| # Copyright (c) 2003-2013 LOGILAB S.A. (Paris, FRANCE). |
| # http://www.logilab.fr/ -- mailto:contact@logilab.fr |
| # Copyright (c) 2009-2010 Arista Networks, Inc. |
| # |
| # This program is free software; you can redistribute it and/or modify it under |
| # the terms of the GNU General Public License as published by the Free Software |
| # Foundation; either version 2 of the License, or (at your option) any later |
| # version. |
| # |
| # This program is distributed in the hope that it will be useful, but WITHOUT |
| # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| # FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License along with |
| # this program; if not, write to the Free Software Foundation, Inc., |
| # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| """basic checker for Python code""" |
| |
| import collections |
| import itertools |
| import sys |
| import re |
| |
| import six |
| from six.moves import zip # pylint: disable=redefined-builtin |
| |
| from logilab.common.ureports import Table |
| |
| import astroid |
| import astroid.bases |
| from astroid import are_exclusive, InferenceError |
| |
| from pylint.interfaces import IAstroidChecker, INFERENCE, INFERENCE_FAILURE, HIGH |
| from pylint.utils import EmptyReport |
| from pylint.reporters import diff_string |
| from pylint.checkers import BaseChecker |
| from pylint.checkers.utils import ( |
| check_messages, |
| clobber_in_except, |
| is_builtin_object, |
| is_inside_except, |
| overrides_a_method, |
| safe_infer, |
| get_argument_from_call, |
| has_known_bases, |
| NoSuchArgumentError, |
| is_import_error, |
| unimplemented_abstract_methods, |
| ) |
| |
| |
| # regex for class/function/variable/constant name |
| CLASS_NAME_RGX = re.compile('[A-Z_][a-zA-Z0-9]+$') |
| MOD_NAME_RGX = re.compile('(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$') |
| CONST_NAME_RGX = re.compile('(([A-Z_][A-Z0-9_]*)|(__.*__))$') |
| COMP_VAR_RGX = re.compile('[A-Za-z_][A-Za-z0-9_]*$') |
| DEFAULT_NAME_RGX = re.compile('[a-z_][a-z0-9_]{2,30}$') |
| CLASS_ATTRIBUTE_RGX = re.compile(r'([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$') |
| # do not require a doc string on system methods |
| NO_REQUIRED_DOC_RGX = re.compile('__.*__') |
| REVERSED_METHODS = (('__getitem__', '__len__'), |
| ('__reversed__', )) |
| |
| PY33 = sys.version_info >= (3, 3) |
| PY3K = sys.version_info >= (3, 0) |
| BAD_FUNCTIONS = ['map', 'filter'] |
| if sys.version_info < (3, 0): |
| BAD_FUNCTIONS.append('input') |
| |
| # Name categories that are always consistent with all naming conventions. |
| EXEMPT_NAME_CATEGORIES = set(('exempt', 'ignore')) |
| |
| # A mapping from builtin-qname -> symbol, to be used when generating messages |
| # about dangerous default values as arguments |
| DEFAULT_ARGUMENT_SYMBOLS = dict( |
| zip(['.'.join([astroid.bases.BUILTINS, x]) for x in ('set', 'dict', 'list')], |
| ['set()', '{}', '[]']) |
| ) |
| |
| del re |
| |
| def _redefines_import(node): |
| """ Detect that the given node (AssName) is inside an |
| exception handler and redefines an import from the tryexcept body. |
| Returns True if the node redefines an import, False otherwise. |
| """ |
| current = node |
| while current and not isinstance(current.parent, astroid.ExceptHandler): |
| current = current.parent |
| if not current or not is_import_error(current.parent): |
| return False |
| try_block = current.parent.parent |
| for import_node in try_block.nodes_of_class((astroid.From, astroid.Import)): |
| for name, alias in import_node.names: |
| if alias: |
| if alias == node.name: |
| return True |
| elif name == node.name: |
| return True |
| return False |
| |
| def in_loop(node): |
| """return True if the node is inside a kind of for loop""" |
| parent = node.parent |
| while parent is not None: |
| if isinstance(parent, (astroid.For, astroid.ListComp, astroid.SetComp, |
| astroid.DictComp, astroid.GenExpr)): |
| return True |
| parent = parent.parent |
| return False |
| |
| def in_nested_list(nested_list, obj): |
| """return true if the object is an element of <nested_list> or of a nested |
| list |
| """ |
| for elmt in nested_list: |
| if isinstance(elmt, (list, tuple)): |
| if in_nested_list(elmt, obj): |
| return True |
| elif elmt == obj: |
| return True |
| return False |
| |
| def _loop_exits_early(loop): |
| """Returns true if a loop has a break statement in its body.""" |
| loop_nodes = (astroid.For, astroid.While) |
| # Loop over body explicitly to avoid matching break statements |
| # in orelse. |
| for child in loop.body: |
| if isinstance(child, loop_nodes): |
| # break statement may be in orelse of child loop. |
| # pylint: disable=superfluous-parens |
| for orelse in (child.orelse or ()): |
| for _ in orelse.nodes_of_class(astroid.Break, skip_klass=loop_nodes): |
| return True |
| continue |
| for _ in child.nodes_of_class(astroid.Break, skip_klass=loop_nodes): |
| return True |
| return False |
| |
| def _is_multi_naming_match(match, node_type, confidence): |
| return (match is not None and |
| match.lastgroup is not None and |
| match.lastgroup not in EXEMPT_NAME_CATEGORIES |
| and (node_type != 'method' or confidence != INFERENCE_FAILURE)) |
| |
| |
| if sys.version_info < (3, 0): |
| PROPERTY_CLASSES = set(('__builtin__.property', 'abc.abstractproperty')) |
| else: |
| PROPERTY_CLASSES = set(('builtins.property', 'abc.abstractproperty')) |
| |
| |
| def _determine_function_name_type(node): |
| """Determine the name type whose regex the a function's name should match. |
| |
| :param node: A function node. |
| :returns: One of ('function', 'method', 'attr') |
| """ |
| if not node.is_method(): |
| return 'function' |
| if node.decorators: |
| decorators = node.decorators.nodes |
| else: |
| decorators = [] |
