You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1070 lines
47 KiB
Python
1070 lines
47 KiB
Python
# Copyright (c) 2003-2014 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.
|
|
"""variables checkers for Python code
|
|
"""
|
|
import os
|
|
import sys
|
|
import re
|
|
from copy import copy
|
|
|
|
import astroid
|
|
from astroid import are_exclusive, builtin_lookup
|
|
from astroid import modutils
|
|
|
|
from pylint.interfaces import IAstroidChecker, INFERENCE, INFERENCE_FAILURE, HIGH
|
|
from pylint.utils import get_global_option
|
|
from pylint.checkers import BaseChecker
|
|
from pylint.checkers.utils import (
|
|
PYMETHODS, is_ancestor_name, is_builtin,
|
|
is_defined_before, is_error, is_func_default, is_func_decorator,
|
|
assign_parent, check_messages, is_inside_except, clobber_in_except,
|
|
get_all_elements, has_known_bases)
|
|
import six
|
|
|
|
SPECIAL_OBJ = re.compile("^_{2}[a-z]+_{2}$")
|
|
|
|
PY3K = sys.version_info >= (3, 0)
|
|
|
|
def in_for_else_branch(parent, stmt):
|
|
"""Returns True if stmt in inside the else branch for a parent For stmt."""
|
|
return (isinstance(parent, astroid.For) and
|
|
any(else_stmt.parent_of(stmt) for else_stmt in parent.orelse))
|
|
|
|
def overridden_method(klass, name):
|
|
"""get overridden method if any"""
|
|
try:
|
|
parent = next(klass.local_attr_ancestors(name))
|
|
except (StopIteration, KeyError):
|
|
return None
|
|
try:
|
|
meth_node = parent[name]
|
|
except KeyError:
|
|
# We have found an ancestor defining <name> but it's not in the local
|
|
# dictionary. This may happen with astroid built from living objects.
|
|
return None
|
|
if isinstance(meth_node, astroid.Function):
|
|
return meth_node
|
|
return None
|
|
|
|
def _get_unpacking_extra_info(node, infered):
|
|
"""return extra information to add to the message for unpacking-non-sequence
|
|
and unbalanced-tuple-unpacking errors
|
|
"""
|
|
more = ''
|
|
infered_module = infered.root().name
|
|
if node.root().name == infered_module:
|
|
if node.lineno == infered.lineno:
|
|
more = ' %s' % infered.as_string()
|
|
elif infered.lineno:
|
|
more = ' defined at line %s' % infered.lineno
|
|
elif infered.lineno:
|
|
more = ' defined at line %s of %s' % (infered.lineno, infered_module)
|
|
return more
|
|
|
|
def _detect_global_scope(node, frame, defframe):
|
|
""" Detect that the given frames shares a global
|
|
scope.
|
|
|
|
Two frames shares a global scope when neither
|
|
of them are hidden under a function scope, as well
|
|
as any of parent scope of them, until the root scope.
|
|
In this case, depending from something defined later on
|
|
will not work, because it is still undefined.
|
|
|
|
Example:
|
|
class A:
|
|
# B has the same global scope as `C`, leading to a NameError.
|
|
class B(C): ...
|
|
class C: ...
|
|
|
|
"""
|
|
def_scope = scope = None
|
|
if frame and frame.parent:
|
|
scope = frame.parent.scope()
|
|
if defframe and defframe.parent:
|
|
def_scope = defframe.parent.scope()
|
|
if isinstance(frame, astroid.Function):
|
|
# If the parent of the current node is a
|
|
# function, then it can be under its scope
|
|
# (defined in, which doesn't concern us) or
|
|
# the `->` part of annotations. The same goes
|
|
# for annotations of function arguments, they'll have
|
|
# their parent the Arguments node.
|
|
if not isinstance(node.parent,
|
|
(astroid.Function, astroid.Arguments)):
|
|
return False
|
|
elif any(not isinstance(f, (astroid.Class, astroid.Module))
|
|
for f in (frame, defframe)):
|
|
# Not interested in other frames, since they are already
|
|
# not in a global scope.
|
|
return False
|
|
|
|
break_scopes = []
|
|
for s in (scope, def_scope):
|
|
# Look for parent scopes. If there is anything different
|
|
# than a module or a class scope, then they frames don't
|
|
# share a global scope.
|
|
parent_scope = s
|
|
while parent_scope:
|
|
if not isinstance(parent_scope, (astroid.Class, astroid.Module)):
|
|
break_scopes.append(parent_scope)
|
|
break
|
|
if parent_scope.parent:
|
|
parent_scope = parent_scope.parent.scope()
|
|
else:
|
|
break
|
|
if break_scopes and len(set(break_scopes)) != 1:
|
|
# Store different scopes than expected.
|
|
# If the stored scopes are, in fact, the very same, then it means
|
|
# that the two frames (frame and defframe) shares the same scope,
|
|
# and we could apply our lineno analysis over them.
|
|
# For instance, this works when they are inside a function, the node
|
|
# that uses a definition and the definition itself.
|
|
return False
|
|
# At this point, we are certain that frame and defframe shares a scope
|
|
# and the definition of the first depends on the second.
|
|
return frame.lineno < defframe.lineno
|
|
|
|
def _fix_dot_imports(not_consumed):
|
|
""" Try to fix imports with multiple dots, by returning a dictionary
|
|
with the import names expanded. The function unflattens root imports,
|
|
like 'xml' (when we have both 'xml.etree' and 'xml.sax'), to 'xml.etree'
|
|
and 'xml.sax' respectively.
