def __init__(self, stmt, context):
self.stmt = stmt
self.context = context
self.stmt_table = {
ast.Expr: self.expr,
ast.Pass: self.parse_pass,
ast.AnnAssign: self.ann_assign,
ast.Assign: self.assign,
ast.If: self.parse_if,
ast.Call: self.call,
ast.Assert: self.parse_assert,
ast.For: self.parse_for,
ast.AugAssign: self.aug_assign,
ast.Break: self.parse_break,
ast.Return: self.parse_return,
}
stmt_type = self.stmt.__class__
if stmt_type in self.stmt_table:
self.lll_node = self.stmt_table[stmt_type]()
elif isinstance(stmt, ast.Name) and stmt.id == "throw":
self.lll_node = LLLnode.from_list(['assert', 0], typ=None, pos=getpos(stmt))
else:
raise StructureException("Unsupported statement type", stmt)
python类Pass()的实例源码
def test_classdef(self):
def cls(bases=None, keywords=None, starargs=None, kwargs=None,
body=None, decorator_list=None):
if bases is None:
bases = []
if keywords is None:
keywords = []
if body is None:
body = [ast.Pass()]
if decorator_list is None:
decorator_list = []
return ast.ClassDef("myclass", bases, keywords, starargs,
kwargs, body, decorator_list)
self.stmt(cls(bases=[ast.Name("x", ast.Store())]),
"must have Load context")
self.stmt(cls(keywords=[ast.keyword("x", ast.Name("x", ast.Store()))]),
"must have Load context")
self.stmt(cls(starargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(kwargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(body=[]), "empty body on ClassDef")
self.stmt(cls(body=[None]), "None disallowed")
self.stmt(cls(decorator_list=[ast.Name("x", ast.Store())]),
"must have Load context")
def test_try(self):
p = ast.Pass()
t = ast.Try([], [], [], [p])
self.stmt(t, "empty body on Try")
t = ast.Try([ast.Expr(ast.Name("x", ast.Store()))], [], [], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], [], [], [])
self.stmt(t, "Try has neither except handlers nor finalbody")
t = ast.Try([p], [], [p], [p])
self.stmt(t, "Try has orelse but no except handlers")
t = ast.Try([p], [ast.ExceptHandler(None, "x", [])], [], [])
self.stmt(t, "empty body on ExceptHandler")
e = [ast.ExceptHandler(ast.Name("x", ast.Store()), "y", [p])]
self.stmt(ast.Try([p], e, [], []), "must have Load context")
e = [ast.ExceptHandler(None, "x", [p])]
t = ast.Try([p], e, [ast.Expr(ast.Name("x", ast.Store()))], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], e, [p], [ast.Expr(ast.Name("x", ast.Store()))])
self.stmt(t, "must have Load context")
def test_classdef(self):
def cls(bases=None, keywords=None, starargs=None, kwargs=None,
body=None, decorator_list=None):
if bases is None:
bases = []
if keywords is None:
keywords = []
if body is None:
body = [ast.Pass()]
if decorator_list is None:
decorator_list = []
return ast.ClassDef("myclass", bases, keywords, starargs,
kwargs, body, decorator_list)
self.stmt(cls(bases=[ast.Name("x", ast.Store())]),
"must have Load context")
self.stmt(cls(keywords=[ast.keyword("x", ast.Name("x", ast.Store()))]),
"must have Load context")
self.stmt(cls(starargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(kwargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(body=[]), "empty body on ClassDef")
self.stmt(cls(body=[None]), "None disallowed")
self.stmt(cls(decorator_list=[ast.Name("x", ast.Store())]),
"must have Load context")
def test_try(self):
p = ast.Pass()
t = ast.Try([], [], [], [p])
self.stmt(t, "empty body on Try")
t = ast.Try([ast.Expr(ast.Name("x", ast.Store()))], [], [], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], [], [], [])
self.stmt(t, "Try has neither except handlers nor finalbody")
t = ast.Try([p], [], [p], [p])
self.stmt(t, "Try has orelse but no except handlers")
t = ast.Try([p], [ast.ExceptHandler(None, "x", [])], [], [])
self.stmt(t, "empty body on ExceptHandler")
e = [ast.ExceptHandler(ast.Name("x", ast.Store()), "y", [p])]
self.stmt(ast.Try([p], e, [], []), "must have Load context")