| for decorator in decorators: |
| # If the function is a property (decorated with @property |
| # or @abc.abstractproperty), the name type is 'attr'. |
| if (isinstance(decorator, astroid.Name) or |
| (isinstance(decorator, astroid.Getattr) and |
| decorator.attrname == 'abstractproperty')): |
| infered = safe_infer(decorator) |
| if infered and infered.qname() in PROPERTY_CLASSES: |
| return 'attr' |
| # If the function is decorated using the prop_method.{setter,getter} |
| # form, treat it like an attribute as well. |
| elif (isinstance(decorator, astroid.Getattr) and |
| decorator.attrname in ('setter', 'deleter')): |
| return 'attr' |
| return 'method' |
| |
| |
| |
| def _has_abstract_methods(node): |
| """ |
| Determine if the given `node` has abstract methods. |
| |
| The methods should be made abstract by decorating them |
| with `abc` decorators. |
| """ |
| return len(unimplemented_abstract_methods(node)) > 0 |
| |
| |
| def report_by_type_stats(sect, stats, old_stats): |
| """make a report of |
| |
| * percentage of different types documented |
| * percentage of different types with a bad name |
| """ |
| # percentage of different types documented and/or with a bad name |
| nice_stats = {} |
| for node_type in ('module', 'class', 'method', 'function'): |
| try: |
| total = stats[node_type] |
| except KeyError: |
| raise EmptyReport() |
| nice_stats[node_type] = {} |
| if total != 0: |
| try: |
| documented = total - stats['undocumented_'+node_type] |
| percent = (documented * 100.) / total |
| nice_stats[node_type]['percent_documented'] = '%.2f' % percent |
| except KeyError: |
| nice_stats[node_type]['percent_documented'] = 'NC' |
| try: |
| percent = (stats['badname_'+node_type] * 100.) / total |
| nice_stats[node_type]['percent_badname'] = '%.2f' % percent |
| except KeyError: |
| nice_stats[node_type]['percent_badname'] = 'NC' |
| lines = ('type', 'number', 'old number', 'difference', |
| '%documented', '%badname') |
| for node_type in ('module', 'class', 'method', 'function'): |
| new = stats[node_type] |
| old = old_stats.get(node_type, None) |
| if old is not None: |
| diff_str = diff_string(old, new) |
| else: |
| old, diff_str = 'NC', 'NC' |
| lines += (node_type, str(new), str(old), diff_str, |
| nice_stats[node_type].get('percent_documented', '0'), |
| nice_stats[node_type].get('percent_badname', '0')) |
| sect.append(Table(children=lines, cols=6, rheaders=1)) |
| |
| def redefined_by_decorator(node): |
| """return True if the object is a method redefined via decorator. |
| |
| For example: |
| @property |
| def x(self): return self._x |
| @x.setter |
| def x(self, value): self._x = value |
| """ |
| if node.decorators: |
| for decorator in node.decorators.nodes: |
| if (isinstance(decorator, astroid.Getattr) and |
| getattr(decorator.expr, 'name', None) == node.name): |
| return True |
| return False |
| |
| class _BasicChecker(BaseChecker): |
| __implements__ = IAstroidChecker |
| name = 'basic' |
| |
| class BasicErrorChecker(_BasicChecker): |
| msgs = { |
| 'E0100': ('__init__ method is a generator', |
| 'init-is-generator', |
| 'Used when the special class method __init__ is turned into a ' |
| 'generator by a yield in its body.'), |
| 'E0101': ('Explicit return in __init__', |
| 'return-in-init', |
| 'Used when the special class method __init__ has an explicit ' |
| 'return value.'), |
| 'E0102': ('%s already defined line %s', |
| 'function-redefined', |
| 'Used when a function / class / method is redefined.'), |
| 'E0103': ('%r not properly in loop', |
| 'not-in-loop', |
| 'Used when break or continue keywords are used outside a loop.'), |
| 'E0104': ('Return outside function', |
| 'return-outside-function', |
| 'Used when a "return" statement is found outside a function or ' |
| 'method.'), |
| 'E0105': ('Yield outside function', |
| 'yield-outside-function', |
| 'Used when a "yield" statement is found outside a function or ' |
| 'method.'), |
| 'E0106': ('Return with argument inside generator', |
| 'return-arg-in-generator', |
| 'Used when a "return" statement with an argument is found ' |
| 'outside in a generator function or method (e.g. with some ' |
| '"yield" statements).', |
| {'maxversion': (3, 3)}), |
| 'E0107': ("Use of the non-existent %s operator", |
| 'nonexistent-operator', |
| "Used when you attempt to use the C-style pre-increment or" |
| "pre-decrement operator -- and ++, which doesn't exist in Python."), |
| 'E0108': ('Duplicate argument name %s in function definition', |
| 'duplicate-argument-name', |
| 'Duplicate argument names in function definitions are syntax' |
| ' errors.'), |
| 'E0110': ('Abstract class %r with abstract methods instantiated', |
| 'abstract-class-instantiated', |
| 'Used when an abstract class with `abc.ABCMeta` as metaclass ' |
| 'has abstract methods and is instantiated.'), |
| 'W0120': ('Else clause on loop without a break statement', |
| 'useless-else-on-loop', |
| 'Loops should only have an else clause if they can exit early ' |
| 'with a break statement, otherwise the statements under else ' |
| 'should be on the same scope as the loop itself.'), |
| } |
| |
| @check_messages('function-redefined') |
| def visit_class(self, node): |
| self._check_redefinition('class', node) |
| |
| @check_messages('init-is-generator', 'return-in-init', |
| 'function-redefined', 'return-arg-in-generator', |
| 'duplicate-argument-name') |
| def visit_function(self, node): |
| if not redefined_by_decorator(node): |
| self._check_redefinition(node.is_method() and 'method' or 'function', node) |
| # checks for max returns, branch, return in __init__ |
| returns = node.nodes_of_class(astroid.Return, |
| skip_klass=(astroid.Function, astroid.Class)) |
| if node.is_method() and node.name == '__init__': |
| if node.is_generator(): |
