source: python/trunk/Lib/test/test_peepholer.py

Last change on this file was 391, checked in by dmik, 11 years ago

python: Merge vendor 2.7.6 to trunk.
  • Property svn:eol-style set to native
File size: 8.6 KB
Line 
1import dis
2import sys
3from cStringIO import StringIO
4import unittest
5
6def disassemble(func):
7 f = StringIO()
8 tmp = sys.stdout
9 sys.stdout = f
10 dis.dis(func)
11 sys.stdout = tmp
12 result = f.getvalue()
13 f.close()
14 return result
15
16def dis_single(line):
17 return disassemble(compile(line, '', 'single'))
18
19class TestTranforms(unittest.TestCase):
20
21 def test_unot(self):
22 # UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE
23 def unot(x):
24 if not x == 2:
25 del x
26 asm = disassemble(unot)
27 for elem in ('UNARY_NOT', 'POP_JUMP_IF_FALSE'):
28 self.assertNotIn(elem, asm)
29 self.assertIn('POP_JUMP_IF_TRUE', asm)
30
31 def test_elim_inversion_of_is_or_in(self):
32 for line, elem in (
33 ('not a is b', '(is not)',),
34 ('not a in b', '(not in)',),
35 ('not a is not b', '(is)',),
36 ('not a not in b', '(in)',),
37 ):
38 asm = dis_single(line)
39 self.assertIn(elem, asm)
40
41 def test_none_as_constant(self):
42 # LOAD_GLOBAL None --> LOAD_CONST None
43 def f(x):
44 None
45 return x
46 asm = disassemble(f)
47 for elem in ('LOAD_GLOBAL',):
48 self.assertNotIn(elem, asm)
49 for elem in ('LOAD_CONST', '(None)'):
50 self.assertIn(elem, asm)
51 def f():
52 'Adding a docstring made this test fail in Py2.5.0'
53 return None
54 self.assertIn('LOAD_CONST', disassemble(f))
55 self.assertNotIn('LOAD_GLOBAL', disassemble(f))
56
57 def test_while_one(self):
58 # Skip over: LOAD_CONST trueconst POP_JUMP_IF_FALSE xx
59 def f():
60 while 1:
61 pass
62 return list
63 asm = disassemble(f)
64 for elem in ('LOAD_CONST', 'POP_JUMP_IF_FALSE'):
65 self.assertNotIn(elem, asm)
66 for elem in ('JUMP_ABSOLUTE',):
67 self.assertIn(elem, asm)
68
69 def test_pack_unpack(self):
70 for line, elem in (
71 ('a, = a,', 'LOAD_CONST',),
72 ('a, b = a, b', 'ROT_TWO',),
73 ('a, b, c = a, b, c', 'ROT_THREE',),
74 ):
75 asm = dis_single(line)
76 self.assertIn(elem, asm)
77 self.assertNotIn('BUILD_TUPLE', asm)
78 self.assertNotIn('UNPACK_TUPLE', asm)
79
80 def test_folding_of_tuples_of_constants(self):
81 for line, elem in (
82 ('a = 1,2,3', '((1, 2, 3))'),
83 ('("a","b","c")', "(('a', 'b', 'c'))"),
84 ('a,b,c = 1,2,3', '((1, 2, 3))'),
85 ('(None, 1, None)', '((None, 1, None))'),
86 ('((1, 2), 3, 4)', '(((1, 2), 3, 4))'),
87 ):
88 asm = dis_single(line)
89 self.assertIn(elem, asm)
90 self.assertNotIn('BUILD_TUPLE', asm)
91
92 # Bug 1053819: Tuple of constants misidentified when presented with:
93 # . . . opcode_with_arg 100 unary_opcode BUILD_TUPLE 1 . . .
