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- # Copyright (c) 2006, 2008-2011, 2013-2014 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr>
- # Copyright (c) 2012-2014 Google, Inc.
- # Copyright (c) 2013-2017 Claudiu Popa <pcmanticore@gmail.com>
- # Copyright (c) 2014 Michal Nowikowski <godfryd@gmail.com>
- # Copyright (c) 2014 Brett Cannon <brett@python.org>
- # Copyright (c) 2014 Arun Persaud <arun@nubati.net>
- # Copyright (c) 2015 Ionel Cristian Maries <contact@ionelmc.ro>
- # Copyright (c) 2016 Alexander Todorov <atodorov@otb.bg>
- # Copyright (c) 2016 Jakub Wilk <jwilk@jwilk.net>
-
- # 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
-
- """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,
- node_frame_class,
- has_known_bases
- )
-
- 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_classdef(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_call(self, node):
- """check property usage"""
- parent = node.parent.frame()
- if (isinstance(parent, astroid.ClassDef) 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_functiondef(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.Call):
- 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.Attribute):
- continue
-
- call = expr.expr
- # skip the test if using super
- if not (isinstance(call, astroid.Call) and
- isinstance(call.func, astroid.Name) and
- call.func.name == 'super'):
- continue
-
- if not klass.newstyle and has_known_bases(klass):
- # super should not be used on an old style class
- self.add_message('super-on-old-class', node=node)
- else:
- # super first arg should be the class
- if not call.args:
- if sys.version_info[0] == 3:
- # unless Python 3
- continue
- else:
- self.add_message('missing-super-argument', node=call)
- continue
-
- # calling super(type(self), self) can lead to recursion loop
- # in derived classes
- arg0 = call.args[0]
- if isinstance(arg0, astroid.Call) and \
- isinstance(arg0.func, astroid.Name) and \
- arg0.func.name == 'type':
- self.add_message('bad-super-call', node=call, args=('type', ))
- continue
-
- # calling super(self.__class__, self) can lead to recursion loop
- # in derived classes
- if len(call.args) >= 2 and \
- isinstance(call.args[1], astroid.Name) and \
- call.args[1].name == 'self' and \
- isinstance(arg0, astroid.Attribute) and \
- arg0.attrname == '__class__':
- self.add_message('bad-super-call', node=call, args=('self.__class__', ))
- continue
-
- try:
- supcls = call.args and next(call.args[0].infer(), None)
- except astroid.InferenceError:
- 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:
- name = supcls.name
- elif call.args and hasattr(call.args[0], 'name'):
- name = call.args[0].name
- if name:
- self.add_message('bad-super-call', node=call, args=(name, ))
-
- visit_asyncfunctiondef = visit_functiondef
-
-
- def register(linter):
- """required method to auto register this checker """
- linter.register_checker(NewStyleConflictChecker(linter))
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