| self.add_message('init-is-generator', node=node) |
| else: |
| values = [r.value for r in returns] |
| # Are we returning anything but None from constructors |
| if [v for v in values |
| if not (v is None or |
| (isinstance(v, astroid.Const) and v.value is None) or |
| (isinstance(v, astroid.Name) and v.name == 'None') |
| )]: |
| self.add_message('return-in-init', node=node) |
| elif node.is_generator(): |
| # make sure we don't mix non-None returns and yields |
| if not PY33: |
| for retnode in returns: |
| if isinstance(retnode.value, astroid.Const) and \ |
| retnode.value.value is not None: |
| self.add_message('return-arg-in-generator', node=node, |
| line=retnode.fromlineno) |
| # Check for duplicate names |
| args = set() |
| for name in node.argnames(): |
| if name in args: |
| self.add_message('duplicate-argument-name', node=node, args=(name,)) |
| else: |
| args.add(name) |
| |
| |
| @check_messages('return-outside-function') |
| def visit_return(self, node): |
| if not isinstance(node.frame(), astroid.Function): |
| self.add_message('return-outside-function', node=node) |
| |
| @check_messages('yield-outside-function') |
| def visit_yield(self, node): |
| if not isinstance(node.frame(), (astroid.Function, astroid.Lambda)): |
| self.add_message('yield-outside-function', node=node) |
| |
| @check_messages('not-in-loop') |
| def visit_continue(self, node): |
| self._check_in_loop(node, 'continue') |
| |
| @check_messages('not-in-loop') |
| def visit_break(self, node): |
| self._check_in_loop(node, 'break') |
| |
| @check_messages('useless-else-on-loop') |
| def visit_for(self, node): |
| self._check_else_on_loop(node) |
| |
| @check_messages('useless-else-on-loop') |
| def visit_while(self, node): |
| self._check_else_on_loop(node) |
| |
| @check_messages('nonexistent-operator') |
| def visit_unaryop(self, node): |
| """check use of the non-existent ++ and -- operator operator""" |
| if ((node.op in '+-') and |
| isinstance(node.operand, astroid.UnaryOp) and |
| (node.operand.op == node.op)): |
| self.add_message('nonexistent-operator', node=node, args=node.op*2) |
| |
| @check_messages('abstract-class-instantiated') |
| def visit_callfunc(self, node): |
| """ Check instantiating abstract class with |
| abc.ABCMeta as metaclass. |
| """ |
| try: |
| infered = next(node.func.infer()) |
| except astroid.InferenceError: |
| return |
| if not isinstance(infered, astroid.Class): |
| return |
| # __init__ was called |
| metaclass = infered.metaclass() |
| abstract_methods = _has_abstract_methods(infered) |
| if metaclass is None: |
| # Python 3.4 has `abc.ABC`, which won't be detected |
| # by ClassNode.metaclass() |
| for ancestor in infered.ancestors(): |
| if ancestor.qname() == 'abc.ABC' and abstract_methods: |
| self.add_message('abstract-class-instantiated', |
| args=(infered.name, ), |
| node=node) |
| break |
| return |
| if metaclass.qname() == 'abc.ABCMeta' and abstract_methods: |
| self.add_message('abstract-class-instantiated', |
| args=(infered.name, ), |
| node=node) |
| |
| def _check_else_on_loop(self, node): |
| """Check that any loop with an else clause has a break statement.""" |
| if node.orelse and not _loop_exits_early(node): |
| self.add_message('useless-else-on-loop', node=node, |
| # This is not optimal, but the line previous |
| # to the first statement in the else clause |
| # will usually be the one that contains the else:. |
| line=node.orelse[0].lineno - 1) |
| |
| def _check_in_loop(self, node, node_name): |
| """check that a node is inside a for or while loop""" |
| _node = node.parent |
| while _node: |
| if isinstance(_node, (astroid.For, astroid.While)): |
| break |
| _node = _node.parent |
| else: |
| self.add_message('not-in-loop', node=node, args=node_name) |
| |
| def _check_redefinition(self, redeftype, node): |
| """check for redefinition of a function / method / class name""" |
| defined_self = node.parent.frame()[node.name] |
| if defined_self is not node and not are_exclusive(node, defined_self): |
| self.add_message('function-redefined', node=node, |
| args=(redeftype, defined_self.fromlineno)) |
| |
| |
| |
| class BasicChecker(_BasicChecker): |
| """checks for : |
| * doc strings |
| * number of arguments, local variables, branches, returns and statements in |
| functions, methods |
| * required module attributes |
| * dangerous default values as arguments |
| * redefinition of function / method / class |
| * uses of the global statement |
| """ |
| |
| __implements__ = IAstroidChecker |
| |
| name = 'basic' |
| msgs = { |
| 'W0101': ('Unreachable code', |
| 'unreachable', |
| 'Used when there is some code behind a "return" or "raise" ' |
| 'statement, which will never be accessed.'), |
| 'W0102': ('Dangerous default value %s as argument', |
| 'dangerous-default-value', |
| 'Used when a mutable value as list or dictionary is detected in ' |
| 'a default value for an argument.'), |
| 'W0104': ('Statement seems to have no effect', |
| 'pointless-statement', |
| 'Used when a statement doesn\'t have (or at least seems to) ' |
| 'any effect.'), |
| 'W0105': ('String statement has no effect', |
| 'pointless-string-statement', |
| 'Used when a string is used as a statement (which of course ' |
| 'has no effect). This is a particular case of W0104 with its ' |
| 'own message so you can easily disable it if you\'re using ' |
| 'those strings as documentation, instead of comments.'), |
| 'W0106': ('Expression "%s" is assigned to nothing', |
| 'expression-not-assigned', |
| 'Used when an expression that is not a function call is assigned ' |
| 'to nothing. Probably something else was intended.'), |
| 'W0108': ('Lambda may not be necessary', |
| 'unnecessary-lambda', |
| 'Used when the body of a lambda expression is a function call ' |
