gh-122943: Rework support of var-positional parameter in Argument Clinic

Include/internal/pycore_modsupport.h

@@ -76,7 +76,7 @@ PyAPI_FUNC(int) _PyArg_ParseStackAndKeywords(
     ...);
 
 // Export for 'math' shared extension
-PyAPI_FUNC(PyObject * const *) _PyArg_UnpackKeywords(
+PyAPI_FUNC(PyObject * const *) _PyArg_UnpackKeywordsEx(
     PyObject *const *args,
     Py_ssize_t nargs,
     PyObject *kwargs,
@@ -85,20 +85,19 @@ PyAPI_FUNC(PyObject * const *) _PyArg_UnpackKeywords(
     int minpos,
     int maxpos,
     int minkw,
+    int varpos,
     PyObject **buf);
 #define _PyArg_UnpackKeywords(args, nargs, kwargs, kwnames, parser, minpos, maxpos, minkw, buf) \
     (((minkw) == 0 && (kwargs) == NULL && (kwnames) == NULL && \
-      (minpos) <= (nargs) && (nargs) <= (maxpos) && (args) != NULL) ? (args) : \
-     _PyArg_UnpackKeywords((args), (nargs), (kwargs), (kwnames), (parser), \
-                           (minpos), (maxpos), (minkw), (buf)))
-
-// Export for '_testclinic' shared extension
-PyAPI_FUNC(PyObject * const *) _PyArg_UnpackKeywordsWithVararg(
-        PyObject *const *args, Py_ssize_t nargs,
-        PyObject *kwargs, PyObject *kwnames,
-        struct _PyArg_Parser *parser,
-        int minpos, int maxpos, int minkw,
-        int vararg, PyObject **buf);
+      (minpos) <= (nargs) && (nargs) <= (maxpos) && (args) != NULL) ? \
+      (args) : \
+     _PyArg_UnpackKeywordsEx((args), (nargs), (kwargs), (kwnames), (parser), \
+                           (minpos), (maxpos), (minkw), 0, (buf)))
+#define _PyArg_UnpackKeywordsWithVararg(args, nargs, kwargs, kwnames, parser, minpos, maxpos, minkw, buf) \
+    (((minkw) == 0 && (kwargs) == NULL && (kwnames) == NULL && \
+      (minpos) <= (nargs) && (args) != NULL) ? (args) : \
+     _PyArg_UnpackKeywordsEx((args), (nargs), (kwargs), (kwnames), (parser), \
+                           (minpos), (maxpos), (minkw), 1, (buf)))
 
 #ifdef __cplusplus
 }

Include/internal/pycore_tuple.h

@@ -20,7 +20,7 @@ extern PyStatus _PyTuple_InitGlobalObjects(PyInterpreterState *);
 
 #define _PyTuple_ITEMS(op) _Py_RVALUE(_PyTuple_CAST(op)->ob_item)
 
-extern PyObject *_PyTuple_FromArray(PyObject *const *, Py_ssize_t);
+PyAPI_FUNC(PyObject *)_PyTuple_FromArray(PyObject *const *, Py_ssize_t);
 PyAPI_FUNC(PyObject *)_PyTuple_FromStackRefSteal(const union _PyStackRef *, Py_ssize_t);
 PyAPI_FUNC(PyObject *)_PyTuple_FromArraySteal(PyObject *const *, Py_ssize_t);
 

Lib/test/clinic.test.c

@@ -4161,23 +4161,22 @@ test_vararg_and_posonly(PyObject *module, PyObject *const *args, Py_ssize_t narg
         goto exit;
     }
     a = args[0];
-    __clinic_args = PyTuple_New(nargs - 1);
-    if (!__clinic_args) {
+    __clinic_args = _PyTuple_FromArray(args + 1, nargs - 1);
+    if (__clinic_args == NULL) {
         goto exit;
     }
-    for (Py_ssize_t i = 0; i < nargs - 1; ++i) {
-        PyTuple_SET_ITEM(__clinic_args, i, Py_NewRef(args[1 + i]));
-    }
     return_value = test_vararg_and_posonly_impl(module, a, __clinic_args);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static PyObject *
 test_vararg_and_posonly_impl(PyObject *module, PyObject *a, PyObject *args)
-/*[clinic end generated code: output=79b75dc07decc8d6 input=9cfa748bbff09877]*/
+/*[clinic end generated code: output=0c11c475e240869e input=9cfa748bbff09877]*/
 
