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.
742 lines
26 KiB
Python
742 lines
26 KiB
Python
# pylint: disable=W0611
|
|
#
|
|
# Copyright (c) 2003-2013 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.
|
|
"""some functions that may be useful for various checkers
|
|
"""
|
|
import functools
|
|
import re
|
|
import sys
|
|
import string
|
|
import warnings
|
|
|
|
import six
|
|
from six.moves import map, builtins # pylint: disable=redefined-builtin
|
|
|
|
import astroid
|
|
from astroid import scoped_nodes
|
|
|
|
BUILTINS_NAME = builtins.__name__
|
|
COMP_NODE_TYPES = (astroid.ListComp, astroid.SetComp,
|
|
astroid.DictComp, astroid.GeneratorExp)
|
|
PY3K = sys.version_info[0] == 3
|
|
|
|
if not PY3K:
|
|
EXCEPTIONS_MODULE = "exceptions"
|
|
else:
|
|
EXCEPTIONS_MODULE = "builtins"
|
|
ABC_METHODS = set(('abc.abstractproperty', 'abc.abstractmethod',
|
|
'abc.abstractclassmethod', 'abc.abstractstaticmethod'))
|
|
ITER_METHOD = '__iter__'
|
|
NEXT_METHOD = 'next' if six.PY2 else '__next__'
|
|
GETITEM_METHOD = '__getitem__'
|
|
CONTAINS_METHOD = '__contains__'
|
|
KEYS_METHOD = 'keys'
|
|
|
|
# Dictionary which maps the number of expected parameters a
|
|
# special method can have to a set of special methods.
|
|
# The following keys are used to denote the parameters restrictions:
|
|
#
|
|
# * None: variable number of parameters
|
|
# * number: exactly that number of parameters
|
|
# * tuple: this are the odd ones. Basically it means that the function
|
|
# can work with any number of arguments from that tuple,
|
|
# although it's best to implement it in order to accept
|
|
# all of them.
|
|
_SPECIAL_METHODS_PARAMS = {
|
|
None: ('__new__', '__init__', '__call__'),
|
|
|
|
0: ('__del__', '__repr__', '__str__', '__bytes__', '__hash__', '__bool__',
|
|
'__dir__', '__len__', '__length_hint__', '__iter__', '__reversed__',
|
|
'__neg__', '__pos__', '__abs__', '__invert__', '__complex__', '__int__',
|
|
'__float__', '__neg__', '__pos__', '__abs__', '__complex__', '__int__',
|
|
'__float__', '__index__', '__enter__', '__aenter__', '__getnewargs_ex__',
|
|
'__getnewargs__', '__getstate__', '__reduce__', '__copy__',
|
|
'__unicode__', '__nonzero__', '__await__', '__aiter__', '__anext__'),
|
|
|
|
1: ('__format__', '__lt__', '__le__', '__eq__', '__ne__', '__gt__',
|
|
'__ge__', '__getattr__', '__getattribute__', '__delattr__',
|
|
'__delete__', '__instancecheck__', '__subclasscheck__',
|
|
'__getitem__', '__missing__', '__delitem__', '__contains__',
|
|
'__add__', '__sub__', '__mul__', '__truediv__', '__floordiv__',
|
|
'__mod__', '__divmod__', '__lshift__', '__rshift__', '__and__',
|
|
'__xor__', '__or__', '__radd__', '__rsub__', '__rmul__', '__rtruediv__',
|
|
'__rmod__', '__rdivmod__', '__rpow__', '__rlshift__', '__rrshift__',
|
|
'__rand__', '__rxor__', '__ror__', '__iadd__', '__isub__', '__imul__',
|
|
'__itruediv__', '__ifloordiv__', '__imod__', '__ilshift__',
|
|
'__irshift__', '__iand__', '__ixor__', '__ior__', '__ipow__',
|
|
'__setstate__', '__reduce_ex__', '__deepcopy__', '__cmp__',
|
|
'__matmul__', '__rmatmul__'),
|
|
|
|
2: ('__setattr__', '__get__', '__set__', '__setitem__'),
|
|
|
|
3: ('__exit__', '__aexit__'),
|
|
|
|
(0, 1): ('__round__', ),
|
|
}
|
|
|
|
SPECIAL_METHODS_PARAMS = {
|
|
name: params
|
|
for params, methods in _SPECIAL_METHODS_PARAMS.items()
|
|
for name in methods
|
|
}
|
|
PYMETHODS = set(SPECIAL_METHODS_PARAMS)
|
|
|
|
|
|
class NoSuchArgumentError(Exception):
|
|
pass
|
|
|
|
def is_inside_except(node):
|
|
"""Returns true if node is inside the name of an except handler."""
