def add_class_tvars(t: ProperType, itype: Instance, isuper: Optional[Instance],
is_classmethod: bool, builtin_type: Callable[[str],
Instance],
original_type: Type) -> 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()
original_type is the value of the type B in the expression B.foo()
"""
# TODO: verify consistency between Q and T
info = itype.type # type: TypeInfo
if is_classmethod:
assert isuper is not None
t = expand_type_by_instance(t, isuper)
# 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).
free_ids = {t.id for t in itype.args if isinstance(t, TypeVarType)}
if isinstance(t, CallableType):
# NOTE: in practice either all or none of the variables are free, since
# visit_type_application() will detect any type argument count mismatch and apply
# a correct number of Anys.
tvars = [
TypeVarDef(n, n, i + 1, [], builtin_type('builtins.object'),
tv.variance)
for (i,
n), tv in zip(enumerate(info.type_vars), info.defn.type_vars)
# use 'is' to avoid id clashes with unrelated variables
if any(tv.id is id for id in free_ids)
]
if is_classmethod:
t = bind_self(t, original_type, is_classmethod=True)
return t.copy_modified(variables=tvars + t.variables)
elif isinstance(t, Overloaded):
return Overloaded([
cast(
CallableType,
add_class_tvars(item, itype, isuper, is_classmethod,
builtin_type, original_type))
for item in t.items()
])
return t
def add_class_tvars(t: ProperType,
itype: Instance,
isuper: Optional[Instance],
is_classmethod: bool,
builtin_type: Callable[[str], Instance],
original_type: Type,
original_vars: Optional[List[TypeVarDef]] = 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()
original_type is the value of the type B in the expression B.foo() or the corresponding
component in case if a union (this is used to bind the self-types); original_vars are type
variables of the class callable on which the method was accessed.
"""
# TODO: verify consistency between Q and T
if is_classmethod:
assert isuper is not None
t = get_proper_type(expand_type_by_instance(t, isuper))
# 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 = bind_self(t, original_type, is_classmethod=True)
return t.copy_modified(variables=tvars + t.variables)
elif isinstance(t, Overloaded):
return Overloaded([
cast(
CallableType,
add_class_tvars(item,
itype,
isuper,
is_classmethod,
builtin_type,
original_type,
original_vars=original_vars))
for item in t.items()
])
return t
def _process_class_node(self, node: Node) -> MypyType:
if isinstance(node, Decorator):
if not node.func.is_static:
assert isinstance(node.func.type, FunctionLike)
return bind_self(
node.func.type,
is_classmethod=node.func.is_class,
)
assert node.func.type
return node.func.type
elif isinstance(node, FuncBase):
assert isinstance(node.type, FunctionLike)
return bind_self(node.type, is_classmethod=False)
assert isinstance(node, Var)
assert node.type
return node.type
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 cached_function_method_signature(ctx: MethodSigContext) -> CallableType:
"""Fixes the `_CachedFunction.__call__` signature to be correct.
It already has *almost* the correct signature, except:
1. the `self` argument needs to be marked as "bound";
2. any `cache_context` argument should be removed;
3. an optional keyword argument `on_invalidated` should be added.
"""
# First we mark this as a bound function signature.
signature = bind_self(ctx.default_signature)
# Secondly, we remove any "cache_context" args.
#
# Note: We should be only doing this if `cache_context=True` is set, but if
# it isn't then the code will raise an exception when its called anyway, so
# its not the end of the world.
context_arg_index = None
for idx, name in enumerate(signature.arg_names):
if name == "cache_context":
context_arg_index = idx
break
arg_types = list(signature.arg_types)
arg_names = list(signature.arg_names)
arg_kinds = list(signature.arg_kinds)
if context_arg_index:
arg_types.pop(context_arg_index)
arg_names.pop(context_arg_index)
arg_kinds.pop(context_arg_index)
# Third, we add an optional "on_invalidate" argument.
#
# This is a callable which accepts no input and returns nothing.
calltyp = CallableType(
arg_types=[],
arg_kinds=[],
arg_names=[],
ret_type=NoneType(),
fallback=ctx.api.named_generic_type("builtins.function", []),
)
arg_types.append(calltyp)
arg_names.append("on_invalidate")
arg_kinds.append(ARG_NAMED_OPT) # Arg is an optional kwarg.
signature = signature.copy_modified(
arg_types=arg_types,
arg_names=arg_names,
arg_kinds=arg_kinds,
)
return signature
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 kinded_get_descriptor(ctx: MethodContext) -> MypyType:
"""
Used to analyze ``@kinded`` method calls.
We do this due to ``__get__`` descriptor magic.
