lib-python.2.7.test.test_peepholer.py Maven / Gradle / Ivy
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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
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_binary_subscr_on_unicode(self):
# valid code get optimized
asm = dis_single('u"foo"[0]')
self.assertIn("(u'f')", asm)
self.assertNotIn('BINARY_SUBSCR', asm)
asm = dis_single('u"\u0061\uffff"[1]')
self.assertIn("(u'\\uffff')", asm)
self.assertNotIn('BINARY_SUBSCR', asm)
# invalid code doesn't get optimized
# out of range
asm = dis_single('u"fuu"[10]')
self.assertIn('BINARY_SUBSCR', asm)
# non-BMP char (see #5057)
asm = dis_single('u"\U00012345"[0]')
self.assertIn('BINARY_SUBSCR', 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,)
with test_support.check_py3k_warnings(
("backquote not supported", SyntaxWarning)):
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)