def test_conditional_a_la_pypy():
from xotl.ql import qst
# >>> dis.dis(compile('x and a or y', '', 'eval'))
# 1 0 LOAD_NAME 0 (x)
# 3 JUMP_IF_FALSE_OR_POP 9
# 6 LOAD_NAME 1 (a)
# >> 9 JUMP_IF_TRUE_OR_POP 15
# 12 LOAD_NAME 2 (y)
# >> 15 RETURN_VALUE
import types
from xotl.ql.revenge import Uncompyled
from xotl.ql.revenge.scanners import InstructionSetBuilder, label
builder = InstructionSetBuilder()
with builder() as Instruction:
Instruction(opname='LOAD_NAME', arg=0, argval='x', starts_line=1)
Instruction(opname='JUMP_IF_FALSE_OR_POP', arg=label('else'))
Instruction(opname='LOAD_NAME', arg=1, argval='a')
Instruction(label='else',
opname='JUMP_IF_TRUE_OR_POP', arg=label('out'))
Instruction(opname='LOAD_NAME', arg=2, argval='y')
Instruction(label='out',
opname='RETURN_VALUE')
code = builder.code
code = types.CodeType(0, 0, 0, 3, 0, code, (), ('x', 'a', 'y'),
(), '', '<module>', 1, b'')
u = Uncompyled(code)
assert u.safe_ast
expected = qst.parse('x and a or y')
assert u.qst == expected
def test_real_pypy_normalization():
from xotl.ql.revenge.scanners import InstructionSetBuilder, label
from xotl.ql.revenge.scanners import getscanner, without_nops
from xotl.ql.revenge.scanners import normalize_pypy_conditional
# The PyPy byte code for `a if x else y`:
builder = InstructionSetBuilder()
with builder() as Instruction:
Instruction(opname='LOAD_NAME',
arg=0, argval='x', argrepr='x',
starts_line=1, is_jump_target=False),
Instruction(opname='POP_JUMP_IF_FALSE',
arg=label('else y'), starts_line=None)
Instruction(opname='LOAD_NAME', arg=1,
argval='a', argrepr='a', starts_line=None)
Instruction(opname='RETURN_VALUE',
arg=None, argval=None, argrepr='', starts_line=None)
Instruction(label='else y',
opname='LOAD_NAME',
arg=2, argval='y', argrepr='y', starts_line=None),
Instruction(opname='RETURN_VALUE',
arg=None, argval=None, argrepr='',
starts_line=None)
expected_program = list(builder)
scanner = getscanner()
tokens, customize = scanner.disassemble(
compile('a if x else y', '', 'eval'),
normalize=(normalize_pypy_conditional, without_nops)
)
instructions = [token.instruction for token in tokens if token.instruction]
assert instructions == expected_program
def test_scanner_normalization_single_return():
from xotl.ql.revenge.scanners import InstructionSetBuilder, label
from xotl.ql.revenge.scanners import keep_single_return
builder = InstructionSetBuilder()
with builder() as Instruction:
Instruction(label='start',
opname='LOAD_NAME', arg=0,
argval='x', argrepr='x',
starts_line=1),
Instruction(opname='POP_JUMP_IF_FALSE', arg=label('back'),
starts_line=None),
Instruction(opname='LOAD_NAME', arg=1,
argval='a', argrepr='a',
starts_line=None),
Instruction(opname='RETURN_VALUE',
arg=None, argval=None, argrepr='',
starts_line=None),
Instruction(label='back',
opname='LOAD_NAME', arg=2,
argval='y', argrepr='y',
starts_line=None),
# Let's make some jumps here but to see other jumps are not affected.
# Since the return value above takes a single byte but the
# JUMP_FORWARD takes 3 bytes, all offsets below that point are to be
# shifted whereas those above will remain.
Instruction(opname='JUMP_ABSOLUTE', arg=label('back'),
starts_line=None)
Instruction(opname='JUMP_FORWARD', arg=label('next'),
starts_line=None),
Instruction(label='next',
opname='FOR_ITER', arg=label('start'), starts_line=None)
Instruction(opname='RETURN_VALUE', arg=None,
argval=None, argrepr='', starts_line=None)
original = list(builder)
builder = InstructionSetBuilder()
with builder() as Instruction:
Instruction(label='start',
opname='LOAD_NAME', arg=0,
argval='x', argrepr='x',
starts_line=1),
Instruction(opname='POP_JUMP_IF_FALSE', arg=label('back'),
starts_line=None),
Instruction(opname='LOAD_NAME', arg=1, argval='a', argrepr='a',
starts_line=None),
Instruction(opname='JUMP_FORWARD', arg=label('retval'),
starts_line=None),
Instruction(label='back',
opname='LOAD_NAME', arg=2,
argval='y', argrepr='y',
starts_line=None),
# Let's make loop here to the instruction just above but to see other
# jumps are not affected.
Instruction(opname='JUMP_ABSOLUTE', arg=label('back'),
starts_line=None)
Instruction(opname='JUMP_FORWARD', arg=label('next'),
starts_line=None),
Instruction(label='next',
opname='FOR_ITER', arg=label('start'), starts_line=None)
Instruction(label='retval',
opname='RETURN_VALUE', arg=None,
argval=None, argrepr='', starts_line=None)
expected = list(builder)
assert list(keep_single_return(original)) == expected