|
|
"""
|
|
# TODO: this should be improved in issue astroid #46
|
|
names = {}
|
|
for name, stmts in six.iteritems(not_consumed):
|
|
if any(isinstance(stmt, astroid.AssName)
|
|
and isinstance(stmt.ass_type(), astroid.AugAssign)
|
|
for stmt in stmts):
|
|
continue
|
|
for stmt in stmts:
|
|
if not isinstance(stmt, (astroid.From, astroid.Import)):
|
|
continue
|
|
for imports in stmt.names:
|
|
second_name = None
|
|
if imports[0] == "*":
|
|
# In case of wildcard imports,
|
|
# pick the name from inside the imported module.
|
|
second_name = name
|
|
else:
|
|
if imports[0].find(".") > -1 or name in imports:
|
|
# Most likely something like 'xml.etree',
|
|
# which will appear in the .locals as 'xml'.
|
|
# Only pick the name if it wasn't consumed.
|
|
second_name = imports[0]
|
|
if second_name and second_name not in names:
|
|
names[second_name] = stmt
|
|
return sorted(names.items(), key=lambda a: a[1].fromlineno)
|
|
|
|
def _find_frame_imports(name, frame):
|
|
"""
|
|
Detect imports in the frame, with the required
|
|
*name*. Such imports can be considered assignments.
|
|
Returns True if an import for the given name was found.
|
|
"""
|
|
imports = frame.nodes_of_class((astroid.Import, astroid.From))
|
|
for import_node in imports:
|
|
for import_name, import_alias in import_node.names:
|
|
# If the import uses an alias, check only that.
|
|
# Otherwise, check only the import name.
|
|
if import_alias:
|
|
if import_alias == name:
|
|
return True
|
|
elif import_name and import_name == name:
|
|
return True
|
|
|
|
|
|
MSGS = {
|
|
'E0601': ('Using variable %r before assignment',
|
|
'used-before-assignment',
|
|
'Used when a local variable is accessed before it\'s \
|
|
assignment.'),
|
|
'E0602': ('Undefined variable %r',
|
|
'undefined-variable',
|
|
'Used when an undefined variable is accessed.'),
|
|
'E0603': ('Undefined variable name %r in __all__',
|
|
'undefined-all-variable',
|
|
'Used when an undefined variable name is referenced in __all__.'),
|
|
'E0604': ('Invalid object %r in __all__, must contain only strings',
|
|
'invalid-all-object',
|
|
'Used when an invalid (non-string) object occurs in __all__.'),
|
|
'E0611': ('No name %r in module %r',
|
|
'no-name-in-module',
|
|
'Used when a name cannot be found in a module.'),
|
|
|
|
'W0601': ('Global variable %r undefined at the module level',
|
|
'global-variable-undefined',
|
|
'Used when a variable is defined through the "global" statement \
|
|
but the variable is not defined in the module scope.'),
|
|
'W0602': ('Using global for %r but no assignment is done',
|
|
'global-variable-not-assigned',
|
|
'Used when a variable is defined through the "global" statement \
|
|
but no assignment to this variable is done.'),
|
|
'W0603': ('Using the global statement', # W0121
|
|
'global-statement',
|
|
'Used when you use the "global" statement to update a global \
|
|
variable. Pylint just try to discourage this \
|
|
usage. That doesn\'t mean you can not use it !'),
|
|
'W0604': ('Using the global statement at the module level', # W0103
|
|
'global-at-module-level',
|
|
'Used when you use the "global" statement at the module level \
|
|
since it has no effect'),
|
|
'W0611': ('Unused %s',
|
|
'unused-import',
|
|
'Used when an imported module or variable is not used.'),
|
|
'W0612': ('Unused variable %r',
|
|
'unused-variable',
|
|
'Used when a variable is defined but not used.'),
|
|
'W0613': ('Unused argument %r',
|
|
'unused-argument',
|
|
'Used when a function or method argument is not used.'),
|
|
'W0614': ('Unused import %s from wildcard import',
|
|
'unused-wildcard-import',
|
|
'Used when an imported module or variable is not used from a \
|
|
\'from X import *\' style import.'),
|
|
|
|
'W0621': ('Redefining name %r from outer scope (line %s)',
|
|
'redefined-outer-name',
|
|
'Used when a variable\'s name hide a name defined in the outer \
|
|
scope.'),
|
|
'W0622': ('Redefining built-in %r',
|
|
'redefined-builtin',
|
|
'Used when a variable or function override a built-in.'),
|
|
'W0623': ('Redefining name %r from %s in exception handler',
|
|
'redefine-in-handler',
|
|
'Used when an exception handler assigns the exception \
|
|
to an existing name'),
|
|
|
|
'W0631': ('Using possibly undefined loop variable %r',
|
|
'undefined-loop-variable',
|
|
'Used when an loop variable (i.e. defined by a for loop or \
|
|
a list comprehension or a generator expression) is used outside \
|
|
the loop.'),
|
|
|
|
'W0632': ('Possible unbalanced tuple unpacking with '
|
|
'sequence%s: '
|
|
'left side has %d label(s), right side has %d value(s)',
|
|
'unbalanced-tuple-unpacking',
|
|
'Used when there is an unbalanced tuple unpacking in assignment'),