|
|
current = node
|
|
while current and not isinstance(current.parent, astroid.ExceptHandler):
|
|
current = current.parent
|
|
|
|
return current and current is current.parent.name
|
|
|
|
|
|
def get_all_elements(node):
|
|
"""Recursively returns all atoms in nested lists and tuples."""
|
|
if isinstance(node, (astroid.Tuple, astroid.List)):
|
|
for child in node.elts:
|
|
for e in get_all_elements(child):
|
|
yield e
|
|
else:
|
|
yield node
|
|
|
|
|
|
def clobber_in_except(node):
|
|
"""Checks if an assignment node in an except handler clobbers an existing
|
|
variable.
|
|
|
|
Returns (True, args for W0623) if assignment clobbers an existing variable,
|
|
(False, None) otherwise.
|
|
"""
|
|
if isinstance(node, astroid.AssignAttr):
|
|
return (True, (node.attrname, 'object %r' % (node.expr.as_string(),)))
|
|
elif isinstance(node, astroid.AssignName):
|
|
name = node.name
|
|
if is_builtin(name):
|
|
return (True, (name, 'builtins'))
|
|
else:
|
|
stmts = node.lookup(name)[1]
|
|
if (stmts and not isinstance(stmts[0].assign_type(),
|
|
(astroid.Assign, astroid.AugAssign,
|
|
astroid.ExceptHandler))):
|
|
return (True, (name, 'outer scope (line %s)' % stmts[0].fromlineno))
|
|
return (False, None)
|
|
|
|
|
|
def is_super(node):
|
|
"""return True if the node is referencing the "super" builtin function
|
|
"""
|
|
if getattr(node, 'name', None) == 'super' and \
|
|
node.root().name == BUILTINS_NAME:
|
|
return True
|
|
return False
|
|
|
|
def is_error(node):
|
|
"""return true if the function does nothing but raising an exception"""
|
|
for child_node in node.get_children():
|
|
if isinstance(child_node, astroid.Raise):
|
|
return True
|
|
return False
|
|
|
|
def is_raising(body):
|
|
"""return true if the given statement node raise an exception"""
|
|
for node in body:
|
|
if isinstance(node, astroid.Raise):
|
|
return True
|
|
return False
|
|
|
|
builtins = builtins.__dict__.copy()
|
|
SPECIAL_BUILTINS = ('__builtins__',) # '__path__', '__file__')
|
|
|
|
def is_builtin_object(node):
|
|
"""Returns True if the given node is an object from the __builtin__ module."""
|
|
return node and node.root().name == BUILTINS_NAME
|
|
|
|
def is_builtin(name):
|
|
"""return true if <name> could be considered as a builtin defined by python
|
|
"""
|
|
return name in builtins or name in SPECIAL_BUILTINS
|
|
|
|
def is_defined_before(var_node):
|
|
"""return True if the variable node is defined by a parent node (list,
|
|
set, dict, or generator comprehension, lambda) or in a previous sibling
|
|
node on the same line (statement_defining ; statement_using)
|
|
"""
|
|
varname = var_node.name
|
|
_node = var_node.parent
|
|
while _node:
|
|
if isinstance(_node, COMP_NODE_TYPES):
|
|
for ass_node in _node.nodes_of_class(astroid.AssignName):
|
|
if ass_node.name == varname:
|
|
return True
|
|
elif isinstance(_node, astroid.For):
|
|
for ass_node in _node.target.nodes_of_class(astroid.AssignName):
|
|
if ass_node.name == varname:
|
|
return True
|
|
elif isinstance(_node, astroid.With):
|
|
for expr, ids in _node.items:
|
|
if expr.parent_of(var_node):
|
|
break
|
|
if (ids and
|
|
isinstance(ids, astroid.AssignName) and
|
|
ids.name == varname):
|
|
return True
|
|
elif isinstance(_node, (astroid.Lambda, astroid.FunctionDef)):
|
|
if _node.args.is_argument(varname):
