Add PyLong_AsInt() function (#72)

vstinner · web-flow · commit 81098119e2e2 · 2023-08-25T00:53:00.000+02:00
diff --git a/docs/api.rst b/docs/api.rst
@@ -75,6 +75,14 @@ Python 3.13
 
    See `Py_IsFinalizing() documentation <https://docs.python.org/dev/c-api/init.html#c.Py_IsFinalizing>`__.
 
+.. c:function:: int PyDict_ContainsString(PyObject *p, const char *key)
+
+   See `PyDict_ContainsString() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict_ContainsString>`__.
+
+.. c:function:: int PyLong_AsInt(PyObject *obj)
+
+   See `PyLong_AsInt() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong_AsInt>`__.
+
 
 Python 3.12
 -----------
diff --git a/docs/changelog.rst b/docs/changelog.rst
@@ -1,6 +1,7 @@
 Changelog
 =========
 
+* 2023-08-25: Add ``PyDict_ContainsString()`` and ``PyLong_AsInt()`` functions.
 * 2023-08-21: Remove support for Python 2.7, Python 3.4 and older.
 * 2023-08-16: Add ``Py_IsFinalizing()`` function.
 * 2023-07-21: Add ``PyDict_GetItemRef()`` function.
diff --git a/pythoncapi_compat.h b/pythoncapi_compat.h
@@ -834,6 +834,28 @@ static inline int PyDict_ContainsString(PyObject *op, const char *key)
 #endif
 
 
+// gh-108445 added PyLong_AsInt() to Python 3.13.0a1
+#if PY_VERSION_HEX < 0x030D00A1
+static inline int PyLong_AsInt(PyObject *obj)
+{
+#ifdef PYPY_VERSION
+    long value = PyLong_AsLong(obj);
+    if (value == -1 && PyErr_Occurred()) {
+        return -1;
+    }
+    if (value < (long)INT_MIN || (long)INT_MAX < value) {
+        PyErr_SetString(PyExc_OverflowError,
+                        "Python int too large to convert to C int");
+        return -1;
+    }
+    return (int)value;
+#else
+    return _PyLong_AsInt(obj);
+#endif
+}
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tests/test_pythoncapi_compat_cext.c b/tests/test_pythoncapi_compat_cext.c
@@ -1209,6 +1209,35 @@ test_dict_api(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
+static PyObject *
+test_long_api(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    // test PyLong_AsInt()
+    assert(!PyErr_Occurred());
+    PyObject *obj = PyLong_FromLong(123);
+    if (obj == NULL) {
+        return NULL;
+    }
+    int value = PyLong_AsInt(obj);
+    assert(value == 123);
+    assert(!PyErr_Occurred());
+    Py_DECREF(obj);
+
+    // test PyLong_AsInt() with overflow
+    PyObject *obj2 = PyLong_FromLongLong((long long)INT_MAX + 1);
+    if (obj2 == NULL) {
+        return NULL;
+    }
+    value = PyLong_AsInt(obj2);
+    assert(value == -1);
+    assert(PyErr_ExceptionMatches(PyExc_OverflowError));
+    PyErr_Clear();
+    Py_DECREF(obj2);
+
+    Py_RETURN_NONE;
+}
+
+
 static struct PyMethodDef methods[] = {
     {"test_object", test_object, METH_NOARGS, _Py_NULL},
     {"test_py_is", test_py_is, METH_NOARGS, _Py_NULL},
@@ -1234,6 +1263,7 @@ static struct PyMethodDef methods[] = {
     {"test_getattr", test_getattr, METH_NOARGS, _Py_NULL},
     {"test_getitem", test_getitem, METH_NOARGS, _Py_NULL},
     {"test_dict_api", test_dict_api, METH_NOARGS, _Py_NULL},
+    {"test_long_api", test_long_api, METH_NOARGS, _Py_NULL},
     {_Py_NULL, _Py_NULL, 0, _Py_NULL}
 };
 
