def add_class_tvars(t: ProperType, isuper: Optional[Instance],
is_classmethod: bool,
original_type: Type,
original_vars: Optional[Sequence[TypeVarLikeDef]] = None) -> Type:
"""Instantiate type variables during analyze_class_attribute_access,
e.g T and Q in the following:
class A(Generic[T]):
@classmethod
def foo(cls: Type[Q]) -> Tuple[T, Q]: ...
class B(A[str]): pass
B.foo()
Args:
t: Declared type of the method (or property)
isuper: Current instance mapped to the superclass where method was defined, this
is usually done by map_instance_to_supertype()
is_classmethod: True if this method is decorated with @classmethod
original_type: The value of the type B in the expression B.foo() or the corresponding
component in case of a union (this is used to bind the self-types)
original_vars: Type variables of the class callable on which the method was accessed
Returns:
Expanded method type with added type variables (when needed).
"""
# TODO: verify consistency between Q and T
# We add class type variables if the class method is accessed on class object
# without applied type arguments, this matches the behavior of __init__().
# For example (continuing the example in docstring):
# A # The type of callable is def [T] () -> A[T], _not_ def () -> A[Any]
# A[int] # The type of callable is def () -> A[int]
# and
# A.foo # The type is generic def [T] () -> Tuple[T, A[T]]
# A[int].foo # The type is non-generic def () -> Tuple[int, A[int]]
#
# This behaviour is useful for defining alternative constructors for generic classes.
# To achieve such behaviour, we add the class type variables that are still free
# (i.e. appear in the return type of the class object on which the method was accessed).
if isinstance(t, CallableType):
tvars = original_vars if original_vars is not None else []
if is_classmethod:
t = freshen_function_type_vars(t)
t = bind_self(t, original_type, is_classmethod=True)
assert isuper is not None
t = cast(CallableType, expand_type_by_instance(t, isuper))
freeze_type_vars(t)
return t.copy_modified(variables=list(tvars) + list(t.variables))
elif isinstance(t, Overloaded):
return Overloaded([cast(CallableType, add_class_tvars(item, isuper,
is_classmethod, original_type,
original_vars=original_vars))
for item in t.items()])
if isuper is not None:
t = cast(ProperType, expand_type_by_instance(t, isuper))
return t
def analyze_instance_member_access(name: str, typ: Instance, mx: MemberContext,
override_info: Optional[TypeInfo]) -> Type:
if name == '__init__' and not mx.is_super:
# Accessing __init__ in statically typed code would compromise
# type safety unless used via super().
mx.msg.fail(message_registry.CANNOT_ACCESS_INIT, mx.context)
return AnyType(TypeOfAny.from_error)
# The base object has an instance type.
info = typ.type
if override_info:
info = override_info
if (state.find_occurrences and info.name == state.find_occurrences[0]
and name == state.find_occurrences[1]):
mx.msg.note("Occurrence of '{}.{}'".format(*state.find_occurrences),
mx.context)
# Look up the member. First look up the method dictionary.
method = info.get_method(name)
if method:
if method.is_property:
assert isinstance(method, OverloadedFuncDef)
first_item = cast(Decorator, method.items[0])
return analyze_var(name, first_item.var, typ, info, mx)
if mx.is_lvalue:
mx.msg.cant_assign_to_method(mx.context)
signature = function_type(method, mx.builtin_type('builtins.function'))
signature = freshen_function_type_vars(signature)
if name == '__new__':
# __new__ is special and behaves like a static method -- don't strip
# the first argument.
pass
else:
if isinstance(signature, FunctionLike) and name != '__call__':
# TODO: use proper treatment of special methods on unions instead
# of this hack here and below (i.e. mx.self_type).
dispatched_type = meet.meet_types(mx.original_type, typ)
signature = check_self_arg(signature, dispatched_type,
method.is_class, mx.context, name,
mx.msg)
signature = bind_self(signature,
mx.self_type,
is_classmethod=method.is_class)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
return member_type
else:
# Not a method.
return analyze_member_var_access(name, typ, info, mx)
def analyze_instance_member_access(name: str,
typ: Instance,
mx: MemberContext,
override_info: Optional[TypeInfo]) -> Type:
if name == '__init__' and not mx.is_super:
# Accessing __init__ in statically typed code would compromise
# type safety unless used via super().
mx.msg.fail(message_registry.CANNOT_ACCESS_INIT, mx.context)
return AnyType(TypeOfAny.from_error)