| 'on the same argument list as the lambda itself; such lambda ' |
| 'expressions are in all but a few cases replaceable with the ' |
| 'function being called in the body of the lambda.'), |
| 'W0109': ("Duplicate key %r in dictionary", |
| 'duplicate-key', |
| 'Used when a dictionary expression binds the same key multiple ' |
| 'times.'), |
| 'W0122': ('Use of exec', |
| 'exec-used', |
| 'Used when you use the "exec" statement (function for Python ' |
| '3), to discourage its usage. That doesn\'t ' |
| 'mean you can not use it !'), |
| 'W0123': ('Use of eval', |
| 'eval-used', |
| 'Used when you use the "eval" function, to discourage its ' |
| 'usage. Consider using `ast.literal_eval` for safely evaluating ' |
| 'strings containing Python expressions ' |
| 'from untrusted sources. '), |
| 'W0141': ('Used builtin function %r', |
| 'bad-builtin', |
| 'Used when a black listed builtin function is used (see the ' |
| 'bad-function option). Usual black listed functions are the ones ' |
| 'like map, or filter , where Python offers now some cleaner ' |
| 'alternative like list comprehension.'), |
| 'W0142': ('Used * or ** magic', |
| 'star-args', |
| 'Used when a function or method is called using `*args` or ' |
| '`**kwargs` to dispatch arguments. This doesn\'t improve ' |
| 'readability and should be used with care.'), |
| 'W0150': ("%s statement in finally block may swallow exception", |
| 'lost-exception', |
| 'Used when a break or a return statement is found inside the ' |
| 'finally clause of a try...finally block: the exceptions raised ' |
| 'in the try clause will be silently swallowed instead of being ' |
| 're-raised.'), |
| 'W0199': ('Assert called on a 2-uple. Did you mean \'assert x,y\'?', |
| 'assert-on-tuple', |
| 'A call of assert on a tuple will always evaluate to true if ' |
| 'the tuple is not empty, and will always evaluate to false if ' |
| 'it is.'), |
| 'C0121': ('Missing required attribute "%s"', # W0103 |
| 'missing-module-attribute', |
| 'Used when an attribute required for modules is missing.'), |
| |
| 'E0109': ('Missing argument to reversed()', |
| 'missing-reversed-argument', |
| 'Used when reversed() builtin didn\'t receive an argument.'), |
| 'E0111': ('The first reversed() argument is not a sequence', |
| 'bad-reversed-sequence', |
| 'Used when the first argument to reversed() builtin ' |
| 'isn\'t a sequence (does not implement __reversed__, ' |
| 'nor __getitem__ and __len__'), |
| |
| } |
| |
| options = (('required-attributes', |
| {'default' : (), 'type' : 'csv', |
| 'metavar' : '<attributes>', |
| 'help' : 'Required attributes for module, separated by a ' |
| 'comma'} |
| ), |
| ('bad-functions', |
| {'default' : BAD_FUNCTIONS, |
| 'type' :'csv', 'metavar' : '<builtin function names>', |
| 'help' : 'List of builtins function names that should not be ' |
| 'used, separated by a comma'} |
| ), |
| ) |
| reports = (('RP0101', 'Statistics by type', report_by_type_stats),) |
| |
| def __init__(self, linter): |
| _BasicChecker.__init__(self, linter) |
| self.stats = None |
| self._tryfinallys = None |
| |
| def open(self): |
| """initialize visit variables and statistics |
| """ |
| self._tryfinallys = [] |
| self.stats = self.linter.add_stats(module=0, function=0, |
| method=0, class_=0) |
| |
| @check_messages('missing-module-attribute') |
| def visit_module(self, node): |
| """check module name, docstring and required arguments |
| """ |
| self.stats['module'] += 1 |
| for attr in self.config.required_attributes: |
| if attr not in node: |
| self.add_message('missing-module-attribute', node=node, args=attr) |
| |
| def visit_class(self, node): # pylint: disable=unused-argument |
| """check module name, docstring and redefinition |
| increment branch counter |
| """ |
| self.stats['class'] += 1 |
| |
| @check_messages('pointless-statement', 'pointless-string-statement', |
| 'expression-not-assigned') |
| def visit_discard(self, node): |
| """check for various kind of statements without effect""" |
| expr = node.value |
| if isinstance(expr, astroid.Const) and isinstance(expr.value, |
| six.string_types): |
| # treat string statement in a separated message |
| # Handle PEP-257 attribute docstrings. |
| # An attribute docstring is defined as being a string right after |
| # an assignment at the module level, class level or __init__ level. |
| scope = expr.scope() |
| if isinstance(scope, (astroid.Class, astroid.Module, astroid.Function)): |
| if isinstance(scope, astroid.Function) and scope.name != '__init__': |
| pass |
| else: |
| sibling = expr.previous_sibling() |
| if (sibling is not None and sibling.scope() is scope and |
| isinstance(sibling, astroid.Assign)): |
| return |
| self.add_message('pointless-string-statement', node=node) |
| return |
| # ignore if this is : |
| # * a direct function call |
| # * the unique child of a try/except body |
| # * a yield (which are wrapped by a discard node in _ast XXX) |
| # warn W0106 if we have any underlying function call (we can't predict |
| # side effects), else pointless-statement |
| if (isinstance(expr, (astroid.Yield, astroid.CallFunc)) or |
| (isinstance(node.parent, astroid.TryExcept) and |
| node.parent.body == [node])): |
| return |
| if any(expr.nodes_of_class(astroid.CallFunc)): |
| self.add_message('expression-not-assigned', node=node, |
| args=expr.as_string()) |
| else: |
| self.add_message('pointless-statement', node=node) |
| |
| @check_messages('unnecessary-lambda') |
| def visit_lambda(self, node): |
| """check whether or not the lambda is suspicious |
| """ |
| # if the body of the lambda is a call expression with the same |
| # argument list as the lambda itself, then the lambda is |
| # possibly unnecessary and at least suspicious. |
| if node.args.defaults: |
| # If the arguments of the lambda include defaults, then a |
