mirror of
https://fuchsia.googlesource.com/third_party/github.com/pylint-dev/pylint
synced 2024-09-21 16:19:21 +00:00
103 lines
3.8 KiB
Python
103 lines
3.8 KiB
Python
# 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
|
|
|
|
import six
|
|
|
|
import astroid
|
|
from pylint.checkers import BaseChecker
|
|
from pylint.checkers.utils import check_messages
|
|
from pylint.checkers.base import _is_none, _node_type
|
|
from pylint.interfaces import IAstroidChecker
|
|
|
|
|
|
BUILTINS = six.moves.builtins.__name__
|
|
|
|
|
|
class MultipleTypesChecker(BaseChecker):
|
|
"""Checks for variable type redefinitions (NoneType excepted)
|
|
|
|
At a function, method, class or module scope
|
|
|
|
This rule could be improved:
|
|
- Currently, if an attribute is set to different types in 2 methods of a
|
|
same class, it won't be detected (see functional test)
|
|
- One could improve the support for inference on assignment with tuples,
|
|
ifexpr, etc. Also it would be great to have support for inference on
|
|
str.split()
|
|
"""
|
|
__implements__ = IAstroidChecker
|
|
|
|
name = 'multiple_types'
|
|
msgs = {'R0204': ('Redefinition of %s type from %s to %s',
|
|
'redefined-variable-type',
|
|
'Used when the type of a variable changes inside a '
|
|
'method or a function.'
|
|
),
|
|
}
|
|
|
|
def visit_classdef(self, _):
|
|
self._assigns.append({})
|
|
|
|
@check_messages('redefined-variable-type')
|
|
def leave_classdef(self, _):
|
|
self._check_and_add_messages()
|
|
|
|
visit_functiondef = visit_classdef
|
|
leave_functiondef = leave_module = leave_classdef
|
|
|
|
def visit_module(self, _):
|
|
self._assigns = [{}]
|
|
|
|
def _check_and_add_messages(self):
|
|
assigns = self._assigns.pop()
|
|
for name, args in assigns.items():
|
|
if len(args) <= 1:
|
|
continue
|
|
orig_node, orig_type = args[0]
|
|
# Check if there is a type in the following nodes that would be
|
|
# different from orig_type.
|
|
for redef_node, redef_type in args[1:]:
|
|
if redef_type == orig_type:
|
|
continue
|
|
# if a variable is defined to several types in a if node,
|
|
# this is not actually redefining.
|
|
orig_parent = orig_node.parent
|
|
redef_parent = redef_node.parent
|
|
if isinstance(orig_parent, astroid.If):
|
|
if orig_parent == redef_parent:
|
|
if (redef_node in orig_parent.orelse and
|
|
orig_node not in orig_parent.orelse):
|
|
orig_node, orig_type = redef_node, redef_type
|
|
continue
|
|
elif (isinstance(redef_parent, astroid.If) and
|
|
redef_parent in orig_parent.nodes_of_class(astroid.If)):
|
|
orig_node, orig_type = redef_node, redef_type
|
|
continue
|
|
orig_type = orig_type.replace(BUILTINS + ".", '')
|
|
redef_type = redef_type.replace(BUILTINS + ".", '')
|
|
self.add_message('redefined-variable-type', node=redef_node,
|
|
args=(name, orig_type, redef_type))
|
|
break
|
|
|
|
def visit_assign(self, node):
|
|
# we don't handle multiple assignment nor slice assignment
|
|
target = node.targets[0]
|
|
if isinstance(target, (astroid.Tuple, astroid.Subscript)):
|
|
return
|
|
# ignore NoneType
|
|
if _is_none(node):
|
|
return
|
|
_type = _node_type(node.value)
|
|
if _type:
|
|
self._assigns[-1].setdefault(target.as_string(), []).append(
|
|
(node, _type.pytype()))
|
|
|
|
|
|
def register(linter):
|
|
"""Required method to auto register this checker.
|
|
|
|
:param linter: Main interface object for Pylint plugins
|
|
:type linter: Pylint object
|
|
"""
|
|
linter.register_checker(MultipleTypesChecker(linter))
|