forked from rocky/python-uncompyle6
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathscanner.py
More file actions
executable file
·301 lines (262 loc) · 9.87 KB
/
scanner.py
File metadata and controls
executable file
·301 lines (262 loc) · 9.87 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
# Copyright (c) 2016 by Rocky Bernstein
# Copyright (c) 2005 by Dan Pascu <dan@windowmaker.org>
# Copyright (c) 2000-2002 by hartmut Goebel <h.goebel@crazy-compilers.com>
# Copyright (c) 1999 John Aycock
#
# See LICENSE
#
"""
scanner/ingestion module. From here we call various version-specific
scanners, e.g. for Python 2.7 or 3.4.
"""
import sys
from uncompyle6 import PYTHON3, IS_PYPY
from uncompyle6.scanners.tok import Token
# The byte code versions we support
PYTHON_VERSIONS = (1.5,
2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7,
3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6)
# FIXME: DRY
if PYTHON3:
intern = sys.intern
L65536 = 65536
def long(l):
return l
else:
L65536 = long(65536) # NOQA
class Code(object):
'''
Class for representing code-objects.
This is similar to the original code object, but additionally
the diassembled code is stored in the attribute '_tokens'.
'''
def __init__(self, co, scanner, classname=None):
for i in dir(co):
if i.startswith('co_'):
setattr(self, i, getattr(co, i))
self._tokens, self._customize = scanner.ingest(co, classname)
class Scanner(object):
def __init__(self, version, show_asm=None, is_pypy=False):
self.version = version
self.show_asm = show_asm
self.is_pypy = is_pypy
if version in PYTHON_VERSIONS:
if is_pypy:
v_str = "opcode_pypy%s" % (int(version * 10))
else:
v_str = "opcode_%s" % (int(version * 10))
exec("from xdis.opcodes import %s" % v_str)
exec("self.opc = %s" % v_str)
else:
raise TypeError("%s is not a Python version I know about" % version)
self.opname = self.opc.opname
# FIXME: This weird Python2 behavior is not Python3
self.resetTokenClass()
def is_jump_forward(self, offset):
"""
Return True if the code at offset is some sort of jump forward.
That is, it is ether "JUMP_FORWARD" or an absolute jump that
goes forward.
"""
if self.code[offset] == self.opc.JUMP_FORWARD:
return True
if self.code[offset] != self.opc.JUMP_ABSOLUTE:
return False
return offset < self.get_target(offset)
def get_target(self, pos, op=None):
if op is None:
op = self.code[pos]
target = self.get_argument(pos)
if op in self.opc.hasjrel:
target += pos + 3
return target
def get_argument(self, pos):
arg = self.code[pos+1] + self.code[pos+2] * 256
return arg
def print_bytecode(self):
for i in self.op_range(0, len(self.code)):
op = self.code[i]
if op in self.opc.hasjabs+self.opc.hasjrel:
dest = self.get_target(i, op)
print('%i\t%s\t%i' % (i, self.opname[op], dest))
else:
print('%i\t%s\t' % (i, self.opname[op]))
def first_instr(self, start, end, instr, target=None, exact=True):
"""
Find the first <instr> in the block from start to end.
<instr> is any python bytecode instruction or a list of opcodes
If <instr> is an opcode with a target (like a jump), a target
destination can be specified which must match precisely if exact
is True, or if exact is False, the instruction which has a target
closest to <target> will be returned.
Return index to it or None if not found.
"""
code = self.code
assert(start >= 0 and end <= len(code))
try:
None in instr
except:
instr = [instr]
result_offset = None
current_distance = len(code)
for offset in self.op_range(start, end):
op = code[offset]
if op in instr:
if target is None:
return offset
dest = self.get_target(offset)
if dest == target:
return offset
elif not exact:
new_distance = abs(target - dest)
if new_distance < current_distance:
current_distance = new_distance
result_offset = offset
return result_offset
def last_instr(self, start, end, instr, target=None, exact=True):
"""
Find the last <instr> in the block from start to end.
<instr> is any python bytecode instruction or a list of opcodes
If <instr> is an opcode with a target (like a jump), a target
destination can be specified which must match precisely if exact
is True, or if exact is False, the instruction which has a target
closest to <target> will be returned.