|
|
# If the name is found inside a default value
|
|
# of a function, then let the search continue
|
|
# in the parent's tree.
|
|
if _node.args.parent_of(var_node):
|
|
try:
|
|
_node.args.default_value(varname)
|
|
_node = _node.parent
|
|
continue
|
|
except astroid.NoDefault:
|
|
pass
|
|
return True
|
|
if getattr(_node, 'name', None) == varname:
|
|
return True
|
|
break
|
|
elif isinstance(_node, astroid.ExceptHandler):
|
|
if isinstance(_node.name, astroid.AssignName):
|
|
ass_node = _node.name
|
|
if ass_node.name == varname:
|
|
return True
|
|
_node = _node.parent
|
|
# possibly multiple statements on the same line using semi colon separator
|
|
stmt = var_node.statement()
|
|
_node = stmt.previous_sibling()
|
|
lineno = stmt.fromlineno
|
|
while _node and _node.fromlineno == lineno:
|
|
for ass_node in _node.nodes_of_class(astroid.AssignName):
|
|
if ass_node.name == varname:
|
|
return True
|
|
for imp_node in _node.nodes_of_class((astroid.ImportFrom, astroid.Import)):
|
|
if varname in [name[1] or name[0] for name in imp_node.names]:
|
|
return True
|
|
_node = _node.previous_sibling()
|
|
return False
|
|
|
|
def is_func_default(node):
|
|
"""return true if the given Name node is used in function default argument's
|
|
value
|
|
"""
|
|
parent = node.scope()
|
|
if isinstance(parent, astroid.FunctionDef):
|
|
for default_node in parent.args.defaults:
|
|
for default_name_node in default_node.nodes_of_class(astroid.Name):
|
|
if default_name_node is node:
|
|
return True
|
|
return False
|
|
|
|
def is_func_decorator(node):
|
|
"""return true if the name is used in function decorator"""
|
|
parent = node.parent
|
|
while parent is not None:
|
|
if isinstance(parent, astroid.Decorators):
|
|
return True
|
|
if (parent.is_statement or
|
|
isinstance(parent, astroid.Lambda) or
|
|
isinstance(parent, (scoped_nodes.ComprehensionScope,
|
|
scoped_nodes.ListComp))):
|
|
break
|
|
parent = parent.parent
|
|
return False
|
|
|
|
def is_ancestor_name(frame, node):
|
|
"""return True if `frame` is a astroid.Class node with `node` in the
|
|
subtree of its bases attribute
|
|
"""
|
|
try:
|
|
bases = frame.bases
|
|
except AttributeError:
|
|
return False
|
|
for base in bases:
|
|
if node in base.nodes_of_class(astroid.Name):
|
|
return True
|
|
return False
|
|
|
|
def assign_parent(node):
|
|
"""return the higher parent which is not an AssName, Tuple or List node
|
|
"""
|
|
while node and isinstance(node, (astroid.AssignName,
|
|
astroid.Tuple,
|
|
astroid.List)):
|
|
node = node.parent
|
|
return node
|
|
|
|
|
|
def overrides_a_method(class_node, name):
|
|
"""return True if <name> is a method overridden from an ancestor"""
|
|
for ancestor in class_node.ancestors():
|
|
if name in ancestor and isinstance(ancestor[name], astroid.FunctionDef):
|
|
return True
|
|
return False
|
|
|
|
def check_messages(*messages):
|
|
"""decorator to store messages that are handled by a checker method"""
|
|
|
|
def store_messages(func):
|
|
func.checks_msgs = messages
|
|
return func
|
|
return store_messages
|
|
|
|
class IncompleteFormatString(Exception):
|
|
"""A format string ended in the middle of a format specifier."""
