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
|
"""Disassembler of Python byte code into mnemonics."""
import sys
import types
from opcode import *
from opcode import __all__ as _opcodes_all
__all__ = ["dis","disassemble","distb","disco"] + _opcodes_all
del _opcodes_all
def dis(x=None):
"""Disassemble classes, methods, functions, or code.
With no argument, disassemble the last traceback.
"""
if x is None:
distb()
return
if hasattr(x, '__func__'):
x = x.__func__
if hasattr(x, '__code__'):
x = x.__code__
if hasattr(x, '__dict__'):
items = sorted(x.__dict__.items())
for name, x1 in items:
if isinstance(x1, (types.MethodType, types.FunctionType,
types.CodeType, type)):
print("Disassembly of %s:" % name)
try:
dis(x1)
except TypeError as msg:
print("Sorry:", msg)
print()
elif hasattr(x, 'co_code'):
disassemble(x)
elif isinstance(x, (bytes, bytearray)):
disassemble_string(x)
else:
raise TypeError("don't know how to disassemble %s objects" %
type(x).__name__)
def distb(tb=None):
"""Disassemble a traceback (default: last traceback)."""
if tb is None:
try:
tb = sys.last_traceback
except AttributeError:
raise RuntimeError("no last traceback to disassemble")
while tb.tb_next: tb = tb.tb_next
disassemble(tb.tb_frame.f_code, tb.tb_lasti)
# XXX This duplicates information from code.h, also duplicated in inspect.py.
# XXX Maybe this ought to be put in a central location, like opcode.py?
flag2name = {
1: "OPTIMIZED",
2: "NEWLOCALS",
4: "VARARGS",
8: "VARKEYWORDS",
16: "NESTED",
32: "GENERATOR",
64: "NOFREE",
}
def pretty_flags(flags):
"""Return pretty representation of code flags."""
names = []
for i in range(32):
flag = 1<<i
if flags & flag:
names.append(flag2name.get(flag, hex(flag)))
flags ^= flag
if not flags:
break
else:
names.append(hex(flags))
return ", ".join(names)
def show_code(co):
"""Show details about a code object."""
print("Name: ", co.co_name)
print("Filename: ", co.co_filename)
print("Argument count: ", co.co_argcount)
print("Kw-only arguments:", co.co_kwonlyargcount)
print("Number of locals: ", co.co_nlocals)
print("Stack size: ", co.co_stacksize)
print("Flags: ", pretty_flags(co.co_flags))
if co.co_consts:
print("Constants:")
for i_c in enumerate(co.co_consts):
print("%4d: %r" % i_c)
if co.co_names:
print("Names:")
for i_n in enumerate(co.co_names):
print("%4d: %s" % i_n)
if co.co_varnames:
print("Variable names:")
for i_n in enumerate(co.co_varnames):
print("%4d: %s" % i_n)
if co.co_freevars:
print("Free variables:")
for i_n in enumerate(co.co_freevars):
print("%4d: %s" % i_n)
if co.co_cellvars:
print("Cell variables:")
for i_n in enumerate(co.co_cellvars):
print("%4d: %s" % i_n)
def disassemble(co, lasti=-1):
"""Disassemble a code object."""
code = co.co_code
labels = findlabels(code)
linestarts = dict(findlinestarts(co))
n = len(code)
i = 0
extended_arg = 0
free = None
while i < n:
op = code[i]
if i in linestarts:
if i > 0:
print()
print("%3d" % linestarts[i], end=' ')
else:
print(' ', end=' ')
if i == lasti: print('-->', end=' ')
else: print(' ', end=' ')
if i in labels: print('>>', end=' ')
else: print(' ', end=' ')
print(repr(i).rjust(4), end=' ')
print(opname[op].ljust(20), end=' ')
i = i+1
if op >= HAVE_ARGUMENT:
oparg = code[i] + code[i+1]*256 + extended_arg
extended_arg = 0
i = i+2
if op == EXTENDED_ARG:
extended_arg = oparg*65536
print(repr(oparg).rjust(5), end=' ')
if op in hasconst:
print('(' + repr(co.co_consts[oparg]) + ')', end=' ')
elif op in hasname:
print('(' + co.co_names[oparg] + ')', end=' ')
elif op in hasjrel:
print('(to ' + repr(i + oparg) + ')', end=' ')
elif op in haslocal:
print('(' + co.co_varnames[oparg] + ')', end=' ')
elif op in hascompare:
print('(' + cmp_op[oparg] + ')', end=' ')
elif op in hasfree:
if free is None:
free = co.co_cellvars + co.co_freevars
print('(' + free[oparg] + ')', end=' ')
print()
def disassemble_string(code, lasti=-1, varnames=None, names=None,
constants=None):
labels = findlabels(code)
n = len(code)
i = 0
while i < n:
op = code[i]
if i == lasti: print('-->', end=' ')
else: print(' ', end=' ')
if i in labels: print('>>', end=' ')
else: print(' ', end=' ')
print(repr(i).rjust(4), end=' ')
print(opname[op].ljust(15), end=' ')
i = i+1
if op >= HAVE_ARGUMENT:
oparg = code[i] + code[i+1]*256
i = i+2
print(repr(oparg).rjust(5), end=' ')
if op in hasconst:
if constants:
print('(' + repr(constants[oparg]) + ')', end=' ')
else:
print('(%d)'%oparg, end=' ')
elif op in hasname:
if names is not None:
print('(' + names[oparg] + ')', end=' ')
else:
print('(%d)'%oparg, end=' ')
elif op in hasjrel:
print('(to ' + repr(i + oparg) + ')', end=' ')
elif op in haslocal:
if varnames:
print('(' + varnames[oparg] + ')', end=' ')
else:
print('(%d)' % oparg, end=' ')
elif op in hascompare:
print('(' + cmp_op[oparg] + ')', end=' ')
print()
disco = disassemble # XXX For backwards compatibility
def findlabels(code):
"""Detect all offsets in a byte code which are jump targets.
Return the list of offsets.
"""
labels = []
n = len(code)
i = 0
while i < n:
op = code[i]
i = i+1
if op >= HAVE_ARGUMENT:
oparg = code[i] + code[i+1]*256
i = i+2
label = -1
if op in hasjrel:
label = i+oparg
elif op in hasjabs:
label = oparg
if label >= 0:
if label not in labels:
labels.append(label)
return labels
def findlinestarts(code):
"""Find the offsets in a byte code which are start of lines in the source.
Generate pairs (offset, lineno) as described in Python/compile.c.
"""
byte_increments = list(code.co_lnotab[0::2])
line_increments = list(code.co_lnotab[1::2])
lastlineno = None
lineno = code.co_firstlineno
addr = 0
for byte_incr, line_incr in zip(byte_increments, line_increments):
if byte_incr:
if lineno != lastlineno:
yield (addr, lineno)
lastlineno = lineno
addr += byte_incr
lineno += line_incr
if lineno != lastlineno:
yield (addr, lineno)
def _test():
"""Simple test program to disassemble a file."""
if sys.argv[1:]:
if sys.argv[2:]:
sys.stderr.write("usage: python dis.py [-|file]\n")
sys.exit(2)
fn = sys.argv[1]
if not fn or fn == "-":
fn = None
else:
fn = None
if fn is None:
f = sys.stdin
else:
f = open(fn)
source = f.read()
if fn is not None:
f.close()
else:
fn = "<stdin>"
code = compile(source, fn, "exec")
dis(code)
if __name__ == "__main__":
_test()
|
