From 723f37595c0c5ca54f313f53cd78f59ebb6fcece Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Wed, 5 Aug 2026 09:21:21 +0300 Subject: [PATCH] gh-64502: Fix Argument Clinic support of optional groups with defaults (GH-155191) Parameters with a default value which are not in any group were always required in the generated argument parsing code, although they were rendered as optional in the signature. They can now be omitted, and ambiguous combinations of optional groups and parameters with a default value are rejected. (cherry picked from commit caac9278306d3cb96b22f51f5003e20b7a6aa18c) Co-authored-by: Serhiy Storchaka Co-Authored-By: Claude Opus 5 (1M context) --- Lib/test/clinic.test.c | 61 ++++++++++++ Lib/test/test_clinic.py | 39 ++++++++ ...6-08-04-17-12-33.gh-issue-64502.Qv7mLp.rst | 3 + Modules/_testclinic.c | 48 ++++++++++ Modules/clinic/_testclinic.c.h | 92 ++++++++++++++++++- Tools/c-analyzer/cpython/_parser.py | 1 + Tools/clinic/libclinic/clanguage.py | 45 +++++++-- 7 files changed, 278 insertions(+), 11 deletions(-) create mode 100644 Misc/NEWS.d/next/Tools-Demos/2026-08-04-17-12-33.gh-issue-64502.Qv7mLp.rst diff --git a/Lib/test/clinic.test.c b/Lib/test/clinic.test.c index bfc15c024de7fde..7e0761f12497cff 100644 --- a/Lib/test/clinic.test.c +++ b/Lib/test/clinic.test.c @@ -5337,6 +5337,67 @@ Test___init___impl(TestObj *self, PyObject *a, int group_right_1, /*[clinic end generated code: output=2bbb8ea60e8f57a6 input=10f5d0f1e8e466ef]*/ +/*[clinic input] +group_and_optional_parameter + [ + a: object + b: object + ] + c: object = None + / +The optional parameter can be omitted with or without the group. +[clinic start generated code]*/ + +PyDoc_STRVAR(group_and_optional_parameter__doc__, +"group_and_optional_parameter([a, b,] c=None)\n" +"The optional parameter can be omitted with or without the group."); + +#define GROUP_AND_OPTIONAL_PARAMETER_METHODDEF \ + {"group_and_optional_parameter", (PyCFunction)group_and_optional_parameter, METH_VARARGS, group_and_optional_parameter__doc__}, + +static PyObject * +group_and_optional_parameter_impl(PyObject *module, int group_left_1, + PyObject *a, PyObject *b, PyObject *c); + +static PyObject * +group_and_optional_parameter(PyObject *module, PyObject *args) +{ + PyObject *return_value = NULL; + int group_left_1 = 0; + PyObject *a = NULL; + PyObject *b = NULL; + PyObject *c = Py_None; + + switch (PyTuple_GET_SIZE(args)) { + case 0: + case 1: + if (!PyArg_ParseTuple(args, "|O:group_and_optional_parameter", &c)) { + goto exit; + } + break; + case 2: + case 3: + if (!PyArg_ParseTuple(args, "OO|O:group_and_optional_parameter", &a, &b, &c)) { + goto exit; + } + group_left_1 = 1; + break; + default: + PyErr_SetString(PyExc_TypeError, "group_and_optional_parameter requires 0 to 3 arguments"); + goto exit; + } + return_value = group_and_optional_parameter_impl(module, group_left_1, a, b, c); + +exit: + return return_value; +} + +static PyObject * +group_and_optional_parameter_impl(PyObject *module, int group_left_1, + PyObject *a, PyObject *b, PyObject *c) +/*[clinic end generated code: output=3faea69eafd5bbbe input=7f0fbb6124f5a972]*/ + + /*[clinic input] Test._pyarg_parsestackandkeywords cls: defining_class diff --git a/Lib/test/test_clinic.py b/Lib/test/test_clinic.py index 737644ff1be5fe2..f5feb781a2eff82 100644 --- a/Lib/test/test_clinic.py +++ b/Lib/test/test_clinic.py @@ -322,6 +322,24 @@ def __init__(self): """ self.expect_failure(block, err, lineno=8) + def test_ambiguous_group_and_optional_parameters(self): + err = ("Function 'my_test_func' has an ambiguous group configuration: " + "a call with 2 argument(s) can be parsed in more than one way.") + block = """ + /*[clinic input] + my_test_func + + [ + a: object + b: object + ] + c: object = None + d: object = None + / + [clinic start generated code]*/ + """ + self.expect_failure(block, err) + def test_star_after_vararg(self): err = "'my_test_func' uses '*' more than once." block = """ @@ -3454,6 +3472,27 @@ def test_vararg_kwonly_req_opt(self): self.assertEqual(fn(1, a=2, b=3), ((1,), 2, 3, None)) self.assertEqual(fn(1, a=2, b=3, c=4), ((1,), 2, 3, 4)) + def test_group_and_opt(self): + # fn([a, b,] c=None) + fn = ac_tester.group_and_opt + self.assertEqual(fn(), (False, None, None, None)) + self.assertEqual(fn(1), (False, None, None, 1)) + self.assertEqual(fn(1, 2), (True, 1, 2, None)) + self.assertEqual(fn(1, 2, 3), (True, 1, 2, 3)) + self.assertRaises(TypeError, fn, 1, 2, 3, 4) + self.assertRaises(TypeError, fn, c=1) + + def test_group_and_two_opt(self): + # fn([a, b, c,] d=None, e=None) + fn = ac_tester.group_and_two_opt + self.assertEqual(fn(), (False, None, None, None, None, None)) + self.assertEqual(fn(1), (False, None, None, None, 1, None)) + self.assertEqual(fn(1, 2), (False, None, None, None, 1, 2)) + self.assertEqual(fn(1, 2, 3), (True, 1, 2, 3, None, None)) + self.assertEqual(fn(1, 2, 3, 4), (True, 1, 2, 3, 4, None)) + self.assertEqual(fn(1, 2, 3, 4, 5), (True, 1, 2, 3, 4, 5)) + self.assertRaises(TypeError, fn, 1, 2, 3, 4, 5, 6) + def test_gh_32092_oob(self): ac_tester.gh_32092_oob(1, 2, 3, 4, kw1=5, kw2=6) diff --git a/Misc/NEWS.d/next/Tools-Demos/2026-08-04-17-12-33.gh-issue-64502.Qv7mLp.rst b/Misc/NEWS.d/next/Tools-Demos/2026-08-04-17-12-33.gh-issue-64502.Qv7mLp.rst new file mode 100644 index 000000000000000..da9647d1fdd369b --- /dev/null +++ b/Misc/NEWS.d/next/Tools-Demos/2026-08-04-17-12-33.gh-issue-64502.Qv7mLp.rst @@ -0,0 +1,3 @@ +Fix Argument Clinic support of parameters with a default value used together +with optional groups. +Such parameters were always required in the generated parsing code. diff --git a/Modules/_testclinic.c b/Modules/_testclinic.c index c352710cf4558d0..32d2bcff9f449bd 100644 --- a/Modules/_testclinic.c +++ b/Modules/_testclinic.c @@ -1090,6 +1090,52 @@ vararg_kwonly_req_opt_impl(PyObject *module, PyObject *args, PyObject *a, +/*[clinic input] +group_and_opt + + [ + a: object + b: object + ] + c: object = None + / + +[clinic start generated code]*/ + +static PyObject * +group_and_opt_impl(PyObject *module, int group_left_1, PyObject *a, + PyObject *b, PyObject *c) +/*[clinic end generated code: output=23413ec545526111 input=8a84d8f44bc8bd0b]*/ +{ + return pack_arguments_newref(4, group_left_1 ? Py_True : Py_False, + a, b, c); +} + + +/*[clinic input] +group_and_two_opt + + [ + a: object + b: object + c: object + ] + d: object = None + e: object = None + / + +[clinic start generated code]*/ + +static PyObject * +group_and_two_opt_impl(PyObject *module, int group_left_1, PyObject *a, + PyObject *b, PyObject *c, PyObject *d, PyObject *e) +/*[clinic end generated code: output=1427c4b3c35f24ff input=cdda98eec1e365ea]*/ +{ + return pack_arguments_newref(6, group_left_1 ? Py_True : Py_False, + a, b, c, d, e); +} + + /*[clinic input] gh_32092_oob @@ -1949,6 +1995,8 @@ static PyMethodDef