|
|
pass
|
|
|
|
class UnsupportedFormatCharacter(Exception):
|
|
"""A format character in a format string is not one of the supported
|
|
format characters."""
|
|
def __init__(self, index):
|
|
Exception.__init__(self, index)
|
|
self.index = index
|
|
|
|
def parse_format_string(format_string):
|
|
"""Parses a format string, returning a tuple of (keys, num_args), where keys
|
|
is the set of mapping keys in the format string, and num_args is the number
|
|
of arguments required by the format string. Raises
|
|
IncompleteFormatString or UnsupportedFormatCharacter if a
|
|
parse error occurs."""
|
|
keys = set()
|
|
num_args = 0
|
|
def next_char(i):
|
|
i += 1
|
|
if i == len(format_string):
|
|
raise IncompleteFormatString
|
|
return (i, format_string[i])
|
|
i = 0
|
|
while i < len(format_string):
|
|
char = format_string[i]
|
|
if char == '%':
|
|
i, char = next_char(i)
|
|
# Parse the mapping key (optional).
|
|
key = None
|
|
if char == '(':
|
|
depth = 1
|
|
i, char = next_char(i)
|
|
key_start = i
|
|
while depth != 0:
|
|
if char == '(':
|
|
depth += 1
|
|
elif char == ')':
|
|
depth -= 1
|
|
i, char = next_char(i)
|
|
key_end = i - 1
|
|
key = format_string[key_start:key_end]
|
|
|
|
# Parse the conversion flags (optional).
|
|
while char in '#0- +':
|
|
i, char = next_char(i)
|
|
# Parse the minimum field width (optional).
|
|
if char == '*':
|
|
num_args += 1
|
|
i, char = next_char(i)
|
|
else:
|
|
while char in string.digits:
|
|
i, char = next_char(i)
|
|
# Parse the precision (optional).
|
|
if char == '.':
|
|
i, char = next_char(i)
|
|
if char == '*':
|
|
num_args += 1
|
|
i, char = next_char(i)
|
|
else:
|
|
while char in string.digits:
|
|
i, char = next_char(i)
|
|
# Parse the length modifier (optional).
|
|
if char in 'hlL':
|
|
i, char = next_char(i)
|
|
# Parse the conversion type (mandatory).
|
|
if PY3K:
|
|
flags = 'diouxXeEfFgGcrs%a'
|
|
else:
|
|
flags = 'diouxXeEfFgGcrs%'
|
|
if char not in flags:
|
|
raise UnsupportedFormatCharacter(i)
|
|
if key:
|
|
keys.add(key)
|
|
elif char != '%':
|
|
num_args += 1
|
|
i += 1
|
|
return keys, num_args
|
|
|
|
|
|
def is_attr_protected(attrname):
|
|
"""return True if attribute name is protected (start with _ and some other
|
|
details), False otherwise.
|
|
"""
|
|
return attrname[0] == '_' and attrname != '_' and not (
|
|
attrname.startswith('__') and attrname.endswith('__'))
|
|
|
|
def node_frame_class(node):
|
|
"""return klass node for a method node (or a staticmethod or a
|
|
classmethod), return null otherwise
|
|
"""
|
|
klass = node.frame()
|
|
|
|
while klass is not None and not isinstance(klass, astroid.ClassDef):
|
|
if klass.parent is None:
|
|
klass = None
|
|
else:
|
|
klass = klass.parent.frame()
|
|
|
|
return klass
|
|
|
|
|
|
def is_attr_private(attrname):
|
|
"""Check that attribute name is private (at least two leading underscores,
|
|
at most one trailing underscore)
|
|
"""
|
|
regex = re.compile('^_{2,}.*[^_]+_?$')
|
|
return regex.match(attrname)
|
|
|
|
def get_argument_from_call(callfunc_node, position=None, keyword=None):
|
|
"""Returns the specified argument from a function call.
