def while_loop(self, instr, loop_block):
kw = dict(lineno=instr.lineno, col_offset=0)
loop_block_map = {instr.i: instr.op for instr in loop_block}
first_i = loop_block[0].i
func = lambda instr: instr.opname == 'JUMP_ABSOLUTE' and instr.oparg == first_i
body_index = rfind_index(loop_block[:-1], func)
if body_index is None:
const_while = True
body_index = len(loop_block) - 1
else:
if body_index + 1 < len(loop_block):
pop_block = loop_block[body_index + 1]
const_while = pop_block.opname != 'POP_BLOCK'
const_else = True
else:
const_while = True
const_else = False
if const_while:
test = _ast.Num(1, **kw)
body_ = self.decompile_block(loop_block[:body_index]).stmnt()
else_block = loop_block[body_index + 1:]
if else_block:
else_ = self.decompile_block(else_block).stmnt()
else:
else_ = []
else:
pop_block = loop_block[body_index + 1]
func = lambda instr: instr.opname in [
'POP_JUMP_IF_FALSE', 'POP_JUMP_IF_TRUE'
] and instr.oparg == pop_block.i
idx = rfind_index(loop_block[:body_index], func)
cond_block = loop_block[:idx]
iter_stmnt = self.decompile_block(cond_block).stmnt()
assert len(iter_stmnt) == 1
test = iter_stmnt[0]
body_ = self.decompile_block(loop_block[idx +
1:body_index]).stmnt()
else_block = loop_block[body_index + 2:]
if else_block:
else_ = self.decompile_block(else_block[:]).stmnt()
else:
else_ = []
while_ = _ast.While(test=test, body=body_, orelse=else_, **kw)
self.ast_stack.append(while_)
def while_stmt(test: _ast.expr, body: List[_ast.stmt]) -> _ast.While:
return _ast.While(test=test, body=body, orelse=[])
def _cfa(body, state, on_gen):
assert isinstance(on_gen, list)
for c in on_gen:
assert callable(c)
cfg = state.cfg
def make_connect(cur_bid):
assert isinstance(cur_bid, int)
def inner(new_bid):
assert isinstance(new_bid, int)
state.connect([cur_bid], [new_bid])
return inner
def push_block(block):
block_id = len(cfg.blocks)
assert block_id not in cfg.blocks
cfg.blocks[block_id] = block
for c in on_gen:
c(block_id)
return block_id
cur_block = []
for b in body:
if REDUCE_FORS_TO_WHILES and isinstance(b, _ast.For):
if isinstance(b.iter, _ast.Call) and isinstance(
b.iter.func,
_ast.Name) and b.iter.func.id in ("range", "xrange"):
if not b.iter.keywords and not b.iter.starargs and not b.iter.kwargs:
end_var = "__wfend_%d_%d_" % (b.lineno, b.col_offset)
iter_var = "__wfiter_%d_%d_" % (b.lineno, b.col_offset)
if len(b.iter.args) in (1, 2):
if len(b.iter.args) == 1:
start = _ast.Num(0)
end = b.iter.args[0]
elif len(b.iter.args) == 2:
start = b.iter.args[0]
end = b.iter.args[1]
else:
start = b.iter.args[0]
end = b.iter.args[1]
cur_block.append(
_ast.Assign([
_ast.Name(
iter_var, _ast.Store(), not_real=True)
],
start,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True))
cur_block.append(
_ast.Assign([
_ast.Name(end_var, _ast.Store(), not_real=True)
],
end,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True))
body = [
_ast.Assign([b.target],
_ast.Name(iter_var,
_ast.Load(),
not_real=True),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True),
_ast.Assign([
_ast.Name(
iter_var, _ast.Store(), not_real=True)
],
_ast.BinOp(
_ast.Name(iter_var,
_ast.Load(),
not_real=True),
_ast.Add(), _ast.Num(1)),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
] + b.body
b = _ast.While(_ast.Compare(
_ast.Name(iter_var, _ast.Load(),
not_real=True), [_ast.Lt()],
[_ast.Name(end_var, _ast.Load(), not_real=True)],
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True),
body,
b.orelse,
not_real=True)
if isinstance(b, (
_ast.Assign,
_ast.AugAssign,
_ast.ClassDef,
_ast.Delete,
_ast.Exec,
_ast.Expr,
_ast.FunctionDef,
_ast.Global,
_ast.Import,
_ast.ImportFrom,
_ast.Print,
_ast.Pass,
)):
cur_block.append(b)
elif isinstance(b, _ast.Assert):
cur_block.append(b)
if isinstance(b.test, _ast.Call) and isinstance(
b.test.func, _ast.Name
) and b.test.func.id == "isinstance" and isinstance(
b.test.args[0], _ast.Name) and isinstance(
b.test.args[1], _ast.Name):
varname = b.test.args[0].id
cast = _ast.Call(_ast.Name(
"__cast__", _ast.Load(), not_real=True, **pos(b)), [
_ast.Name(
varname, _ast.Store(), not_real=True, **pos(b)),
b.test.args[1]
], [],
None,
None,
not_real=True,
**pos(b))
assign = _ast.Assign([
_ast.Name(varname, _ast.Store(), not_real=True, **pos(b))
],
cast,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
