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Issue #13169: The maximal repetition number in a regular expression has been 

increased from 65534 to 2147483647 (on 32-bit platform) or 4294967294 (on
64-bit).
This commit is contained in:
Serhiy Storchaka 2013-02-16 16:55:54 +02:00
parent 178e6fef9e a0eb809995
commit 165ee9645b
7 changed files with 62 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Lib/sre_compile.py
View File

@ -13,6 +13,7 @@
import _sre, sys
import sre_parse
from sre_constants import *
from _sre import MAXREPEAT
assert _sre.MAGIC == MAGIC, "SRE module mismatch"

4
Lib/sre_constants.py
View File

@ -15,10 +15,6 @@
MAGIC = 20031017
# max code word in this release
MAXREPEAT = 65535
# SRE standard exception (access as sre.error)
# should this really be here?

9
Lib/sre_parse.py
View File

@ -15,6 +15,7 @@
import sys
from sre_constants import *
from _sre import MAXREPEAT
SPECIAL_CHARS = ".\\[{()*+?^$|"
REPEAT_CHARS = "*+?{"
@ -537,10 +538,14 @@ def _parse(source, state):
continue
if lo:
min = int(lo)
if min >= MAXREPEAT:
raise OverflowError("the repetition number is too large")
if hi:
max = int(hi)
if max < min:
raise error("bad repeat interval")
if max >= MAXREPEAT:
raise OverflowError("the repetition number is too large")
if max < min:
raise error("bad repeat interval")
else:
raise error("not supported")
# figure out which item to repeat

34
Lib/test/test_re.py
View File

@ -1,4 +1,5 @@
from test.support import verbose, run_unittest, gc_collect, bigmemtest, _2G
from test.support import verbose, run_unittest, gc_collect, bigmemtest, _2G, \
cpython_only
import io
import re
from re import Scanner
@ -980,6 +981,37 @@ class ReTests(unittest.TestCase):
self.assertEqual(re.findall(r"(?i)(a)\1", "aa \u0100"), ['a'])
self.assertEqual(re.match(r"(?s).{1,3}", "\u0100\u0100").span(), (0, 2))
def test_repeat_minmax_overflow(self):
# Issue #13169
string = "x" * 100000
self.assertEqual(re.match(r".{65535}", string).span(), (0, 65535))
self.assertEqual(re.match(r".{,65535}", string).span(), (0, 65535))
self.assertEqual(re.match(r".{65535,}?", string).span(), (0, 65535))
self.assertEqual(re.match(r".{65536}", string).span(), (0, 65536))
self.assertEqual(re.match(r".{,65536}", string).span(), (0, 65536))
self.assertEqual(re.match(r".{65536,}?", string).span(), (0, 65536))
# 2**128 should be big enough to overflow both SRE_CODE and Py_ssize_t.
self.assertRaises(OverflowError, re.compile, r".{%d}" % 2**128)
self.assertRaises(OverflowError, re.compile, r".{,%d}" % 2**128)
self.assertRaises(OverflowError, re.compile, r".{%d,}?" % 2**128)
self.assertRaises(OverflowError, re.compile, r".{%d,%d}" % (2**129, 2**128))
@cpython_only
def test_repeat_minmax_overflow_maxrepeat(self):
try:
from _sre import MAXREPEAT
except ImportError:
self.skipTest('requires _sre.MAXREPEAT constant')
string = "x" * 100000
self.assertIsNone(re.match(r".{%d}" % (MAXREPEAT - 1), string))
self.assertEqual(re.match(r".{,%d}" % (MAXREPEAT - 1), string).span(),
(0, 100000))
self.assertIsNone(re.match(r".{%d,}?" % (MAXREPEAT - 1), string))
self.assertRaises(OverflowError, re.compile, r".{%d}" % MAXREPEAT)
self.assertRaises(OverflowError, re.compile, r".{,%d}" % MAXREPEAT)
self.assertRaises(OverflowError, re.compile, r".{%d,}?" % MAXREPEAT)
def run_re_tests():
from test.re_tests import tests, SUCCEED, FAIL, SYNTAX_ERROR
if verbose:

4
Misc/NEWS
View File

@ -253,6 +253,10 @@ Core and Builtins
Library
-------
- Issue #13169: The maximal repetition number in a regular expression has been
increased from 65534 to 2147483647 (on 32-bit platform) or 4294967294 (on
64-bit).
- Issue #17143: Fix a missing import in the trace module. Initial patch by
Berker Peksag.