 /*[clinic input]
 test_vararg
@@ -4228,26 +4227,34 @@ test_vararg(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
         .kwtuple = KWTUPLE,
     };
     #undef KWTUPLE
-    PyObject *argsbuf[2];
+    PyObject *argsbuf[1];
+    PyObject * const *fastargs;
     PyObject *a;
     PyObject *__clinic_args = NULL;
 
-    args = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, 1, argsbuf);
-    if (!args) {
+    fastargs = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    a = fastargs[0];
+    __clinic_args = nargs > 1
+        ? _PyTuple_FromArray(args + 1, nargs - 1)
+        : PyTuple_New(0);
+    if (__clinic_args == NULL) {
         goto exit;
     }
-    a = args[0];
-    __clinic_args = args[1];
     return_value = test_vararg_impl(module, a, __clinic_args);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static PyObject *
 test_vararg_impl(PyObject *module, PyObject *a, PyObject *args)
-/*[clinic end generated code: output=1411e464f358a7ba input=81d33815ad1bae6e]*/
+/*[clinic end generated code: output=e7d7da6a7e008125 input=81d33815ad1bae6e]*/
 
 /*[clinic input]
 test_vararg_with_default
@@ -4300,37 +4307,45 @@ test_vararg_with_default(PyObject *module, PyObject *const *args, Py_ssize_t nar
         .kwtuple = KWTUPLE,
     };
     #undef KWTUPLE
-    PyObject *argsbuf[3];
+    PyObject *argsbuf[2];
+    PyObject * const *fastargs;
     Py_ssize_t noptargs = Py_MIN(nargs, 1) + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
     PyObject *a;
     PyObject *__clinic_args = NULL;
     int b = 0;
 
-    args = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, 1, argsbuf);
-    if (!args) {
+    fastargs = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
         goto exit;
     }
-    a = args[0];
-    __clinic_args = args[1];
+    a = fastargs[0];
     if (!noptargs) {
         goto skip_optional_kwonly;
     }
-    b = PyObject_IsTrue(args[2]);
+    b = PyObject_IsTrue(fastargs[1]);
     if (b < 0) {
         goto exit;
     }
 skip_optional_kwonly:
+    __clinic_args = nargs > 1
+        ? _PyTuple_FromArray(args + 1, nargs - 1)
+        : PyTuple_New(0);
+    if (__clinic_args == NULL) {
+        goto exit;
+    }
     return_value = test_vararg_with_default_impl(module, a, __clinic_args, b);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static PyObject *
 test_vararg_with_default_impl(PyObject *module, PyObject *a, PyObject *args,
                               int b)
-/*[clinic end generated code: output=f09d4b917063ca41 input=6e110b54acd9b22d]*/
+/*[clinic end generated code: output=46781f9920ecedcf input=6e110b54acd9b22d]*/
 
 /*[clinic input]
 test_vararg_with_only_defaults
@@ -4383,42 +4398,48 @@ test_vararg_with_only_defaults(PyObject *module, PyObject *const *args, Py_ssize
         .kwtuple = KWTUPLE,
     };
     #undef KWTUPLE
-    PyObject *argsbuf[3];
+    PyObject *argsbuf[2];
+    PyObject * const *fastargs;
     Py_ssize_t noptargs = 0 + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 0;
     PyObject *__clinic_args = NULL;
     int b = 0;
     PyObject *c = " ";
 