Return index to it or None if not found.
"""
code = self.code
# Make sure requested positions do not go out of
# code bounds
if not (start>=0 and end<=len(code)):
return None
try:
None in instr
except:
instr = [instr]
result_offset = None
current_distance = len(code)
for offset in self.op_range(start, end):
op = code[offset]
if op in instr:
if target is None:
result_offset = offset
else:
dest = self.get_target(offset)
if dest == target:
current_distance = 0
result_offset = offset
elif not exact:
new_distance = abs(target - dest)
if new_distance <= current_distance:
current_distance = new_distance
result_offset = offset
return result_offset
def all_instr(self, start, end, instr, target=None, include_beyond_target=False):
"""
Find all <instr> in the block from start to end.
<instr> is any python bytecode instruction or a list of opcodes
If <instr> is an opcode with a target (like a jump), a target
destination can be specified which must match precisely.
Return a list with indexes to them or [] if none found.
"""
code = self.code
assert(start >= 0 and end <= len(code))
try:
None in instr
except:
instr = [instr]
result = []
for offset in self.op_range(start, end):
op = code[offset]
if op in instr:
if target is None:
result.append(offset)
else:
t = self.get_target(offset)
if include_beyond_target and t >= target:
result.append(offset)
elif t == target:
result.append(offset)
return result
def op_hasArgument(self, op):
return self.op_size(op) > 1
def op_range(self, start, end):
"""
Iterate through positions of opcodes, skipping
arguments.
"""
while start < end:
yield start
start += self.op_size(self.code[start])
def op_size(self, op):
"""
Return size of operator with its arguments
for given opcode <op>.
"""
if op < self.opc.HAVE_ARGUMENT:
if self.version >= 3.6:
return 2
else:
return 1
else:
if self.version >= 3.6:
return 2
else:
return 3
def remove_mid_line_ifs(self, ifs):
"""
Go through passed offsets, filtering ifs
located somewhere mid-line.
"""
filtered = []
for i in ifs:
# For each offset, if line number of current and next op
# is the same
if self.lines[i].l_no == self.lines[i+3].l_no:
# Skip last op on line if it is some sort of POP_JUMP.
if self.code[self.prev[self.lines[i].next]] in (self.opc.PJIT, self.opc.PJIF):
continue
filtered.append(i)
return filtered
def resetTokenClass(self):
return self.setTokenClass(Token)
def restrict_to_parent(self, target, parent):
"""Restrict target to parent structure boundaries."""
if not (parent['start'] < target < parent['end']):
target = parent['end']
return target
def setTokenClass(self, tokenClass):
# assert isinstance(tokenClass, types.ClassType)
self.Token = tokenClass
return self.Token
def op_has_argument(op, opc):
return op >= opc.HAVE_ARGUMENT
def parse_fn_counts(argc):
return ((argc & 0xFF), (argc >> 8) & 0xFF, (argc >> 16) & 0x7FFF)
def get_scanner(version, is_pypy=False, show_asm=None):
# Pick up appropriate scanner
if version in PYTHON_VERSIONS:
v_str = "%s" % (int(version * 10))
if PYTHON3:
import importlib
if is_pypy:
scan = importlib.import_module("uncompyle6.scanners.pypy%s" % v_str)
else:
scan = importlib.import_module("uncompyle6.scanners.scanner%s" % v_str)
if False: print(scan) # Avoid unused scan
else:
if is_pypy:
exec("import uncompyle6.scanners.pypy%s as scan" % v_str)
else:
exec("import uncompyle6.scanners.scanner%s as scan" % v_str)
if is_pypy:
scanner = eval("scan.ScannerPyPy%s(show_asm=show_asm)" % v_str)
else:
scanner = eval("scan.Scanner%s(show_asm=show_asm)" % v_str)
else:
raise RuntimeError("Unsupported Python version %s" % version)
return scanner
if __name__ == "__main__":
import inspect, uncompyle6
co = inspect.currentframe().f_code
scanner = get_scanner(uncompyle6.PYTHON_VERSION, IS_PYPY, True)
tokens, customize = scanner.ingest(co, {})