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Diffstat (limited to 'venv/Lib/site-packages/astroid/brain/brain_builtin_inference.py')
| -rw-r--r-- | venv/Lib/site-packages/astroid/brain/brain_builtin_inference.py | 829 |
1 files changed, 0 insertions, 829 deletions
diff --git a/venv/Lib/site-packages/astroid/brain/brain_builtin_inference.py b/venv/Lib/site-packages/astroid/brain/brain_builtin_inference.py deleted file mode 100644 index 2dd7cc5..0000000 --- a/venv/Lib/site-packages/astroid/brain/brain_builtin_inference.py +++ /dev/null @@ -1,829 +0,0 @@ -# Copyright (c) 2014-2018 Claudiu Popa <pcmanticore@gmail.com> -# Copyright (c) 2014-2015 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr> -# Copyright (c) 2015-2016 Ceridwen <ceridwenv@gmail.com> -# Copyright (c) 2015 Rene Zhang <rz99@cornell.edu> -# Copyright (c) 2018 Bryce Guinta <bryce.paul.guinta@gmail.com> - -# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html -# For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER - -"""Astroid hooks for various builtins.""" - -from functools import partial -from textwrap import dedent - -import six -from astroid import ( - MANAGER, - UseInferenceDefault, - AttributeInferenceError, - inference_tip, - InferenceError, - NameInferenceError, - AstroidTypeError, - MroError, -) -from astroid import arguments -from astroid.builder import AstroidBuilder -from astroid import helpers -from astroid import nodes -from astroid import objects -from astroid import scoped_nodes -from astroid import util - - -OBJECT_DUNDER_NEW = "object.__new__" - - -def _extend_str(class_node, rvalue): - """function to extend builtin str/unicode class""" - code = dedent( - """ - class whatever(object): - def join(self, iterable): - return {rvalue} - def replace(self, old, new, count=None): - return {rvalue} - def format(self, *args, **kwargs): - return {rvalue} - def encode(self, encoding='ascii', errors=None): - return '' - def decode(self, encoding='ascii', errors=None): - return u'' - def capitalize(self): - return {rvalue} - def title(self): - return {rvalue} - def lower(self): - return {rvalue} - def upper(self): - return {rvalue} - def swapcase(self): - return {rvalue} - def index(self, sub, start=None, end=None): - return 0 - def find(self, sub, start=None, end=None): - return 0 - def count(self, sub, start=None, end=None): - return 0 - def strip(self, chars=None): - return {rvalue} - def lstrip(self, chars=None): - return {rvalue} - def rstrip(self, chars=None): - return {rvalue} - def rjust(self, width, fillchar=None): - return {rvalue} - def center(self, width, fillchar=None): - return {rvalue} - def ljust(self, width, fillchar=None): - return {rvalue} - """ - ) - code = code.format(rvalue=rvalue) - fake = AstroidBuilder(MANAGER).string_build(code)["whatever"] - for method in fake.mymethods(): - method.parent = class_node - method.lineno = None - method.col_offset = None - if "__class__" in method.locals: - method.locals["__class__"] = [class_node] - class_node.locals[method.name] = [method] - method.parent = class_node - - -def _extend_builtins(class_transforms): - builtin_ast = MANAGER.builtins_module - for class_name, transform in class_transforms.items(): - transform(builtin_ast[class_name]) - - -_extend_builtins( - { - "bytes": partial(_extend_str, rvalue="b''"), - "str": partial(_extend_str, rvalue="''"), - } -) - - -def _builtin_filter_predicate(node, builtin_name): - if isinstance(node.func, nodes.Name) and node.func.name == builtin_name: - return True - if isinstance(node.func, nodes.Attribute): - return ( - node.func.attrname == "fromkeys" - and isinstance(node.func.expr, nodes.Name) - and node.func.expr.name == "dict" - ) - return False - - -def register_builtin_transform(transform, builtin_name): - """Register a new transform function for the given *builtin_name*. - - The transform function must accept two parameters, a node and - an optional context. - """ - - def _transform_wrapper(node, context=None): - result = transform(node, context=context) - if result: - if not result.parent: - # Let the transformation function determine - # the parent for its result. Otherwise, - # we