-    args = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 0, 0, 0, 0, argsbuf);
-    if (!args) {
+    fastargs = _PyArg_UnpackKeywordsWithVararg(args, nargs, NULL, kwnames, &_parser, 0, 0, 0, argsbuf);
+    if (!fastargs) {
         goto exit;
     }
-    __clinic_args = args[0];
     if (!noptargs) {
         goto skip_optional_kwonly;
     }
-    if (args[1]) {
-        b = PyObject_IsTrue(args[1]);
+    if (fastargs[0]) {
+        b = PyObject_IsTrue(fastargs[0]);
         if (b < 0) {
             goto exit;
         }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
     }
-    c = args[2];
+    c = fastargs[1];
 skip_optional_kwonly:
+    __clinic_args = _PyTuple_FromArray(args, nargs);
+    if (__clinic_args == NULL) {
+        goto exit;
+    }
     return_value = test_vararg_with_only_defaults_impl(module, __clinic_args, b, c);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static PyObject *
 test_vararg_with_only_defaults_impl(PyObject *module, PyObject *args, int b,
                                     PyObject *c)
-/*[clinic end generated code: output=cc6590b8805d5433 input=fa56a709a035666e]*/
+/*[clinic end generated code: output=d03daf5067039c03 input=fa56a709a035666e]*/
 
 /*[clinic input]
 test_paramname_module
@@ -4945,20 +4966,19 @@ Test___init__(PyObject *self, PyObject *args, PyObject *kwargs)
         !_PyArg_NoKeywords("Test", kwargs)) {
         goto exit;
     }
-    if (!_PyArg_CheckPositional("Test", PyTuple_GET_SIZE(args), 0, PY_SSIZE_T_MAX)) {
-        goto exit;
-    }
-    __clinic_args = PyTuple_GetSlice(0, -1);
+    __clinic_args = Py_NewRef(args);
     return_value = Test___init___impl((TestObj *)self, __clinic_args);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static int
 Test___init___impl(TestObj *self, PyObject *args)
-/*[clinic end generated code: output=0ed1009fe0dcf98d input=2a8bd0033c9ac772]*/
+/*[clinic end generated code: output=f172425cec373cd6 input=2a8bd0033c9ac772]*/
 
 
 /*[clinic input]
@@ -4989,20 +5009,19 @@ Test(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         !_PyArg_NoKeywords("Test", kwargs)) {
         goto exit;
     }
-    if (!_PyArg_CheckPositional("Test", PyTuple_GET_SIZE(args), 0, PY_SSIZE_T_MAX)) {
-        goto exit;
-    }
-    __clinic_args = PyTuple_GetSlice(0, -1);
+    __clinic_args = Py_NewRef(args);
     return_value = Test_impl(type, __clinic_args);
 
 exit:
+    /* Cleanup for args */
     Py_XDECREF(__clinic_args);
+
     return return_value;
 }
 
 static PyObject *
 Test_impl(PyTypeObject *type, PyObject *args)
-/*[clinic end generated code: output=8b219f6633e2a2e9 input=70ad829df3dd9b84]*/
+/*[clinic end generated code: output=ee1e8892a67abd4a input=70ad829df3dd9b84]*/
 
 
 /*[clinic input]

Lib/test/test_clinic.py

@@ -3393,6 +3393,15 @@ def test_posonly_varpos(self):
         self.assertEqual(fn(1, 2), (1, 2, ()))
         self.assertEqual(fn(1, 2, 3, 4), (1, 2, (3, 4)))
 
+    def test_posonly_req_opt_varpos(self):
+        # fn(a, b=False, /, *args)
+        fn = ac_tester.posonly_req_opt_varpos
+        self.assertRaises(TypeError, fn)
+        self.assertRaises(TypeError, fn, a=1)
+        self.assertEqual(fn(1), (1, False, ()))
+        self.assertEqual(fn(1, 2), (1, 2, ()))
+        self.assertEqual(fn(1, 2, 3, 4), (1, 2, (3, 4)))
+
     def test_posonly_poskw_varpos(self):
         # fn(a, /, b, *args)
         fn = ac_tester.posonly_poskw_varpos
@@ -3401,23 +3410,26 @@ def test_posonly_poskw_varpos(self):
         self.assertEqual(fn(1, b=2), (1, 2, ()))
         self.assertEqual(fn(1, 2, 3, 4), (1, 2, (3, 4)))
         self.assertRaises(TypeError, fn, b=4)
-        self.assertRaises(TypeError, fn, 1, 2, 3, b=4)
+        errmsg = re.escape("given by name ('b') and position (2)")
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, 2, 3, b=4)
 