e = [ast.ExceptHandler(None, "x", [p])]
t = ast.Try([p], e, [ast.Expr(ast.Name("x", ast.Store()))], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], e, [p], [ast.Expr(ast.Name("x", ast.Store()))])
self.stmt(t, "must have Load context")
def add_init_if_not_existing(class_node):
"""Add a default empty __init__ function if it doesn't exist in the class node"""
for stmt in class_node.body:
if isinstance(stmt, ast.FunctionDef) and stmt.name == "__init__":
return
class_node.body.append(ast.FunctionDef(
name="__init__",
args=ast.arguments(
args=[ast.arg(arg="self", annotation=None, lineno=class_node.lineno)],
vararg=None,
kwonlyargs=[],
kw_defaults=[],
kwarg=None,
defaults=[]
),
body=[ast.Pass()],
decorator_list=[],
returns=None,
lineno=class_node.lineno
))
def mutate_unpack(self, node):
target = node.targets[0]
value = node.value
new_targets = []
new_values = []
for target_element, value_element in zip(target.elts, value.elts):
if not self.is_overridden(node, getattr(target_element, 'id', None)):
new_targets.append(target_element)
new_values.append(value_element)
if len(new_targets) == len(target.elts):
raise MutationResign()
if not new_targets:
return ast.Pass()
elif len(new_targets) == 1:
node.targets = new_targets
node.value = new_values[0]
return node
else:
target.elts = new_targets
value.elts = new_values
return node
def get_coverable_nodes(cls):
return {
ast.Assert,
ast.Assign,
ast.AugAssign,
ast.Break,
ast.Continue,
ast.Delete,
ast.Expr,
ast.Global,
ast.Import,
ast.ImportFrom,
ast.Nonlocal,
ast.Pass,
ast.Raise,
ast.Return,
ast.FunctionDef,
ast.ClassDef,
ast.TryExcept,
ast.TryFinally,
ast.ExceptHandler,
ast.If,
ast.For,
ast.While,
}
def get_coverable_nodes(cls):
return {
ast.Assert,
ast.Assign,
ast.AugAssign,
ast.Break,
ast.Continue,
ast.Delete,
ast.Expr,
ast.Global,
ast.Import,
ast.ImportFrom,
ast.Nonlocal,
ast.Pass,
ast.Raise,
ast.Return,
ast.ClassDef,
ast.FunctionDef,
ast.Try,
ast.ExceptHandler,
ast.If,
ast.For,
ast.While,
}
def test_classdef(self):
def cls(bases=None, keywords=None, starargs=None, kwargs=None,
body=None, decorator_list=None):
if bases is None:
bases = []
if keywords is None:
keywords = []
if body is None:
body = [ast.Pass()]
if decorator_list is None:
decorator_list = []
return ast.ClassDef("myclass", bases, keywords, starargs,
kwargs, body, decorator_list)
self.stmt(cls(bases=[ast.Name("x", ast.Store())]),
"must have Load context")
self.stmt(cls(keywords=[ast.keyword("x", ast.Name("x", ast.Store()))]),
"must have Load context")
self.stmt(cls(starargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(kwargs=ast.Name("x", ast.Store())),
"must have Load context")
self.stmt(cls(body=[]), "empty body on ClassDef")
self.stmt(cls(body=[None]), "None disallowed")
self.stmt(cls(decorator_list=[ast.Name("x", ast.Store())]),
"must have Load context")
def test_try(self):
p = ast.Pass()
t = ast.Try([], [], [], [p])
self.stmt(t, "empty body on Try")
t = ast.Try([ast.Expr(ast.Name("x", ast.Store()))], [], [], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], [], [], [])
self.stmt(t, "Try has neither except handlers nor finalbody")
t = ast.Try([p], [], [p], [p])
self.stmt(t, "Try has orelse but no except handlers")
t = ast.Try([p], [ast.ExceptHandler(None, "x", [])], [], [])
self.stmt(t, "empty body on ExceptHandler")
e = [ast.ExceptHandler(ast.Name("x", ast.Store()), "y", [p])]
self.stmt(ast.Try([p], e, [], []), "must have Load context")
e = [ast.ExceptHandler(None, "x", [p])]
t = ast.Try([p], e, [ast.Expr(ast.Name("x", ast.Store()))], [p])
self.stmt(t, "must have Load context")
t = ast.Try([p], e, [p], [ast.Expr(ast.Name("x", ast.Store()))])
self.stmt(t, "must have Load context")
def filter_block(node_list):
"""
Remove no-op code (``pass``), or any code after
an unconditional jump (``return``, ``break``, ``continue``, ``raise``).