set it to be the node we transformed from. - result.parent = node - - if result.lineno is None: - result.lineno = node.lineno - if result.col_offset is None: - result.col_offset = node.col_offset - return iter([result]) - - MANAGER.register_transform( - nodes.Call, - inference_tip(_transform_wrapper), - partial(_builtin_filter_predicate, builtin_name=builtin_name), - ) - - -def _container_generic_inference(node, context, node_type, transform): - args = node.args - if not args: - return node_type() - if len(node.args) > 1: - raise UseInferenceDefault() - - arg, = args - transformed = transform(arg) - if not transformed: - try: - inferred = next(arg.infer(context=context)) - except (InferenceError, StopIteration): - raise UseInferenceDefault() - if inferred is util.Uninferable: - raise UseInferenceDefault() - transformed = transform(inferred) - if not transformed or transformed is util.Uninferable: - raise UseInferenceDefault() - return transformed - - -def _container_generic_transform(arg, klass, iterables, build_elts): - if isinstance(arg, klass): - return arg - elif isinstance(arg, iterables): - if all(isinstance(elt, nodes.Const) for elt in arg.elts): - elts = [elt.value for elt in arg.elts] - else: - # TODO: Does not handle deduplication for sets. - elts = filter(None, map(helpers.safe_infer, arg.elts)) - elif isinstance(arg, nodes.Dict): - # Dicts need to have consts as strings already. - if not all(isinstance(elt[0], nodes.Const) for elt in arg.items): - raise UseInferenceDefault() - elts = [item[0].value for item in arg.items] - elif isinstance(arg, nodes.Const) and isinstance( - arg.value, (six.string_types, six.binary_type) - ): - elts = arg.value - else: - return - return klass.from_elements(elts=build_elts(elts)) - - -def _infer_builtin_container( - node, context, klass=None, iterables=None, build_elts=None -): - transform_func = partial( - _container_generic_transform, - klass=klass, - iterables=iterables, - build_elts=build_elts, - ) - - return _container_generic_inference(node, context, klass, transform_func) - - -# pylint: disable=invalid-name -infer_tuple = partial( - _infer_builtin_container, - klass=nodes.Tuple, - iterables=( - nodes.List, - nodes.Set, - objects.FrozenSet, - objects.DictItems, - objects.DictKeys, - objects.DictValues, - ), - build_elts=tuple, -) - -infer_list = partial( - _infer_builtin_container, - klass=nodes.List, - iterables=( - nodes.Tuple, - nodes.Set, - objects.FrozenSet, - objects.DictItems, - objects.DictKeys, - objects.DictValues, - ), - build_elts=list, -) - -infer_set = partial( - _infer_builtin_container, - klass=nodes.Set, - iterables=(nodes.List, nodes.Tuple, objects.FrozenSet, objects.DictKeys), - build_elts=set, -) - -infer_frozenset = partial( - _infer_builtin_container, - klass=objects.FrozenSet, - iterables=(nodes.List, nodes.Tuple, nodes.Set, objects.FrozenSet, objects.DictKeys), - build_elts=frozenset, -) - - -def _get_elts(arg, context): - is_iterable = lambda n: isinstance(n, (nodes.List, nodes.Tuple, nodes.Set)) - try: - inferred = next(arg.infer(context)) - except (InferenceError, NameInferenceError): - raise UseInferenceDefault() - if isinstance(inferred, nodes.Dict): - items = inferred.items - elif is_iterable(inferred): - items = [] - for elt in inferred.elts: - # If an item is not a pair of two items, - # then fallback to the default inference. - # Also, take in consideration only hashable items, - # tuples and consts. We are choosing Names as well. - if not is_iterable(elt): - raise UseInferenceDefault() - if len(elt.elts) != 2: - raise UseInferenceDefault() - if not isinstance(elt.elts[0], (nodes.Tuple, nodes.Const, nodes.Name)): - raise UseInferenceDefault() - items.append(tuple(elt.elts)) - else: - raise UseInferenceDefault() - return items - - -def infer_dict(node, context=None): - """Try to infer a dict call to a Dict node. - - The function treats the following cases: - - * dict() - * dict(mapping) - * dict(iterable) - * dict(iterable, **kwargs) - * dict(mapping, **kwargs) - * dict(**kwargs) - - If a case can't be inferred, we'll fallback to default inference. - """ - call = arguments.CallSite.from_call(node) - if call.has_invalid_arguments() or call.has_invalid_keywords(): - raise UseInferenceDefault - - args = call.positional_arguments - kwargs = list(call.keyword_arguments.items()) - - if not args and not kwargs: - # dict() - return nodes.Dict() - elif kwargs and not args: - # dict(a=1, b=2, c=4) - items = [(nodes.Const(key), value) for key, value in kwargs] - elif len(args) == 1 and kwargs: - # dict(some_iterable, b=2, c=4) - elts = _get_elts(args[0], context) - keys = [(nodes.Const(key), value) for key, value in kwargs] - items = elts + keys - elif len(args) == 1: - items = _get_elts(args[0], context) - else: - raise UseInferenceDefault() - - value = nodes.Dict( - col_offset=node.col_offset, lineno=node.lineno, parent=node.parent - ) - value.postinit(items) - return value - - -def infer_super(node, context=None): - """Understand super calls. - - There are some restrictions for what can be understood: - - * unbounded super (one argument form) is not understood. - - * if the super call is not inside a function (classmethod or method), - then the default inference will be used. - - * if the super arguments can't be inferred, the default inference - will be used. - """ - if len(node.args) == 1: - # Ignore unbounded super. - raise UseInferenceDefault - - scope = node.scope() - if not isinstance(scope, nodes.FunctionDef): - # Ignore non-method uses of super. - raise UseInferenceDefault - if scope.type not in ("classmethod", "method"): - # Not interested in staticmethods. - raise UseInferenceDefault - - cls = scoped_nodes.get_wrapping_class(scope) - if not len(node.args): - mro_pointer = cls - # In we are in a classmethod, the interpreter will fill - # automatically the class as the second argument, not an instance. - if scope.type == "classmethod": - mro_type = cls - else: - mro_type = cls.instantiate_class() - else: - try: - mro_pointer = next(node.args[0].infer(context=context)) - except InferenceError: - raise UseInferenceDefault - try: - mro_type = next(node.args[1].infer(context=context)) - except InferenceError: - raise UseInferenceDefault - - if mro_pointer is util.Uninferable or mro_type is util.Uninferable: - # No way we could understand this. - raise UseInferenceDefault - - super_obj = objects.Super( - mro_pointer=mro_pointer, mro_type=mro_type, self_class=cls, scope=scope - ) - super_obj.parent = node - return super_obj - - -def _infer_getattr_args(node, context): - if len(node.args) not in (2, 3): - # Not a valid getattr call. - raise UseInferenceDefault - - try: - obj = next(node.args[0].infer(context=context)) - attr = next(node.args[1].infer(context=context)) - except InferenceError: - raise UseInferenceDefault - - if obj is util.Uninferable or attr is util.Uninferable: - # If one of the arguments is something we can't infer, - # then also make the result of the getattr call something - # which is unknown. - return util.Uninferable, util.Uninferable - - is_string = isinstance(attr, nodes.Const) and isinstance( - attr.value, six.string_types - ) - if not is_string: - raise UseInferenceDefault - - return obj, attr.value - - -def infer_getattr(node, context=None): - """Understand getattr calls - - If one of the arguments is an Uninferable object, then the - result will be an Uninferable object. Otherwise, the normal attribute - lookup will be done. - """ - obj, attr = _infer_getattr_args(node, context) - if ( - obj is util.Uninferable - or attr is util.Uninferable - or not hasattr(obj, "igetattr") - ): - return util.Uninferable - - try: - return next(obj.igetattr(attr, context=context)) - except (StopIteration, InferenceError, AttributeInferenceError): - if len(node.args) == 3: - # Try to infer the default and return it instead. - try: - return next(node.args[2].infer(context=context)) - except InferenceError: - raise UseInferenceDefault - - raise UseInferenceDefault - - -def infer_hasattr(node, context=None): - """Understand hasattr calls - - This always guarantees three possible outcomes for calling - hasattr: Const(False) when we are sure that the object - doesn't have the intended attribute, Const(True) when - we know that the object has the