|
|
|
|
'W0633': ('Attempting to unpack a non-sequence%s',
|
|
'unpacking-non-sequence',
|
|
'Used when something which is not '
|
|
'a sequence is used in an unpack assignment'),
|
|
|
|
'W0640': ('Cell variable %s defined in loop',
|
|
'cell-var-from-loop',
|
|
'A variable used in a closure is defined in a loop. '
|
|
'This will result in all closures using the same value for '
|
|
'the closed-over variable.'),
|
|
|
|
}
|
|
|
|
class VariablesChecker(BaseChecker):
|
|
"""checks for
|
|
* unused variables / imports
|
|
* undefined variables
|
|
* redefinition of variable from builtins or from an outer scope
|
|
* use of variable before assignment
|
|
* __all__ consistency
|
|
"""
|
|
|
|
__implements__ = IAstroidChecker
|
|
|
|
name = 'variables'
|
|
msgs = MSGS
|
|
priority = -1
|
|
options = (("init-import",
|
|
{'default': 0, 'type' : 'yn', 'metavar' : '<y_or_n>',
|
|
'help' : 'Tells whether we should check for unused import in \
|
|
__init__ files.'}),
|
|
("dummy-variables-rgx",
|
|
{'default': ('_$|dummy'),
|
|
'type' :'regexp', 'metavar' : '<regexp>',
|
|
'help' : 'A regular expression matching the name of dummy \
|
|
variables (i.e. expectedly not used).'}),
|
|
("additional-builtins",
|
|
{'default': (), 'type' : 'csv',
|
|
'metavar' : '<comma separated list>',
|
|
'help' : 'List of additional names supposed to be defined in \
|
|
builtins. Remember that you should avoid to define new builtins when possible.'
|
|
}),
|
|
("callbacks",
|
|
{'default' : ('cb_', '_cb'), 'type' : 'csv',
|
|
'metavar' : '<callbacks>',
|
|
'help' : 'List of strings which can identify a callback '
|
|
'function by name. A callback name must start or '
|
|
'end with one of those strings.'}
|
|
)
|
|
)
|
|
def __init__(self, linter=None):
|
|
BaseChecker.__init__(self, linter)
|
|
self._to_consume = None
|
|
self._checking_mod_attr = None
|
|
|
|
def visit_module(self, node):
|
|
"""visit module : update consumption analysis variable
|
|
checks globals doesn't overrides builtins
|
|
"""
|
|
self._to_consume = [(copy(node.locals), {}, 'module')]
|
|
for name, stmts in six.iteritems(node.locals):
|
|
if is_builtin(name) and not is_inside_except(stmts[0]):
|
|
# do not print Redefining builtin for additional builtins
|
|
self.add_message('redefined-builtin', args=name, node=stmts[0])
|
|
|
|
@check_messages('unused-import', 'unused-wildcard-import',
|
|
'redefined-builtin', 'undefined-all-variable',
|
|
'invalid-all-object')
|
|
def leave_module(self, node):
|
|
"""leave module: check globals
|
|
"""
|
|
assert len(self._to_consume) == 1
|
|
not_consumed = self._to_consume.pop()[0]
|
|
# attempt to check for __all__ if defined
|
|
if '__all__' in node.locals:
|
|
assigned = next(node.igetattr('__all__'))
|
|
if assigned is not astroid.YES:
|
|
for elt in getattr(assigned, 'elts', ()):
|
|
try:
|
|
elt_name = next(elt.infer())
|
|
except astroid.InferenceError:
|
|
continue
|
|
|
|
if not isinstance(elt_name, astroid.Const) \
|
|
or not isinstance(elt_name.value, six.string_types):
|
|
self.add_message('invalid-all-object',
|
|
args=elt.as_string(), node=elt)
|
|
continue
|
|
elt_name = elt_name.value
|
|
# If elt is in not_consumed, remove it from not_consumed
|
|
if elt_name in not_consumed:
|
|
del not_consumed[elt_name]
|
|
continue
|
|
if elt_name not in node.locals:
|
|
if not node.package:
|
|
self.add_message('undefined-all-variable',
|
|
args=elt_name,
|
|
node=elt)
|
|
else:
|
|
basename = os.path.splitext(node.file)[0]
|
|
if os.path.basename(basename) == '__init__':
|
|
name = node.name + "." + elt_name
|
|
try:
|
|
modutils.file_from_modpath(name.split("."))
|
|
except ImportError:
|
|
self.add_message('undefined-all-variable',
|
|
args=elt_name,
|
|
node=elt)
|
|
except SyntaxError:
|
|
# don't yield an syntax-error warning,
|
|
# because it will be later yielded
|
|
# when the file will be checked
|
|
pass
|
|
# don't check unused imports in __init__ files
|
|
if not self.config.init_import and node.package:
|
|
return
|
|
|
|
self._check_imports(not_consumed)
|
|
|
|
def _check_imports(self, not_consumed):
|
|
local_names = _fix_dot_imports(not_consumed)
|
|
checked = set()
|
|
for name, stmt in local_names:
|
|
for imports in stmt.names:
|
|
real_name = imported_name = imports[0]
|
|
if imported_name == "*":
|
|
real_name = name
|
|
as_name = imports[1]
|
|
if real_name in checked:
|
|
continue
|
|
if name not in (real_name, as_name):
|
|
continue
|
|
checked.add(real_name)
|
|
|
|
if (isinstance(stmt, astroid.Import) or
|
|
(isinstance(stmt, astroid.From) and
|
|
not stmt.modname)):
|
|
if (isinstance(stmt, astroid.From) and
|
|
SPECIAL_OBJ.search(imported_name)):
