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
|
import dis
import sys
from cStringIO import StringIO
import unittest
def disassemble(func):
f = StringIO()
tmp = sys.stdout
sys.stdout = f
dis.dis(func)
sys.stdout = tmp
result = f.getvalue()
f.close()
return result
def dis_single(line):
return disassemble(compile(line, '', 'single'))
class TestTranforms(unittest.TestCase):
def test_unot(self):
# UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE
def unot(x):
if not x == 2:
del x
asm = disassemble(unot)
for elem in ('UNARY_NOT', 'POP_JUMP_IF_FALSE'):
self.assertNotIn(elem, asm)
self.assertIn('POP_JUMP_IF_TRUE', asm)
def test_elim_inversion_of_is_or_in(self):
for line, elem in (
('not a is b', '(is not)',),
('not a in b', '(not in)',),
('not a is not b', '(is)',),
('not a not in b', '(in)',),
):
asm = dis_single(line)
self.assertIn(elem, asm)
def test_none_as_constant(self):
# LOAD_GLOBAL None --> LOAD_CONST None
def f(x):
None
return x
asm = disassemble(f)
for elem in ('LOAD_GLOBAL',):
self.assertNotIn(elem, asm)
for elem in ('LOAD_CONST', '(None)'):
self.assertIn(elem, asm)
def f():
'Adding a docstring made this test fail in Py2.5.0'
return None
self.assertIn('LOAD_CONST', disassemble(f))
self.assertNotIn('LOAD_GLOBAL', disassemble(f))
def test_while_one(self):
# Skip over: LOAD_CONST trueconst POP_JUMP_IF_FALSE xx
def f():
while 1:
pass
return list
asm = disassemble(f)
for elem in ('LOAD_CONST', 'POP_JUMP_IF_FALSE'):
self.assertNotIn(elem, asm)
for elem in ('JUMP_ABSOLUTE',):
self.assertIn(elem, asm)
def test_pack_unpack(self):
for line, elem in (
('a, = a,', 'LOAD_CONST',),
('a, b = a, b', 'ROT_TWO',),
('a, b, c = a, b, c', 'ROT_THREE',),
):
asm = dis_single(line)
self.assertIn(elem, asm)
self.assertNotIn('BUILD_TUPLE', asm)
self.assertNotIn('UNPACK_TUPLE', asm)
def test_folding_of_tuples_of_constants(self):
for line, elem in (
('a = 1,2,3', '((1, 2, 3))'),
('("a","b","c")', "(('a', 'b', 'c'))"),
('a,b,c = 1,2,3', '((1, 2, 3))'),
('(None, 1, None)', '((None, 1, None))'),
('((1, 2), 3, 4)', '(((1, 2), 3, 4))'),
):
asm = dis_single(line)
self.assertIn(elem, asm)
self.assertNotIn('BUILD_TUPLE', asm)
# Bug 1053819: Tuple of constants misidentified when presented with:
# . . . opcode_with_arg 100 unary_opcode BUILD_TUPLE 1 . . .
# The following would segfault upon compilation
def crater():
(~[
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
],)
def test_folding_of_binops_on_constants(self):
for line, elem in (
('a = 2+3+4', '(9)'), # chained fold
('"@"*4', "('@@@@')"), # check string ops
('a="abc" + "def"', "('abcdef')"), # check string ops
('a = 3**4', '(81)'), # binary power
('a = 3*4', '(12)'), # binary multiply
('a = 13//4', '(3)'), # binary floor divide
('a = 14%4', '(2)'), # binary modulo
('a = 2+3', '(5)'), # binary add
('a = 13-4', '(9)'), # binary subtract
('a = (12,13)[1]', '(13)'), # binary subscr
('a = 13 << 2', '(52)'), # binary lshift
('a = 13 >> 2', '(3)'), # binary rshift
('a = 13 & 7', '(5)'), # binary and
('a = 13 ^ 7', '(10)'), # binary xor
('a = 13 | 7', '(15)'), # binary or
):
asm = dis_single(line)
self.assertIn(elem, asm, asm)
self.assertNotIn('BINARY_', asm)
# Verify that unfoldables are skipped
asm = dis_single('a=2+"b"')
self.assertIn('(2)', asm)
self.assertIn("('b')", asm)
# Verify that large sequences do not result from folding
asm = dis_single('a="x"*1000')
self.assertIn('(1000)', asm)
def test_folding_of_unaryops_on_constants(self):
for line, elem in (
('`1`', "('1')"), # unary convert
('-0.5', '(-0.5)'), # unary negative
('~-2', '(1)'), # unary invert
):
asm = dis_single(line)
self.assertIn(elem, asm, asm)
self.assertNotIn('UNARY_', asm)
# Verify that unfoldables are skipped
for line, elem in (
('-"abc"', "('abc')"), # unary negative
('~"abc"', "('abc')"), # unary invert
):
asm = dis_single(line)
self.assertIn(elem, asm, asm)
self.assertIn('UNARY_', asm)
def test_elim_extra_return(self):
# RETURN LOAD_CONST None RETURN --> RETURN
def f(x):
return x
asm = disassemble(f)
self.assertNotIn('LOAD_CONST', asm)
self.assertNotIn('(None)', asm)
self.assertEqual(asm.split().count('RETURN_VALUE'), 1)
def test_elim_jump_to_return(self):
# JUMP_FORWARD to RETURN --> RETURN
def f(cond, true_value, false_value):
return true_value if cond else false_value
asm = disassemble(f)
self.assertNotIn('JUMP_FORWARD', asm)
self.assertNotIn('JUMP_ABSOLUTE', asm)
self.assertEqual(asm.split().count('RETURN_VALUE'), 2)
def test_elim_jump_after_return1(self):
# Eliminate dead code: jumps immediately after returns can't be reached
def f(cond1, cond2):
if cond1: return 1
if cond2: return 2
while 1:
return 3
while 1:
if cond1: return 4
return 5
return 6
asm = disassemble(f)
self.assertNotIn('JUMP_FORWARD', asm)
self.assertNotIn('JUMP_ABSOLUTE', asm)
self.assertEqual(asm.split().count('RETURN_VALUE'), 6)
def test_elim_jump_after_return2(self):
# Eliminate dead code: jumps immediately after returns can't be reached
def f(cond1, cond2):
while 1:
if cond1: return 4
asm = disassemble(f)
self.assertNotIn('JUMP_FORWARD', asm)
# There should be one jump for the while loop.
self.assertEqual(asm.split().count('JUMP_ABSOLUTE'), 1)
self.assertEqual(asm.split().count('RETURN_VALUE'), 2)
def test_main(verbose=None):
import sys
from test import test_support
test_classes = (TestTranforms,)
test_support.run_unittest(*test_classes)
# verify reference counting
if verbose and hasattr(sys, "gettotalrefcount"):
import gc
counts = [None] * 5
for i in xrange(len(counts)):
test_support.run_unittest(*test_classes)
gc.collect()
counts[i] = sys.gettotalrefcount()
print counts
if __name__ == "__main__":
test_main(verbose=True)
|
