import dis
import re
import sys
from io import StringIO
import unittest
from math import copysign
from test.bytecode_helper import BytecodeTestCase
class TestTranforms(BytecodeTestCase):
def test_unot(self):
# UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE'
def unot(x):
if not x == 2:
del x
self.assertNotInBytecode(unot, 'UNARY_NOT')
self.assertNotInBytecode(unot, 'POP_JUMP_IF_FALSE')
self.assertInBytecode(unot, 'POP_JUMP_IF_TRUE')
def test_elim_inversion_of_is_or_in(self):
for line, cmp_op 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',),
):
code = compile(line, '', 'single')
self.assertInBytecode(code, 'COMPARE_OP', cmp_op)
def test_global_as_constant(self):
# LOAD_GLOBAL None/True/False --> LOAD_CONST None/True/False
def f(x):
None
None
return x
def g(x):
True
return x
def h(x):
False
return x
for func, elem in ((f, None), (g, True), (h, False)):
self.assertNotInBytecode(func, 'LOAD_GLOBAL')
self.assertInBytecode(func, 'LOAD_CONST', elem)
def f():
'Adding a docstring made this test fail in Py2.5.0'
return None
self.assertNotInBytecode(f, 'LOAD_GLOBAL')
self.assertInBytecode(f, 'LOAD_CONST', None)
def test_while_one(self):
# Skip over: LOAD_CONST trueconst POP_JUMP_IF_FALSE xx
def f():
while 1:
pass
return list
for elem in ('LOAD_CONST', 'POP_JUMP_IF_FALSE'):
self.assertNotInBytecode(f, elem)
for elem in ('JUMP_ABSOLUTE',):
self.assertInBytecode(f, elem)
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',),
):
code = compile(line,'','single')
self.assertInBytecode(code, elem)
self.assertNotInBytecode(code, 'BUILD_TUPLE')
self.assertNotInBytecode(code, 'UNPACK_TUPLE')
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)),
):
code = compile(line,'','single')
self.assertInBytecode(code, 'LOAD_CONST', elem)
self.assertNotInBytecode(code, 'BUILD_TUPLE')
# Long tuples should be folded too.
code = compile(repr(tuple(range(10000))),'','single')
self.assertNotInBytecode(code, 'BUILD_TUPLE')
# One LOAD_CONST for the tuple, one for the None return value
load_consts = [instr for instr in dis.get_instructions(code)
if instr.opname == 'LOAD_CONST']
self.assertEqual(len(load_consts), 2)
# 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_lists_of_constants(self):
for line, elem in (
# in/not in constants with BUILD_LIST should be folded to a tuple:
('a in [1,2,3]', (1, 2, 3)),
('a not in ["a","b","c"]', ('a', 'b', 'c')),
('a in [None, 1, None]', (None, 1, None)),
('a not in [(1, 2), 3, 4]', ((1, 2), 3, 4)),
):
code = compile(line, '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', elem)
self.assertNotInBytecode(code, 'BUILD_LIST')
def test_folding_of_sets_of_constants(self):
for line, elem in (
# in/not in constants with BUILD_SET should be folded to a frozenset:
('a in {1,2,3}', frozenset({1, 2, 3})),
('a not in {"a","b","c"}', frozenset({'a', 'c', 'b'})),
('a in {None, 1, None}', frozenset({1, None})),
('a not in {(1, 2), 3, 4}', frozenset({(1, 2), 3, 4})),
('a in {1, 2, 3, 3, 2, 1}', frozenset({1, 2, 3})),
):
code = compile(line, '', 'single')
self.assertNotInBytecode(code, 'BUILD_SET')
self.assertInBytecode(code, 'LOAD_CONST', elem)
# Ensure that the resulting code actually works:
def f(a):
return a in {1, 2, 3}
def g(a):
return a not in {1, 2, 3}
self.assertTrue(f(3))
self.assertTrue(not f(4))
self.assertTrue(not g(3))
self.assertTrue(g(4))
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
):
code = compile(line, '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', elem)
for instr in dis.get_instructions(code):
self.assertFalse(instr.opname.startswith('BINARY_'))
# Verify that unfoldables are skipped
code = compile('a=2+"b"', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', 2)
self.assertInBytecode(code, 'LOAD_CONST', 'b')
# Verify that large sequences do not result from folding
code = compile('a="x"*1000', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', 1000)
def test_binary_subscr_on_unicode(self):
# valid code get optimized
code = compile('"foo"[0]', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', 'f')
