Description
Bug report
The inspect getsource method fails to return the full source code of a target function if it has been decorated with a decorator that has been passed an argument with its own argument of a lambda function. This only happens if the decorator argument with the lambda is not the first argument of the decorator and there is an argument before it with a bracket e.g. a class or tuple.
from inspect import getsource
def decor(*args):
def decorator(f):
print(getsource(f))
return decorator
@decor(dict(fun=lambda x: x+1)) # Works
def foo1():
pass
@decor(dict(fun=lambda x: x+1), list()) # Works
def foo2():
pass
@decor("1", 1, 0.1, [], {}, dict(fun=lambda x: x+1), list()) # Works
def foo3():
pass
@decor(list(), dict(fun=lambda x: x+1)) # Fails
def foo4():
pass
@decor((1, 2), dict(fun=lambda x: x+1)) # Fails
def foo5():
pass
@decor((), (lambda x: x+1)) # Fails
def foo6():
passThe first three examples above will print the correct source code however the final three examples will print only:
@decor(list(), dict(fun=lambda x: x+1))
@decor((1, 2), dict(fun=lambda x: x+1))
@decor((), (lambda x: x+1))
The issue is caused by the inspect class BlockFinder wrongly setting self.indecorator to False when the token ")" is passed in the stream to tokeneater. This results in the lambda being able to incorrectly raise an EndOfBlock.
Potential Solution
By tracking if a "(" token has been ran whilst self.indecorator is True and preventing self.indecorator from going False until a ")" token is passed the issue is avoided.
The updated BlockFinder class which prevents this issue:
class BlockFinder:
"""Provide a tokeneater() method to detect the end of a code block."""
def __init__(self):
self.indent = 0
self.islambda = False
self.started = False
self.passline = False
self.indecorator = False
self.decoratorhasargs = False
self.last = 1
self.body_col0 = None
self.decorator_open_bracket = False
self.decorator_args_open_bracket = 0
def tokeneater(self, type, token, srowcol, erowcol, line):
if not self.started and not self.indecorator:
if token == "@":
self.indecorator = True
elif token in ("def", "class", "lambda"):
if token == "lambda":
self.islambda = True
self.started = True
self.passline = True
elif token == "(":
if self.indecorator:
self.decoratorhasargs = True
if self.decorator_open_bracket:
self.decorator_args_open_bracket += 1
else:
self.decorator_open_bracket = True
elif token == ")":
if self.indecorator and self.decorator_args_open_bracket:
self.decorator_args_open_bracket -= 1
elif self.indecorator:
self.indecorator = False
self.decorator_open_bracket = False
self.decoratorhasargs = False
elif type == tokenize.NEWLINE:
self.passline = False
self.last = srowcol[0]
if self.islambda:
raise EndOfBlock
if self.indecorator and not self.decoratorhasargs:
self.indecorator = False
elif self.passline:
pass
elif type == tokenize.INDENT:
if self.body_col0 is None and self.started:
self.body_col0 = erowcol[1]
self.indent = self.indent + 1
self.passline = True
elif type == tokenize.DEDENT:
self.indent = self.indent - 1
if self.indent <= 0:
raise EndOfBlock
elif type == tokenize.COMMENT:
if self.body_col0 is not None and srowcol[1] >= self.body_col0:
self.last = srowcol[0]
elif self.indent == 0 and type not in (tokenize.COMMENT, tokenize.NL):
raise EndOfBlockYour environment
- CPython versions tested on: 3.10.8
- Operating system and architecture: Windows / Linux