attribute and Uninferable - when we are unsure of the outcome of the function call. - """ - try: - obj, attr = _infer_getattr_args(node, context) - if ( - obj is util.Uninferable - or attr is util.Uninferable - or not hasattr(obj, "getattr") - ): - return util.Uninferable - obj.getattr(attr, context=context) - except UseInferenceDefault: - # Can't infer something from this function call. - return util.Uninferable - except AttributeInferenceError: - # Doesn't have it. - return nodes.Const(False) - return nodes.Const(True) - - -def infer_callable(node, context=None): - """Understand callable calls - - This follows Python's semantics, where an object - is callable if it provides an attribute __call__, - even though that attribute is something which can't be - called. - """ - if len(node.args) != 1: - # Invalid callable call. - raise UseInferenceDefault - - argument = node.args[0] - try: - inferred = next(argument.infer(context=context)) - except InferenceError: - return util.Uninferable - if inferred is util.Uninferable: - return util.Uninferable - return nodes.Const(inferred.callable()) - - -def infer_bool(node, context=None): - """Understand bool calls.""" - if len(node.args) > 1: - # Invalid bool call. - raise UseInferenceDefault - - if not node.args: - return nodes.Const(False) - - argument = node.args[0] - try: - inferred = next(argument.infer(context=context)) - except InferenceError: - return util.Uninferable - if inferred is util.Uninferable: - return util.Uninferable - - bool_value = inferred.bool_value() - if bool_value is util.Uninferable: - return util.Uninferable - return nodes.Const(bool_value) - - -def infer_type(node, context=None): - """Understand the one-argument form of *type*.""" - if len(node.args) != 1: - raise UseInferenceDefault - - return helpers.object_type(node.args[0], context) - - -def infer_slice(node, context=None): - """Understand `slice` calls.""" - args = node.args - if not 0 < len(args) <= 3: - raise UseInferenceDefault - - infer_func = partial(helpers.safe_infer, context=context) - args = [infer_func(arg) for arg in args] - for arg in args: - if not arg or arg is util.Uninferable: - raise UseInferenceDefault - if not isinstance(arg, nodes.Const): - raise UseInferenceDefault - if not isinstance(arg.value, (type(None), int)): - raise UseInferenceDefault - - if len(args) < 3: - # Make sure we have 3 arguments. - args.extend([None] * (3 - len(args))) - - slice_node = nodes.Slice( - lineno=node.lineno, col_offset=node.col_offset, parent=node.parent - ) - slice_node.postinit(*args) - return slice_node - - -def _infer_object__new__decorator(node, context=None): - # Instantiate class immediately - # since that's what @object.__new__ does - return iter((node.instantiate_class(),)) - - -def _infer_object__new__decorator_check(node): - """Predicate before inference_tip - - Check if the given ClassDef has an @object.__new__ decorator - """ - if not node.decorators: - return False - - for decorator in node.decorators.nodes: - if isinstance(decorator, nodes.Attribute): - if decorator.as_string() == OBJECT_DUNDER_NEW: - return True - return False - - -def infer_issubclass(callnode, context=None): - """Infer issubclass() calls - - :param nodes.Call callnode: an `issubclass` call - :param InferenceContext: the context for the inference - :rtype nodes.Const: Boolean Const value of the `issubclass` call - :raises UseInferenceDefault: If the node cannot be inferred - """ - call = arguments.CallSite.from_call(callnode) - if call.keyword_arguments: - # issubclass doesn't support keyword arguments - raise UseInferenceDefault("TypeError: issubclass() takes no keyword arguments") - if len(call.positional_arguments) != 2: - raise UseInferenceDefault( - "Expected two arguments, got {count}".format( - count=len(call.positional_arguments) - ) - ) - # The left hand argument is the obj to be checked - obj_node, class_or_tuple_node = call.positional_arguments - - try: - obj_type = next(obj_node.infer(context=context)) - except InferenceError as exc: - raise UseInferenceDefault from exc - if not isinstance(obj_type, nodes.ClassDef): - raise UseInferenceDefault("TypeError: arg 