| # judgment cannot be made because there is no way to check |
| # that the defaults defined by the lambda are the same as |
| # the defaults defined by the function called in the body |
| # of the lambda. |
| return |
| call = node.body |
| if not isinstance(call, astroid.CallFunc): |
| # The body of the lambda must be a function call expression |
| # for the lambda to be unnecessary. |
| return |
| # XXX are lambda still different with astroid >= 0.18 ? |
| # *args and **kwargs need to be treated specially, since they |
| # are structured differently between the lambda and the function |
| # call (in the lambda they appear in the args.args list and are |
| # indicated as * and ** by two bits in the lambda's flags, but |
| # in the function call they are omitted from the args list and |
| # are indicated by separate attributes on the function call node). |
| ordinary_args = list(node.args.args) |
| if node.args.kwarg: |
| if (not call.kwargs |
| or not isinstance(call.kwargs, astroid.Name) |
| or node.args.kwarg != call.kwargs.name): |
| return |
| elif call.kwargs: |
| return |
| if node.args.vararg: |
| if (not call.starargs |
| or not isinstance(call.starargs, astroid.Name) |
| or node.args.vararg != call.starargs.name): |
| return |
| elif call.starargs: |
| return |
| # The "ordinary" arguments must be in a correspondence such that: |
| # ordinary_args[i].name == call.args[i].name. |
| if len(ordinary_args) != len(call.args): |
| return |
| for i in range(len(ordinary_args)): |
| if not isinstance(call.args[i], astroid.Name): |
| return |
| if node.args.args[i].name != call.args[i].name: |
| return |
| if (isinstance(node.body.func, astroid.Getattr) and |
| isinstance(node.body.func.expr, astroid.CallFunc)): |
| # Chained call, the intermediate call might |
| # return something else (but we don't check that, yet). |
| return |
| self.add_message('unnecessary-lambda', line=node.fromlineno, node=node) |
| |
| @check_messages('dangerous-default-value') |
| def visit_function(self, node): |
| """check function name, docstring, arguments, redefinition, |
| variable names, max locals |
| """ |
| self.stats[node.is_method() and 'method' or 'function'] += 1 |
| self._check_dangerous_default(node) |
| |
| def _check_dangerous_default(self, node): |
| # check for dangerous default values as arguments |
| is_iterable = lambda n: isinstance(n, (astroid.List, |
| astroid.Set, |
| astroid.Dict)) |
| for default in node.args.defaults: |
| try: |
| value = next(default.infer()) |
| except astroid.InferenceError: |
| continue |
| |
| if (isinstance(value, astroid.Instance) and |
| value.qname() in DEFAULT_ARGUMENT_SYMBOLS): |
| |
| if value is default: |
| msg = DEFAULT_ARGUMENT_SYMBOLS[value.qname()] |
| elif type(value) is astroid.Instance or is_iterable(value): |
| # We are here in the following situation(s): |
| # * a dict/set/list/tuple call which wasn't inferred |
| # to a syntax node ({}, () etc.). This can happen |
| # when the arguments are invalid or unknown to |
| # the inference. |
| # * a variable from somewhere else, which turns out to be a list |
| # or a dict. |
| if is_iterable(default): |
| msg = value.pytype() |
| elif isinstance(default, astroid.CallFunc): |
| msg = '%s() (%s)' % (value.name, value.qname()) |
| else: |
| msg = '%s (%s)' % (default.as_string(), value.qname()) |
| else: |
| # this argument is a name |
| msg = '%s (%s)' % (default.as_string(), |
| DEFAULT_ARGUMENT_SYMBOLS[value.qname()]) |
| self.add_message('dangerous-default-value', |
| node=node, |
| args=(msg, )) |
| |
| @check_messages('unreachable', 'lost-exception') |
| def visit_return(self, node): |
| """1 - check is the node has a right sibling (if so, that's some |
| unreachable code) |
| 2 - check is the node is inside the finally clause of a try...finally |
| block |
| """ |
| self._check_unreachable(node) |
| # Is it inside final body of a try...finally bloc ? |
| self._check_not_in_finally(node, 'return', (astroid.Function,)) |
| |
| @check_messages('unreachable') |
| def visit_continue(self, node): |
| """check is the node has a right sibling (if so, that's some unreachable |
| code) |
| """ |
| self._check_unreachable(node) |
| |
| @check_messages('unreachable', 'lost-exception') |
| def visit_break(self, node): |
| """1 - check is the node has a right sibling (if so, that's some |
| unreachable code) |
| 2 - check is the node is inside the finally clause of a try...finally |
| block |
| """ |
| # 1 - Is it right sibling ? |
| self._check_unreachable(node) |
| # 2 - Is it inside final body of a try...finally bloc ? |
| self._check_not_in_finally(node, 'break', (astroid.For, astroid.While,)) |
| |
| @check_messages('unreachable') |
| def visit_raise(self, node): |
| """check if the node has a right sibling (if so, that's some unreachable |
| code) |
| """ |
| self._check_unreachable(node) |
| |
| @check_messages('exec-used') |
| def visit_exec(self, node): |
| """just print a warning on exec statements""" |
| self.add_message('exec-used', node=node) |
| |
| @check_messages('bad-builtin', 'star-args', 'eval-used', |
| 'exec-used', 'missing-reversed-argument', |
| 'bad-reversed-sequence') |
| def visit_callfunc(self, node): |
| """visit a CallFunc node -> check if this is not a blacklisted builtin |
| call and check for * or ** use |
| """ |
| if isinstance(node.func, astroid.Name): |
| name = node.func.name |
| # ignore the name if it's not a builtin (i.e. not defined in the |
| # locals nor globals scope) |
| if not (name in node.frame() or |
| name in node.root()): |
| if name == 'exec': |
| self.add_message('exec-used', node=node) |
| elif name == 'reversed': |
| self._check_reversed(node) |
| elif name == 'eval': |
| self.add_message('eval-used', node=node) |
| if name in self.config.bad_functions: |
