| import dis | |
| import unittest | |
| from test.support.bytecode_helper import BytecodeTestCase | |
| def count_instr_recursively(f, opname): | |
| count = 0 | |
| for instr in dis.get_instructions(f): | |
| if instr.opname == opname: | |
| count += 1 | |
| if hasattr(f, '__code__'): | |
| f = f.__code__ | |
| for c in f.co_consts: | |
| if hasattr(c, 'co_code'): | |
| count += count_instr_recursively(c, opname) | |
| return count | |
| class TestTranforms(BytecodeTestCase): | |
| def check_jump_targets(self, code): | |
| instructions = list(dis.get_instructions(code)) | |
| targets = {instr.offset: instr for instr in instructions} | |
| for instr in instructions: | |
| if 'JUMP_' not in instr.opname: | |
| continue | |
| tgt = targets[instr.argval] | |
| # jump to unconditional jump | |
| if tgt.opname in ('JUMP_ABSOLUTE', 'JUMP_FORWARD'): | |
| self.fail(f'{instr.opname} at {instr.offset} ' | |
| f'jumps to {tgt.opname} at {tgt.offset}') | |
| # unconditional jump to RETURN_VALUE | |
| if (instr.opname in ('JUMP_ABSOLUTE', 'JUMP_FORWARD') and | |
| tgt.opname == 'RETURN_VALUE'): | |
| self.fail(f'{instr.opname} at {instr.offset} ' | |
| f'jumps to {tgt.opname} at {tgt.offset}') | |
| # JUMP_IF_*_OR_POP jump to conditional jump | |
| if '_OR_POP' in instr.opname and 'JUMP_IF_' in tgt.opname: | |
| self.fail(f'{instr.opname} at {instr.offset} ' | |
| f'jumps to {tgt.opname} at {tgt.offset}') | |
| def check_lnotab(self, code): | |
| "Check that the lnotab byte offsets are sensible." | |
| code = dis._get_code_object(code) | |
| lnotab = list(dis.findlinestarts(code)) | |
| # Don't bother checking if the line info is sensible, because | |
| # most of the line info we can get at comes from lnotab. | |
| min_bytecode = min(t[0] for t in lnotab) | |
| max_bytecode = max(t[0] for t in lnotab) | |
| self.assertGreaterEqual(min_bytecode, 0) | |
| self.assertLess(max_bytecode, len(code.co_code)) | |
| # This could conceivably test more (and probably should, as there | |
| # aren't very many tests of lnotab), if peepholer wasn't scheduled | |
| # to be replaced anyway. | |
| 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') | |
| self.check_lnotab(unot) | |
| def test_elim_inversion_of_is_or_in(self): | |
| for line, cmp_op, invert in ( | |
| ('not a is b', 'IS_OP', 1,), | |
| ('not a is not b', 'IS_OP', 0,), | |
| ('not a in b', 'CONTAINS_OP', 1,), | |
| ('not a not in b', 'CONTAINS_OP', 0,), | |
| ): | |
| code = compile(line, '', 'single') | |
| self.assertInBytecode(code, cmp_op, invert) | |
| self.check_lnotab(code) | |
| def test_global_as_constant(self): | |
| # LOAD_GLOBAL None/True/False --> LOAD_CONST None/True/False | |
| def f(): | |
| x = None | |
| x = 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) | |
| self.check_lnotab(func) | |
| 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) | |
| self.check_lnotab(f) | |
| 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) | |
| self.check_lnotab(f) | |
| 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') | |
| self.check_lnotab(code) | |
| 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') | |
| self.check_lnotab(code) | |
| # 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) | |
| self.check_lnotab(code) | |
| # 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, | |
| ],) | |
| self.check_lnotab(crater) | |
| 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') | |
| self.check_lnotab(code) | |
| 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) | |
| self.check_lnotab(code) | |
