1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
# 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,
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 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)
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, ))
def register(linter):
"""required method to auto register this checker """
linter.register_checker(NewStyleConflictChecker(linter))
|
