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v0.8.1
https://github.com/python/cpython
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
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
asdl.h
#ifndef Py_LIMITED_API
#ifndef Py_ASDL_H
#define Py_ASDL_H

typedef PyObject * identifier;
typedef PyObject * string;
typedef PyObject * object;
typedef PyObject * constant;

/* It would be nice if the code generated by asdl_c.py was completely
   independent of Python, but it is a goal the requires too much work
   at this stage.  So, for example, I'll represent identifiers as
   interned Python strings.
*/

/* XXX A sequence should be typed so that its use can be typechecked. */

typedef struct {
    Py_ssize_t size;
    void *elements[1];
} asdl_seq;

typedef struct {
    Py_ssize_t size;
    int elements[1];
} asdl_int_seq;

asdl_seq *_Py_asdl_seq_new(Py_ssize_t size, PyArena *arena);
asdl_int_seq *_Py_asdl_int_seq_new(Py_ssize_t size, PyArena *arena);

#define asdl_seq_GET(S, I) (S)->elements[(I)]
#define asdl_seq_LEN(S) ((S) == NULL ? 0 : (S)->size)
#ifdef Py_DEBUG
#define asdl_seq_SET(S, I, V) \
    do { \
        Py_ssize_t _asdl_i = (I); \
        assert((S) != NULL); \
        assert(0 <= _asdl_i && _asdl_i < (S)->size); \
        (S)->elements[_asdl_i] = (V); \
    } while (0)
#else
#define asdl_seq_SET(S, I, V) (S)->elements[I] = (V)
#endif

#endif /* !Py_ASDL_H */
#endif /* Py_LIMITED_API */
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