|
|
|
|
:param callfunc_node: Node representing a function call to check.
|
|
:param int position: position of the argument.
|
|
:param str keyword: the keyword of the argument.
|
|
|
|
:returns: The node representing the argument, None if the argument is not found.
|
|
:raises ValueError: if both position and keyword are None.
|
|
:raises NoSuchArgumentError: if no argument at the provided position or with
|
|
the provided keyword.
|
|
"""
|
|
if position is None and keyword is None:
|
|
raise ValueError('Must specify at least one of: position or keyword.')
|
|
if position is not None:
|
|
try:
|
|
return callfunc_node.args[position]
|
|
except IndexError:
|
|
pass
|
|
if keyword and callfunc_node.keywords:
|
|
for arg in callfunc_node.keywords:
|
|
if arg.arg == keyword:
|
|
return arg.value
|
|
|
|
raise NoSuchArgumentError
|
|
|
|
def inherit_from_std_ex(node):
|
|
"""
|
|
Return true if the given class node is subclass of
|
|
exceptions.Exception.
|
|
"""
|
|
if node.name in ('Exception', 'BaseException') \
|
|
and node.root().name == EXCEPTIONS_MODULE:
|
|
return True
|
|
return any(inherit_from_std_ex(parent)
|
|
for parent in node.ancestors(recurs=False))
|
|
|
|
def error_of_type(handler, error_type):
|
|
"""
|
|
Check if the given exception handler catches
|
|
the given error_type.
|
|
|
|
The *handler* parameter is a node, representing an ExceptHandler node.
|
|
The *error_type* can be an exception, such as AttributeError, or it
|
|
can be a tuple of errors.
|
|
The function will return True if the handler catches any of the
|
|
given errors.
|
|
"""
|
|
if not isinstance(error_type, tuple):
|
|
error_type = (error_type, )
|
|
expected_errors = {error.__name__ for error in error_type}
|
|
if not handler.type:
|
|
# bare except. While this indeed catches anything, if the desired errors
|
|
# aren't specified directly, then we just ignore it.
|
|
return False
|
|
return handler.catch(expected_errors)
|
|
|
|
|
|
def is_import_error(handler):
|
|
warnings.warn("This function is deprecated in the favour of "
|
|
"error_of_type. It will be removed in Pylint 1.6.",
|
|
DeprecationWarning, stacklevel=2)
|
|
return error_of_type(handler, ImportError)
|
|
|
|
|
|
def decorated_with_property(node):
|
|
""" Detect if the given function node is decorated with a property. """
|
|
if not node.decorators:
|
|
return False
|
|
for decorator in node.decorators.nodes:
|
|
if not isinstance(decorator, astroid.Name):
|
|
continue
|
|
try:
|
|
for infered in decorator.infer():
|
|
if isinstance(infered, astroid.ClassDef):
|
|
if (infered.root().name == BUILTINS_NAME and
|
|
infered.name == 'property'):
|
|
return True
|
|
for ancestor in infered.ancestors():
|
|
if (ancestor.name == 'property' and
|
|
ancestor.root().name == BUILTINS_NAME):
|
|
return True
|
|
except astroid.InferenceError:
|
|
pass
|
|
|
|
|
|
def decorated_with(func, qnames):
|
|
"""Determine if the `func` node has a decorator with the qualified name `qname`."""
|
|
decorators = func.decorators.nodes if func.decorators else []
|
|
for decorator_node in decorators:
|
|
dec = safe_infer(decorator_node)
|
|
if dec and dec.qname() in qnames:
|
|
return True
|
|
|
|
|
|
def unimplemented_abstract_methods(node, is_abstract_cb=None):
|
|
"""
|
|
Get the unimplemented abstract methods for the given *node*.
|
|
|
|
A method can be considered abstract if the callback *is_abstract_cb*
|
|
returns a ``True`` value. The check defaults to verifying that
|
|
a method is decorated with abstract methods.