| # 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.check_lnotab(f) | |
| self.assertTrue(not g(3)) | |
| self.assertTrue(g(4)) | |
| self.check_lnotab(g) | |
| 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_')) | |
| self.check_lnotab(code) | |
| # Verify that unfoldables are skipped | |
| code = compile('a=2+"b"', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', 2) | |
| self.assertInBytecode(code, 'LOAD_CONST', 'b') | |
| self.check_lnotab(code) | |
| # Verify that large sequences do not result from folding | |
| code = compile('a="x"*10000', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', 10000) | |
| self.assertNotIn("x"*10000, code.co_consts) | |
| self.check_lnotab(code) | |
| code = compile('a=1<<1000', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', 1000) | |
| self.assertNotIn(1<<1000, code.co_consts) | |
| self.check_lnotab(code) | |
| code = compile('a=2**1000', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', 1000) | |
| self.assertNotIn(2**1000, code.co_consts) | |
| self.check_lnotab(code) | |
| 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') | |
| self.check_lnotab(code) | |
| code = compile('"\u0061\uffff"[1]', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', '\uffff') | |
| self.assertNotInBytecode(code,'BINARY_SUBSCR') | |
| self.check_lnotab(code) | |
| # With PEP 393, non-BMP char get optimized | |
| code = compile('"\U00012345"[0]', '', 'single') | |
| self.assertInBytecode(code, 'LOAD_CONST', '\U00012345') | |
| self.assertNotInBytecode(code, 'BINARY_SUBSCR') | |
| self.check_lnotab(code) | |
| # invalid code doesn't get optimized | |
| # out of range | |
| code = compile('"fuu"[10]', '', 'single') | |
| self.assertInBytecode(code, 'BINARY_SUBSCR') | |
| self.check_lnotab(code) | |
| 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_')) | |
| self.check_lnotab(code) | |
| # Check that -0.0 works after marshaling | |
| def negzero(): | |
| return -(1.0-1.0) | |
| for instr in dis.get_instructions(negzero): | |
| self.assertFalse(instr.opname.startswith('UNARY_')) | |
| self.check_lnotab(negzero) | |
| # 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) | |
| self.check_lnotab(code) | |
| 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) | |
| self.check_lnotab(f) | |
| def test_elim_jump_to_return(self): | |
| # JUMP_FORWARD to RETURN --> RETURN | |
| def f(cond, true_value, false_value): | |
| # Intentionally use two-line expression to test issue37213. | |
| return (true_value if cond | |
| else false_value) | |
| self.check_jump_targets(f) | |
| 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) | |
| self.check_lnotab(f) | |
| def test_elim_jump_to_uncond_jump(self): | |
| # POP_JUMP_IF_FALSE to JUMP_FORWARD --> POP_JUMP_IF_FALSE to non-jump | |
| def f(): | |
| if a: | |
| # Intentionally use two-line expression to test issue37213. | |
| if (c | |
| or d): | |
| foo() | |
| else: | |
| baz() | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| def test_elim_jump_to_uncond_jump2(self): | |
| # POP_JUMP_IF_FALSE to JUMP_ABSOLUTE --> POP_JUMP_IF_FALSE to non-jump | |
| def f(): | |
| while a: | |
| # Intentionally use two-line expression to test issue37213. | |
| if (c | |
| or d): | |
| a = foo() | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| def test_elim_jump_to_uncond_jump3(self): | |
| # Intentionally use two-line expressions to test issue37213. | |
| # JUMP_IF_FALSE_OR_POP to JUMP_IF_FALSE_OR_POP --> JUMP_IF_FALSE_OR_POP to non-jump | |
| def f(a, b, c): | |
| return ((a and b) | |