tester_methods[] = { VARARG_WITH_DEFAULT2_METHODDEF VARARG_WITH_ONLY_DEFAULTS_METHODDEF VARARG_KWONLY_REQ_OPT_METHODDEF + GROUP_AND_OPT_METHODDEF + GROUP_AND_TWO_OPT_METHODDEF GH_32092_OOB_METHODDEF GH_32092_KW_PASS_METHODDEF GH_99233_REFCOUNT_METHODDEF diff --git a/Modules/clinic/_testclinic.c.h b/Modules/clinic/_testclinic.c.h index 63cef8aac43db6a..c249bba13cbcd09 100644 --- a/Modules/clinic/_testclinic.c.h +++ b/Modules/clinic/_testclinic.c.h @@ -2771,6 +2771,96 @@ vararg_kwonly_req_opt(PyObject *module, PyObject *const *args, Py_ssize_t nargs, return return_value; } +PyDoc_STRVAR(group_and_opt__doc__, +"group_and_opt([a, b,] c=None)"); + +#define GROUP_AND_OPT_METHODDEF \ + {"group_and_opt", (PyCFunction)group_and_opt, METH_VARARGS, group_and_opt__doc__}, + +static PyObject * +group_and_opt_impl(PyObject *module, int group_left_1, PyObject *a, + PyObject *b, PyObject *c); + +static PyObject * +group_and_opt(PyObject *module, PyObject *args) +{ + PyObject *return_value = NULL; + int group_left_1 = 0; + PyObject *a = NULL; + PyObject *b = NULL; + PyObject *c = Py_None; + + switch (PyTuple_GET_SIZE(args)) { + case 0: + case 1: + if (!PyArg_ParseTuple(args, "|O:group_and_opt", &c)) { + goto exit; + } + break; + case 2: + case 3: + if (!PyArg_ParseTuple(args, "OO|O:group_and_opt", &a, &b, &c)) { + goto exit; + } + group_left_1 = 1; + break; + default: + PyErr_SetString(PyExc_TypeError, "group_and_opt requires 0 to 3 arguments"); + goto exit; + } + return_value = group_and_opt_impl(module, group_left_1, a, b, c); + +exit: + return return_value; +} + +PyDoc_STRVAR(group_and_two_opt__doc__, +"group_and_two_opt([a, b, c,] d=None, e=None)"); + +#define GROUP_AND_TWO_OPT_METHODDEF \ + {"group_and_two_opt", (PyCFunction)group_and_two_opt, METH_VARARGS, group_and_two_opt__doc__}, + +static PyObject * +group_and_two_opt_impl(PyObject *module, int group_left_1, PyObject *a, + PyObject *b, PyObject *c, PyObject *d, PyObject *e); + +static PyObject * +group_and_two_opt(PyObject *module, PyObject *args) +{ + PyObject *return_value = NULL; + int group_left_1 = 0; + PyObject *a = NULL; + PyObject *b = NULL; + PyObject *c = NULL; + PyObject *d = Py_None; + PyObject *e = Py_None; + + switch (PyTuple_GET_SIZE(args)) { + case 0: + case 1: + case 2: + if (!PyArg_ParseTuple(args, "|OO:group_and_two_opt", &d, &e)) { + goto exit; + } + break; + case 3: + case 4: + case 5: + if (!PyArg_ParseTuple(args, "OOO|OO:group_and_two_opt", &a, &b, &c, &d, &e)) { + goto exit; + } + group_left_1 = 1; + break; + default: + PyErr_SetString(PyExc_TypeError, "group_and_two_opt requires 0 to 5 arguments"); + goto exit; + } + return_value = group_and_two_opt_impl(module, group_left_1, a, b, c, d, e); + +exit: + return return_value; +} + PyDoc_STRVAR(gh_32092_oob__doc__, "gh_32092_oob($module, /, pos1, pos2, *varargs, kw1=None, kw2=None)\n" "--\n" @@ -3385,4 +3475,4 @@ _testclinic_TestClass_get_defining_class_arg(PyObject *self, PyTypeObject *cls, exit: return return_value; } -/*[clinic end generated code: output=c556818496a3ec72 input=a9049054013a1b77]*/ +/*[clinic end generated code: output=eafedd2a830669f5 input=a9049054013a1b77]*/ diff --git a/Tools/c-analyzer/cpython/_parser.py b/Tools/c-analyzer/cpython/_parser.py index 12010f0e9c05491..28dd5fe9ff88aff 100644 --- a/Tools/c-analyzer/cpython/_parser.py +++ b/Tools/c-analyzer/cpython/_parser.py @@ -317,6 +317,7 @@ def