|
|
# Filter special objects (__doc__, __all__) etc.,
|
|
# because they can be imported for exporting.
|
|
continue
|
|
if as_name is None:
|
|
msg = "import %s" % imported_name
|
|
else:
|
|
msg = "%s imported as %s" % (imported_name, as_name)
|
|
self.add_message('unused-import', args=msg, node=stmt)
|
|
elif isinstance(stmt, astroid.From) and stmt.modname != '__future__':
|
|
if SPECIAL_OBJ.search(imported_name):
|
|
# Filter special objects (__doc__, __all__) etc.,
|
|
# because they can be imported for exporting.
|
|
continue
|
|
if imported_name == '*':
|
|
self.add_message('unused-wildcard-import',
|
|
args=name, node=stmt)
|
|
else:
|
|
if as_name is None:
|
|
msg = "%s imported from %s" % (imported_name, stmt.modname)
|
|
else:
|
|
fields = (imported_name, stmt.modname, as_name)
|
|
msg = "%s imported from %s as %s" % fields
|
|
self.add_message('unused-import', args=msg, node=stmt)
|
|
del self._to_consume
|
|
|
|
def visit_class(self, node):
|
|
"""visit class: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'class'))
|
|
|
|
def leave_class(self, _):
|
|
"""leave class: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here (no sense)
|
|
self._to_consume.pop()
|
|
|
|
def visit_lambda(self, node):
|
|
"""visit lambda: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'lambda'))
|
|
|
|
def leave_lambda(self, _):
|
|
"""leave lambda: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here
|
|
self._to_consume.pop()
|
|
|
|
def visit_genexpr(self, node):
|
|
"""visit genexpr: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'comprehension'))
|
|
|
|
def leave_genexpr(self, _):
|
|
"""leave genexpr: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here
|
|
self._to_consume.pop()
|
|
|
|
def visit_dictcomp(self, node):
|
|
"""visit dictcomp: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'comprehension'))
|
|
|
|
def leave_dictcomp(self, _):
|
|
"""leave dictcomp: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here
|
|
self._to_consume.pop()
|
|
|
|
def visit_setcomp(self, node):
|
|
"""visit setcomp: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'comprehension'))
|
|
|
|
def leave_setcomp(self, _):
|
|
"""leave setcomp: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here
|
|
self._to_consume.pop()
|
|
|
|
def visit_function(self, node):
|
|
"""visit function: update consumption analysis variable and check locals
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'function'))
|
|
if not (self.linter.is_message_enabled('redefined-outer-name') or
|
|
self.linter.is_message_enabled('redefined-builtin')):
|
|
return
|
|
globs = node.root().globals
|
|
for name, stmt in node.items():
|
|
if is_inside_except(stmt):
|
|
continue
|
|
if name in globs and not isinstance(stmt, astroid.Global):
|
|
line = globs[name][0].fromlineno
|
|
dummy_rgx = self.config.dummy_variables_rgx
|
|
if not dummy_rgx.match(name):
|
|
self.add_message('redefined-outer-name', args=(name, line), node=stmt)
|
|
elif is_builtin(name):
|
|
# do not print Redefining builtin for additional builtins
|
|
self.add_message('redefined-builtin', args=name, node=stmt)
|
|
|
|
def leave_function(self, node):
|
|
"""leave function: check function's locals are consumed"""
|
|
not_consumed = self._to_consume.pop()[0]
|
|
if not (self.linter.is_message_enabled('unused-variable') or
|
|
self.linter.is_message_enabled('unused-argument')):
|
|
return
|
|
# don't check arguments of function which are only raising an exception
|
|
if is_error(node):
|
|
return
|
|
# don't check arguments of abstract methods or within an interface
|
|
is_method = node.is_method()
|
|
klass = node.parent.frame()
|
|
if is_method and (klass.type == 'interface' or node.is_abstract()):
|
|
return
|
|
if is_method and isinstance(klass, astroid.Class):
|
|
confidence = INFERENCE if has_known_bases(klass) else INFERENCE_FAILURE
|
|
else:
|
|
confidence = HIGH
|
|
authorized_rgx = self.config.dummy_variables_rgx
|
|
called_overridden = False
|
|
argnames = node.argnames()
|
|
global_names = set()
|
|
nonlocal_names = set()
|
|
for global_stmt in node.nodes_of_class(astroid.Global):
|
|
global_names.update(set(global_stmt.names))
|
|
for nonlocal_stmt in node.nodes_of_class(astroid.Nonlocal):
|
|
nonlocal_names.update(set(nonlocal_stmt.names))
|
|
|
|
for name, stmts in six.iteritems(not_consumed):
|
|
# ignore some special names specified by user configuration
|
|
if authorized_rgx.match(name):
|
|
continue
|
|
# ignore names imported by the global statement
|
|
# FIXME: should only ignore them if it's assigned latter
|
|
stmt = stmts[0]
|
|
if isinstance(stmt, astroid.Global):
|
|
continue
|
|
if isinstance(stmt, (astroid.Import, astroid.From)):
|
|
# Detect imports, assigned to global statements.
|
|
if global_names:
|
|
skip = False
|
|
for import_name, import_alias in stmt.names:
