1 """

     2 The regular expression engine in '_sre' can segfault when interpreting

     3 bogus bytecode.

     4 

     5 It is unclear whether this is a real bug or a "won't fix" case like

     6 bogus_code_obj.py, because it requires bytecode that is built by hand,

     7 as opposed to compiled by 're' from a string-source regexp.  The

     8 difference with bogus_code_obj, though, is that the only existing regexp

     9 compiler is written in Python, so that the C code has no choice but

    10 accept arbitrary bytecode from Python-level.

    11 

    12 The test below builds and runs random bytecodes until 'match' crashes

    13 Python.  I have not investigated why exactly segfaults occur nor how

    14 hard they would be to fix.  Here are a few examples of 'code' that

    15 segfault for me:

    16 

    17     [21, 50814, 8, 29, 16]

    18     [21, 3967, 26, 10, 23, 54113]

    19     [29, 23, 0, 2, 5]

    20     [31, 64351, 0, 28, 3, 22281, 20, 4463, 9, 25, 59154, 15245, 2,

    21                   16343, 3, 11600, 24380, 10, 37556, 10, 31, 15, 31]

    22 

    23 Here is also a 'code' that triggers an infinite uninterruptible loop:

    24 

    25     [29, 1, 8, 21, 1, 43083, 6]

    26 

    27 """

    28 

    29 import _sre, random

    30 

    31 def pick():

    32     n = random.randrange(-65536, 65536)

    33     if n < 0:

    34         n &= 31

    35     return n

    36 

    37 ss = ["", "world", "x" * 500]

    38 

    39 while 1:

    40     code = [pick() for i in range(random.randrange(5, 25))]

    41     print code

    42     pat = _sre.compile(None, 0, code)

    43     for s in ss:

    44         try:

    45             pat.match(s)

    46         except RuntimeError:

    47             pass