cur_block.append(assign)
elif isinstance(b, (_ast.Break, _ast.Continue)):
f = state.add_break if isinstance(
b, _ast.Break) else state.add_continue
if cur_block:
j = Jump()
cur_block.append(j)
block_id = push_block(cur_block)
f(j.set_dest)
f(make_connect(block_id))
else:
for c in on_gen:
f(c)
return []
elif isinstance(b, _ast.If):
br = Branch(b.test, lineno=b.lineno)
cur_block.append(br)
next_block = push_block(cur_block)
on_gen = None # make sure this doesn't get used
cur_block = []
gen_true = [br.set_true, make_connect(next_block)]
gen_false = [br.set_false, make_connect(next_block)]
if ENFORCE_NO_MULTIMULTI:
on_gen = gen_true
j1 = Jump()
gen_true = [make_connect(push_block([j1])), j1.set_dest]
on_gen = gen_false
j2 = Jump()
gen_false = [make_connect(push_block([j2])), j2.set_dest]
on_gen = None
assert b.body
body = b.body
if isinstance(b.test, _ast.Call) and isinstance(
b.test.func, _ast.Name
) and b.test.func.id == "isinstance" and isinstance(
b.test.args[0], _ast.Name) and isinstance(
b.test.args[1], _ast.Name):
varname = b.test.args[0].id
cast = _ast.Call(_ast.Name(
"__cast__", _ast.Load(), not_real=True, **pos(b)), [
_ast.Name(
varname, _ast.Store(), not_real=True, **pos(b)),
b.test.args[1]
], [],
None,
None,
not_real=True,
**pos(b))
assign = _ast.Assign([
_ast.Name(varname, _ast.Store(), not_real=True, **pos(b))
],
cast,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
body = [assign] + body
if ADD_IF_ASSERTS:
body = [_ast.Assert(b.test, None, not_real=True, **pos(b))
] + body
ending_gen = _cfa(body, state, gen_true)
if b.orelse:
ending_gen += _cfa(b.orelse, state, gen_false)
else:
ending_gen += gen_false
on_gen = ending_gen
if not on_gen and PRUNE_UNREACHABLE_BLOCKS:
return []
elif isinstance(b, _ast.TryExcept):
j = Jump()
cur_block.append(j)
next_block = push_block(cur_block)
on_gen = [j.set_dest, make_connect(next_block)]
cur_block = []
on_gen = _cfa(b.body, state, on_gen)
# Set this to evaluate a string to try to defeat simple flow analysis
br = Branch(_ast.Str("nonzero"))
next_block = push_block([br])
on_except = [br.set_false, make_connect(next_block)]
on_fine = [br.set_true, make_connect(next_block)]
assert len(b.handlers) >= 1
# for handler in b.handlers:
# on_except = _cfa(b.handlers[0].body, state, on_except)
if b.orelse:
on_fine = _cfa(b.orelse, state, on_fine)
if ENFORCE_NO_MULTIMULTI:
j = Jump()
on_gen = on_fine
next_block = push_block([j])
on_fine = [j.set_dest, make_connect(next_block)]
j = Jump()
on_gen = on_except
next_block = push_block([j])
on_except = [j.set_dest, make_connect(next_block)]
on_gen = on_fine + on_except
cur_block = []
elif isinstance(b, _ast.TryFinally):
j = Jump()
cur_block.append(j)
next_block = push_block(cur_block)
on_gen = [j.set_dest, make_connect(next_block)]
cur_block = []
on_gen = _cfa(b.body, state, on_gen)
on_gen = _cfa(b.finalbody, state, on_gen)
elif isinstance(b, _ast.While):
# This could also be architected as having no extra block and having two jump statements, but I don't like that
if cur_block:
j = Jump()
cur_block.append(j)
on_gen = [make_connect(push_block(cur_block)), j.set_dest]
cur_block = []
always_true = False
always_false = False
if isinstance(b.test, _ast.Name):
if b.test.id == "True":
always_true = True
elif b.test.id == "False":
always_false = True
elif isinstance(b.test, _ast.Num):
if b.test.n:
always_true = True
else:
always_false = True
if always_true:
br = Jump()
on_true = br.set_dest
elif always_false:
br = Jump()
on_false = br.set_dest
else:
br = Branch(b.test)
on_true = br.set_true
on_false = br.set_false
init_id = push_block([br])
on_gen = None
assert cur_block == [] # just checking
if not always_false:
gen_true = [on_true, make_connect(init_id)]
if not always_true:
gen_false = [on_false, make_connect(init_id)]
if ENFORCE_NO_MULTIMULTI:
if not always_false:
on_gen = gen_true
j1 = Jump()
gen_true = [make_connect(push_block([j1])), j1.set_dest]
if not always_true:
on_gen = gen_false
j2 = Jump()
gen_false = [make_connect(push_block([j2])), j2.set_dest]
on_gen = None
ending_gen = []
if not always_false:
state.push_loop()
assert b.body
loop_ending_gen = _cfa(b.body, state, gen_true)
loop_ending_gen += state.get_continues()
for c in loop_ending_gen:
c(init_id)
ending_gen = state.get_breaks()