| self.add_message('bad-builtin', node=node, args=name) |
| if node.starargs or node.kwargs: |
| scope = node.scope() |
| if isinstance(scope, astroid.Function): |
| toprocess = [(n, vn) for (n, vn) in ((node.starargs, scope.args.vararg), |
| (node.kwargs, scope.args.kwarg)) if n] |
| if toprocess: |
| for cfnode, fargname in toprocess[:]: |
| if getattr(cfnode, 'name', None) == fargname: |
| toprocess.remove((cfnode, fargname)) |
| if not toprocess: |
| return # star-args can be skipped |
| self.add_message('star-args', node=node.func) |
| |
| @check_messages('assert-on-tuple') |
| def visit_assert(self, node): |
| """check the use of an assert statement on a tuple.""" |
| if node.fail is None and isinstance(node.test, astroid.Tuple) and \ |
| len(node.test.elts) == 2: |
| self.add_message('assert-on-tuple', node=node) |
| |
| @check_messages('duplicate-key') |
| def visit_dict(self, node): |
| """check duplicate key in dictionary""" |
| keys = set() |
| for k, _ in node.items: |
| if isinstance(k, astroid.Const): |
| key = k.value |
| if key in keys: |
| self.add_message('duplicate-key', node=node, args=key) |
| keys.add(key) |
| |
| def visit_tryfinally(self, node): |
| """update try...finally flag""" |
| self._tryfinallys.append(node) |
| |
| def leave_tryfinally(self, node): # pylint: disable=unused-argument |
| """update try...finally flag""" |
| self._tryfinallys.pop() |
| |
| def _check_unreachable(self, node): |
| """check unreachable code""" |
| unreach_stmt = node.next_sibling() |
| if unreach_stmt is not None: |
| self.add_message('unreachable', node=unreach_stmt) |
| |
| def _check_not_in_finally(self, node, node_name, breaker_classes=()): |
| """check that a node is not inside a finally clause of a |
| try...finally statement. |
| If we found before a try...finally bloc a parent which its type is |
| in breaker_classes, we skip the whole check.""" |
| # if self._tryfinallys is empty, we're not a in try...finally bloc |
| if not self._tryfinallys: |
| return |
| # the node could be a grand-grand...-children of the try...finally |
| _parent = node.parent |
| _node = node |
| while _parent and not isinstance(_parent, breaker_classes): |
| if hasattr(_parent, 'finalbody') and _node in _parent.finalbody: |
| self.add_message('lost-exception', node=node, args=node_name) |
| return |
| _node = _parent |
| _parent = _node.parent |
| |
| def _check_reversed(self, node): |
| """ check that the argument to `reversed` is a sequence """ |
| try: |
| argument = safe_infer(get_argument_from_call(node, position=0)) |
| except NoSuchArgumentError: |
| self.add_message('missing-reversed-argument', node=node) |
| else: |
| if argument is astroid.YES: |
| return |
| if argument is None: |
| # Nothing was infered. |
| # Try to see if we have iter(). |
| if isinstance(node.args[0], astroid.CallFunc): |
| try: |
| func = next(node.args[0].func.infer()) |
| except InferenceError: |
| return |
| if (getattr(func, 'name', None) == 'iter' and |
| is_builtin_object(func)): |
| self.add_message('bad-reversed-sequence', node=node) |
| return |
| |
| if isinstance(argument, astroid.Instance): |
| if (argument._proxied.name == 'dict' and |
| is_builtin_object(argument._proxied)): |
| self.add_message('bad-reversed-sequence', node=node) |
| return |
| elif any(ancestor.name == 'dict' and is_builtin_object(ancestor) |
| for ancestor in argument._proxied.ancestors()): |
| # mappings aren't accepted by reversed() |
| self.add_message('bad-reversed-sequence', node=node) |
| return |
| |
| for methods in REVERSED_METHODS: |
| for meth in methods: |
| try: |
| argument.getattr(meth) |
| except astroid.NotFoundError: |
| break |
| else: |
| break |
| else: |
| # Check if it is a .deque. It doesn't seem that |
| # we can retrieve special methods |
| # from C implemented constructs. |
| if argument._proxied.qname().endswith(".deque"): |
| return |
| self.add_message('bad-reversed-sequence', node=node) |
| elif not isinstance(argument, (astroid.List, astroid.Tuple)): |
| # everything else is not a proper sequence for reversed() |
| self.add_message('bad-reversed-sequence', node=node) |
| |
| _NAME_TYPES = { |
| 'module': (MOD_NAME_RGX, 'module'), |
| 'const': (CONST_NAME_RGX, 'constant'), |
| 'class': (CLASS_NAME_RGX, 'class'), |
| 'function': (DEFAULT_NAME_RGX, 'function'), |
| 'method': (DEFAULT_NAME_RGX, 'method'), |
| 'attr': (DEFAULT_NAME_RGX, 'attribute'), |
| 'argument': (DEFAULT_NAME_RGX, 'argument'), |
| 'variable': (DEFAULT_NAME_RGX, 'variable'), |
| 'class_attribute': (CLASS_ATTRIBUTE_RGX, 'class attribute'), |
| 'inlinevar': (COMP_VAR_RGX, 'inline iteration'), |
| } |
| |
| def _create_naming_options(): |
| name_options = [] |
| for name_type, (rgx, human_readable_name) in six.iteritems(_NAME_TYPES): |
| name_type = name_type.replace('_', '-') |
| name_options.append(( |
| '%s-rgx' % (name_type,), |
| {'default': rgx, 'type': 'regexp', 'metavar': '<regexp>', |
| 'help': 'Regular expression matching correct %s names' % (human_readable_name,)})) |
| name_options.append(( |
| '%s-name-hint' % (name_type,), |
| {'default': rgx.pattern, 'type': 'string', 'metavar': '<string>', |
| 'help': 'Naming hint for %s names' % (human_readable_name,)})) |
| return tuple(name_options) |
| |
| class NameChecker(_BasicChecker): |
| msgs = { |
| 'C0102': ('Black listed name "%s"', |
| 'blacklisted-name', |
| 'Used when the name is listed in the black list (unauthorized ' |
| 'names).'), |
| 'C0103': ('Invalid %s name "%s"%s', |
| 'invalid-name', |
| 'Used when the name doesn\'t match the regular expression ' |
| 'associated to its type (constant, variable, class...).'), |
| } |
| |
| options = (('good-names', |
| {'default' : ('i', 'j', 'k', 'ex', 'Run', '_'), |
| 'type' :'csv', 'metavar' : '<names>', |
