# -*- coding: utf-8 -*- # Copyright (c) 2013-2014 LOGILAB S.A. (Paris, FRANCE) # Copyright (c) 2013-2014 Google, Inc. # Copyright (c) 2014-2017 Claudiu Popa # Copyright (c) 2014 Cosmin Poieana # Copyright (c) 2014 Vlad Temian # Copyright (c) 2014 Arun Persaud # Copyright (c) 2015 Cezar # Copyright (c) 2015 Chris Rebert # Copyright (c) 2015 Ionel Cristian Maries # Copyright (c) 2016 Jared Garst # Copyright (c) 2017 Martin # Copyright (c) 2017 Christopher Zurcher # Copyright (c) 2017 Łukasz Rogalski # Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html # For details: https://github.com/PyCQA/pylint/blob/master/COPYING """Checkers for various standard library functions.""" import sys import astroid from astroid.bases import Instance from astroid.node_classes import Const from pylint.interfaces import IAstroidChecker from pylint.checkers import BaseChecker from pylint.checkers import utils OPEN_FILES = {'open', 'file'} UNITTEST_CASE = 'unittest.case' THREADING_THREAD = 'threading.Thread' COPY_COPY = 'copy.copy' OS_ENVIRON = 'os._Environ' ENV_GETTERS = {'os.getenv'} SUBPROCESS_POPEN = 'subprocess.Popen' if sys.version_info >= (3, 0): OPEN_MODULE = '_io' else: OPEN_MODULE = '__builtin__' def _check_mode_str(mode): # check type if not isinstance(mode, str): return False # check syntax modes = set(mode) _mode = "rwatb+Ux" creating = "x" in modes if modes - set(_mode) or len(mode) > len(modes): return False # check logic reading = "r" in modes writing = "w" in modes appending = "a" in modes text = "t" in modes binary = "b" in modes if "U" in modes: if writing or appending or creating: return False reading = True if text and binary: return False total = reading + writing + appending + creating if total > 1: return False if not (reading or writing or appending or creating): return False return True class StdlibChecker(BaseChecker): __implements__ = (IAstroidChecker,) name = 'stdlib' msgs = { 'W1501': ('"%s" is not a valid mode for open.', 'bad-open-mode', 'Python supports: r, w, a[, x] modes with b, +, ' 'and U (only with r) options. ' 'See http://docs.python.org/2/library/functions.html#open'), 'W1502': ('Using datetime.time in a boolean context.', 'boolean-datetime', 'Using datetime.time in a boolean context can hide ' 'subtle bugs when the time they represent matches ' 'midnight UTC. This behaviour was fixed in Python 3.5. ' 'See http://bugs.python.org/issue13936 for reference.', {'maxversion': (3, 5)}), 'W1503': ('Redundant use of %s with constant ' 'value %r', 'redundant-unittest-assert', 'The first argument of assertTrue and assertFalse is ' 'a condition. If a constant is passed as parameter, that ' 'condition will be always true. In this case a warning ' 'should be emitted.'), 'W1505': ('Using deprecated method %s()', 'deprecated-method', 'The method is marked as deprecated and will be removed in ' 'a future version of Python. Consider looking for an ' 'alternative in the documentation.'), 'W1506': ('threading.Thread needs the target function', 'bad-thread-instantiation', 'The warning is emitted when a threading.Thread class ' 'is instantiated without the target function being passed. ' 'By default, the first parameter is the group param, not the target param. '), 'W1507': ('Using copy.copy(os.environ). Use os.environ.copy() ' 'instead. ', 'shallow-copy-environ', 'os.environ is not a dict object but proxy object, so ' 'shallow copy has still effects on original object. ' 'See https://bugs.python.org/issue15373 for reference. '), 'E1507': ('%s does not support %s type argument', 'invalid-envvar-value', 'Env manipulation functions support only string type arguments. ' 'See https://docs.python.org/3/library/os.html#os.getenv. '), 'W1508': ('%s default type is %s. Expected str or None.', 'invalid-envvar-default', 'Env manipulation functions return None or str values. ' 'Supplying anything different as a default may cause bugs. ' 'See https://docs.python.org/3/library/os.html#os.getenv. '), 'W1509': ('Using preexec_fn keyword which may be unsafe in the presence ' 'of threads', 'subprocess-popen-preexec-fn', 'The preexec_fn parameter is not safe to use in the presence ' 'of threads in your application. The child process could ' 'deadlock before exec is called. If you must use it, keep it ' 'trivial! Minimize the number of libraries you call into.' 