"""
if len(node_list) == 1:
return node_list
new_list = []
for node in node_list:
if type(node) == ast.Pass:
continue
new_list.append(node)
if type(node) in (ast.Return, ast.Break, ast.Continue, ast.Raise):
break
if len(new_list) == len(node_list):
return node_list
else:
return new_list
def _translate_body(self, body, types, allow_loose_in_edges=False, allow_loose_out_edges=False):
cfg_factory = CFGFactory(self._id_gen)
for child in body:
if isinstance(child, (ast.AnnAssign, ast.Expr)):
cfg_factory.add_stmts(self.visit(child, types))
elif isinstance(child, ast.If):
cfg_factory.complete_basic_block()
if_cfg = self.visit(child, types)
cfg_factory.append_cfg(if_cfg)
elif isinstance(child, ast.While):
cfg_factory.complete_basic_block()
while_cfg = self.visit(child, types)
cfg_factory.append_cfg(while_cfg)
elif isinstance(child, ast.Break):
cfg_factory.complete_basic_block()
break_cfg = self.visit(child, types)
cfg_factory.append_cfg(break_cfg)
elif isinstance(child, ast.Continue):
cfg_factory.complete_basic_block()
cont_cfg = self.visit(child, types)
cfg_factory.append_cfg(cont_cfg)
elif isinstance(child, ast.Pass):
if cfg_factory.incomplete_block():
pass
else:
cfg_factory.append_cfg(_dummy_cfg(self._id_gen))
else:
raise NotImplementedError(f"The statement {str(type(child))} is not yet translatable to CFG!")
cfg_factory.complete_basic_block()
if not allow_loose_in_edges and cfg_factory.cfg and cfg_factory.cfg.loose_in_edges:
cfg_factory.prepend_cfg(_dummy_cfg(self._id_gen))
if not allow_loose_out_edges and cfg_factory.cfg and cfg_factory.cfg.loose_out_edges:
cfg_factory.append_cfg(_dummy_cfg(self._id_gen))
return cfg_factory.cfg
def visit_If(self, node):
node = self.generic_visit(node)
if (node.orelse
and len(node.orelse) == 1
and isinstance(node.orelse[0], ast.Pass)
):
node.orelse = []
if (len(node.body) == 1
and isinstance(node.body[0], ast.Pass)
):
if node.orelse:
node_test = ast.UnaryOp(op=ast.Not(), operand=node.test)
if (len(node.orelse) == 1
and isinstance(node.orelse[0], ast.If)
):
node_test = ast.BoolOp\
( op = ast.And()
, values = [node_test, node.orelse[0].test]
)
node.test = ast.copy_location(node_test, node.orelse[0].test)
node.body = node.orelse[0].body
node.orelse = node.orelse[0].orelse
else:
node.test = ast.copy_location(node_test, node.test)
node.body = node.orelse
node.orelse = []
else:
node = None
return node
def isStatement(a):
"""Determine whether the given node is a statement (vs an expression)"""
return type(a) in [ ast.Module, ast.Interactive, ast.Expression, ast.Suite,
ast.FunctionDef, ast.ClassDef, ast.Return, ast.Delete,
ast.Assign, ast.AugAssign, ast.For, ast.While,
ast.If, ast.With, ast.Raise, ast.Try,
ast.Assert, ast.Import, ast.ImportFrom, ast.Global,
ast.Expr, ast.Pass, ast.Break, ast.Continue ]
def try_except_pass(context, config):
node = context.node
if len(node.body) == 1:
if (not config['check_typed_exception'] and
node.type is not None and
getattr(node.type, 'id', None) != 'Exception'):
return
if isinstance(node.body[0], ast.Pass):
return bandit.Issue(
severity=bandit.LOW,
confidence=bandit.HIGH,
text=("Try, Except, Pass detected.")