1 must be class") - - # The right hand argument is the class(es) that the given - # object is to be checked against. - try: - class_container = _class_or_tuple_to_container( - class_or_tuple_node, context=context - ) - except InferenceError as exc: - raise UseInferenceDefault from exc - try: - issubclass_bool = helpers.object_issubclass(obj_type, class_container, context) - except AstroidTypeError as exc: - raise UseInferenceDefault("TypeError: " + str(exc)) from exc - except MroError as exc: - raise UseInferenceDefault from exc - return nodes.Const(issubclass_bool) - - -def infer_isinstance(callnode, context=None): - """Infer isinstance calls - - :param nodes.Call callnode: an isinstance call - :param InferenceContext: context for call - (currently unused but is a common interface for inference) - :rtype nodes.Const: Boolean Const value of isinstance call - - :raises UseInferenceDefault: If the node cannot be inferred - """ - call = arguments.CallSite.from_call(callnode) - if call.keyword_arguments: - # isinstance doesn't support keyword arguments - raise UseInferenceDefault("TypeError: isinstance() takes no keyword arguments") - if len(call.positional_arguments) != 2: - raise UseInferenceDefault( - "Expected two arguments, got {count}".format( - count=len(call.positional_arguments) - ) - ) - # The left hand argument is the obj to be checked - obj_node, class_or_tuple_node = call.positional_arguments - # The right hand argument is the class(es) that the given - # obj is to be check is an instance of - try: - class_container = _class_or_tuple_to_container( - class_or_tuple_node, context=context - ) - except InferenceError: - raise UseInferenceDefault - try: - isinstance_bool = helpers.object_isinstance(obj_node, class_container, context) - except AstroidTypeError as exc: - raise UseInferenceDefault("TypeError: " + str(exc)) - except MroError as exc: - raise UseInferenceDefault from exc - if isinstance_bool is util.Uninferable: - raise UseInferenceDefault - return nodes.Const(isinstance_bool) - - -def _class_or_tuple_to_container(node, context=None): - # Move inferences results into container - # to simplify later logic - # raises InferenceError if any of the inferences fall through - node_infer = next(node.infer(context=context)) - # arg2 MUST be a type or a TUPLE of types - # for isinstance - if isinstance(node_infer, nodes.Tuple): - class_container = [ - next(node.infer(context=context)) for node in node_infer.elts - ] - class_container = [ - klass_node for klass_node in class_container if klass_node is not None - ] - else: - class_container = [node_infer] - return class_container - - -def infer_len(node, context=None): - """Infer length calls - - :param nodes.Call node: len call to infer - :param context.InferenceContext: node context - :rtype nodes.Const: a Const node with the inferred length, if possible - """ - call = arguments.CallSite.from_call(node) - if call.keyword_arguments: - raise UseInferenceDefault("TypeError: len() must take no keyword arguments") - if len(call.positional_arguments) != 1: - raise UseInferenceDefault( - "TypeError: len() must take exactly one argument " - "({len}) given".format(len=len(call.positional_arguments)) - ) - [argument_node] = call.positional_arguments - try: - return nodes.Const(helpers.object_len(argument_node, context=context)) - except (AstroidTypeError, InferenceError) as exc: - raise UseInferenceDefault(str(exc)) from exc - - -def infer_str(node, context=None): - """Infer str() calls - - :param nodes.Call node: str() call to infer - :param context.InferenceContext: node context - :rtype nodes.Const: a Const containing an empty string - """ - call = arguments.CallSite.from_call(node) - if call.keyword_arguments: - raise UseInferenceDefault("TypeError: str() must take no keyword arguments") - try: - return nodes.Const("") - except (AstroidTypeError, InferenceError) as exc: - raise UseInferenceDefault(str(exc)) from exc - - -def infer_int(node, context=None): - """Infer int() calls - - :param nodes.Call node: int() call to infer - :param context.InferenceContext: node context - :rtype nodes.Const: a Const containing the integer