| import dis |
| import sys |
| from io 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 JUMP_IF_FALSE POP_TOP --> JUMP_IF_TRUE POP_TOP' |
| def unot(x): |
| if not x == 2: |
| del x |
| asm = disassemble(unot) |
| for elem in ('UNARY_NOT', 'JUMP_IF_FALSE'): |
| self.assert_(elem not in asm) |
| for elem in ('JUMP_IF_TRUE', 'POP_TOP'): |
| self.assert_(elem in 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.assert_(elem in asm) |
| |
| 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, name in ((f, 'None'), (g, 'True'), (h, 'False')): |
| asm = disassemble(func) |
| for elem in ('LOAD_GLOBAL',): |
| self.assert_(elem not in asm) |
| for elem in ('LOAD_CONST', '('+name+')'): |
| self.assert_(elem in asm) |
| def f(): |
| 'Adding a docstring made this test fail in Py2.5.0' |
| return None |
| self.assert_('LOAD_CONST' in disassemble(f)) |
| self.assert_('LOAD_GLOBAL' not in disassemble(f)) |
| |
| def test_while_one(self): |
| # Skip over: LOAD_CONST trueconst JUMP_IF_FALSE xx POP_TOP |
| def f(): |
| while 1: |
| pass |
| return list |
| asm = disassemble(f) |
| for elem in ('LOAD_CONST', 'JUMP_IF_FALSE'): |
| self.assert_(elem not in asm) |
| for elem in ('JUMP_ABSOLUTE',): |
| self.assert_(elem in 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.assert_(elem in asm) |
| self.assert_('BUILD_TUPLE' not in asm) |
| self.assert_('UNPACK_TUPLE' not in 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.assert_(elem in asm) |
| self.assert_('BUILD_TUPLE' not in 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.assert_(elem in asm, asm) |
| self.assert_('BINARY_' not in asm) |
| |
| # Verify that unfoldables are skipped |
| asm = dis_single('a=2+"b"') |
| self.assert_('(2)' in asm) |
| self.assert_("('b')" in asm) |
| |
| # Verify that large sequences do not result from folding |
| asm = dis_single('a="x"*1000') |
| self.assert_('(1000)' in asm) |
| |
| def test_folding_of_unaryops_on_constants(self): |
| for line, elem in ( |
| ('-0.5', '(-0.5)'), # unary negative |
| ('~-2', '(1)'), # unary invert |
| ): |
| asm = dis_single(line) |
| self.assert_(elem in asm, asm) |
| self.assert_('UNARY_' not in asm) |
| |
| # Verify that unfoldables are skipped |
| for line, elem in ( |
| ('-"abc"', "('abc')"), # unary negative |
| ('~"abc"', "('abc')"), # unary invert |
| ): |
| asm = dis_single(line) |
| self.assert_(elem in asm, asm) |
| self.assert_('UNARY_' in asm) |
| |
| def test_elim_extra_return(self): |
| # RETURN LOAD_CONST None RETURN --> RETURN |
| def f(x): |
| return x |
| asm = disassemble(f) |
| self.assert_('LOAD_CONST' not in asm) |
| self.assert_('(None)' not in 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.assert_('JUMP_FORWARD' not in asm) |
| self.assert_('JUMP_ABSOLUTE' not in 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.assert_('JUMP_FORWARD' not in asm) |
| self.assert_('JUMP_ABSOLUTE' not in 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.assert_('JUMP_FORWARD' not in 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_make_function_doesnt_bail(self): |
| def f(): |
| def g()->1+1: |
| pass |
| return g |
| asm = disassemble(f) |
| self.assert_('BINARY_ADD' not in asm) |
| |
| |
| def test_main(verbose=None): |
| import sys |
| from test import support |
| test_classes = (TestTranforms,) |
| 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) |