|
|
# If the import uses an alias, check only that.
|
|
# Otherwise, check only the import name.
|
|
if import_alias:
|
|
if import_alias in global_names:
|
|
skip = True
|
|
break
|
|
elif import_name in global_names:
|
|
skip = True
|
|
break
|
|
if skip:
|
|
continue
|
|
|
|
# care about functions with unknown argument (builtins)
|
|
if name in argnames:
|
|
if is_method:
|
|
# don't warn for the first argument of a (non static) method
|
|
if node.type != 'staticmethod' and name == argnames[0]:
|
|
continue
|
|
# don't warn for argument of an overridden method
|
|
if not called_overridden:
|
|
overridden = overridden_method(klass, node.name)
|
|
called_overridden = True
|
|
if overridden is not None and name in overridden.argnames():
|
|
continue
|
|
if node.name in PYMETHODS and node.name not in ('__init__', '__new__'):
|
|
continue
|
|
# don't check callback arguments
|
|
if any(node.name.startswith(cb) or node.name.endswith(cb)
|
|
for cb in self.config.callbacks):
|
|
continue
|
|
self.add_message('unused-argument', args=name, node=stmt,
|
|
confidence=confidence)
|
|
else:
|
|
if stmt.parent and isinstance(stmt.parent, astroid.Assign):
|
|
if name in nonlocal_names:
|
|
continue
|
|
self.add_message('unused-variable', args=name, node=stmt)
|
|
|
|
@check_messages('global-variable-undefined', 'global-variable-not-assigned', 'global-statement',
|
|
'global-at-module-level', 'redefined-builtin')
|
|
def visit_global(self, node):
|
|
"""check names imported exists in the global scope"""
|
|
frame = node.frame()
|
|
if isinstance(frame, astroid.Module):
|
|
self.add_message('global-at-module-level', node=node)
|
|
return
|
|
module = frame.root()
|
|
default_message = True
|
|
for name in node.names:
|
|
try:
|
|
assign_nodes = module.getattr(name)
|
|
except astroid.NotFoundError:
|
|
# unassigned global, skip
|
|
assign_nodes = []
|
|
for anode in assign_nodes:
|
|
if anode.parent is None:
|
|
# node returned for builtin attribute such as __file__,
|
|
# __doc__, etc...
|
|
continue
|
|
if anode.frame() is frame:
|
|
# same scope level assignment
|
|
break
|
|
else:
|
|
if not _find_frame_imports(name, frame):
|
|
self.add_message('global-variable-not-assigned',
|
|
args=name, node=node)
|
|
default_message = False
|
|
if not assign_nodes:
|
|
continue
|
|
for anode in assign_nodes:
|
|
if anode.parent is None:
|
|
self.add_message('redefined-builtin', args=name, node=node)
|
|
break
|
|
if anode.frame() is module:
|
|
# module level assignment
|
|
break
|
|
else:
|
|
# global undefined at the module scope
|
|
self.add_message('global-variable-undefined', args=name, node=node)
|
|
default_message = False
|
|
if default_message:
|
|
self.add_message('global-statement', node=node)
|
|
|
|
def _check_late_binding_closure(self, node, assignment_node):
|
|
def _is_direct_lambda_call():
|
|
return (isinstance(node_scope.parent, astroid.CallFunc)
|
|
and node_scope.parent.func is node_scope)
|
|
|
|
node_scope = node.scope()
|
|
if not isinstance(node_scope, (astroid.Lambda, astroid.Function)):
|
|
return
|
|
if isinstance(node.parent, astroid.Arguments):
|
|
return
|
|
|
|
if isinstance(assignment_node, astroid.Comprehension):
|
|
if assignment_node.parent.parent_of(node.scope()):
|
|
self.add_message('cell-var-from-loop', node=node, args=node.name)
|
|
else:
|
|
assign_scope = assignment_node.scope()
|
|
maybe_for = assignment_node
|
|
while not isinstance(maybe_for, astroid.For):
|
|
if maybe_for is assign_scope:
|
|
break
|
|
maybe_for = maybe_for.parent
|
|
else:
|
|
if (maybe_for.parent_of(node_scope)
|
|
and not _is_direct_lambda_call()
|
|
and not isinstance(node_scope.statement(), astroid.Return)):
|
|
self.add_message('cell-var-from-loop', node=node, args=node.name)
|
|
|
|
def _loopvar_name(self, node, name):
|
|
# filter variables according to node's scope
|
|
# XXX used to filter parents but don't remember why, and removing this
|
|
# fixes a W0631 false positive reported by Paul Hachmann on 2008/12 on
|
|
# python-projects (added to func_use_for_or_listcomp_var test)
|
|
#astmts = [stmt for stmt in node.lookup(name)[1]
|
|
# if hasattr(stmt, 'ass_type')] and
|
|
# not stmt.statement().parent_of(node)]
|
|
if not self.linter.is_message_enabled('undefined-loop-variable'):
|
|
return
|
|
astmts = [stmt for stmt in node.lookup(name)[1]
|
|
if hasattr(stmt, 'ass_type')]