|
|
The function will work only for new-style classes. For old-style
|
|
classes, it will simply return an empty dictionary.
|
|
For the rest of them, it will return a dictionary of abstract method
|
|
names and their inferred objects.
|
|
"""
|
|
if is_abstract_cb is None:
|
|
is_abstract_cb = functools.partial(
|
|
decorated_with, qnames=ABC_METHODS)
|
|
visited = {}
|
|
try:
|
|
mro = reversed(node.mro())
|
|
except NotImplementedError:
|
|
# Old style class, it will not have a mro.
|
|
return {}
|
|
except astroid.ResolveError:
|
|
# Probably inconsistent hierarchy, don'try
|
|
# to figure this out here.
|
|
return {}
|
|
for ancestor in mro:
|
|
for obj in ancestor.values():
|
|
infered = obj
|
|
if isinstance(obj, astroid.AssignName):
|
|
infered = safe_infer(obj)
|
|
if not infered:
|
|
# Might be an abstract function,
|
|
# but since we don't have enough information
|
|
# in order to take this decision, we're taking
|
|
# the *safe* decision instead.
|
|
if obj.name in visited:
|
|
del visited[obj.name]
|
|
continue
|
|
if not isinstance(infered, astroid.FunctionDef):
|
|
if obj.name in visited:
|
|
del visited[obj.name]
|
|
if isinstance(infered, astroid.FunctionDef):
|
|
# It's critical to use the original name,
|
|
# since after inferring, an object can be something
|
|
# else than expected, as in the case of the
|
|
# following assignment.
|
|
#
|
|
# class A:
|
|
# def keys(self): pass
|
|
# __iter__ = keys
|
|
abstract = is_abstract_cb(infered)
|
|
if abstract:
|
|
visited[obj.name] = infered
|
|
elif not abstract and obj.name in visited:
|
|
del visited[obj.name]
|
|
return visited
|
|
|
|
|
|
def node_ignores_exception(node, exception):
|
|
"""Check if the node is in a TryExcept which handles the given exception."""
|
|
current = node
|
|
ignores = (astroid.ExceptHandler, astroid.TryExcept)
|
|
while current and not isinstance(current.parent, ignores):
|
|
current = current.parent
|
|
|
|
func = functools.partial(error_of_type,
|
|
error_type=(exception, ))
|
|
if current and isinstance(current.parent, astroid.TryExcept):
|
|
if any(map(func, current.parent.handlers)):
|
|
return True
|
|
return False
|
|
|
|
|
|
def class_is_abstract(node):
|
|
"""return true if the given class node should be considered as an abstract
|
|
class
|
|
"""
|
|
for method in node.methods():
|
|
if method.parent.frame() is node:
|
|
if method.is_abstract(pass_is_abstract=False):
|
|
return True
|
|
return False
|
|
|
|
|
|
def _hasattr(value, attr):
|
|
try:
|
|
value.getattr(attr)
|
|
return True
|
|
except astroid.NotFoundError:
|
|
return False
|
|
|
|
|
|
def is_comprehension(node):
|
|
comprehensions = (astroid.ListComp,
|
|
astroid.SetComp,
|
|
astroid.DictComp,
|
|
astroid.GeneratorExp)
|
|
return isinstance(node, comprehensions)
|
|
|
|
|
|
def _supports_mapping_protocol(value):
|
|
return _hasattr(value, GETITEM_METHOD) and _hasattr(value, KEYS_METHOD)
|
|
|
|
|
|
def _supports_membership_test_protocol(value):
|
|
return _hasattr(value, CONTAINS_METHOD)
|
|
|
|
|
|
def _supports_iteration_protocol(value):
|
|
return _hasattr(value, ITER_METHOD) or _hasattr(value, GETITEM_METHOD)
|
|
|
|
|
|
def _supports_subscript_protocol(value):
|
|
return _hasattr(value, GETITEM_METHOD)
|
|
|
|
|
|
def _is_abstract_class_name(name):
|
|
lname = name.lower()
|
|
is_mixin = lname.endswith('mixin')
|
|
is_abstract = lname.startswith('abstract')
|
|