# The base object has an instance type.
info = typ.type
if override_info:
info = override_info
if (state.find_occurrences and
info.name() == state.find_occurrences[0] and
name == state.find_occurrences[1]):
mx.msg.note("Occurrence of '{}.{}'".format(*state.find_occurrences), mx.context)
# Look up the member. First look up the method dictionary.
method = info.get_method(name)
if method:
if method.is_property:
assert isinstance(method, OverloadedFuncDef)
first_item = cast(Decorator, method.items[0])
return analyze_var(name, first_item.var, typ, info, mx)
if mx.is_lvalue:
mx.msg.cant_assign_to_method(mx.context)
signature = function_type(method, mx.builtin_type('builtins.function'))
signature = freshen_function_type_vars(signature)
if name == '__new__':
# __new__ is special and behaves like a static method -- don't strip
# the first argument.
pass
else:
signature = bind_self(signature, mx.original_type)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
return member_type
else:
# Not a method.
return analyze_member_var_access(name, typ, info, mx)
def _intersection_hook(context: FunctionSigContext):
has_intersection = 'pfun.Intersection' in str(context.default_signature)
is_generic = context.default_signature.is_generic()
if not has_intersection or not is_generic:
return context.default_signature
formal_to_actual = map_actuals_to_formals(
context.context.arg_kinds, context.context.arg_names,
context.default_signature.arg_kinds,
context.default_signature.arg_names,
lambda i: context.api.expr_checker.accept(context.args[0][i]))
callee = freshen_function_type_vars(context.default_signature)
callee = (
context.api.expr_checker.infer_function_type_arguments_using_context(
callee, context.context))
args = [arg for args in context.args for arg in args]
callee = context.api.expr_checker.infer_function_type_arguments(
callee, args, context.context.arg_kinds, formal_to_actual,
context.context)
intersection_translator = TranslateIntersection(context.api,
context.context,
inferred=True)
translated = callee.accept(intersection_translator)
return translated
def analyze_member_access(name: str,
typ: Type,
node: Context,
is_lvalue: bool,
is_super: bool,
is_operator: bool,
builtin_type: Callable[[str], Instance],
not_ready_callback: Callable[[str, Context], None],
msg: MessageBuilder,
*,
original_type: Type,
override_info: TypeInfo = None,
chk: 'mypy.checker.TypeChecker' = None) -> Type:
"""Return the type of attribute `name` of typ.
This is a general operation that supports various different variations:
1. lvalue or non-lvalue access (i.e. setter or getter access)
2. supertype access (when using super(); is_super == True and
override_info should refer to the supertype)
original_type is the most precise inferred or declared type of the base object
that we have available. typ is generally a supertype of original_type.
When looking for an attribute of typ, we may perform recursive calls targeting
the fallback type, for example.
original_type is always the type used in the initial call.
"""
if isinstance(typ, Instance):
if name == '__init__' and not is_super:
# Accessing __init__ in statically typed code would compromise
# type safety unless used via super().
msg.fail(messages.CANNOT_ACCESS_INIT, node)
return AnyType()
# The base object has an instance type.
info = typ.type
if override_info:
info = override_info
if (experiments.find_occurrences
and info.name() == experiments.find_occurrences[0]
and name == experiments.find_occurrences[1]):
msg.note(
"Occurrence of '{}.{}'".format(*experiments.find_occurrences),
node)
# Look up the member. First look up the method dictionary.
method = info.get_method(name)
if method:
if method.is_property:
assert isinstance(method, OverloadedFuncDef)
return analyze_var(name, method.items[0].var, typ, info, node,
is_lvalue, msg, original_type,
not_ready_callback)
if is_lvalue:
msg.cant_assign_to_method(node)
signature = function_type(method,
builtin_type('builtins.function'))
signature = freshen_function_type_vars(signature)
if name == '__new__':
# __new__ is special and behaves like a static method -- don't strip
# the first argument.
pass
else:
signature = bind_self(signature, original_type)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
return member_type
else:
# Not a method.
return analyze_member_var_access(name,
typ,
info,
node,
is_lvalue,
is_super,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, AnyType):
# The base object has dynamic type.
return AnyType()
elif isinstance(typ, NoneTyp):
if chk and chk.should_suppress_optional_error([typ]):
return AnyType()
# The only attribute NoneType has are those it inherits from object
return analyze_member_access(name,
builtin_type('builtins.object'),
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, UnionType):
# The base object has dynamic type.
msg.disable_type_names += 1
results = [
analyze_member_access(name,
subtype,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk) for subtype in typ.items
]
msg.disable_type_names -= 1
return UnionType.make_simplified_union(results)
elif isinstance(typ, TupleType):
# Actually look up from the fallback instance type.
return analyze_member_access(name,
typ.fallback,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, TypedDictType):
# Actually look up from the fallback instance type.
return analyze_member_access(name,
typ.fallback,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, FunctionLike) and typ.is_type_obj():