|
|
# filter variables according their respective scope test is_statement
|
|
# and parent to avoid #74747. This is not a total fix, which would
|
|
# introduce a mechanism similar to special attribute lookup in
|
|
# modules. Also, in order to get correct inference in this case, the
|
|
# scope lookup rules would need to be changed to return the initial
|
|
# assignment (which does not exist in code per se) as well as any later
|
|
# modifications.
|
|
if not astmts or (astmts[0].is_statement or astmts[0].parent) \
|
|
and astmts[0].statement().parent_of(node):
|
|
_astmts = []
|
|
else:
|
|
_astmts = astmts[:1]
|
|
for i, stmt in enumerate(astmts[1:]):
|
|
if (astmts[i].statement().parent_of(stmt)
|
|
and not in_for_else_branch(astmts[i].statement(), stmt)):
|
|
continue
|
|
_astmts.append(stmt)
|
|
astmts = _astmts
|
|
if len(astmts) == 1:
|
|
ass = astmts[0].ass_type()
|
|
if isinstance(ass, (astroid.For, astroid.Comprehension, astroid.GenExpr)) \
|
|
and not ass.statement() is node.statement():
|
|
self.add_message('undefined-loop-variable', args=name, node=node)
|
|
|
|
@check_messages('redefine-in-handler')
|
|
def visit_excepthandler(self, node):
|
|
for name in get_all_elements(node.name):
|
|
clobbering, args = clobber_in_except(name)
|
|
if clobbering:
|
|
self.add_message('redefine-in-handler', args=args, node=name)
|
|
|
|
def visit_assname(self, node):
|
|
if isinstance(node.ass_type(), astroid.AugAssign):
|
|
self.visit_name(node)
|
|
|
|
def visit_delname(self, node):
|
|
self.visit_name(node)
|
|
|
|
@check_messages(*(MSGS.keys()))
|
|
def visit_name(self, node):
|
|
"""check that a name is defined if the current scope and doesn't
|
|
redefine a built-in
|
|
"""
|
|
stmt = node.statement()
|
|
if stmt.fromlineno is None:
|
|
# name node from a astroid built from live code, skip
|
|
assert not stmt.root().file.endswith('.py')
|
|
return
|
|
name = node.name
|
|
frame = stmt.scope()
|
|
# if the name node is used as a function default argument's value or as
|
|
# a decorator, then start from the parent frame of the function instead
|
|
# of the function frame - and thus open an inner class scope
|
|
if (is_func_default(node) or is_func_decorator(node)
|
|
or is_ancestor_name(frame, node)):
|
|
start_index = len(self._to_consume) - 2
|
|
else:
|
|
start_index = len(self._to_consume) - 1
|
|
# iterates through parent scopes, from the inner to the outer
|
|
base_scope_type = self._to_consume[start_index][-1]
|
|
for i in range(start_index, -1, -1):
|
|
to_consume, consumed, scope_type = self._to_consume[i]
|
|
# if the current scope is a class scope but it's not the inner
|
|
# scope, ignore it. This prevents to access this scope instead of
|
|
# the globals one in function members when there are some common
|
|
# names. The only exception is when the starting scope is a
|
|
# comprehension and its direct outer scope is a class
|
|
if scope_type == 'class' and i != start_index and not (
|
|
base_scope_type == 'comprehension' and i == start_index-1):
|
|
# Detect if we are in a local class scope, as an assignment.
|
|
# For example, the following is fair game.
|
|
#
|
|
# class A:
|
|
# b = 1
|
|
# c = lambda b=b: b * b
|
|
#
|
|
# class B:
|
|
# tp = 1
|
|
# def func(self, arg: tp):
|
|
# ...
|
|
|
|
in_annotation = (
|
|
PY3K and isinstance(frame, astroid.Function)
|
|
and node.statement() is frame and
|
|
(node in frame.args.annotations
|
|
or node is frame.args.varargannotation
|
|
or node is frame.args.kwargannotation))
|
|
if in_annotation:
|
|
frame_locals = frame.parent.scope().locals
|
|
else:
|
|
frame_locals = frame.locals
|
|
if not ((isinstance(frame, astroid.Class) or in_annotation)
|
|
and name in frame_locals):
|
|
continue
|
|
# the name has already been consumed, only check it's not a loop
|
|
# variable used outside the loop
|
|
if name in consumed:
|
|
defnode = assign_parent(consumed[name][0])
|
|
self._check_late_binding_closure(node, defnode)
|
|
self._loopvar_name(node, name)
|
|
break
|
|
# mark the name as consumed if it's defined in this scope
|
|
# (i.e. no KeyError is raised by "to_consume[name]")
|
|
try:
|
|
consumed[name] = to_consume[name]
|
|
except KeyError:
|
|
continue
|
|
# checks for use before assignment
|
|
defnode = assign_parent(to_consume[name][0])
|
|
if defnode is not None:
|
|
self._check_late_binding_closure(node, defnode)
|
|
defstmt = defnode.statement()
|
|
defframe = defstmt.frame()
|
|
maybee0601 = True
|
|
if not frame is defframe:
|
|
maybee0601 = _detect_global_scope(node, frame, defframe)
|
|
elif defframe.parent is None:
|
|
# we are at the module level, check the name is not
|
|
# defined in builtins
|
|
if name in defframe.scope_attrs or builtin_lookup(name)[1]:
|
|
maybee0601 = False
|
|
else:
|
|
# we are in a local scope, check the name is not
|
|
# defined in global or builtin scope
|
|
if defframe.root().lookup(name)[1]:
|
|
maybee0601 = False
|
|
else:
|
|
# check if we have a nonlocal
|
|
if name in defframe.locals:
|
|
maybee0601 = not any(isinstance(child, astroid.Nonlocal)
|
|
and name in child.names
|
|
for child in defframe.get_children())