is_base = lname.startswith('base') or lname.endswith('base')
|
|
return is_mixin or is_abstract or is_base
|
|
|
|
|
|
def is_inside_abstract_class(node):
|
|
while node is not None:
|
|
if isinstance(node, astroid.ClassDef):
|
|
if class_is_abstract(node):
|
|
return True
|
|
name = getattr(node, 'name', None)
|
|
if name is not None and _is_abstract_class_name(name):
|
|
return True
|
|
node = node.parent
|
|
return False
|
|
|
|
|
|
def is_iterable(value):
|
|
if isinstance(value, astroid.ClassDef):
|
|
if not has_known_bases(value):
|
|
return True
|
|
# classobj can only be iterable if it has an iterable metaclass
|
|
meta = value.metaclass()
|
|
if meta is not None:
|
|
if _supports_iteration_protocol(meta):
|
|
return True
|
|
if isinstance(value, astroid.Instance):
|
|
if not has_known_bases(value):
|
|
return True
|
|
if _supports_iteration_protocol(value):
|
|
return True
|
|
return False
|
|
|
|
|
|
def is_mapping(value):
|
|
if isinstance(value, astroid.ClassDef):
|
|
if not has_known_bases(value):
|
|
return True
|
|
# classobj can only be a mapping if it has a metaclass is mapping
|
|
meta = value.metaclass()
|
|
if meta is not None:
|
|
if _supports_mapping_protocol(meta):
|
|
return True
|
|
if isinstance(value, astroid.Instance):
|
|
if not has_known_bases(value):
|
|
return True
|
|
if _supports_mapping_protocol(value):
|
|
return True
|
|
return False
|
|
|
|
|
|
def supports_membership_test(value):
|
|
if isinstance(value, astroid.ClassDef):
|
|
if not has_known_bases(value):
|
|
return True
|
|
meta = value.metaclass()
|
|
if meta is not None and _supports_membership_test_protocol(meta):
|
|
return True
|
|
if isinstance(value, astroid.Instance):
|
|
if not has_known_bases(value):
|
|
return True
|
|
if _supports_membership_test_protocol(value):
|
|
return True
|
|
return is_iterable(value)
|
|
|
|
|
|
def supports_subscript(value):
|
|
if isinstance(value, astroid.ClassDef):
|
|
if not has_known_bases(value):
|
|
return True
|
|
meta = value.metaclass()
|
|
if meta is not None and _supports_subscript_protocol(meta):
|
|
return True
|
|
if isinstance(value, astroid.Instance):
|
|
if not has_known_bases(value):
|
|
return True
|
|
if _supports_subscript_protocol(value):
|
|
return True
|
|
return False
|
|
|
|
# TODO(cpopa): deprecate these or leave them as aliases?
|
|
def safe_infer(node, context=None):
|
|
"""Return the inferred value for the given node.
|
|
|
|
Return None if inference failed or if there is some ambiguity (more than
|
|
one node has been inferred).
|
|
"""
|
|
try:
|
|
inferit = node.infer(context=context)
|
|
value = next(inferit)
|
|
except astroid.InferenceError:
|
|
return
|
|
try:
|
|
next(inferit)
|
|
return # None if there is ambiguity on the inferred node
|
|
except astroid.InferenceError:
|
|
return # there is some kind of ambiguity
|
|
except StopIteration:
|
|
return value
|
|
|
|
|
|
def has_known_bases(klass, context=None):
|
|
"""Return true if all base classes of a class could be inferred."""
|
|
try:
|
|
return klass._all_bases_known
|
|
except AttributeError:
|
|
pass
|
|
for base in klass.bases:
|
|
result = safe_infer(base, context=context)
|
|
# TODO: check for A->B->A->B pattern in class structure too?
|
|
if (not isinstance(result, astroid.ClassDef) or
|
|
result is klass or
|
|
not has_known_bases(result, context=context)):
|
|
klass._all_bases_known = False
|
|
return False
|
|
klass._all_bases_known = True
|
|
return True
|