'https://docs.python.org/3/library/subprocess.html#popen-constructor'), } deprecated = { 0: [ 'cgi.parse_qs', 'cgi.parse_qsl', 'ctypes.c_buffer', 'distutils.command.register.register.check_metadata', 'distutils.command.sdist.sdist.check_metadata', 'tkinter.Misc.tk_menuBar', 'tkinter.Menu.tk_bindForTraversal', ], 2: { (2, 6, 0): [ 'commands.getstatus', 'os.popen2', 'os.popen3', 'os.popen4', 'macostools.touched', ], (2, 7, 0): [ 'unittest.case.TestCase.assertEquals', 'unittest.case.TestCase.assertNotEquals', 'unittest.case.TestCase.assertAlmostEquals', 'unittest.case.TestCase.assertNotAlmostEquals', 'unittest.case.TestCase.assert_', 'xml.etree.ElementTree.Element.getchildren', 'xml.etree.ElementTree.Element.getiterator', 'xml.etree.ElementTree.XMLParser.getiterator', 'xml.etree.ElementTree.XMLParser.doctype', ], }, 3: { (3, 0, 0): [ 'inspect.getargspec', 'unittest.case.TestCase._deprecate.deprecated_func', ], (3, 1, 0): [ 'base64.encodestring', 'base64.decodestring', 'ntpath.splitunc', ], (3, 2, 0): [ 'cgi.escape', 'configparser.RawConfigParser.readfp', 'xml.etree.ElementTree.Element.getchildren', 'xml.etree.ElementTree.Element.getiterator', 'xml.etree.ElementTree.XMLParser.getiterator', 'xml.etree.ElementTree.XMLParser.doctype', ], (3, 3, 0): [ 'inspect.getmoduleinfo', 'logging.warn', 'logging.Logger.warn', 'logging.LoggerAdapter.warn', 'nntplib._NNTPBase.xpath', 'platform.popen', ], (3, 4, 0): [ 'importlib.find_loader', 'plistlib.readPlist', 'plistlib.writePlist', 'plistlib.readPlistFromBytes', 'plistlib.writePlistToBytes', ], (3, 4, 4): [ 'asyncio.tasks.async', ], (3, 5, 0): [ 'fractions.gcd', 'inspect.getargvalues', 'inspect.formatargspec', 'inspect.formatargvalues', 'inspect.getcallargs', 'platform.linux_distribution', 'platform.dist', ], (3, 6, 0): [ 'importlib._bootstrap_external.FileLoader.load_module', ], }, } def _check_bad_thread_instantiation(self, node): if not node.kwargs and not node.keywords and len(node.args) <= 1: self.add_message('bad-thread-instantiation', node=node) def _check_for_preexec_fn_in_Popen(self, node): if node.keywords: for keyword in node.keywords: if keyword.arg == 'preexec_fn': self.add_message('subprocess-popen-preexec-fn', node=node) def _check_shallow_copy_environ(self, node): arg = utils.get_argument_from_call(node, position=0) for inferred in arg.inferred(): if inferred.qname() == OS_ENVIRON: self.add_message('shallow-copy-environ', node=node) break @utils.check_messages('bad-open-mode', 'redundant-unittest-assert', 'deprecated-method', 'bad-thread-instantiation', 'shallow-copy-environ', 'invalid-envvar-value', 'invalid-envvar-default', 'subprocess-popen-preexec-fn') def visit_call(self, node): """Visit a Call node.""" try: for inferred in node.func.infer(): if inferred is astroid.Uninferable: continue elif inferred.root().name == OPEN_MODULE: if getattr(node.func, 'name', None) in OPEN_FILES: self._check_open_mode(node) elif inferred.root().name == UNITTEST_CASE: self._check_redundant_assert(node, inferred) elif isinstance(inferred, astroid.ClassDef): if inferred.qname() == THREADING_THREAD: self._check_bad_thread_instantiation(node) elif inferred.qname() == SUBPROCESS_POPEN: self._check_for_preexec_fn_in_Popen(node) elif isinstance(inferred, astroid.FunctionDef): name = inferred.qname() if name == COPY_COPY: self._check_shallow_copy_environ(node) elif name