18
Modules/_sre.c
View File

@ -492,7 +492,7 @@ SRE_COUNT(SRE_STATE* state, SRE_CODE* pattern, Py_ssize_t maxcount)
Py_ssize_t i;
/* adjust end */
if (maxcount < (end - ptr) / state->charsize && maxcount != 65535)
if (maxcount < (end - ptr) / state->charsize && maxcount != SRE_MAXREPEAT)
end = ptr + maxcount*state->charsize;
switch (pattern[0]) {
@ -1109,7 +1109,7 @@ entrance:
} else {
/* general case */
LASTMARK_SAVE();
while ((Py_ssize_t)ctx->pattern[2] == 65535
while ((Py_ssize_t)ctx->pattern[2] == SRE_MAXREPEAT
|| ctx->count <= (Py_ssize_t)ctx->pattern[2]) {
state->ptr = ctx->ptr;
DO_JUMP(JUMP_MIN_REPEAT_ONE,jump_min_repeat_one,
@ -1195,7 +1195,7 @@ entrance:
}
if ((ctx->count < ctx->u.rep->pattern[2] ||
ctx->u.rep->pattern[2] == 65535) &&
ctx->u.rep->pattern[2] == SRE_MAXREPEAT) &&
state->ptr != ctx->u.rep->last_ptr) {
/* we may have enough matches, but if we can
match another item, do so */
@ -1273,7 +1273,7 @@ entrance:
LASTMARK_RESTORE();
if (ctx->count >= ctx->u.rep->pattern[2]
&& ctx->u.rep->pattern[2] != 65535)
&& ctx->u.rep->pattern[2] != SRE_MAXREPEAT)
RETURN_FAILURE;
ctx->u.rep->count = ctx->count;
@ -3037,7 +3037,7 @@ _validate_inner(SRE_CODE *code, SRE_CODE *end, Py_ssize_t groups)
GET_ARG; max = arg;
if (min > max)
FAIL;
if (max > 65535)
if (max > SRE_MAXREPEAT)
FAIL;
if (!_validate_inner(code, code+skip-4, groups))
FAIL;
@ -3056,7 +3056,7 @@ _validate_inner(SRE_CODE *code, SRE_CODE *end, Py_ssize_t groups)
GET_ARG; max = arg;
if (min > max)
FAIL;
if (max > 65535)
if (max > SRE_MAXREPEAT)
FAIL;
if (!_validate_inner(code, code+skip-3, groups))
FAIL;
@ -3942,6 +3942,12 @@ PyMODINIT_FUNC PyInit__sre(void)
Py_DECREF(x);
}
x = PyLong_FromUnsignedLong(SRE_MAXREPEAT);
if (x) {
PyDict_SetItemString(d, "MAXREPEAT", x);
Py_DECREF(x);
}
x = PyUnicode_FromString(copyright);
if (x) {
PyDict_SetItemString(d, "copyright", x);

5
Modules/sre.h
View File

@ -16,6 +16,11 @@
/* size of a code word (must be unsigned short or larger, and
large enough to hold a UCS4 character) */
#define SRE_CODE Py_UCS4
#if SIZEOF_SIZE_T > 4
# define SRE_MAXREPEAT (~(SRE_CODE)0)
#else
# define SRE_MAXREPEAT ((SRE_CODE)PY_SSIZE_T_MAX + 1u)
#endif
typedef struct {
PyObject_VAR_HEAD