value of the int() call - """ - call = arguments.CallSite.from_call(node) - if call.keyword_arguments: - raise UseInferenceDefault("TypeError: int() must take no keyword arguments") - - if call.positional_arguments: - try: - first_value = next(call.positional_arguments[0].infer(context=context)) - except InferenceError as exc: - raise UseInferenceDefault(str(exc)) from exc - - if first_value is util.Uninferable: - raise UseInferenceDefault - - if isinstance(first_value, nodes.Const) and isinstance( - first_value.value, (int, str) - ): - try: - actual_value = int(first_value.value) - except ValueError: - return nodes.Const(0) - return nodes.Const(actual_value) - - return nodes.Const(0) - - -def infer_dict_fromkeys(node, context=None): - """Infer dict.fromkeys - - :param nodes.Call node: dict.fromkeys() call to infer - :param context.InferenceContext: node context - :rtype nodes.Dict: - a Dictionary containing the values that astroid was able to infer. - In case the inference failed for any reason, an empty dictionary - will be inferred instead. - """ - - def _build_dict_with_elements(elements): - new_node = nodes.Dict( - col_offset=node.col_offset, lineno=node.lineno, parent=node.parent - ) - new_node.postinit(elements) - return new_node - - call = arguments.CallSite.from_call(node) - if call.keyword_arguments: - raise UseInferenceDefault("TypeError: int() must take no keyword arguments") - if len(call.positional_arguments) not in {1, 2}: - raise UseInferenceDefault( - "TypeError: Needs between 1 and 2 positional arguments" - ) - - default = nodes.Const(None) - values = call.positional_arguments[0] - try: - inferred_values = next(values.infer(context=context)) - except InferenceError: - return _build_dict_with_elements([]) - if inferred_values is util.Uninferable: - return _build_dict_with_elements([]) - - # Limit to a couple of potential values, as this can become pretty complicated - accepted_iterable_elements = (nodes.Const,) - if isinstance(inferred_values, (nodes.List, nodes.Set, nodes.Tuple)): - elements = inferred_values.elts - for element in elements: - if not isinstance(element, accepted_iterable_elements): - # Fallback to an empty dict - return _build_dict_with_elements([]) - - elements_with_value = [(element, default) for element in elements] - return _build_dict_with_elements(elements_with_value) - - elif isinstance(inferred_values, nodes.Const) and isinstance( - inferred_values.value, (str, bytes) - ): - elements = [ - (nodes.Const(element), default) for element in inferred_values.value - ] - return _build_dict_with_elements(elements) - elif isinstance(inferred_values, nodes.Dict): - keys = inferred_values.itered() - for key in keys: - if not isinstance(key, accepted_iterable_elements): - # Fallback to an empty dict - return _build_dict_with_elements([]) - - elements_with_value = [(element, default) for element in keys] - return _build_dict_with_elements(elements_with_value) - - # Fallback to an empty dictionary - return _build_dict_with_elements([]) - - -# Builtins inference -register_builtin_transform(infer_bool, "bool") -register_builtin_transform(infer_super, "super") -register_builtin_transform(infer_callable, "callable") -register_builtin_transform(infer_getattr, "getattr") -register_builtin_transform(infer_hasattr, "hasattr") -register_builtin_transform(infer_tuple, "tuple") -register_builtin_transform(infer_set, "set") -register_builtin_transform(infer_list, "list") -register_builtin_transform(infer_dict, "dict") -register_builtin_transform(infer_frozenset, "frozenset") -register_builtin_transform(infer_type, "type") -register_builtin_transform(infer_slice, "slice") -register_builtin_transform(infer_isinstance, "isinstance") -register_builtin_transform(infer_issubclass, "issubclass") -register_builtin_transform(infer_len, "len") -register_builtin_transform(infer_str, "str") -register_builtin_transform(infer_int, "int") -register_builtin_transform(infer_dict_fromkeys, "dict.fromkeys") - - -# Infer object.__new__ calls -MANAGER.register_transform( - nodes.ClassDef, - inference_tip(_infer_object__new__decorator), - _infer_object__new__decorator_check, -) |