in ENV_GETTERS: self._check_env_function(node, inferred) self._check_deprecated_method(node, inferred) except astroid.InferenceError: return @utils.check_messages('boolean-datetime') def visit_unaryop(self, node): if node.op == 'not': self._check_datetime(node.operand) @utils.check_messages('boolean-datetime') def visit_if(self, node): self._check_datetime(node.test) @utils.check_messages('boolean-datetime') def visit_ifexp(self, node): self._check_datetime(node.test) @utils.check_messages('boolean-datetime') def visit_boolop(self, node): for value in node.values: self._check_datetime(value) def _check_deprecated_method(self, node, inferred): py_vers = sys.version_info[0] if isinstance(node.func, astroid.Attribute): func_name = node.func.attrname elif isinstance(node.func, astroid.Name): func_name = node.func.name else: # Not interested in other nodes. return # Reject nodes which aren't of interest to us. acceptable_nodes = (astroid.BoundMethod, astroid.UnboundMethod, astroid.FunctionDef) if not isinstance(inferred, acceptable_nodes): return qname = inferred.qname() if qname in self.deprecated[0]: self.add_message('deprecated-method', node=node, args=(func_name, )) else: for since_vers, func_list in self.deprecated[py_vers].items(): if since_vers <= sys.version_info and qname in func_list: self.add_message('deprecated-method', node=node, args=(func_name, )) break def _check_redundant_assert(self, node, infer): if (isinstance(infer, astroid.BoundMethod) and node.args and isinstance(node.args[0], astroid.Const) and infer.name in ['assertTrue', 'assertFalse']): self.add_message('redundant-unittest-assert', args=(infer.name, node.args[0].value, ), node=node) def _check_datetime(self, node): """ Check that a datetime was infered. If so, emit boolean-datetime warning. """ try: infered = next(node.infer()) except astroid.InferenceError: return if (isinstance(infered, Instance) and infered.qname() == 'datetime.time'): self.add_message('boolean-datetime', node=node) def _check_open_mode(self, node): """Check that the mode argument of an open or file call is valid.""" try: mode_arg = utils.get_argument_from_call(node, position=1, keyword='mode') except utils.NoSuchArgumentError: return if mode_arg: mode_arg = utils.safe_infer(mode_arg) if (isinstance(mode_arg, astroid.Const) and not _check_mode_str(mode_arg.value)): self.add_message('bad-open-mode', node=node, args=mode_arg.value) def _check_env_function(self, node, infer): env_name_kwarg = 'key' env_value_kwarg = 'default' if node.keywords: kwargs = {keyword.arg: keyword.value for keyword in node.keywords} else: kwargs = None if node.args: env_name_arg = node.args[0] elif kwargs and env_name_kwarg in kwargs: env_name_arg = kwargs[env_name_kwarg] else: env_name_arg = None if env_name_arg: self._check_invalid_envvar_value( node=node, message='invalid-envvar-value', call_arg=utils.safe_infer(env_name_arg), infer=infer, allow_none=False ) if len(node.args) == 2: env_value_arg = node.args[1] elif kwargs and env_value_kwarg in kwargs: env_value_arg = kwargs[env_value_kwarg] else: env_value_arg = None if env_value_arg: self._check_invalid_envvar_value( node=node, infer=infer, message='invalid-envvar-default', call_arg=utils.safe_infer(env_value_arg), allow_none=True, ) def _check_invalid_envvar_value(self, node, infer, message, call_arg, allow_none): if call_arg in (astroid.Uninferable, None): return name = infer.qname() if isinstance(call_arg, Const): emit = False if call_arg.value is None: emit = not allow_none elif not isinstance(call_arg.value, str): emit = True if emit: self.add_message(message, node=node, args=(name, call_arg.pytype())) else: self.add_message(message, node=node, args=(name, call_arg.pytype())) def register(linter): """required method to auto register this checker """ linter.register_checker(StdlibChecker(linter))