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- 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 JUMP_IF_FALSE POP_TOP --> JUMP_IF_TRUE POP_TOP'
- def unot(x):
- if not x == 2:
- del x
- asm = disassemble(unot)
- for elem in ('UNARY_NOT', 'JUMP_IF_FALSE'):
- self.assert_(elem not in asm)
- for elem in ('JUMP_IF_TRUE', 'POP_TOP'):
- self.assert_(elem in 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.assert_(elem in 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.assert_(elem not in asm)
- for elem in ('LOAD_CONST', '(None)'):
- self.assert_(elem in asm)
- def f():
- 'Adding a docstring made this test fail in Py2.5.0'
- return None
- self.assert_('LOAD_CONST' in disassemble(f))
- self.assert_('LOAD_GLOBAL' not in disassemble(f))
-
- def test_while_one(self):
- # Skip over: LOAD_CONST trueconst JUMP_IF_FALSE xx POP_TOP
- def f():
- while 1:
- pass
- return list
- asm = disassemble(f)
- for elem in ('LOAD_CONST', 'JUMP_IF_FALSE'):
- self.assert_(elem not in asm)
- for elem in ('JUMP_ABSOLUTE',):
- self.assert_(elem in 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.assert_(elem in asm)
- self.assert_('BUILD_TUPLE' not in asm)
- self.assert_('UNPACK_TUPLE' not in 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.assert_(elem in asm)
- self.assert_('BUILD_TUPLE' not in 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.assert_(elem in asm, asm)
- self.assert_('BINARY_' not in asm)
-
- # Verify that unfoldables are skipped
- asm = dis_single('a=2+"b"')
- self.assert_('(2)' in asm)
- self.assert_("('b')" in asm)
-
- # Verify that large sequences do not result from folding
- asm = dis_single('a="x"*1000')
- self.assert_('(1000)' in 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.assert_(elem in asm, asm)
- self.assert_('UNARY_' not in asm)
-
- # Verify that unfoldables are skipped
- for line, elem in (
- ('-"abc"', "('abc')"), # unary negative
- ('~"abc"', "('abc')"), # unary invert
- ):
- asm = dis_single(line)
- self.assert_(elem in asm, asm)
- self.assert_('UNARY_' in asm)
-
- def test_elim_extra_return(self):
- # RETURN LOAD_CONST None RETURN --> RETURN
- def f(x):
- return x
- asm = disassemble(f)
- self.assert_('LOAD_CONST' not in asm)
- self.assert_('(None)' not in 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.assert_('JUMP_FORWARD' not in asm)
- self.assert_('JUMP_ABSOLUTE' not in 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.assert_('JUMP_FORWARD' not in asm)
- self.assert_('JUMP_ABSOLUTE' not in 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.assert_('JUMP_FORWARD' not in 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)
-