)
def test_funcdef(self):
a = ast.arguments([], None, None, [], None, None, [], [])
f = ast.FunctionDef("x", a, [], [], None)
self.stmt(f, "empty body on FunctionDef")
f = ast.FunctionDef("x", a, [ast.Pass()], [ast.Name("x", ast.Store())],
None)
self.stmt(f, "must have Load context")
f = ast.FunctionDef("x", a, [ast.Pass()], [],
ast.Name("x", ast.Store()))
self.stmt(f, "must have Load context")
def fac(args):
return ast.FunctionDef("x", args, [ast.Pass()], [], None)
self._check_arguments(fac, self.stmt)
def test_for(self):
x = ast.Name("x", ast.Store())
y = ast.Name("y", ast.Load())
p = ast.Pass()
self.stmt(ast.For(x, y, [], []), "empty body on For")
self.stmt(ast.For(ast.Name("x", ast.Load()), y, [p], []),
"must have Store context")
self.stmt(ast.For(x, ast.Name("y", ast.Store()), [p], []),
"must have Load context")
e = ast.Expr(ast.Name("x", ast.Store()))
self.stmt(ast.For(x, y, [e], []), "must have Load context")
self.stmt(ast.For(x, y, [p], [e]), "must have Load context")
def test_while(self):
self.stmt(ast.While(ast.Num(3), [], []), "empty body on While")
self.stmt(ast.While(ast.Name("x", ast.Store()), [ast.Pass()], []),
"must have Load context")
self.stmt(ast.While(ast.Num(3), [ast.Pass()],
[ast.Expr(ast.Name("x", ast.Store()))]),
"must have Load context")
def test_if(self):
self.stmt(ast.If(ast.Num(3), [], []), "empty body on If")
i = ast.If(ast.Name("x", ast.Store()), [ast.Pass()], [])
self.stmt(i, "must have Load context")
i = ast.If(ast.Num(3), [ast.Expr(ast.Name("x", ast.Store()))], [])
self.stmt(i, "must have Load context")
i = ast.If(ast.Num(3), [ast.Pass()],
[ast.Expr(ast.Name("x", ast.Store()))])
self.stmt(i, "must have Load context")
def test_try_logger_empty_else(self):
self.config.logger = io.StringIO()
def get_logs():
logger = self.config.logger
logger.seek(0)
return logger.readlines()
self.check_optimize("""
try:
func1()
except Exception:
func2()
else:
pass
pass
finally:
func3()
""", """
try:
func1()
except Exception:
func2()
finally:
func3()
""")
self.assertEqual(get_logs(),
['<string>:6: fatoptimizer: Remove dead code (empty else block in try/except): Pass()\n',
'<string>:7: fatoptimizer: Remove dead code (empty else block in try/except): Pass()\n'])
def test_try_logger_empty_body(self):
self.config.logger = io.StringIO()
def get_logs():
logger = self.config.logger
logger.seek(0)
return logger.readlines()
self.check_optimize("""
try:
pass
except Exception:
func2()
finally:
func3()
""", """
func3()
""")
self.assertEqual(get_logs(),
['<string>:2: fatoptimizer: Remove dead code '
'(empty try block): Pass()\n',
'<string>:3: fatoptimizer: Remove dead code '
"(empty try block): "
"ExceptHandler(type=Name(id='Exception', "
"ctx=Load()), name=None, "
"body=[Expr(value=Call(func=Name(id='(...)\n"])
def test_replace_with_constant(self):
# list => tuple
self.check_optimize('for x in [1, 2, 3]: pass',
'for x in (1, 2, 3): pass')
# set => frozenset
self.check_optimize('for x in {1, 2, 3}: pass',
ast.For(target=ast.Name(id='x', ctx=ast.Store()),
iter=ast.Constant(frozenset((1, 2, 3))),
body=[ast.Pass()],
orelse=[]))
# don't optimize if items are not constants
self.check_dont_optimize('for x in [1, x]: pass')
self.check_dont_optimize('for x in {1, x}: pass')
def is_empty_body(node_list):
if not node_list:
return True
return all(isinstance(node, ast.Pass) for node in node_list)
def _replace_node(self, node, node_list):
if node_list:
return node_list
# FIXME: move this in NodeTransformer?
new_node = ast.Pass()
copy_lineno(node, new_node)
return new_node
def visit_Call(self, node):
if not self.config.inlining:
return
# FIXME: renaming variables to avoid clashes
# or do something like:
# .saved_locals = locals()
# set params to args
# body of called function
# locals() = .saved_locals
# how to things that aren't just a return
# how to handle early return
# FIXME: what guards are needed?
# etc
expansion = self.can_inline(node)
if not expansion:
return node
funcdef = expansion.funcdef
# Substitute the Call with the expression of the single return stmt
# within the callee.
# This assumes a single Return or Pass stmt
stmt = funcdef.body[0]
if isinstance(stmt, ast.Return):
returned_expr = funcdef.body[0].value
# Rename params/args
v = RenameVisitor(node, funcdef, expansion.actual_pos_args)
new_expr = v.visit(returned_expr)
else:
assert isinstance(stmt, ast.Pass)
new_expr = self.new_constant(stmt, None)
return new_expr
def test_funcdef(self):
a = ast.arguments([], None, [], [], None, [])
f = ast.FunctionDef("x", a, [], [], None)
self.stmt(f, "empty body on FunctionDef")
f = ast.FunctionDef("x", a, [ast.Pass()], [ast.Name("x", ast.Store())],
None)
self.stmt(f, "must have Load context")
f = ast.FunctionDef("x", a, [ast.Pass()], [],
ast.Name("x", ast.Store()))
self.stmt(f, "must have Load context")
def fac(args):
return ast.FunctionDef("x", args, [ast.Pass()], [], None)
self._check_arguments(fac, self.stmt)
def test_for(self):
x = ast.Name("x", ast.Store())
y = ast.Name("y", ast.Load())
p = ast.Pass()
self.stmt(ast.For(x, y, [], []), "empty body on For")
self.stmt(ast.For(ast.Name("x", ast.Load()), y, [p], []),
"must have Store context")
self.stmt(ast.For(x, ast.Name("y", ast.Store()), [p], []),
"must have Load context")
e = ast.Expr(ast.Name("x", ast.Store()))
self.stmt(ast.For(x, y, [e], []), "must have Load context")
self.stmt(ast.For(x, y, [p], [e]), "must have Load context")
def test_while(self):
self.stmt(ast.While(ast.Num(3), [], []), "empty body on While")
self.stmt(ast.While(ast.Name("x", ast.Store()), [ast.Pass()], []),
"must have Load context")
self.stmt(ast.While(ast.Num(3), [ast.Pass()],
[ast.Expr(ast.Name("x", ast.Store()))]),
"must have Load context")
def test_if(self):
self.stmt(ast.If(ast.Num(3), [], []), "empty body on If")
i = ast.If(ast.Name("x", ast.Store()), [ast.Pass()], [])
self.stmt(i, "must have Load context")
i = ast.If(ast.Num(3), [ast.Expr(ast.Name("x", ast.Store()))], [])
self.stmt(i, "must have Load context")
i = ast.If(ast.Num(3), [ast.Pass()],
[ast.Expr(ast.Name("x", ast.Store()))])
self.stmt(i, "must have Load context")
