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bpo-23689: re module, fix memory leak when a match is terminated by a signal or memory allocation failure #32283

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Merged
serhiy-storchaka merged 11 commits into from Apr 3, 2022
Merged

bpo-23689: re module, fix memory leak when a match is terminated by a signal or memory allocation failure #32283

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e5317fe
1. add variables
wjssz Apr 3, 2022
28e4d2d
2. add _CompileData class to _compile.py
wjssz Apr 3, 2022
7493fad
3. add repeat_count parameter to _sre.compile() function
wjssz Apr 3, 2022
b928335
4. emit repeat_count in sre_compile.py
wjssz Apr 3, 2022
dfec05d
5. change _validate_outer() parameter
wjssz Apr 3, 2022
db7e88b
6. validate in _validate_inner() / _validate_outer()
wjssz Apr 3, 2022
a43cb6e
7. allocate repeats_array for SRE_STATE
wjssz Apr 3, 2022
1560a0c
8. support code in sre_lib.h
wjssz Apr 3, 2022
96be025
9. add unit-tests
wjssz Apr 3, 2022
7ee3e66
a. skip -= field_number
wjssz Apr 3, 2022
e95b19f
b. improve unit-test
wjssz Apr 3, 2022
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2. add _CompileData class to _compile.py 
_CompileData can store intermediate data.
  • Loading branch information
@wjssz
wjssz committed Apr 3, 2022
commit 28e4d2d97f39897ad437683ee2710573579fd665
43 changes: 25 additions & 18 deletions Lib/re/_compiler.py
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Original file line number Diff line number Diff line change
Expand Up @@ -67,14 +67,21 @@
_ignorecase_fixes = {i: tuple(j for j in t if i != j)
for t in _equivalences for i in t}

class _CompileData:
__slots__ = ('code', 'repeat_count')
def __init__(self):
self.code = []
self.repeat_count = 0

def _combine_flags(flags, add_flags, del_flags,
TYPE_FLAGS=_parser.TYPE_FLAGS):
if add_flags & TYPE_FLAGS:
flags &= ~TYPE_FLAGS
return (flags | add_flags) & ~del_flags

def _compile(code, pattern, flags):
def _compile(data, pattern, flags):
# internal: compile a (sub)pattern
code = data.code
emit = code.append
_len = len
LITERAL_CODES = _LITERAL_CODES
Expand Down Expand Up @@ -147,15 +154,15 @@ def _compile(code, pattern, flags):
skip = _len(code); emit(0)
emit(av[0])
emit(av[1])
_compile(code, av[2], flags)
_compile(data, av[2], flags)
emit(SUCCESS)
code[skip] = _len(code) - skip
else:
emit(REPEATING_CODES[op][0])
skip = _len(code); emit(0)
emit(av[0])
emit(av[1])
_compile(code, av[2], flags)
_compile(data, av[2], flags)
code[skip] = _len(code) - skip
emit(REPEATING_CODES[op][1])
elif op is SUBPATTERN:
Expand All @@ -164,7 +171,7 @@ def _compile(code, pattern, flags):
emit(MARK)
emit((group-1)*2)
# _compile_info(code, p, _combine_flags(flags, add_flags, del_flags))
_compile(code, p, _combine_flags(flags, add_flags, del_flags))
_compile(data, p, _combine_flags(flags, add_flags, del_flags))
if group:
emit(MARK)
emit((group-1)*2+1)
Expand All @@ -176,7 +183,7 @@ def _compile(code, pattern, flags):
# pop their stack if they reach it
emit(ATOMIC_GROUP)
skip = _len(code); emit(0)
_compile(code, av, flags)
_compile(data, av, flags)
emit(SUCCESS)
code[skip] = _len(code) - skip
elif op in SUCCESS_CODES:
Expand All @@ -191,13 +198,13 @@ def _compile(code, pattern, flags):
if lo != hi:
raise error("look-behind requires fixed-width pattern")
emit(lo) # look behind
_compile(code, av[1], flags)
_compile(data, av[1], flags)
emit(SUCCESS)
code[skip] = _len(code) - skip
elif op is CALL:
emit(op)
skip = _len(code); emit(0)
_compile(code, av, flags)
_compile(data, av, flags)
emit(SUCCESS)
code[skip] = _len(code) - skip
elif op is AT:
Expand All @@ -216,7 +223,7 @@ def _compile(code, pattern, flags):
for av in av[1]:
skip = _len(code); emit(0)
# _compile_info(code, av, flags)
_compile(code, av, flags)
_compile(data, av, flags)
emit(JUMP)
tailappend(_len(code)); emit(0)
code[skip] = _len(code) - skip
Expand Down Expand Up @@ -244,12 +251,12 @@ def _compile(code, pattern, flags):
emit(op)
emit(av[0]-1)
skipyes = _len(code); emit(0)
_compile(code, av[1], flags)
_compile(data, av[1], flags)
if av[2]:
emit(JUMP)
skipno = _len(code); emit(0)
code[skipyes] = _len(code) - skipyes + 1
_compile(code, av[2], flags)
_compile(data, av[2], flags)
code[skipno] = _len(code) - skipno
else:
code[skipyes] = _len(code) - skipyes + 1
Expand Down Expand Up @@ -608,17 +615,17 @@ def isstring(obj):
def _code(p, flags):

flags = p.state.flags | flags
code = []
data = _CompileData()

# compile info block
_compile_info(code, p, flags)
_compile_info(data.code, p, flags)

# compile the pattern
_compile(code, p.data, flags)
_compile(data, p.data, flags)

code.append(SUCCESS)
data.code.append(SUCCESS)

return code
return data

def _hex_code(code):
return '[%s]' % ', '.join('%#0*x' % (_sre.CODESIZE*2+2, x) for x in code)
Expand Down Expand Up @@ -781,11 +788,11 @@ def compile(p, flags=0):
else:
pattern = None

code = _code(p, flags)
data = _code(p, flags)

if flags & SRE_FLAG_DEBUG:
print()
dis(code)
dis(data.code)

# map in either direction
groupindex = p.state.groupdict
Expand All @@ -794,7 +801,7 @@ def compile(p, flags=0):
indexgroup[i] = k

return _sre.compile(
pattern, flags | p.state.flags, code,
pattern, flags | p.state.flags, data.code,
p.state.groups-1,
groupindex, tuple(indexgroup)
)