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()

6 files changed, 73 insertions, 69 deletions

diff --git a/Objects/abstract.c b/Objects/abstract.c
index b57190d..55d3b3a 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2427,6 +2427,24 @@ PyMapping_SetItemString(PyObject *o, const char *key, PyObject *value)
 }
 
 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)
 {
     PyObject *v;
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 329581c..1fb795f 100644
--- a/Objects/dictobject.c
+++ b/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);
diff --git a/Objects/genericaliasobject.c b/Objects/genericaliasobject.c
index ca17244..bf13ed3 100644
--- a/Objects/genericaliasobject.c
+++ b/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 ((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 (tmp != NULL) {
-        Py_DECREF(tmp);
-        if (PyObject_GetOptionalAttr(p, &_Py_ID(__args__), &tmp) < 0) {
-            goto done;
-        }
-        if (tmp != NULL) {
-            Py_DECREF(tmp);
-            // 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;
diff --git a/Objects/object.c b/Objects/object.c
index 7aeda50..15c2bf6 100644
--- a/Objects/object.c
+++ b/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
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 84c5050..893d842 100644
--- a/Objects/typeobject.c
+++ b/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;
         }
     }
diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index 3493ab3..bf56056 100644
--- a/Objects/unionobject.c
+++ b/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 ((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 (tmp) {
-        Py_DECREF(tmp);
-        if (PyObject_GetOptionalAttr(p, &_Py_ID(__args__), &tmp) < 0) {
-            goto exit;
-        }
-        if (tmp) {
-            // 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 *