"""
assert isinstance(ctx.type, Instance)
assert isinstance(ctx.type.args[0], CallableType)
wrapped_method = ctx.type.args[0]
self_type = wrapped_method.arg_types[0]
signature = bind_self(
wrapped_method,
is_classmethod=isinstance(self_type, TypeType),
)
return ctx.type.copy_modified(args=[signature])
def analyze_decorator_or_funcbase_access(
defn: Union[Decorator, FuncBase],
itype: Instance,
info: TypeInfo,
self_type: Optional[Type],
name: str,
mx: MemberContext,
) -> Type:
"""Analyzes the type behind method access.
The function itself can possibly be decorated.
See: https://github.com/python/mypy/issues/10409
"""
if isinstance(defn, Decorator):
return analyze_var(name, defn.var, itype, info, mx)
return bind_self(
function_type(defn, mx.chk.named_type('builtins.function')),
original_type=self_type,
)
def cached_function_method_signature(ctx: MethodSigContext) -> CallableType:
"""Fixes the `_CachedFunction.__call__` signature to be correct.
It already has *almost* the correct signature, except:
1. the `self` argument needs to be marked as "bound"; and
2. any `cache_context` argument should be removed.
"""
# First we mark this as a bound function signature.
signature = bind_self(ctx.default_signature)
# Secondly, we remove any "cache_context" args.
#
# Note: We should be only doing this if `cache_context=True` is set, but if
# it isn't then the code will raise an exception when its called anyway, so
# its not the end of the world.
context_arg_index = None
for idx, name in enumerate(signature.arg_names):
if name == "cache_context":
context_arg_index = idx
break
if context_arg_index:
arg_types = list(signature.arg_types)
arg_types.pop(context_arg_index)
arg_names = list(signature.arg_names)
arg_names.pop(context_arg_index)
arg_kinds = list(signature.arg_kinds)
arg_kinds.pop(context_arg_index)
signature = signature.copy_modified(
arg_types=arg_types,
arg_names=arg_names,
arg_kinds=arg_kinds,
)
return signature
def analyze_class_attribute_access(
itype: Instance,
name: str,
mx: MemberContext,
override_info: Optional[TypeInfo] = None,
original_vars: Optional[List[TypeVarDef]] = None) -> Optional[Type]:
"""Analyze access to an attribute on a class object.
itype is the return type of the class object callable, original_type is the type
of E in the expression E.var, original_vars are type variables of the class callable
(for generic classes).
"""
info = itype.type
if override_info:
info = override_info
node = info.get(name)
if not node:
if info.fallback_to_any:
return AnyType(TypeOfAny.special_form)
return None
is_decorated = isinstance(node.node, Decorator)
is_method = is_decorated or isinstance(node.node, FuncBase)
if mx.is_lvalue:
if is_method:
mx.msg.cant_assign_to_method(mx.context)
if isinstance(node.node, TypeInfo):
mx.msg.fail(message_registry.CANNOT_ASSIGN_TO_TYPE, mx.context)
# If a final attribute was declared on `self` in `__init__`, then it
# can't be accessed on the class object.
if node.implicit and isinstance(node.node, Var) and node.node.is_final:
mx.msg.fail(
message_registry.CANNOT_ACCESS_FINAL_INSTANCE_ATTR.format(
node.node.name), mx.context)
# An assignment to final attribute on class object is also always an error,
# independently of types.
if mx.is_lvalue and not mx.chk.get_final_context():
check_final_member(name, info, mx.msg, mx.context)
if info.is_enum and not (mx.is_lvalue or is_decorated or is_method):
enum_literal = LiteralType(name, fallback=itype)
# When we analyze enums, the corresponding Instance is always considered to be erased
# due to how the signature of Enum.__new__ is `(cls: Type[_T], value: object) -> _T`
# in typeshed. However, this is really more of an implementation detail of how Enums
# are typed, and we really don't want to treat every single Enum value as if it were
# from type variable substitution. So we reset the 'erased' field here.
return itype.copy_modified(erased=False, last_known_value=enum_literal)
t = node.type
if t:
if isinstance(t, PartialType):
symnode = node.node
assert isinstance(symnode, Var)
return mx.chk.handle_partial_var_type(t, mx.is_lvalue, symnode,
mx.context)
# Find the class where method/variable was defined.
if isinstance(node.node, Decorator):
super_info = node.node.var.info # type: Optional[TypeInfo]
elif isinstance(node.node, (Var, SYMBOL_FUNCBASE_TYPES)):
super_info = node.node.info
else:
super_info = None
# Map the type to how it would look as a defining class. For example:
# class C(Generic[T]): ...
# class D(C[Tuple[T, S]]): ...
# D[int, str].method()
# Here itype is D[int, str], isuper is C[Tuple[int, str]].
if not super_info:
isuper = None
else:
isuper = map_instance_to_supertype(itype, super_info)
if isinstance(node.node, Var):
assert isuper is not None
# Check if original variable type has type variables. For example:
# class C(Generic[T]):
# x: T
# C.x # Error, ambiguous access
# C[int].x # Also an error, since C[int] is same as C at runtime
if isinstance(t, TypeVarType) or has_type_vars(t):
# Exception: access on Type[...], including first argument of class methods is OK.
if not isinstance(get_proper_type(mx.original_type),
TypeType) or node.implicit:
if node.node.is_classvar:
message = message_registry.GENERIC_CLASS_VAR_ACCESS
else:
message = message_registry.GENERIC_INSTANCE_VAR_CLASS_ACCESS
mx.msg.fail(message, mx.context)
# Erase non-mapped variables, but keep mapped ones, even if there is an error.
# In the above example this means that we infer following types:
# C.x -> Any
# C[int].x -> int
t = erase_typevars(expand_type_by_instance(t, isuper))
is_classmethod = (
(is_decorated and cast(Decorator, node.node).func.is_class)
or (isinstance(node.node, FuncBase) and node.node.is_class))
t = get_proper_type(t)
if isinstance(t, FunctionLike) and is_classmethod:
t = check_self_arg(t, mx.self_type, False, mx.context, name,
mx.msg)
result = add_class_tvars(t,
isuper,
is_classmethod,
mx.self_type,
original_vars=original_vars)
if not mx.is_lvalue:
result = analyze_descriptor_access(mx.original_type,
result,
mx.builtin_type,
mx.msg,
mx.context,
chk=mx.chk)
return result
elif isinstance(node.node, Var):
mx.not_ready_callback(name, mx.context)
return AnyType(TypeOfAny.special_form)
if isinstance(node.node, TypeVarExpr):
mx.msg.fail(
message_registry.CANNOT_USE_TYPEVAR_AS_EXPRESSION.format(
info.name, name), mx.context)
return AnyType(TypeOfAny.from_error)
if isinstance(node.node, TypeInfo):
return type_object_type(node.node, mx.builtin_type)
if isinstance(node.node, MypyFile):
# Reference to a module object.
return mx.builtin_type('types.ModuleType')
if (isinstance(node.node, TypeAlias)
and isinstance(get_proper_type(node.node.target), Instance)):
return instance_alias_type(node.node, mx.builtin_type)
if is_decorated:
assert isinstance(node.node, Decorator)
if node.node.type:
return node.node.type
else:
mx.not_ready_callback(name, mx.context)
return AnyType(TypeOfAny.from_error)
else:
assert isinstance(node.node, FuncBase)
typ = function_type(node.node, mx.builtin_type('builtins.function'))
# Note: if we are accessing class method on class object, the cls argument is bound.
# Annotated and/or explicit class methods go through other code paths above, for
# unannotated implicit class methods we do this here.
if node.node.is_class:
typ = bind_self(typ, is_classmethod=True)
return typ
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_descriptor_access(instance_type: Type, descriptor_type: Type,
builtin_type: Callable[[str], Instance],
msg: MessageBuilder, context: Context, *,
chk: 'mypy.checker.TypeChecker') -> Type:
"""Type check descriptor access.
Arguments:
instance_type: The type of the instance on which the descriptor
attribute is being accessed (the type of ``a`` in ``a.f`` when
``f`` is a descriptor).
descriptor_type: The type of the descriptor attribute being accessed
(the type of ``f`` in ``a.f`` when ``f`` is a descriptor).
context: The node defining the context of this inference.
Return:
The return type of the appropriate ``__get__`` overload for the descriptor.
