| # Copyright (c) 2005-2014 LOGILAB S.A. (Paris, FRANCE). |
| # http://www.logilab.fr/ -- mailto:contact@logilab.fr |
| # |
| # 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. |
| """check for new / old style related problems |
| """ |
| import sys |
| |
| import astroid |
| |
| from pylint.interfaces import IAstroidChecker, INFERENCE, INFERENCE_FAILURE, HIGH |
| from pylint.checkers import BaseChecker |
| from pylint.checkers.utils import ( |
| check_messages, |
| has_known_bases, |
| node_frame_class, |
| ) |
| |
| MSGS = { |
| 'E1001': ('Use of __slots__ on an old style class', |
| 'slots-on-old-class', |
| 'Used when an old style class uses the __slots__ attribute.', |
| {'maxversion': (3, 0)}), |
| 'E1002': ('Use of super on an old style class', |
| 'super-on-old-class', |
| 'Used when an old style class uses the super builtin.', |
| {'maxversion': (3, 0)}), |
| 'E1003': ('Bad first argument %r given to super()', |
| 'bad-super-call', |
| 'Used when another argument than the current class is given as \ |
| first argument of the super builtin.'), |
| 'E1004': ('Missing argument to super()', |
| 'missing-super-argument', |
| 'Used when the super builtin didn\'t receive an \ |
| argument.', |
| {'maxversion': (3, 0)}), |
| 'W1001': ('Use of "property" on an old style class', |
| 'property-on-old-class', |
| 'Used when Pylint detect the use of the builtin "property" \ |
| on an old style class while this is relying on new style \ |
| classes features.', |
| {'maxversion': (3, 0)}), |
| 'C1001': ('Old-style class defined.', |
| 'old-style-class', |
| 'Used when a class is defined that does not inherit from another' |
| 'class and does not inherit explicitly from "object".', |
| {'maxversion': (3, 0)}) |
| } |
| |
| |
| class NewStyleConflictChecker(BaseChecker): |
| """checks for usage of new style capabilities on old style classes and |
| other new/old styles conflicts problems |
| * use of property, __slots__, super |
| * "super" usage |
| """ |
| |
| __implements__ = (IAstroidChecker,) |
| |
| # configuration section name |
| name = 'newstyle' |
| # messages |
| msgs = MSGS |
| priority = -2 |
| # configuration options |
| options = () |
| |
| @check_messages('slots-on-old-class', 'old-style-class') |
| def visit_class(self, node): |
| """ Check __slots__ in old style classes and old |
| style class definition. |
| """ |
| if '__slots__' in node and not node.newstyle: |
| confidence = (INFERENCE if has_known_bases(node) |
| else INFERENCE_FAILURE) |
| self.add_message('slots-on-old-class', node=node, |
| confidence=confidence) |
| # The node type could be class, exception, metaclass, or |
| # interface. Presumably, the non-class-type nodes would always |
| # have an explicit base class anyway. |
| if not node.bases and node.type == 'class' and not node.metaclass(): |
| # We use confidence HIGH here because this message should only ever |
| # be emitted for classes at the root of the inheritance hierarchyself. |
| self.add_message('old-style-class', node=node, confidence=HIGH) |
| |
| @check_messages('property-on-old-class') |
| def visit_callfunc(self, node): |
| """check property usage""" |
| parent = node.parent.frame() |
| if (isinstance(parent, astroid.Class) and |
| not parent.newstyle and |
| isinstance(node.func, astroid.Name)): |
| confidence = (INFERENCE if has_known_bases(parent) |
| else INFERENCE_FAILURE) |
| name = node.func.name |
| if name == 'property': |
| self.add_message('property-on-old-class', node=node, |
| confidence=confidence) |
| |
| @check_messages('super-on-old-class', 'bad-super-call', 'missing-super-argument') |
| def visit_function(self, node): |
| """check use of super""" |
| # ignore actual functions or method within a new style class |
| if not node.is_method(): |
| return |
| klass = node.parent.frame() |
| for stmt in node.nodes_of_class(astroid.CallFunc): |
| if node_frame_class(stmt) != node_frame_class(node): |
| # Don't look down in other scopes. |
| continue |
| expr = stmt.func |
| if not isinstance(expr, astroid.Getattr): |
| continue |
| call = expr.expr |
| # skip the test if using super |
| if isinstance(call, astroid.CallFunc) and \ |
| isinstance(call.func, astroid.Name) and \ |
| call.func.name == 'super': |
| confidence = (INFERENCE if has_known_bases(klass) |
| else INFERENCE_FAILURE) |
| if not klass.newstyle: |
| # super should not be used on an old style class |
| self.add_message('super-on-old-class', node=node, |
| confidence=confidence) |
| else: |
| # super first arg should be the class |
| if not call.args and sys.version_info[0] == 3: |
| # unless Python 3 |
| continue |
| |
| try: |
| supcls = (call.args and next(call.args[0].infer()) |
| or None) |
| except astroid.InferenceError: |
| continue |
| |
| if supcls is None: |
| self.add_message('missing-super-argument', node=call, |
| confidence=confidence) |
| continue |
| |
| if klass is not supcls: |
| name = None |
| # if supcls is not YES, then supcls was infered |
| # and use its name. Otherwise, try to look |
| # for call.args[0].name |
| if supcls is not astroid.YES: |
| name = supcls.name |
| else: |
| if hasattr(call.args[0], 'name'): |
| name = call.args[0].name |
| if name is not None: |
| self.add_message('bad-super-call', |
| node=call, |
| args=(name, ), |
| confidence=confidence) |
| |
| |
| def register(linter): |
| """required method to auto register this checker """ |
| linter.register_checker(NewStyleConflictChecker(linter)) |