| 'help' : 'Good variable names which should always be accepted,' |
| ' separated by a comma'} |
| ), |
| ('bad-names', |
| {'default' : ('foo', 'bar', 'baz', 'toto', 'tutu', 'tata'), |
| 'type' :'csv', 'metavar' : '<names>', |
| 'help' : 'Bad variable names which should always be refused, ' |
| 'separated by a comma'} |
| ), |
| ('name-group', |
| {'default' : (), |
| 'type' :'csv', 'metavar' : '<name1:name2>', |
| 'help' : ('Colon-delimited sets of names that determine each' |
| ' other\'s naming style when the name regexes' |
| ' allow several styles.')} |
| ), |
| ('include-naming-hint', |
| {'default': False, 'type' : 'yn', 'metavar' : '<y_or_n>', |
| 'help': 'Include a hint for the correct naming format with invalid-name'} |
| ), |
| ) + _create_naming_options() |
| |
| |
| def __init__(self, linter): |
| _BasicChecker.__init__(self, linter) |
| self._name_category = {} |
| self._name_group = {} |
| self._bad_names = {} |
| |
| def open(self): |
| self.stats = self.linter.add_stats(badname_module=0, |
| badname_class=0, badname_function=0, |
| badname_method=0, badname_attr=0, |
| badname_const=0, |
| badname_variable=0, |
| badname_inlinevar=0, |
| badname_argument=0, |
| badname_class_attribute=0) |
| for group in self.config.name_group: |
| for name_type in group.split(':'): |
| self._name_group[name_type] = 'group_%s' % (group,) |
| |
| @check_messages('blacklisted-name', 'invalid-name') |
| def visit_module(self, node): |
| self._check_name('module', node.name.split('.')[-1], node) |
| self._bad_names = {} |
| |
| def leave_module(self, node): # pylint: disable=unused-argument |
| for all_groups in six.itervalues(self._bad_names): |
| if len(all_groups) < 2: |
| continue |
| groups = collections.defaultdict(list) |
| min_warnings = sys.maxsize |
| for group in six.itervalues(all_groups): |
| groups[len(group)].append(group) |
| min_warnings = min(len(group), min_warnings) |
| if len(groups[min_warnings]) > 1: |
| by_line = sorted(groups[min_warnings], |
| key=lambda group: min(warning[0].lineno for warning in group)) |
| warnings = itertools.chain(*by_line[1:]) |
| else: |
| warnings = groups[min_warnings][0] |
| for args in warnings: |
| self._raise_name_warning(*args) |
| |
| @check_messages('blacklisted-name', 'invalid-name') |
| def visit_class(self, node): |
| self._check_name('class', node.name, node) |
| for attr, anodes in six.iteritems(node.instance_attrs): |
| if not list(node.instance_attr_ancestors(attr)): |
| self._check_name('attr', attr, anodes[0]) |
| |
| @check_messages('blacklisted-name', 'invalid-name') |
| def visit_function(self, node): |
| # Do not emit any warnings if the method is just an implementation |
| # of a base class method. |
| confidence = HIGH |
| if node.is_method(): |
| if overrides_a_method(node.parent.frame(), node.name): |
| return |
| confidence = (INFERENCE if has_known_bases(node.parent.frame()) |
| else INFERENCE_FAILURE) |
| |
| self._check_name(_determine_function_name_type(node), |
| node.name, node, confidence) |
| # Check argument names |
| args = node.args.args |
| if args is not None: |
| self._recursive_check_names(args, node) |
| |
| @check_messages('blacklisted-name', 'invalid-name') |
| def visit_global(self, node): |
| for name in node.names: |
| self._check_name('const', name, node) |
| |
| @check_messages('blacklisted-name', 'invalid-name') |
| def visit_assname(self, node): |
| """check module level assigned names""" |
| frame = node.frame() |
| ass_type = node.ass_type() |
| if isinstance(ass_type, astroid.Comprehension): |
| self._check_name('inlinevar', node.name, node) |
| elif isinstance(frame, astroid.Module): |
| if isinstance(ass_type, astroid.Assign) and not in_loop(ass_type): |
| if isinstance(safe_infer(ass_type.value), astroid.Class): |
| self._check_name('class', node.name, node) |
| else: |
| if not _redefines_import(node): |
| # Don't emit if the name redefines an import |
| # in an ImportError except handler. |
| self._check_name('const', node.name, node) |
| elif isinstance(ass_type, astroid.ExceptHandler): |
| self._check_name('variable', node.name, node) |
| elif isinstance(frame, astroid.Function): |
| # global introduced variable aren't in the function locals |
| if node.name in frame and node.name not in frame.argnames(): |
| if not _redefines_import(node): |
| self._check_name('variable', node.name, node) |
| elif isinstance(frame, astroid.Class): |
| if not list(frame.local_attr_ancestors(node.name)): |
| self._check_name('class_attribute', node.name, node) |
| |
| def _recursive_check_names(self, args, node): |
| """check names in a possibly recursive list <arg>""" |
| for arg in args: |
| if isinstance(arg, astroid.AssName): |
| self._check_name('argument', arg.name, node) |
| else: |
| self._recursive_check_names(arg.elts, node) |
| |
| def _find_name_group(self, node_type): |
| return self._name_group.get(node_type, node_type) |
| |
| def _raise_name_warning(self, node, node_type, name, confidence): |
| type_label = _NAME_TYPES[node_type][1] |
| hint = '' |
| if self.config.include_naming_hint: |
| hint = ' (hint: %s)' % (getattr(self.config, node_type + '_name_hint')) |
| self.add_message('invalid-name', node=node, args=(type_label, name, hint), |
| confidence=confidence) |
| self.stats['badname_' + node_type] += 1 |
| |
| def _check_name(self, node_type, name, node, confidence=HIGH): |
| """check for a name using the type's regexp""" |
| if is_inside_except(node): |
| clobbering, _ = clobber_in_except(node) |
| if clobbering: |
| return |
| if name in self.config.good_names: |
| return |
| if name in self.config.bad_names: |
| self.stats['badname_' + node_type] += 1 |
| self.add_message('blacklisted-name', node=node, args=name) |
| return |
| regexp = getattr(self.config, node_type + '_rgx') |