clean_lines(text): _abs('Modules/posixmodule.c'): (20_000, 500), _abs('Modules/termios.c'): (10_000, 800), _abs('Modules/_testcapimodule.c'): (20_000, 400), + _abs('Modules/_testclinic.c'): (20_000, 400), _abs('Modules/expat/expat.h'): (10_000, 400), _abs('Objects/stringlib/unicode_format.h'): (10_000, 400), _abs('Objects/typeobject.c'): (35_000, 200), diff --git a/Tools/clinic/libclinic/clanguage.py b/Tools/clinic/libclinic/clanguage.py index fa52d18289c8bec..b9b1993cf76eee8 100644 --- a/Tools/clinic/libclinic/clanguage.py +++ b/Tools/clinic/libclinic/clanguage.py @@ -1,6 +1,5 @@ from __future__ import annotations import itertools -import sys import textwrap from typing import TYPE_CHECKING, Literal, Final from operator import attrgetter @@ -12,7 +11,7 @@ from libclinic.codegen import CRenderData, TemplateDict, CodeGen from libclinic.language import Language from libclinic.function import ( - Module, Class, Function, Parameter, + Module, Class, Function, Parameter, ParamTuple, permute_optional_groups, GETTER, SETTER, METHOD_INIT) from libclinic.converters import self_converter @@ -21,6 +20,20 @@ from libclinic.app import Clinic +def count_required(subset: ParamTuple) -> int: + """Return the number of arguments which cannot be omitted. + + A parameter in an optional group is passed together with its group, + so only trailing parameters with a default value can be omitted. + """ + count = len(subset) + for p in reversed(subset): + if p.group or not p.is_optional(): + break + count -= 1 + return count + + def c_id(name: str) -> str: if len(name) == 1 and ord(name) < 256: if name.isalnum(): @@ -301,18 +314,26 @@ def render_option_group_parsing( assert group is not None group.append(p) - count_min = sys.maxsize - count_max = -1 + # Map the number of arguments to the subset which accepts it. + subsets: dict[int, ParamTuple] = {} + for subset in permute_optional_groups(left, required, right): + for count in range(count_required(subset), len(subset) + 1): + if count in subsets: + fail(f"Function {f.full_name!r} has an ambiguous group " + f"configuration: a call with {count} argument(s) " + f"can be parsed in more than one way.") + subsets[count] = subset if limited_capi: nargs = 'PyTuple_Size(args)' else: nargs = 'PyTuple_GET_SIZE(args)' out.append(f"switch ({nargs}) {{\n") - for subset in permute_optional_groups(left, required, right): - count = len(subset) - count_min = min(count_min, count) - count_max = max(count_max, count) + for count, subset in sorted(subsets.items()): + if count < len(subset): + # The omitted parameters are parsed by the following case. + out.append(f" case {count}:\n") + continue if count == 0: out.append(""" case 0: @@ -324,7 +345,11 @@ def render_option_group_parsing( d: dict[str, str | int] = {} d['count'] = count d['name'] = f.name - d['format_units'] = "".join(p.converter.format_unit for p in subset) + format_units = [p.converter.format_unit for p in subset] + n_required = count_required(subset) + if n_required < count: + format_units.insert(n_required, '|') + d['format_units'] = "".join(format_units) parse_arguments: list[str] = [] for p in subset: @@ -351,7 +376,7 @@ def render_option_group_parsing( out.append(" default:\n") s = ' PyErr_SetString(PyExc_TypeError, "{} requires {} to {} arguments");\n' - out.append(s.format(f.full_name, count_min, count_max)) + out.append(s.format(f.full_name, min(subsets), max(subsets))) out.append(' goto exit;\n') out.append("}")