pythongh-122943: Rework support of var-positional parameter in Argume…

…nt Clinic

Move creation of a tuple for var-positional parameter out of
_PyArg_UnpackKeywordsWithVararg().
Merge _PyArg_UnpackKeywordsWithVararg() with _PyArg_UnpackKeywords().
Add a new parameter in _PyArg_UnpackKeywords().

The "parameters" and "converters" attributes of ParseArgsCodeGen no
longer contain the var-positional parameter. It is now available as the
"varpos" attribute. Optimize code generation for var-positional
parameter and reuse the same generating code for functions with and without
keyword parameters.

Include/internal/pycore_modsupport.h

@@ -85,20 +85,14 @@ 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) \
+#define _PyArg_UnpackKeywords(args, nargs, kwargs, kwnames, parser, minpos, maxpos, minkw, varpos, buf) \
     (((minkw) == 0 && (kwargs) == NULL && (kwnames) == NULL && \
-      (minpos) <= (nargs) && (nargs) <= (maxpos) && (args) != NULL) ? (args) : \
+      (minpos) <= (nargs) && (varpos || (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), (maxpos), (minkw), (varpos), (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/test_clinic.py

@@ -2694,7 +2694,7 @@ def test_cli_force(self):
             # Verify by checking the checksum.
             checksum = (
                 "/*[clinic end generated code: "
-                "output=0acbef4794cb933e input=9543a8d2da235301]*/\n"
+                "output=843576e3ffe85e2d input=9543a8d2da235301]*/\n"
             )
             with open(fn, encoding='utf-8') as f:
                 generated = f.read()
@@ -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)))