"""
instance_type = get_proper_type(instance_type)
descriptor_type = get_proper_type(descriptor_type)
if isinstance(descriptor_type, UnionType):
# Map the access over union types
return make_simplified_union([
analyze_descriptor_access(instance_type,
typ,
builtin_type,
msg,
context,
chk=chk) for typ in descriptor_type.items
])
elif not isinstance(descriptor_type, Instance):
return descriptor_type
if not descriptor_type.type.has_readable_member('__get__'):
return descriptor_type
dunder_get = descriptor_type.type.get_method('__get__')
if dunder_get is None:
msg.fail(
message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format(
descriptor_type), context)
return AnyType(TypeOfAny.from_error)
function = function_type(dunder_get, builtin_type('builtins.function'))
bound_method = bind_self(function, descriptor_type)
typ = map_instance_to_supertype(descriptor_type, dunder_get.info)
dunder_get_type = expand_type_by_instance(bound_method, typ)
if isinstance(instance_type, FunctionLike) and instance_type.is_type_obj():
owner_type = instance_type.items()[0].ret_type
instance_type = NoneType()
elif isinstance(instance_type, TypeType):
owner_type = instance_type.item
instance_type = NoneType()
else:
owner_type = instance_type
_, inferred_dunder_get_type = chk.expr_checker.check_call(
dunder_get_type, [
TempNode(instance_type, context=context),
TempNode(TypeType.make_normalized(owner_type), context=context)
], [ARG_POS, ARG_POS], context)
inferred_dunder_get_type = get_proper_type(inferred_dunder_get_type)
if isinstance(inferred_dunder_get_type, AnyType):
# check_call failed, and will have reported an error
return inferred_dunder_get_type
if not isinstance(inferred_dunder_get_type, CallableType):
msg.fail(
message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format(
descriptor_type), context)
return AnyType(TypeOfAny.from_error)
return inferred_dunder_get_type.ret_type
def analyze_member_var_access(name: str, itype: Instance, info: TypeInfo,
mx: MemberContext) -> Type:
"""Analyse attribute access that does not target a method.
This is logically part of analyze_member_access and the arguments are similar.
original_type is the type of E in the expression E.var
"""
# It was not a method. Try looking up a variable.
v = lookup_member_var_or_accessor(info, name, mx.is_lvalue)
vv = v
if isinstance(vv, Decorator):
# The associated Var node of a decorator contains the type.
v = vv.var
if isinstance(vv, TypeInfo):
# If the associated variable is a TypeInfo synthesize a Var node for
# the purposes of type checking. This enables us to type check things
# like accessing class attributes on an inner class.
v = Var(name, type=type_object_type(vv, mx.builtin_type))
v.info = info
if isinstance(vv, TypeAlias) and isinstance(get_proper_type(vv.target),
Instance):
# Similar to the above TypeInfo case, we allow using
# qualified type aliases in runtime context if it refers to an
# instance type. For example:
# class C:
# A = List[int]
# x = C.A() <- this is OK
typ = instance_alias_type(vv, mx.builtin_type)
v = Var(name, type=typ)
v.info = info
if isinstance(v, Var):
implicit = info[name].implicit
# An assignment to final attribute is always an error,
# independently of types.
if mx.is_lvalue and not mx.chk.get_final_context():
check_final_member(name, info, mx.msg, mx.context)
return analyze_var(name, v, itype, info, mx, implicit=implicit)
elif isinstance(v, FuncDef):
assert False, "Did not expect a function"
elif (not v
and name not in ['__getattr__', '__setattr__', '__getattribute__']
and not mx.is_operator):
if not mx.is_lvalue:
for method_name in ('__getattribute__', '__getattr__'):
method = info.get_method(method_name)
# __getattribute__ is defined on builtins.object and returns Any, so without
# the guard this search will always find object.__getattribute__ and conclude
# that the attribute exists
if method and method.info.fullname != 'builtins.object':
function = function_type(
method, mx.builtin_type('builtins.function'))
bound_method = bind_self(function, mx.self_type)
typ = map_instance_to_supertype(itype, method.info)
getattr_type = get_proper_type(
expand_type_by_instance(bound_method, typ))
if isinstance(getattr_type, CallableType):
result = getattr_type.ret_type
# Call the attribute hook before returning.
fullname = '{}.{}'.format(method.info.fullname, name)
hook = mx.chk.plugin.get_attribute_hook(fullname)
if hook:
result = hook(
AttributeContext(
get_proper_type(mx.original_type), result,
mx.context, mx.chk))
return result
else:
setattr_meth = info.get_method('__setattr__')
if setattr_meth and setattr_meth.info.fullname != 'builtins.object':
setattr_func = function_type(
setattr_meth, mx.builtin_type('builtins.function'))
bound_type = bind_self(setattr_func, mx.self_type)
typ = map_instance_to_supertype(itype, setattr_meth.info)
setattr_type = get_proper_type(
expand_type_by_instance(bound_type, typ))
if isinstance(
setattr_type,
CallableType) and len(setattr_type.arg_types) > 0:
return setattr_type.arg_types[-1]
if itype.type.fallback_to_any:
return AnyType(TypeOfAny.special_form)
# Could not find the member.
if mx.is_super:
mx.msg.undefined_in_superclass(name, mx.context)
return AnyType(TypeOfAny.from_error)
else:
if mx.chk and mx.chk.should_suppress_optional_error([itype]):
return AnyType(TypeOfAny.from_error)
return mx.msg.has_no_attr(mx.original_type, itype, name, mx.context,
mx.module_symbol_table)