# Class attribute.
# TODO super?
ret_type = typ.items()[0].ret_type
if isinstance(ret_type, TupleType):
ret_type = ret_type.fallback
if isinstance(ret_type, Instance):
if not is_operator:
# When Python sees an operator (eg `3 == 4`), it automatically translates that
# into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an
# optimization.
#
# While it normally it doesn't matter which of the two versions are used, it
# does cause inconsistencies when working with classes. For example, translating
# `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to
# compare two int _instances_. What we really want is `type(int).__eq__`, which
# is meant to compare two types or classes.
#
# This check makes sure that when we encounter an operator, we skip looking up
# the corresponding method in the current instance to avoid this edge case.
# See https://github.com/python/mypy/pull/1787 for more info.
result = analyze_class_attribute_access(
ret_type,
name,
node,
is_lvalue,
builtin_type,
not_ready_callback,
msg,
original_type=original_type)
if result:
return result
# Look up from the 'type' type.
return analyze_member_access(name,
typ.fallback,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
else:
assert False, 'Unexpected type {}'.format(repr(ret_type))
elif isinstance(typ, FunctionLike):
# Look up from the 'function' type.
return analyze_member_access(name,
typ.fallback,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, TypeVarType):
return analyze_member_access(name,
typ.upper_bound,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
elif isinstance(typ, DeletedType):
msg.deleted_as_rvalue(typ, node)
return AnyType()
elif isinstance(typ, TypeType):
# Similar to FunctionLike + is_type_obj() above.
item = None
if isinstance(typ.item, Instance):
item = typ.item
elif isinstance(typ.item, TypeVarType):
if isinstance(typ.item.upper_bound, Instance):
item = typ.item.upper_bound
if item and not is_operator:
# See comment above for why operators are skipped
result = analyze_class_attribute_access(
item,
name,
node,
is_lvalue,
builtin_type,
not_ready_callback,
msg,
original_type=original_type)
if result:
return result
fallback = builtin_type('builtins.type')
if item is not None:
fallback = item.type.metaclass_type or fallback
return analyze_member_access(name,
fallback,
node,
is_lvalue,
is_super,
is_operator,
builtin_type,
not_ready_callback,
msg,
original_type=original_type,
chk=chk)
if chk and chk.should_suppress_optional_error([typ]):
return AnyType()
return msg.has_no_attr(original_type, name, node)
def analyze_var(name: str,
var: Var,
itype: Instance,
info: TypeInfo,
mx: MemberContext,
*,
implicit: bool = False) -> Type:
"""Analyze access to an attribute via a Var node.
This is conceptually part of analyze_member_access and the arguments are similar.
itype is the class object in which var is defined
original_type is the type of E in the expression E.var
if implicit is True, the original Var was created as an assignment to self
"""
# Found a member variable.
itype = map_instance_to_supertype(itype, var.info)
typ = var.type
if typ:
if isinstance(typ, PartialType):
return mx.chk.handle_partial_var_type(typ, mx.is_lvalue, var,
mx.context)
if mx.is_lvalue and var.is_property and not var.is_settable_property:
# TODO allow setting attributes in subclass (although it is probably an error)
mx.msg.read_only_property(name, itype.type, mx.context)
if mx.is_lvalue and var.is_classvar:
mx.msg.cant_assign_to_classvar(name, mx.context)
t = get_proper_type(expand_type_by_instance(typ, itype))
result = t # type: Type
typ = get_proper_type(typ)
if var.is_initialized_in_class and isinstance(
typ, FunctionLike) and not typ.is_type_obj():
if mx.is_lvalue:
if var.is_property:
if not var.is_settable_property:
mx.msg.read_only_property(name, itype.type, mx.context)
else:
mx.msg.cant_assign_to_method(mx.context)
if not var.is_staticmethod:
