From 3d3e7b0adaf62a2ed9925f93c3fad9cadd835b4a Mon Sep 17 00:00:00 2001 From: Tomasz Pytel Date: Fri, 4 Apr 2025 11:48:57 -0400 Subject: [PATCH] =?utf8?q?[3.12]=20gh-128632:=20fix=20segfault=20on=20nest?= =?utf8?q?ed=20=5F=5Fclassdict=5F=5F=20type=20param=20(GH=E2=80=A6=20(#132?= =?utf8?q?090)?= MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit (cherry picked from commit 891c61c1fa480928dd60cce8bbc8764630c95025) Co-authored-by: Tomasz Pytel --- Lib/test/test_syntax.py | 19 +++++++++++++++ ...-01-11-20-11-28.gh-issue-128632.ryhnKs.rst | 2 ++ Python/symtable.c | 24 +++++++++++++++++++ 3 files changed, 45 insertions(+) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-01-11-20-11-28.gh-issue-128632.ryhnKs.rst diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py index 099667c73561..36a7f5a873dc 100644 --- a/Lib/test/test_syntax.py +++ b/Lib/test/test_syntax.py @@ -2244,6 +2244,25 @@ if x: self.assertRaises(IndentationError, exec, code) + @support.cpython_only + def test_disallowed_type_param_names(self): + # See gh-128632 + + self._check_error(f"class A[__classdict__]: pass", + f"reserved name '__classdict__' cannot be used for type parameter") + self._check_error(f"def f[__classdict__](): pass", + f"reserved name '__classdict__' cannot be used for type parameter") + self._check_error(f"type T[__classdict__] = tuple[__classdict__]", + f"reserved name '__classdict__' cannot be used for type parameter") + + # These compilations are here to make sure __class__, __classcell__ and __classdictcell__ + # don't break in the future like __classdict__ did in this case. + for name in ('__class__', '__classcell__', '__classdictcell__'): + compile(f""" +class A: + class B[{name}]: pass + """, "", mode="exec") + @support.cpython_only def test_nested_named_except_blocks(self): code = "" diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-01-11-20-11-28.gh-issue-128632.ryhnKs.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-01-11-20-11-28.gh-issue-128632.ryhnKs.rst new file mode 100644 index 000000000000..8cb23fc2d9e7 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-01-11-20-11-28.gh-issue-128632.ryhnKs.rst @@ -0,0 +1,2 @@ +Disallow ``__classdict__`` as the name of a type parameter. Using this +name would previously crash the interpreter in some circumstances. diff --git a/Python/symtable.c b/Python/symtable.c index f99ca4fdd06f..da17485acdd4 100644 --- a/Python/symtable.c +++ b/Python/symtable.c @@ -2191,6 +2191,24 @@ symtable_visit_expr(struct symtable *st, expr_ty e) VISIT_QUIT(st, 1); } +static int +symtable_visit_type_param_check_reserved_name(struct symtable *st, type_param_ty tp, identifier name) +{ + if (_PyUnicode_Equal(name, &_Py_ID(__classdict__))) { + PyObject *error_msg = PyUnicode_FromFormat("reserved name '%U' cannot be " + "used for type parameter", name); + PyErr_SetObject(PyExc_SyntaxError, error_msg); + Py_DECREF(error_msg); + PyErr_RangedSyntaxLocationObject(st->st_filename, + tp->lineno, + tp->col_offset + 1, + tp->end_lineno, + tp->end_col_offset + 1); + return 0; + } + return 1; +} + static int symtable_visit_type_param(struct symtable *st, type_param_ty tp) { @@ -2201,6 +2219,8 @@ symtable_visit_type_param(struct symtable *st, type_param_ty tp) } switch(tp->kind) { case TypeVar_kind: + if (!symtable_visit_type_param_check_reserved_name(st, tp, tp->v.TypeVar.name)) + VISIT_QUIT(st, 0); if (!symtable_add_def(st, tp->v.TypeVar.name, DEF_TYPE_PARAM | DEF_LOCAL, LOCATION(tp))) VISIT_QUIT(st, 0); if (tp->v.TypeVar.bound) { @@ -2219,10 +2239,14 @@ symtable_visit_type_param(struct symtable *st, type_param_ty tp) } break; case TypeVarTuple_kind: + if (!symtable_visit_type_param_check_reserved_name(st, tp, tp->v.TypeVarTuple.name)) + VISIT_QUIT(st, 0); if (!symtable_add_def(st, tp->v.TypeVarTuple.name, DEF_TYPE_PARAM | DEF_LOCAL, LOCATION(tp))) VISIT_QUIT(st, 0); break; case ParamSpec_kind: + if (!symtable_visit_type_param_check_reserved_name(st, tp, tp->v.ParamSpec.name)) + VISIT_QUIT(st, 0); if (!symtable_add_def(st, tp->v.ParamSpec.name, DEF_TYPE_PARAM | DEF_LOCAL, LOCATION(tp))) VISIT_QUIT(st, 0); break; -- 2.47.3