     def test_poskw_varpos(self):
         # fn(a, *args)
         fn = ac_tester.poskw_varpos
         self.assertRaises(TypeError, fn)
         self.assertRaises(TypeError, fn, 1, b=2)
         self.assertEqual(fn(a=1), (1, ()))
-        self.assertRaises(TypeError, fn, 1, a=2)
+        errmsg = re.escape("given by name ('a') and position (1)")
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, a=2)
         self.assertEqual(fn(1), (1, ()))
         self.assertEqual(fn(1, 2, 3, 4), (1, (2, 3, 4)))
 
     def test_poskw_varpos_kwonly_opt(self):
         # fn(a, *args, b=False)
         fn = ac_tester.poskw_varpos_kwonly_opt
         self.assertRaises(TypeError, fn)
-        self.assertRaises(TypeError, fn, 1, a=2)
+        errmsg = re.escape("given by name ('a') and position (1)")
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, a=2)
         self.assertEqual(fn(1, b=2), (1, (), True))
         self.assertEqual(fn(1, 2, 3, 4), (1, (2, 3, 4), False))
         self.assertEqual(fn(1, 2, 3, 4, b=5), (1, (2, 3, 4), True))
@@ -3428,7 +3440,8 @@ def test_poskw_varpos_kwonly_opt2(self):
         # fn(a, *args, b=False, c=False)
         fn = ac_tester.poskw_varpos_kwonly_opt2
         self.assertRaises(TypeError, fn)
-        self.assertRaises(TypeError, fn, 1, a=2)
+        errmsg = re.escape("given by name ('a') and position (1)")
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, a=2)
         self.assertEqual(fn(1, b=2), (1, (), 2, False))
         self.assertEqual(fn(1, b=2, c=3), (1, (), 2, 3))
         self.assertEqual(fn(1, 2, 3), (1, (2, 3), False, False))
@@ -3490,9 +3503,10 @@ def test_null_or_tuple_for_varargs(self):
         self.assertEqual(fn(covariant=True, name='a'), ('a', (), True))
 
         self.assertRaises(TypeError, fn, covariant=True)
-        self.assertRaises(TypeError, fn, 1, name='a')
-        self.assertRaises(TypeError, fn, 1, 2, 3, name='a', covariant=True)
-        self.assertRaises(TypeError, fn, 1, 2, 3, covariant=True, name='a')
+        errmsg = re.escape("given by name ('name') and position (1)")
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, name='a')
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, 2, 3, name='a', covariant=True)
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1, 2, 3, covariant=True, name='a')
 
     def test_cloned_func_exception_message(self):
         incorrect_arg = -1  # f1() and f2() accept a single str
@@ -3568,14 +3582,15 @@ def test_defclass_posonly_varpos(self):
         cls = ac_tester.TestClass
         obj = cls()
         fn = obj.defclass_posonly_varpos
-        self.assertRaises(TypeError, fn)
-        self.assertRaises(TypeError, fn, 1)
+        errmsg = 'takes at least 2 positional arguments'
+        self.assertRaisesRegex(TypeError, errmsg, fn)
+        self.assertRaisesRegex(TypeError, errmsg, fn, 1)
         self.assertEqual(fn(1, 2), (cls, 1, 2, ()))
         self.assertEqual(fn(1, 2, 3, 4), (cls, 1, 2, (3, 4)))
         fn = cls.defclass_posonly_varpos
         self.assertRaises(TypeError, fn)
-        self.assertRaises(TypeError, fn, obj)
-        self.assertRaises(TypeError, fn, obj, 1)
+        self.assertRaisesRegex(TypeError, errmsg, fn, obj)
+        self.assertRaisesRegex(TypeError, errmsg, fn, obj, 1)
         self.assertEqual(fn(obj, 1, 2), (cls, 1, 2, ()))
         self.assertEqual(fn(obj, 1, 2, 3, 4), (cls, 1, 2, (3, 4)))