# Class-level function objects and classmethods become bound methods:
# the former to the instance, the latter to the class.
functype = typ
# Use meet to narrow original_type to the dispatched type.
# For example, assume
# * A.f: Callable[[A1], None] where A1 <: A (maybe A1 == A)
# * B.f: Callable[[B1], None] where B1 <: B (maybe B1 == B)
# * x: Union[A1, B1]
# In `x.f`, when checking `x` against A1 we assume x is compatible with A
# and similarly for B1 when checking agains B
dispatched_type = meet.meet_types(mx.original_type, itype)
signature = freshen_function_type_vars(functype)
signature = check_self_arg(signature, dispatched_type,
var.is_classmethod, mx.context,
name, mx.msg)
signature = bind_self(signature, mx.self_type,
var.is_classmethod)
expanded_signature = get_proper_type(
expand_type_by_instance(signature, itype))
freeze_type_vars(expanded_signature)
if var.is_property:
# A property cannot have an overloaded type => the cast is fine.
assert isinstance(expanded_signature, CallableType)
result = expanded_signature.ret_type
else:
result = expanded_signature
else:
if not var.is_ready:
mx.not_ready_callback(var.name, mx.context)
# Implicit 'Any' type.
result = AnyType(TypeOfAny.special_form)
fullname = '{}.{}'.format(var.info.fullname, name)
hook = mx.chk.plugin.get_attribute_hook(fullname)
if result and not mx.is_lvalue and not implicit:
result = analyze_descriptor_access(mx.original_type,
result,
mx.builtin_type,
mx.msg,
mx.context,
chk=mx.chk)
if hook:
result = hook(
AttributeContext(get_proper_type(mx.original_type), result,
mx.context, mx.chk))
return result
def _analyze_member_access(name: str,
typ: Type,
mx: MemberContext,
override_info: Optional[TypeInfo] = None) -> Type:
# TODO: this and following functions share some logic with subtypes.find_member,
# consider refactoring.
if isinstance(typ, Instance):
if name == '__init__' and not mx.is_super:
# Accessing __init__ in statically typed code would compromise
# type safety unless used via super().
mx.msg.fail(messages.CANNOT_ACCESS_INIT, mx.context)
return AnyType(TypeOfAny.from_error)
# The base object has an instance type.
info = typ.type
if override_info:
info = override_info
if (experiments.find_occurrences and
info.name() == experiments.find_occurrences[0] and
name == experiments.find_occurrences[1]):
mx.msg.note("Occurrence of '{}.{}'".format(*experiments.find_occurrences), mx.context)
# Look up the member. First look up the method dictionary.
method = info.get_method(name)
if method:
if method.is_property:
assert isinstance(method, OverloadedFuncDef)
first_item = cast(Decorator, method.items[0])
return analyze_var(name, first_item.var, typ, info, mx)
if mx.is_lvalue:
mx.msg.cant_assign_to_method(mx.context)
signature = function_type(method, mx.builtin_type('builtins.function'))
signature = freshen_function_type_vars(signature)
if name == '__new__':
# __new__ is special and behaves like a static method -- don't strip
# the first argument.
pass
else:
signature = bind_self(signature, mx.original_type)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
return member_type
else:
# Not a method.
return analyze_member_var_access(name, typ, info, mx)
elif isinstance(typ, AnyType):
# The base object has dynamic type.
return AnyType(TypeOfAny.from_another_any, source_any=typ)
elif isinstance(typ, NoneTyp):
if mx.chk.should_suppress_optional_error([typ]):
return AnyType(TypeOfAny.from_error)
is_python_3 = mx.chk.options.python_version[0] >= 3
# In Python 2 "None" has exactly the same attributes as "object". Python 3 adds a single
# extra attribute, "__bool__".
if is_python_3 and name == '__bool__':
return CallableType(arg_types=[],
arg_kinds=[],
arg_names=[],
ret_type=mx.builtin_type('builtins.bool'),
fallback=mx.builtin_type('builtins.function'))
else:
return _analyze_member_access(name, mx.builtin_type('builtins.object'), mx)
elif isinstance(typ, UnionType):
# The base object has dynamic type.
mx.msg.disable_type_names += 1
results = [_analyze_member_access(name, subtype, mx)
for subtype in typ.relevant_items()]
mx.msg.disable_type_names -= 1
return UnionType.make_simplified_union(results)
elif isinstance(typ, (TupleType, TypedDictType, LiteralType)):
# Actually look up from the fallback instance type.
return _analyze_member_access(name, typ.fallback, mx)
elif isinstance(typ, FunctionLike) and typ.is_type_obj():
# Class attribute.
# TODO super?
ret_type = typ.items()[0].ret_type
if isinstance(ret_type, TupleType):
ret_type = ret_type.fallback
if isinstance(ret_type, Instance):
if not mx.is_operator:
