gh-137821: Improve Argument Clinic definitions in the `_json` module (#140780)

Lib/test/test_json/test_scanstring.py

@@ -144,7 +144,7 @@ def test_bad_escapes(self):
 
     def test_overflow(self):
         with self.assertRaises(OverflowError):
-            self.json.decoder.scanstring(b"xxx", sys.maxsize+1)
+            self.json.decoder.scanstring("xxx", sys.maxsize+1)
 
 
 class TestPyScanstring(TestScanstring, PyTest): pass

Misc/NEWS.d/next/Core_and_Builtins/2025-10-30-15-33-07.gh-issue-137821.8_Iavt.rst

@@ -1 +0,0 @@
-Convert ``_json`` module to use Argument Clinic

Misc/NEWS.d/next/Library/2025-10-30-15-33-07.gh-issue-137821.8_Iavt.rst

@@ -0,0 +1,2 @@
+Convert ``_json`` module to use Argument Clinic.
+Patched by Yoonho Hann.

Modules/_json.c

@@ -645,7 +645,7 @@ scanstring_unicode(PyObject *pystr, Py_ssize_t end, int strict, Py_ssize_t *next
 
 /*[clinic input]
 _json.scanstring as py_scanstring
-    pystr: object
+    pystr: unicode
     end: Py_ssize_t
     strict: bool = True
     /
@@ -664,74 +664,41 @@ after the end quote.
 static PyObject *
 py_scanstring_impl(PyObject *module, PyObject *pystr, Py_ssize_t end,
                    int strict)
-/*[clinic end generated code: output=961740cfae07cdb3 input=9d46d7df7ac749b0]*/
+/*[clinic end generated code: output=961740cfae07cdb3 input=cff59e47498f4d8e]*/
 {
-    PyObject *rval;
     Py_ssize_t next_end = -1;
-    if (PyUnicode_Check(pystr)) {
+    PyObject *rval = scanstring_unicode(pystr, end, strict, &next_end);
-        rval = scanstring_unicode(pystr, end, strict, &next_end);
-    }
-    else {
-        PyErr_Format(PyExc_TypeError,
-                     "first argument must be a string, not %.80s",
-                     Py_TYPE(pystr)->tp_name);
-        return NULL;
-    }
     return _build_rval_index_tuple(rval, next_end);
 }
 
 /*[clinic input]
 _json.encode_basestring_ascii as py_encode_basestring_ascii
-    pystr: object
+    pystr: unicode
     /
 
 Return an ASCII-only JSON representation of a Python string
 [clinic start generated code]*/
 
 static PyObject *
-py_encode_basestring_ascii(PyObject *module, PyObject *pystr)
+py_encode_basestring_ascii_impl(PyObject *module, PyObject *pystr)
-/*[clinic end generated code: output=a8afcd88eba0b572 input=f4085ccd5928ea55]*/
+/*[clinic end generated code: output=7b3841287cf211df input=4f3609498aff2de5]*/
 {
-    PyObject *rval;
+    return ascii_escape_unicode(pystr);
-    /* Return an ASCII-only JSON representation of a Python string */
-    /* METH_O */
-    if (PyUnicode_Check(pystr)) {
-        rval = ascii_escape_unicode(pystr);
-    }
-    else {
-        PyErr_Format(PyExc_TypeError,
-                     "first argument must be a string, not %.80s",
-                     Py_TYPE(pystr)->tp_name);
-        return NULL;
-    }
-    return rval;
 }
 
 /*[clinic input]
 _json.encode_basestring as py_encode_basestring
-    pystr: object
+    pystr: unicode
     /
 
 Return a JSON representation of a Python string
 [clinic start generated code]*/
 
 static PyObject *
-py_encode_basestring(PyObject *module, PyObject *pystr)
+py_encode_basestring_impl(PyObject *module, PyObject *pystr)
-/*[clinic end generated code: output=c87752300776d3b1 input=c3c7ef6e72624f6e]*/
+/*[clinic end generated code: output=900950f95df3f1c9 input=d42ef714b2c07386]*/
 {
-    PyObject *rval;
+    return escape_unicode(pystr);
-    /* Return a JSON representation of a Python string */
-    /* METH_O */
-    if (PyUnicode_Check(pystr)) {
-        rval = escape_unicode(pystr);
-    }
-    else {
-        PyErr_Format(PyExc_TypeError,
-                     "first argument must be a string, not %.80s",
-                     Py_TYPE(pystr)->tp_name);
-        return NULL;
-    }
-    return rval;
 }
 
 static void

Modules/clinic/_json.c.h

@@ -37,6 +37,10 @@ py_scanstring(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (!_PyArg_CheckPositional("scanstring", nargs, 2, 3)) {
         goto exit;
     }
+    if (!PyUnicode_Check(args[0])) {
+        _PyArg_BadArgument("scanstring", "argument 1", "str", args[0]);
+        goto exit;
+    }
     pystr = args[0];
     {
         Py_ssize_t ival = -1;
@@ -73,6 +77,26 @@ PyDoc_STRVAR(py_encode_basestring_ascii__doc__,
 #define PY_ENCODE_BASESTRING_ASCII_METHODDEF    \
     {"encode_basestring_ascii", (PyCFunction)py_encode_basestring_ascii, METH_O, py_encode_basestring_ascii__doc__},
 
+static PyObject *
+py_encode_basestring_ascii_impl(PyObject *module, PyObject *pystr);
+
+static PyObject *
+py_encode_basestring_ascii(PyObject *module, PyObject *arg)
+{
+    PyObject *return_value = NULL;
+    PyObject *pystr;
+
+    if (!PyUnicode_Check(arg)) {
+        _PyArg_BadArgument("encode_basestring_ascii", "argument", "str", arg);
+        goto exit;
+    }
+    pystr = arg;
+    return_value = py_encode_basestring_ascii_impl(module, pystr);
+
+exit:
+    return return_value;
+}
+
 PyDoc_STRVAR(py_encode_basestring__doc__,
 "encode_basestring($module, pystr, /)\n"
 "--\n"
@@ -81,4 +105,24 @@ PyDoc_STRVAR(py_encode_basestring__doc__,
 
 #define PY_ENCODE_BASESTRING_METHODDEF    \
     {"encode_basestring", (PyCFunction)py_encode_basestring, METH_O, py_encode_basestring__doc__},
-/*[clinic end generated code: output=d3aa505efc0acb3f input=a9049054013a1b77]*/
+
+static PyObject *
+py_encode_basestring_impl(PyObject *module, PyObject *pystr);
+
+static PyObject *
+py_encode_basestring(PyObject *module, PyObject *arg)
+{
+    PyObject *return_value = NULL;
+    PyObject *pystr;
+
+    if (!PyUnicode_Check(arg)) {
+        _PyArg_BadArgument("encode_basestring", "argument", "str", arg);
+        goto exit;
+    }
+    pystr = arg;
+    return_value = py_encode_basestring_impl(module, pystr);
+
+exit:
+    return return_value;
+}
+/*[clinic end generated code: output=5bdd16375c95a4d9 input=a9049054013a1b77]*/