1 import dis 2 import sys 3 from cStringIO import StringIO 4 import unittest 5 6 def 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 16 def dis_single(line): 17 return disassemble(compile(line, '', 'single')) 18 19 class 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) 222 223 224 def 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 242 243 if __name__ == "__main__": 244 test_main(verbose=True) 245