94 # The following would segfault upon compilation
95 def crater():
96 (~[
97 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
98 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
99 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
100 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
101 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
102 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
103 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
104 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
105 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
106 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
107 ],)
108
109 def test_folding_of_binops_on_constants(self):
110 for line, elem in (
111 ('a = 2+3+4', '(9)'), # chained fold
112 ('"@"*4', "('@@@@')"), # check string ops
113 ('a="abc" + "def"', "('abcdef')"), # check string ops
114 ('a = 3**4', '(81)'), # binary power
115 ('a = 3*4', '(12)'), # binary multiply
116 ('a = 13//4', '(3)'), # binary floor divide
117 ('a = 14%4', '(2)'), # binary modulo
118 ('a = 2+3', '(5)'), # binary add
119 ('a = 13-4', '(9)'), # binary subtract
120 ('a = (12,13)[1]', '(13)'), # binary subscr
121 ('a = 13 << 2', '(52)'), # binary lshift
122 ('a = 13 >> 2', '(3)'), # binary rshift
123 ('a = 13 & 7', '(5)'), # binary and
124 ('a = 13 ^ 7', '(10)'), # binary xor
125 ('a = 13 | 7', '(15)'), # binary or
126 ):
127 asm = dis_single(line)
128 self.assertIn(elem, asm, asm)
129 self.assertNotIn('BINARY_', asm)
130
131 # Verify that unfoldables are skipped
132 asm = dis_single('a=2+"b"')
133 self.assertIn('(2)', asm)
134 self.assertIn("('b')", asm)
135
136 # Verify that large sequences do not result from folding
137 asm = dis_single('a="x"*1000')
138 self.assertIn('(1000)', asm)
139
140 def test_binary_subscr_on_unicode(self):
141 # unicode strings don't get optimized
142 asm = dis_single('u"foo"[0]')
143 self.assertNotIn("(u'f')", asm)
144 self.assertIn('BINARY_SUBSCR', asm)
145 asm = dis_single('u"\u0061\uffff"[1]')
146 self.assertNotIn("(u'\\uffff')", asm)
147 self.assertIn('BINARY_SUBSCR', asm)
148
149 # out of range
150 asm = dis_single('u"fuu"[10]')
151 self.assertIn('BINARY_SUBSCR', asm)
152 # non-BMP char (see #5057)
153 asm = dis_single('u"\U00012345"[0]')
154 self.assertIn('BINARY_SUBSCR', asm)
155 asm = dis_single('u"\U00012345abcdef"[3]')
156 self.assertIn('BINARY_SUBSCR', asm)
157
158
159 def test_folding_of_unaryops_on_constants(self):
160 for line, elem in (
161 ('`1`', "('1')"), # unary convert
162 ('-0.5', '(-0.5)'), # unary negative
163 ('~-2', '(1)'), # unary invert
164 ):
165 asm = dis_single(line)
166 self.assertIn(elem, asm, asm)
167 self.assertNotIn('UNARY_', asm)
168
169 # Verify that unfoldables are skipped
170 for line, elem in (
171 ('-"abc"', "('abc')"), # unary negative
172 ('~"abc"', "('abc')"), # unary invert
173 ):
174 asm = dis_single(line)
175 self.assertIn(elem, asm, asm)
176 self.assertIn('UNARY_', asm)
177
178 def test_elim_extra_return(self):
179 # RETURN LOAD_CONST None RETURN --> RETURN
180 def f(x):
181 return x
182 asm = disassemble(f)
183 self.assertNotIn('LOAD_CONST', asm)
184 self.assertNotIn('(None)', asm)
185 self.assertEqual(asm.split().count('RETURN_VALUE'), 1)
186
187 def test_elim_jump_to_return(self):
188 # JUMP_FORWARD to RETURN --> RETURN
189 def f(cond, true_value, false_value):
190 return true_value if cond else false_value
191 asm = disassemble(f)
192 self.assertNotIn('JUMP_FORWARD', asm)
193 self.assertNotIn('JUMP_ABSOLUTE', asm)
194 self.assertEqual(asm.split().count('RETURN_VALUE'), 2)
195
196 def test_elim_jump_after_return1(self):
197 # Eliminate dead code: jumps immediately after returns can't be reached
198 def f(cond1, cond2):
199 if cond1: return 1
200 if cond2: return 2
201 while 1:
202 return 3
203 while 1:
204 if cond1: return 4
205 return 5
206 return 6
207 asm = disassemble(f)
208 self.assertNotIn('JUMP_FORWARD', asm)
209 self.assertNotIn('JUMP_ABSOLUTE', asm)
210 self.assertEqual(asm.split().count('RETURN_VALUE'), 6)
211
212 def test_elim_jump_after_return2(self):
213 # Eliminate dead code: jumps immediately after returns can't be reached
214 def f(cond1, cond2):
215 while 1:
216 if cond1: return 4
217 asm = disassemble(f)
218 self.assertNotIn('JUMP_FORWARD', asm)
219 # There should be one jump for the while loop.
220 self.assertEqual(asm.split().count('JUMP_ABSOLUTE'), 1)
221 self.assertEqual(asm.split().count('RETURN_VALUE'), 2)
222
223
224def test_main(verbose=None):
225 import sys
226 from test import test_support
227 test_classes = (TestTranforms,)
228
229 with test_support.check_py3k_warnings(
230 ("backquote not supported", SyntaxWarning)):
231 test_support.run_unittest(*test_classes)
232
233 # verify reference counting
234 if verbose and hasattr(sys, "gettotalrefcount"):
235 import gc
236 counts = [None] * 5
237 for i in xrange(len(counts)):
238 test_support.run_unittest(*test_classes)
239 gc.collect()
240 counts[i] = sys.gettotalrefcount()
241 print counts
242
243if __name__ == "__main__":
244 test_main(verbose=True)
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