# When Python sees an operator (eg `3 == 4`), it automatically translates that
# into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an
# optimization.
#
# While it normally it doesn't matter which of the two versions are used, it
# does cause inconsistencies when working with classes. For example, translating
# `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to
# compare two int _instances_. What we really want is `type(int).__eq__`, which
# is meant to compare two types or classes.
#
# This check makes sure that when we encounter an operator, we skip looking up
# the corresponding method in the current instance to avoid this edge case.
# See https://github.com/python/mypy/pull/1787 for more info.
result = analyze_class_attribute_access(ret_type, name, mx)
if result:
return result
# Look up from the 'type' type.
return _analyze_member_access(name, typ.fallback, mx)
else:
assert False, 'Unexpected type {}'.format(repr(ret_type))
elif isinstance(typ, FunctionLike):
# Look up from the 'function' type.
return _analyze_member_access(name, typ.fallback, mx)
elif isinstance(typ, TypeVarType):
return _analyze_member_access(name, typ.upper_bound, mx)
elif isinstance(typ, DeletedType):
mx.msg.deleted_as_rvalue(typ, mx.context)
return AnyType(TypeOfAny.from_error)
elif isinstance(typ, TypeType):
# Similar to FunctionLike + is_type_obj() above.
item = None
fallback = mx.builtin_type('builtins.type')
ignore_messages = mx.msg.copy()
ignore_messages.disable_errors()
if isinstance(typ.item, Instance):
item = typ.item
elif isinstance(typ.item, AnyType):
mx = mx.copy_modified(messages=ignore_messages)
return _analyze_member_access(name, fallback, mx)
elif isinstance(typ.item, TypeVarType):
if isinstance(typ.item.upper_bound, Instance):
item = typ.item.upper_bound
elif isinstance(typ.item, TupleType):
item = typ.item.fallback
elif isinstance(typ.item, FunctionLike) and typ.item.is_type_obj():
item = typ.item.fallback
elif isinstance(typ.item, TypeType):
# Access member on metaclass object via Type[Type[C]]
if isinstance(typ.item.item, Instance):
item = typ.item.item.type.metaclass_type
if item and not mx.is_operator:
# See comment above for why operators are skipped
result = analyze_class_attribute_access(item, name, mx)
if result:
if not (isinstance(result, AnyType) and item.type.fallback_to_any):
return result
else:
# We don't want errors on metaclass lookup for classes with Any fallback
mx = mx.copy_modified(messages=ignore_messages)
if item is not None:
fallback = item.type.metaclass_type or fallback
return _analyze_member_access(name, fallback, mx)
if mx.chk.should_suppress_optional_error([typ]):
return AnyType(TypeOfAny.from_error)
return mx.msg.has_no_attr(mx.original_type, typ, name, mx.context)
def analyze_member_access(name: str,
typ: Type,
node: Context,
is_lvalue: bool,
is_super: bool,
is_operator: bool,
builtin_type: Callable[[str], Instance],
not_ready_callback: Callable[[str, Context], None],
msg: MessageBuilder, *,
original_type: Type,
chk: 'mypy.checker.TypeChecker',
override_info: Optional[TypeInfo] = None) -> Type:
"""Return the type of attribute `name` of typ.
This is a general operation that supports various different variations:
1. lvalue or non-lvalue access (i.e. setter or getter access)
2. supertype access (when using super(); is_super == True and
override_info should refer to the supertype)
original_type is the most precise inferred or declared type of the base object
that we have available. typ is generally a supertype of original_type.
When looking for an attribute of typ, we may perform recursive calls targeting
the fallback type, for example.
original_type is always the type used in the initial call.
"""
# TODO: this and following functions share some logic with subtypes.find_member,
# consider refactoring.
if isinstance(typ, Instance):
if name == '__init__' and not is_super:
# Accessing __init__ in statically typed code would compromise
# type safety unless used via super().
msg.fail(messages.CANNOT_ACCESS_INIT, node)
return AnyType(TypeOfAny.from_error)
# The base object has an instance type.
info = typ.type
if override_info:
info = override_info
if (experiments.find_occurrences and
info.name() == experiments.find_occurrences[0] and
name == experiments.find_occurrences[1]):
msg.note("Occurrence of '{}.{}'".format(*experiments.find_occurrences), node)
