Add PyLong_GetSign() function (#99)

Author: vstinner

docs/api.rst

@@ -26,6 +26,13 @@ Latest version of the header file:
 `pythoncapi_compat.h <https://raw.githubusercontent.com/python/pythoncapi-compat/master/pythoncapi_compat.h>`_.
 
 
+Python 3.14
+-----------
+
+.. c:function:: int PyLong_GetSign(PyObject *obj, int *sign)
+
+   See `PyLong_GetSign() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong_GetSign>`__.
+
 Python 3.13
 -----------
 

docs/changelog.rst

@@ -1,6 +1,7 @@
 Changelog
 =========
 
+* 2024-06-03: Add ``PyLong_GetSign()``.
 * 2024-04-23: Drop Python 3.5 support. It cannot be tested anymore (pip fails).
 * 2024-04-02: Add ``PyDict_SetDefaultRef()`` function.
 * 2024-03-29: Add ``PyList_GetItemRef()`` function.

pythoncapi_compat.h

@@ -1339,6 +1339,21 @@ PyDict_SetDefaultRef(PyObject *d, PyObject *key, PyObject *default_value,
 #endif
 
 
+// gh-116560 added PyLong_GetSign() to Python 3.14a4
+#if PY_VERSION_HEX < 0x030E00A1
+static inline int PyLong_GetSign(PyObject *obj, int *sign)
+{
+    if (!PyLong_Check(obj)) {
+        PyErr_Format(PyExc_TypeError, "expect int, got %s", Py_TYPE(obj)->tp_name);
+        return -1;
+    }
+
+    *sign = _PyLong_Sign(obj);
+    return 0;
+}
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif

tests/test_pythoncapi_compat_cext.c

@@ -53,6 +53,7 @@
 // Marker to check that pointer value was set
 static const char uninitialized[] = "uninitialized";
 #define UNINITIALIZED_OBJ ((PyObject *)uninitialized)
+#define UNINITIALIZED_INT 0x83ff979
 
 
 static PyObject*
@@ -1413,6 +1414,11 @@ test_long_api(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
     PyErr_Clear();
     Py_DECREF(obj2);
 
+    // test PyLong_GetSign()
+    int sign = UNINITIALIZED_INT;
+    assert(PyLong_GetSign(obj, &sign) == 0);
+    assert(sign == 1);
+
     Py_RETURN_NONE;
 }