name);
-    return ok;
+    return rc;
 }
 
 int
@@ -1149,18 +1147,23 @@ PyObject_GetOptionalAttrString(PyObject *obj, const char *name, PyObject **resul
 }
 
 int
-PyObject_HasAttr(PyObject *v, PyObject *name)
+PyObject_HasAttrWithError(PyObject *obj, PyObject *name)
 {
     PyObject *res;
-    if (PyObject_GetOptionalAttr(v, name, &res) < 0) {
+    int rc = PyObject_GetOptionalAttr(obj, name, &res);
+    Py_XDECREF(res);
+    return rc;
+}
+
+int
+PyObject_HasAttr(PyObject *obj, PyObject *name)
+{
+    int rc = PyObject_HasAttrWithError(obj, name);
+    if (rc < 0) {
         PyErr_Clear();
         return 0;
     }
-    if (res == NULL) {
-        return 0;
-    }
-    Py_DECREF(res);
-    return 1;
+    return rc;
 }
 
 int

Objects/typeobject.c

@@ -3879,16 +3879,14 @@ type_new_get_bases(type_new_ctx *ctx, PyObject **type)
         if (PyType_Check(base)) {
             continue;
         }
-        PyObject *mro_entries;
-        if (PyObject_GetOptionalAttr(base, &_Py_ID(__mro_entries__),
-                                 &mro_entries) < 0) {
+        int rc = PyObject_HasAttrWithError(base, &_Py_ID(__mro_entries__));
+        if (rc < 0) {
             return -1;
         }
-        if (mro_entries != NULL) {
+        if (rc) {
             PyErr_SetString(PyExc_TypeError,
                             "type() doesn't support MRO entry resolution; "
                             "use types.new_class()");
-            Py_DECREF(mro_entries);
             return -1;
         }
     }

Objects/unionobject.c

@@ -186,28 +186,21 @@ union_repr_item(_PyUnicodeWriter *writer, PyObject *p)
 {
     PyObject *qualname = NULL;
     PyObject *module = NULL;
-    PyObject *tmp;
     PyObject *r = NULL;
-    int err;
+    int rc;
 
     if (p == (PyObject *)&_PyNone_Type) {
         return _PyUnicodeWriter_WriteASCIIString(writer, "None", 4);
     }
 
-    if (PyObject_GetOptionalAttr(p, &_Py_ID(__origin__), &tmp) < 0) {
-        goto exit;
-    }
-
-    if (tmp) {
-        Py_DECREF(tmp);
-        if (PyObject_GetOptionalAttr(p, &_Py_ID(__args__), &tmp) < 0) {
-            goto exit;
-        }
-        if (tmp) {
+    if ((rc = PyObject_HasAttrWithError(p, &_Py_ID(__origin__))) > 0 &&
+        (rc = PyObject_HasAttrWithError(p, &_Py_ID(__args__))) > 0)
+    {
         // It looks like a GenericAlias
-            Py_DECREF(tmp);
         goto use_repr;
     }
+    if (rc < 0) {
+        goto exit;
     }
 
     if (PyObject_GetOptionalAttr(p, &_Py_ID(__qualname__), &qualname) < 0) {
@@ -244,9 +237,9 @@ exit:
     if (r == NULL) {
         return -1;
     }
-    err = _PyUnicodeWriter_WriteStr(writer, r);
+    rc = _PyUnicodeWriter_WriteStr(writer, r);
     Py_DECREF(r);
-    return err;
+    return rc;
 }
 
 static PyObject *

PC/python3dll.c

@@ -359,6 +359,8 @@ EXPORT_FUNC(PyMapping_GetOptionalItem)
 EXPORT_FUNC(PyMapping_GetOptionalItemString)
 EXPORT_FUNC(PyMapping_HasKey)
 EXPORT_FUNC(PyMapping_HasKeyString)
+EXPORT_FUNC(PyMapping_HasKeyStringWithError)
+EXPORT_FUNC(PyMapping_HasKeyWithError)
 EXPORT_FUNC(PyMapping_Items)
 EXPORT_FUNC(PyMapping_Keys)
 EXPORT_FUNC(PyMapping_Length)
@@ -480,6 +482,8 @@ EXPORT_FUNC(PyObject_GetOptionalAttrString)
 EXPORT_FUNC(PyObject_GetTypeData)
 EXPORT_FUNC(PyObject_HasAttr)
 EXPORT_FUNC(PyObject_HasAttrString)
+EXPORT_FUNC(PyObject_HasAttrStringWithError)
+EXPORT_FUNC(PyObject_HasAttrWithError)
 EXPORT_FUNC(PyObject_Hash)
 EXPORT_FUNC(PyObject_HashNotImplemented)
 EXPORT_FUNC(PyObject_Init)

Python/errors.c

@@ -1776,13 +1776,11 @@ PyErr_SyntaxLocationObjectEx(PyObject *filename, int lineno, int col_offset,
         }
     }
     if ((PyObject *)Py_TYPE(exc) != PyExc_SyntaxError) {
-        if (PyObject_GetOptionalAttr(exc, &_Py_ID(msg), &tmp) < 0) {
+        int rc = PyObject_HasAttrWithError(exc, &_Py_ID(msg));
+        if (rc < 0) {
             _PyErr_Clear(tstate);
         }
-        else if (tmp) {
-            Py_DECREF(tmp);
-        }
-        else {
+        else if (!rc) {
             tmp = PyObject_Str(exc);
             if (tmp) {
                 if (PyObject_SetAttr(exc, &_Py_ID(msg), tmp)) {
@@ -1795,13 +1793,11 @@ PyErr_SyntaxLocationObjectEx(PyObject *filename, int lineno, int col_offset,
             }
         }
 
-        if (PyObject_GetOptionalAttr(exc, &_Py_ID(print_file_and_line), &tmp) < 0) {
+        rc = PyObject_HasAttrWithError(exc, &_Py_ID(print_file_and_line));
+        if (rc < 0) {
             _PyErr_Clear(tstate);
         }
-        else if (tmp) {
-            Py_DECREF(tmp);
-        }
-        else {
+        else if (!rc) {
             if (PyObject_SetAttr(exc, &_Py_ID(print_file_and_line), Py_None)) {
                 _PyErr_Clear(tstate);
             }

Python/import.c

@@ -2887,12 +2887,11 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
         }
     }
     else {
-        PyObject *path;
-        if (PyObject_GetOptionalAttr(mod, &_Py_ID(__path__), &path) < 0) {
+        int has_path = PyObject_HasAttrWithError(mod, &_Py_ID(__path__));
+        if (has_path < 0) {
             goto error;
         }
-        if (path) {
-            Py_DECREF(path);
+        if (has_path) {
             final_mod = PyObject_CallMethodObjArgs(
                         IMPORTLIB(interp), &_Py_ID(_handle_fromlist),
                         mod, fromlist, IMPORT_FUNC(interp), NULL);

Python/suggestions.c

@@ -245,14 +245,12 @@ get_suggestions_for_name_error(PyObject* name, PyFrameObject* frame)
             goto error;
         }
 
-        PyObject *value;
-        res = PyObject_GetOptionalAttr(self, name, &value);
+        res = PyObject_HasAttrWithError(self, name);
         Py_DECREF(locals);
         if (res < 0) {
             goto error;
         }
-        if (value) {
-            Py_DECREF(value);
+        if (res) {
             Py_DECREF(dir);
             return PyUnicode_FromFormat("self.%U", name);
         }