| and c) | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| self.assertEqual(count_instr_recursively(f, 'JUMP_IF_FALSE_OR_POP'), 2) | |
| # JUMP_IF_TRUE_OR_POP to JUMP_IF_TRUE_OR_POP --> JUMP_IF_TRUE_OR_POP to non-jump | |
| def f(a, b, c): | |
| return ((a or b) | |
| or c) | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| self.assertEqual(count_instr_recursively(f, 'JUMP_IF_TRUE_OR_POP'), 2) | |
| # JUMP_IF_FALSE_OR_POP to JUMP_IF_TRUE_OR_POP --> POP_JUMP_IF_FALSE to non-jump | |
| def f(a, b, c): | |
| return ((a and b) | |
| or c) | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| self.assertNotInBytecode(f, 'JUMP_IF_FALSE_OR_POP') | |
| self.assertInBytecode(f, 'JUMP_IF_TRUE_OR_POP') | |
| self.assertInBytecode(f, 'POP_JUMP_IF_FALSE') | |
| # JUMP_IF_TRUE_OR_POP to JUMP_IF_FALSE_OR_POP --> POP_JUMP_IF_TRUE to non-jump | |
| def f(a, b, c): | |
| return ((a or b) | |
| and c) | |
| self.check_jump_targets(f) | |
| self.check_lnotab(f) | |
| self.assertNotInBytecode(f, 'JUMP_IF_TRUE_OR_POP') | |
| self.assertInBytecode(f, 'JUMP_IF_FALSE_OR_POP') | |
| self.assertInBytecode(f, 'POP_JUMP_IF_TRUE') | |
| 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.assertLessEqual(len(returns), 6) | |
| self.check_lnotab(f) | |
| 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.assertLessEqual(len(returns), 2) | |
| self.check_lnotab(f) | |
| def test_make_function_doesnt_bail(self): | |
| def f(): | |
| def g()->1+1: | |
| pass | |
| return g | |
| self.assertNotInBytecode(f, 'BINARY_ADD') | |
| self.check_lnotab(f) | |
| 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_')) | |
| self.check_lnotab(code) | |
| def test_in_literal_list(self): | |
| def containtest(): | |
| return x in [a, b] | |
| self.assertEqual(count_instr_recursively(containtest, 'BUILD_LIST'), 0) | |
| self.check_lnotab(containtest) | |
| def test_iterate_literal_list(self): | |
| def forloop(): | |
| for x in [a, b]: | |
| pass | |
| self.assertEqual(count_instr_recursively(forloop, 'BUILD_LIST'), 0) | |
| self.check_lnotab(forloop) | |
| def test_condition_with_binop_with_bools(self): | |
| def f(): | |
| if True or False: | |
| return 1 | |
| return 0 | |
| self.assertEqual(f(), 1) | |
| self.check_lnotab(f) | |
| def test_if_with_if_expression(self): | |
| # Check bpo-37289 | |
| def f(x): | |
| if (True if x else False): | |
| return True | |
| return False | |
| self.assertTrue(f(True)) | |
| self.check_lnotab(f) | |
| def test_trailing_nops(self): | |
| # Check the lnotab of a function that even after trivial | |
| # optimization has trailing nops, which the lnotab adjustment has to | |
| # handle properly (bpo-38115). | |
| def f(x): | |
| while 1: | |
| return 3 | |
| while 1: | |
| return 5 | |
| return 6 | |
| self.check_lnotab(f) | |
| def test_assignment_idiom_in_comprehensions(self): | |
| def listcomp(): | |
| return [y for x in a for y in [f(x)]] | |
| self.assertEqual(count_instr_recursively(listcomp, 'FOR_ITER'), 1) | |
| def setcomp(): | |
| return {y for x in a for y in [f(x)]} | |
| self.assertEqual(count_instr_recursively(setcomp, 'FOR_ITER'), 1) | |
| def dictcomp(): | |
| return {y: y for x in a for y in [f(x)]} | |
| self.assertEqual(count_instr_recursively(dictcomp, 'FOR_ITER'), 1) | |
| def genexpr(): | |
| return (y for x in a for y in [f(x)]) | |
| self.assertEqual(count_instr_recursively(genexpr, 'FOR_ITER'), 1) | |
| 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_bpo_42057(self): | |
| for i in range(10): | |
| try: | |
| raise Exception | |
| except Exception or Exception: | |
| pass | |
| if __name__ == "__main__": | |
| unittest.main() |