|
|
|
|
# Handle a couple of class scoping issues.
|
|
annotation_return = False
|
|
# The class reuses itself in the class scope.
|
|
recursive_klass = (frame is defframe and
|
|
defframe.parent_of(node) and
|
|
isinstance(defframe, astroid.Class) and
|
|
node.name == defframe.name)
|
|
if (self._to_consume[-1][-1] == 'lambda' and
|
|
isinstance(frame, astroid.Class)
|
|
and name in frame.locals):
|
|
maybee0601 = True
|
|
elif (isinstance(defframe, astroid.Class) and
|
|
isinstance(frame, astroid.Function)):
|
|
# Special rule for function return annotations,
|
|
# which uses the same name as the class where
|
|
# the function lives.
|
|
if (PY3K and node is frame.returns and
|
|
defframe.parent_of(frame.returns)):
|
|
maybee0601 = annotation_return = True
|
|
|
|
if (maybee0601 and defframe.name in defframe.locals and
|
|
defframe.locals[name][0].lineno < frame.lineno):
|
|
# Detect class assignments with the same
|
|
# name as the class. In this case, no warning
|
|
# should be raised.
|
|
maybee0601 = False
|
|
elif recursive_klass:
|
|
maybee0601 = True
|
|
else:
|
|
maybee0601 = maybee0601 and stmt.fromlineno <= defstmt.fromlineno
|
|
|
|
if (maybee0601
|
|
and not is_defined_before(node)
|
|
and not are_exclusive(stmt, defstmt, ('NameError',
|
|
'Exception',
|
|
'BaseException'))):
|
|
if recursive_klass or (defstmt is stmt and
|
|
isinstance(node, (astroid.DelName,
|
|
astroid.AssName))):
|
|
self.add_message('undefined-variable', args=name, node=node)
|
|
elif annotation_return:
|
|
self.add_message('undefined-variable', args=name, node=node)
|
|
elif self._to_consume[-1][-1] != 'lambda':
|
|
# E0601 may *not* occurs in lambda scope.
|
|
self.add_message('used-before-assignment', args=name, node=node)
|
|
elif self._to_consume[-1][-1] == 'lambda':
|
|
# E0601 can occur in class-level scope in lambdas, as in
|
|
# the following example:
|
|
# class A:
|
|
# x = lambda attr: f + attr
|
|
# f = 42
|
|
if isinstance(frame, astroid.Class) and name in frame.locals:
|
|
if isinstance(node.parent, astroid.Arguments):
|
|
# Doing the following is fine:
|
|
# class A:
|
|
# x = 42
|
|
# y = lambda attr=x: attr
|
|
if stmt.fromlineno <= defstmt.fromlineno:
|
|
self.add_message('used-before-assignment',
|
|
args=name, node=node)
|
|
else:
|
|
self.add_message('undefined-variable',
|
|
args=name, node=node)
|
|
|
|
if isinstance(node, astroid.AssName): # Aug AssName
|
|
del consumed[name]
|
|
else:
|
|
del to_consume[name]
|
|
# check it's not a loop variable used outside the loop
|
|
self._loopvar_name(node, name)
|
|
break
|
|
else:
|
|
# we have not found the name, if it isn't a builtin, that's an
|
|
# undefined name !
|
|
if not (name in astroid.Module.scope_attrs or is_builtin(name)
|
|
or name in self.config.additional_builtins):
|
|
self.add_message('undefined-variable', args=name, node=node)
|
|
|
|
@check_messages('no-name-in-module')
|
|
def visit_import(self, node):
|
|
"""check modules attribute accesses"""
|
|
for name, _ in node.names:
|
|
parts = name.split('.')
|
|
try:
|
|
module = next(node.infer_name_module(parts[0]))
|
|
except astroid.ResolveError:
|
|
continue
|
|
self._check_module_attrs(node, module, parts[1:])
|
|
|
|
@check_messages('no-name-in-module')
|
|
def visit_from(self, node):
|
|
"""check modules attribute accesses"""
|
|
name_parts = node.modname.split('.')
|
|
level = getattr(node, 'level', None)
|
|
try:
|
|
module = node.root().import_module(name_parts[0], level=level)
|
|
except Exception: # pylint: disable=broad-except
|
|
return
|
|
module = self._check_module_attrs(node, module, name_parts[1:])
|
|
if not module:
|
|
return
|
|
for name, _ in node.names:
|
|
if name == '*':
|
|
continue
|
|
self._check_module_attrs(node, module, name.split('.'))
|
|
|
|
@check_messages('unbalanced-tuple-unpacking', 'unpacking-non-sequence')
|
|
def visit_assign(self, node):
|
|
"""Check unbalanced tuple unpacking for assignments
|
|
and unpacking non-sequences.
|
|
"""
|
|
if not isinstance(node.targets[0], (astroid.Tuple, astroid.List)):
|
|
return
|
|
|
|
targets = node.targets[0].itered()
|
|
try:
|
|
for infered in node.value.infer():
|
|
self._check_unpacking(infered, node, targets)
|
|
except astroid.InferenceError:
|
|
return
|
|
|
|
def _check_unpacking(self, infered, node, targets):
|
|
""" Check for unbalanced tuple unpacking
|
|
and unpacking non sequences.