state.pop_loop()
if not always_true:
if b.orelse:
ending_gen += _cfa(b.orelse, state, gen_false)
else:
ending_gen += gen_false
on_gen = ending_gen
if not on_gen and PRUNE_UNREACHABLE_BLOCKS:
return []
elif isinstance(b, _ast.For):
iter_func = _ast.Attribute(b.iter,
"__iter__",
_ast.Load(),
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
iter_call = _ast.Call(iter_func, [], [],
None,
None,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
# iter_var = _make_temp_name()
iter_var = "__foriter_%d_%d_" % (b.lineno, b.col_offset)
iter_assign = _ast.Assign(
[_ast.Name(iter_var, _ast.Store(), not_real=True, **pos(b))],
iter_call,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
cur_block.append(iter_assign)
j = Jump()
cur_block.append(j)
on_gen = [make_connect(push_block(cur_block)), j.set_dest]
cur_block = []
br = Branch(
HasNext(
_ast.Name(iter_var, _ast.Load(), not_real=True, **pos(b)),
**pos(b)), **pos(b))
init_id = push_block([br])
on_gen = None
assert cur_block == [] # just checking
gen_true = [br.set_true, make_connect(init_id)]
gen_false = [br.set_false, make_connect(init_id)]
if ENFORCE_NO_MULTIMULTI:
on_gen = gen_true
j1 = Jump()
gen_true = [make_connect(push_block([j1])), j1.set_dest]
on_gen = gen_false
j2 = Jump()
gen_false = [make_connect(push_block([j2])), j2.set_dest]
on_gen = None
ending_gen = []
state.push_loop()
next_func = _ast.Attribute(_ast.Name(iter_var,
_ast.Load(),
not_real=True,
**pos(b)),
"next",
_ast.Load(),
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
next = _ast.Call(next_func, [], [],
None,
None,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
next_assign = _ast.Assign([b.target],
next,
not_real=True,
lineno=b.lineno,
col_offset=b.col_offset)
next_iter_gen = _cfa([next_assign] + b.body, state, gen_true)
next_iter_gen += state.get_continues()
for c in next_iter_gen:
c(init_id)
loop_done_gen = list(state.get_breaks())
state.pop_loop()
if b.orelse:
# if b.orelse and loop_ending_blocks:
loop_done_gen += _cfa(b.orelse, state, gen_false)
else:
loop_done_gen += gen_false
on_gen = loop_done_gen
if not on_gen and PRUNE_UNREACHABLE_BLOCKS:
return []
elif isinstance(b, (_ast.Return, _ast.Raise)):
cur_block.append(b)
block_id = push_block(cur_block)
state.returns.append(make_connect(block_id))
return []
elif isinstance(b, _ast.With):
# XXX totally ignores the functionality of with statements
# Have to save the context manager because the expression might not be valid later
mgr_name = "__mgr_%s_%s_" % (b.lineno, b.col_offset)
save_mgr = _ast.Assign([
_ast.Name(mgr_name,
_ast.Store(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
],
b.context_expr,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
enter_func = _ast.Attribute(_ast.Name(mgr_name,
_ast.Load(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True),
"__enter__",
_ast.Load(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
bind = _ast.Call(enter_func, [], [],
None,
None,
lineno=b.lineno,
col_offset="__enter__()",
not_real=True)
if b.optional_vars:
assert isinstance(b.optional_vars, _ast.AST)
init = _ast.Assign([b.optional_vars],
bind,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
else:
init = _ast.Expr(bind,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
exit_func = _ast.Attribute(_ast.Name(mgr_name,
_ast.Load(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True),
"__exit__",
_ast.Load(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
if SIMPLE_WITH_EXIT:
exit_call = _ast.Call(exit_func, [], [],
None,
None,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
else:
none_ = _ast.Name("None",
_ast.Load(),
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
exit_call = _ast.Call(exit_func, [none_, none_, none_], [],
None,
None,
lineno=b.lineno,
col_offset=b.col_offset,
not_real=True)
exit = _ast.Expr(exit_call,
lineno=b.lineno,
col_offset="__exit__()",
not_real=True)
cur_block.extend([save_mgr, init])
j = Jump()
cur_block.append(j)
next_block = push_block(cur_block)
on_gen = [j.set_dest, make_connect(next_block)]
cur_block = []
body = b.body + [exit]
next_gen = _cfa(body, state, on_gen)
on_gen = next_gen
else:
raise Exception(b)
if cur_block:
j = Jump()
cur_block.append(j)
next = push_block(cur_block)
return [j.set_dest, make_connect(next)]
return on_gen
return on_gen