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) |