| match = regexp.match(name) |
| |
| if _is_multi_naming_match(match, node_type, confidence): |
| name_group = self._find_name_group(node_type) |
| bad_name_group = self._bad_names.setdefault(name_group, {}) |
| warnings = bad_name_group.setdefault(match.lastgroup, []) |
| warnings.append((node, node_type, name, confidence)) |
| |
| if match is None: |
| self._raise_name_warning(node, node_type, name, confidence) |
| |
| |
| class DocStringChecker(_BasicChecker): |
| msgs = { |
| 'C0111': ('Missing %s docstring', # W0131 |
| 'missing-docstring', |
| 'Used when a module, function, class or method has no docstring.' |
| 'Some special methods like __init__ doesn\'t necessary require a ' |
| 'docstring.'), |
| 'C0112': ('Empty %s docstring', # W0132 |
| 'empty-docstring', |
| 'Used when a module, function, class or method has an empty ' |
| 'docstring (it would be too easy ;).'), |
| } |
| options = (('no-docstring-rgx', |
| {'default' : NO_REQUIRED_DOC_RGX, |
| 'type' : 'regexp', 'metavar' : '<regexp>', |
| 'help' : 'Regular expression which should only match ' |
| 'function or class names that do not require a ' |
| 'docstring.'} |
| ), |
| ('docstring-min-length', |
| {'default' : -1, |
| 'type' : 'int', 'metavar' : '<int>', |
| 'help': ('Minimum line length for functions/classes that' |
| ' require docstrings, shorter ones are exempt.')} |
| ), |
| ) |
| |
| |
| def open(self): |
| self.stats = self.linter.add_stats(undocumented_module=0, |
| undocumented_function=0, |
| undocumented_method=0, |
| undocumented_class=0) |
| @check_messages('missing-docstring', 'empty-docstring') |
| def visit_module(self, node): |
| self._check_docstring('module', node) |
| |
| @check_messages('missing-docstring', 'empty-docstring') |
| def visit_class(self, node): |
| if self.config.no_docstring_rgx.match(node.name) is None: |
| self._check_docstring('class', node) |
| |
| @check_messages('missing-docstring', 'empty-docstring') |
| def visit_function(self, node): |
| if self.config.no_docstring_rgx.match(node.name) is None: |
| ftype = node.is_method() and 'method' or 'function' |
| if isinstance(node.parent.frame(), astroid.Class): |
| overridden = False |
| confidence = (INFERENCE if has_known_bases(node.parent.frame()) |
| else INFERENCE_FAILURE) |
| # check if node is from a method overridden by its ancestor |
| for ancestor in node.parent.frame().ancestors(): |
| if node.name in ancestor and \ |
| isinstance(ancestor[node.name], astroid.Function): |
| overridden = True |
| break |
| self._check_docstring(ftype, node, |
| report_missing=not overridden, |
| confidence=confidence) |
| else: |
| self._check_docstring(ftype, node) |
| |
| def _check_docstring(self, node_type, node, report_missing=True, |
| confidence=HIGH): |
| """check the node has a non empty docstring""" |
| docstring = node.doc |
| if docstring is None: |
| if not report_missing: |
| return |
| if node.body: |
| lines = node.body[-1].lineno - node.body[0].lineno + 1 |
| else: |
| lines = 0 |
| max_lines = self.config.docstring_min_length |
| |
| if node_type != 'module' and max_lines > -1 and lines < max_lines: |
| return |
| self.stats['undocumented_'+node_type] += 1 |
| if (node.body and isinstance(node.body[0], astroid.Discard) and |
| isinstance(node.body[0].value, astroid.CallFunc)): |
| # Most likely a string with a format call. Let's see. |
| func = safe_infer(node.body[0].value.func) |
| if (isinstance(func, astroid.BoundMethod) |
| and isinstance(func.bound, astroid.Instance)): |
| # Strings in Python 3, others in Python 2. |
| if PY3K and func.bound.name == 'str': |
| return |
| elif func.bound.name in ('str', 'unicode', 'bytes'): |
| return |
| self.add_message('missing-docstring', node=node, args=(node_type,), |
| confidence=confidence) |
| elif not docstring.strip(): |
| self.stats['undocumented_'+node_type] += 1 |
| self.add_message('empty-docstring', node=node, args=(node_type,), |
| confidence=confidence) |
| |
| |
| class PassChecker(_BasicChecker): |
| """check if the pass statement is really necessary""" |
| msgs = {'W0107': ('Unnecessary pass statement', |
| 'unnecessary-pass', |
| 'Used when a "pass" statement that can be avoided is ' |
| 'encountered.'), |
| } |
| @check_messages('unnecessary-pass') |
| def visit_pass(self, node): |
| if len(node.parent.child_sequence(node)) > 1: |
| self.add_message('unnecessary-pass', node=node) |
| |
| |
| class LambdaForComprehensionChecker(_BasicChecker): |
| """check for using a lambda where a comprehension would do. |
| |
| See <http://www.artima.com/weblogs/viewpost.jsp?thread=98196> |
| where GvR says comprehensions would be clearer. |
| """ |
| |
| msgs = {'W0110': ('map/filter on lambda could be replaced by comprehension', |
| 'deprecated-lambda', |
| 'Used when a lambda is the first argument to "map" or ' |
| '"filter". It could be clearer as a list ' |
| 'comprehension or generator expression.', |
| {'maxversion': (3, 0)}), |
| } |
| |
| @check_messages('deprecated-lambda') |
| def visit_callfunc(self, node): |
| """visit a CallFunc node, check if map or filter are called with a |
| lambda |
| """ |
| if not node.args: |
| return |
| if not isinstance(node.args[0], astroid.Lambda): |
| return |
| infered = safe_infer(node.func) |
| if (is_builtin_object(infered) |
| and infered.name in ['map', 'filter']): |
| self.add_message('deprecated-lambda', node=node) |
| |
| |
| def register(linter): |
| """required method to auto register this checker""" |
| linter.register_checker(BasicErrorChecker(linter)) |
| linter.register_checker(BasicChecker(linter)) |
| linter.register_checker(NameChecker(linter)) |
| linter.register_checker(DocStringChecker(linter)) |
| linter.register_checker(PassChecker(linter)) |
| linter.register_checker(LambdaForComprehensionChecker(linter)) |