# Look up the member. First look up the method dictionary.
method = info.get_method(name)
if method:
if method.is_property:
assert isinstance(method, OverloadedFuncDef)
first_item = cast(Decorator, method.items[0])
return analyze_var(name, first_item.var, typ, info, node, is_lvalue, msg,
original_type, not_ready_callback, chk=chk)
if is_lvalue:
msg.cant_assign_to_method(node)
signature = function_type(method, builtin_type('builtins.function'))
signature = freshen_function_type_vars(signature)
if name == '__new__':
# __new__ is special and behaves like a static method -- don't strip
# the first argument.
pass
else:
signature = bind_self(signature, original_type)
typ = map_instance_to_supertype(typ, method.info)
member_type = expand_type_by_instance(signature, typ)
freeze_type_vars(member_type)
return member_type
else:
# Not a method.
return analyze_member_var_access(name, typ, info, node,
is_lvalue, is_super, builtin_type,
not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, AnyType):
# The base object has dynamic type.
return AnyType(TypeOfAny.from_another_any, source_any=typ)
elif isinstance(typ, NoneTyp):
if chk.should_suppress_optional_error([typ]):
return AnyType(TypeOfAny.from_error)
# The only attribute NoneType has are those it inherits from object
return analyze_member_access(name, builtin_type('builtins.object'), node, is_lvalue,
is_super, is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, UnionType):
# The base object has dynamic type.
msg.disable_type_names += 1
results = [analyze_member_access(name, subtype, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
for subtype in typ.relevant_items()]
msg.disable_type_names -= 1
return UnionType.make_simplified_union(results)
elif isinstance(typ, TupleType):
# Actually look up from the fallback instance type.
return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, TypedDictType):
# Actually look up from the fallback instance type.
return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, FunctionLike) and typ.is_type_obj():
# Class attribute.
# TODO super?
ret_type = typ.items()[0].ret_type
if isinstance(ret_type, TupleType):
ret_type = ret_type.fallback
if isinstance(ret_type, Instance):
if not is_operator:
# When Python sees an operator (eg `3 == 4`), it automatically translates that
# into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an
# optimization.
#
# While it normally it doesn't matter which of the two versions are used, it
# does cause inconsistencies when working with classes. For example, translating
# `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to
# compare two int _instances_. What we really want is `type(int).__eq__`, which
# is meant to compare two types or classes.
#
# This check makes sure that when we encounter an operator, we skip looking up
# the corresponding method in the current instance to avoid this edge case.
# See https://github.com/python/mypy/pull/1787 for more info.
result = analyze_class_attribute_access(ret_type, name, node, is_lvalue,
builtin_type, not_ready_callback, msg,
original_type=original_type)
if result:
return result
# Look up from the 'type' type.
return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
else:
assert False, 'Unexpected type {}'.format(repr(ret_type))
elif isinstance(typ, FunctionLike):
# Look up from the 'function' type.
return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, TypeVarType):
return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
elif isinstance(typ, DeletedType):
msg.deleted_as_rvalue(typ, node)
return AnyType(TypeOfAny.from_error)
elif isinstance(typ, TypeType):
# Similar to FunctionLike + is_type_obj() above.
item = None
fallback = builtin_type('builtins.type')
ignore_messages = msg.copy()
ignore_messages.disable_errors()
if isinstance(typ.item, Instance):
item = typ.item
elif isinstance(typ.item, AnyType):
return analyze_member_access(name, fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback,
ignore_messages, original_type=original_type, chk=chk)
elif isinstance(typ.item, TypeVarType):
if isinstance(typ.item.upper_bound, Instance):
item = typ.item.upper_bound
elif isinstance(typ.item, TupleType):
item = typ.item.fallback
elif isinstance(typ.item, FunctionLike) and typ.item.is_type_obj():
item = typ.item.fallback
elif isinstance(typ.item, TypeType):
# Access member on metaclass object via Type[Type[C]]
if isinstance(typ.item.item, Instance):
item = typ.item.item.type.metaclass_type
if item and not is_operator:
# See comment above for why operators are skipped
result = analyze_class_attribute_access(item, name, node, is_lvalue,
builtin_type, not_ready_callback, msg,
original_type=original_type)
if result:
if not (isinstance(result, AnyType) and item.type.fallback_to_any):
return result
else:
# We don't want errors on metaclass lookup for classes with Any fallback
msg = ignore_messages
if item is not None:
fallback = item.type.metaclass_type or fallback
return analyze_member_access(name, fallback, node, is_lvalue, is_super,
is_operator, builtin_type, not_ready_callback, msg,
original_type=original_type, chk=chk)
if chk.should_suppress_optional_error([typ]):
return AnyType(TypeOfAny.from_error)
return msg.has_no_attr(original_type, typ, name, node)