self.assertNotInBytecode(code, 'BINARY_SUBSCR')
code = compile('"\u0061\uffff"[1]', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', '\uffff')
self.assertNotInBytecode(code,'BINARY_SUBSCR')
# With PEP 393, non-BMP char get optimized
code = compile('"\U00012345"[0]', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', '\U00012345')
self.assertNotInBytecode(code, 'BINARY_SUBSCR')
# invalid code doesn't get optimized
# out of range
code = compile('"fuu"[10]', '', 'single')
self.assertInBytecode(code, 'BINARY_SUBSCR')
def test_folding_of_unaryops_on_constants(self):
for line, elem in (
('-0.5', -0.5), # unary negative
('-0.0', -0.0), # -0.0
('-(1.0-1.0)', -0.0), # -0.0 after folding
('-0', 0), # -0
('~-2', 1), # unary invert
('+1', 1), # unary positive
):
code = compile(line, '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', elem)
for instr in dis.get_instructions(code):
self.assertFalse(instr.opname.startswith('UNARY_'))
# Check that -0.0 works after marshaling
def negzero():
return -(1.0-1.0)
for instr in dis.get_instructions(code):
self.assertFalse(instr.opname.startswith('UNARY_'))
# Verify that unfoldables are skipped
for line, elem, opname in (
('-"abc"', 'abc', 'UNARY_NEGATIVE'),
('~"abc"', 'abc', 'UNARY_INVERT'),
):
code = compile(line, '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', elem)
self.assertInBytecode(code, opname)
def test_elim_extra_return(self):
# RETURN LOAD_CONST None RETURN --> RETURN
def f(x):
return x
self.assertNotInBytecode(f, 'LOAD_CONST', None)
returns = [instr for instr in dis.get_instructions(f)
if instr.opname == 'RETURN_VALUE']
self.assertEqual(len(returns), 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
self.assertNotInBytecode(f, 'JUMP_FORWARD')
self.assertNotInBytecode(f, 'JUMP_ABSOLUTE')
returns = [instr for instr in dis.get_instructions(f)
if instr.opname == 'RETURN_VALUE']
self.assertEqual(len(returns), 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
self.assertNotInBytecode(f, 'JUMP_FORWARD')
self.assertNotInBytecode(f, 'JUMP_ABSOLUTE')
returns = [instr for instr in dis.get_instructions(f)
if instr.opname == 'RETURN_VALUE']
self.assertEqual(len(returns), 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
self.assertNotInBytecode(f, 'JUMP_FORWARD')
# There should be one jump for the while loop.
returns = [instr for instr in dis.get_instructions(f)
if instr.opname == 'JUMP_ABSOLUTE']
self.assertEqual(len(returns), 1)
returns = [instr for instr in dis.get_instructions(f)
if instr.opname == 'RETURN_VALUE']
self.assertEqual(len(returns), 2)
def test_make_function_doesnt_bail(self):
def f():
def g()->1+1:
pass
return g
self.assertNotInBytecode(f, 'BINARY_ADD')
def test_constant_folding(self):
# Issue #11244: aggressive constant folding.
exprs = [
'3 * -5',
'-3 * 5',
'2 * (3 * 4)',
'(2 * 3) * 4',
'(-1, 2, 3)',
'(1, -2, 3)',
'(1, 2, -3)',
'(1, 2, -3) * 6',
'lambda x: x in {(3 * -5) + (-1 - 6), (1, -2, 3) * 2, None}',
]
for e in exprs:
code = compile(e, '', 'single')
for instr in dis.get_instructions(code):
self.assertFalse(instr.opname.startswith('UNARY_'))
self.assertFalse(instr.opname.startswith('BINARY_'))
self.assertFalse(instr.opname.startswith('BUILD_'))
class TestBuglets(unittest.TestCase):
def test_bug_11510(self):
# folded constant set optimization was commingled with the tuple
# unpacking optimization which would fail if the set had duplicate
# elements so that the set length was unexpected
def f():
x, y = {1, 1}
return x, y
with self.assertRaises(ValueError):
f()
def test_main(verbose=None):
import sys
from test import support
test_classes = (TestTranforms, TestBuglets)
support.run_unittest(*test_classes)
# verify reference counting
if verbose and hasattr(sys, 'gettotalrefcount'):
import gc
counts = [None] * 5
for i in range(len(counts)):
support.run_unittest(*test_classes)
gc.collect()
counts[i] = sys.gettotalrefcount()
print(counts)
if __name__ == "__main__":
test_main(verbose=True)