|
|
"""
|
|
if infered is astroid.YES:
|
|
return
|
|
if (isinstance(infered.parent, astroid.Arguments) and
|
|
isinstance(node.value, astroid.Name) and
|
|
node.value.name == infered.parent.vararg):
|
|
# Variable-length argument, we can't determine the length.
|
|
return
|
|
if isinstance(infered, (astroid.Tuple, astroid.List)):
|
|
# attempt to check unpacking is properly balanced
|
|
values = infered.itered()
|
|
if len(targets) != len(values):
|
|
# Check if we have starred nodes.
|
|
if any(isinstance(target, astroid.Starred)
|
|
for target in targets):
|
|
return
|
|
self.add_message('unbalanced-tuple-unpacking', node=node,
|
|
args=(_get_unpacking_extra_info(node, infered),
|
|
len(targets),
|
|
len(values)))
|
|
# attempt to check unpacking may be possible (ie RHS is iterable)
|
|
elif isinstance(infered, astroid.Instance):
|
|
for meth in ('__iter__', '__getitem__'):
|
|
try:
|
|
infered.getattr(meth)
|
|
break
|
|
except astroid.NotFoundError:
|
|
continue
|
|
else:
|
|
self.add_message('unpacking-non-sequence', node=node,
|
|
args=(_get_unpacking_extra_info(node, infered),))
|
|
else:
|
|
self.add_message('unpacking-non-sequence', node=node,
|
|
args=(_get_unpacking_extra_info(node, infered),))
|
|
|
|
|
|
def _check_module_attrs(self, node, module, module_names):
|
|
"""check that module_names (list of string) are accessible through the
|
|
given module
|
|
if the latest access name corresponds to a module, return it
|
|
"""
|
|
assert isinstance(module, astroid.Module), module
|
|
ignored_modules = get_global_option(self, 'ignored-modules',
|
|
default=[])
|
|
while module_names:
|
|
name = module_names.pop(0)
|
|
if name == '__dict__':
|
|
module = None
|
|
break
|
|
try:
|
|
module = next(module.getattr(name)[0].infer())
|
|
if module is astroid.YES:
|
|
return None
|
|
except astroid.NotFoundError:
|
|
if module.name in ignored_modules:
|
|
return None
|
|
self.add_message('no-name-in-module',
|
|
args=(name, module.name), node=node)
|
|
return None
|
|
except astroid.InferenceError:
|
|
return None
|
|
if module_names:
|
|
# FIXME: other message if name is not the latest part of
|
|
# module_names ?
|
|
modname = module and module.name or '__dict__'
|
|
self.add_message('no-name-in-module', node=node,
|
|
args=('.'.join(module_names), modname))
|
|
return None
|
|
if isinstance(module, astroid.Module):
|
|
return module
|
|
return None
|
|
|
|
|
|
class VariablesChecker3k(VariablesChecker):
|
|
'''Modified variables checker for 3k'''
|
|
# listcomp have now also their scope
|
|
|
|
def visit_listcomp(self, node):
|
|
"""visit dictcomp: update consumption analysis variable
|
|
"""
|
|
self._to_consume.append((copy(node.locals), {}, 'comprehension'))
|
|
|
|
def leave_listcomp(self, _):
|
|
"""leave dictcomp: update consumption analysis variable
|
|
"""
|
|
# do not check for not used locals here
|
|
self._to_consume.pop()
|
|
|
|
def leave_module(self, node):
|
|
""" Update consumption analysis variable
|
|
for metaclasses.
|
|
"""
|
|
module_locals = self._to_consume[0][0]
|
|
module_imports = self._to_consume[0][1]
|
|
consumed = {}
|
|
|
|
for klass in node.nodes_of_class(astroid.Class):
|
|
found = metaclass = name = None
|
|
if not klass._metaclass:
|
|
# Skip if this class doesn't use
|
|
# explictly a metaclass, but inherits it from ancestors
|
|
continue
|
|
|
|
metaclass = klass.metaclass()
|
|
|
|
# Look the name in the already found locals.
|
|
# If it's not found there, look in the module locals
|
|
# and in the imported modules.
|
|
if isinstance(klass._metaclass, astroid.Name):
|
|
name = klass._metaclass.name
|
|
elif metaclass:
|
|
# if it uses a `metaclass=module.Class`
|
|
name = metaclass.root().name
|
|
|
|
if name:
|
|
found = consumed.setdefault(
|
|
name, module_locals.get(name, module_imports.get(name)))
|
|
|
|
if found is None and not metaclass:
|
|
name = None
|
|
if isinstance(klass._metaclass, astroid.Name):
|
|
name = klass._metaclass.name
|
|
elif isinstance(klass._metaclass, astroid.Getattr):
|
|
name = klass._metaclass.as_string()
|
|
|
|
if name is not None:
|
|
if not (name in astroid.Module.scope_attrs or
|
|
is_builtin(name) or
|
|
name in self.config.additional_builtins or
|
|
name in node.locals):
|
|
self.add_message('undefined-variable',
|
|
node=klass,
|
|
args=(name, ))
|
|
# Pop the consumed items, in order to
|
|
# avoid having unused-import false positives
|
|
for name in consumed:
|
|
module_locals.pop(name, None)
|
|
super(VariablesChecker3k, self).leave_module(node)
|
|
|
|
if sys.version_info >= (3, 0):
|
|
VariablesChecker = VariablesChecker3k
|
|
|
|
|
|
def register(linter):
|
|
"""required method to auto register this checker"""
|
|
linter.register_checker(VariablesChecker(linter))
|