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v0.8.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 8de34cdb952a2e3b8d7a9a213845cad01a8cece3 authored by Pablo Galindo on 02 September 2020, 20:30:51 UTC, committed by GitHub on 02 September 2020, 20:30:51 UTC 
[3.9] bpo-41690: Use a loop to collect args in the parser instead of recursion (GH-22053) (GH-22067)
 
This program can segfault the parser by stack overflow:

```
import ast

code = "f(" + ",".join(['a' for _ in range(100000)]) + ")"
print("Ready!")
ast.parse(code)
```

the reason is that the rule for arguments has a simple recursion when collecting args:

args[expr_ty]:
    [...]
    | a=named_expression b=[',' c=args { c }] {
        [...] }.
(cherry picked from commit 4a97b1517a6b5ff22e2984b677a680b07ff0ce11)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
1 parent a763ee3
Raw File
Tip revision: 8de34cdb952a2e3b8d7a9a213845cad01a8cece3 authored by Pablo Galindo on 02 September 2020, 20:30:51 UTC
[3.9] bpo-41690: Use a loop to collect args in the parser instead of recursion (GH-22053) (GH-22067)
Tip revision: 8de34cd
cellobject.h 
/* Cell object interface */
#ifndef Py_LIMITED_API
#ifndef Py_CELLOBJECT_H
#define Py_CELLOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
    PyObject_HEAD
    PyObject *ob_ref;       /* Content of the cell or NULL when empty */
} PyCellObject;

PyAPI_DATA(PyTypeObject) PyCell_Type;

#define PyCell_Check(op) Py_IS_TYPE(op, &PyCell_Type)

PyAPI_FUNC(PyObject *) PyCell_New(PyObject *);
PyAPI_FUNC(PyObject *) PyCell_Get(PyObject *);
PyAPI_FUNC(int) PyCell_Set(PyObject *, PyObject *);

#define PyCell_GET(op) (((PyCellObject *)(op))->ob_ref)
#define PyCell_SET(op, v) (((PyCellObject *)(op))->ob_ref = v)

#ifdef __cplusplus
}
#endif
#endif /* !Py_TUPLEOBJECT_H */
#endif /* Py_LIMITED_API */
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