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 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) 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) 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() if __name__ == "__main__": unittest.main()