def add_field(var: Var, is_initialized_in_class: bool = False,
is_property: bool = False) -> None:
var.info = info
var.is_initialized_in_class = is_initialized_in_class
var.is_property = is_property
var._fullname = '%s.%s' % (info.fullname(), var.name())
info.names[var.name()] = SymbolTableNode(MDEF, var)
def make_accessors(self, n: Var) -> List[Node]:
if n.type:
t = n.type
else:
t = AnyType()
return [self.make_getter_wrapper(n.name(), t),
self.make_setter_wrapper(n.name(), t),
self.make_dynamic_getter_wrapper(n.name(), t),
self.make_dynamic_setter_wrapper(n.name(), t)]
def _make_frozen(ctx: 'mypy.plugin.ClassDefContext', attributes: List[Attribute]) -> None:
"""Turn all the attributes into properties to simulate frozen classes."""
for attribute in attributes:
if attribute.name in ctx.cls.info.names:
# This variable belongs to this class so we can modify it.
node = ctx.cls.info.names[attribute.name].node
assert isinstance(node, Var)
node.is_property = True
else:
# This variable belongs to a super class so create new Var so we
# can modify it.
var = Var(attribute.name, ctx.cls.info[attribute.name].type)
var.info = ctx.cls.info
var._fullname = '%s.%s' % (ctx.cls.info.fullname(), var.name())
ctx.cls.info.names[var.name()] = SymbolTableNode(MDEF, var)
var.is_property = True
def analyze_var(
name: str,
var: Var,
itype: Instance,
info: TypeInfo,
node: Context,
is_lvalue: bool,
msg: MessageBuilder,
not_ready_callback: Callable[[str, Context], None],
) -> Type:
"""Analyze access to an attribute via a Var node.
This is conceptually part of analyze_member_access and the arguments are similar.
"""
# Found a member variable.
itype = map_instance_to_supertype(itype, var.info)
typ = var.type
if typ:
if isinstance(typ, PartialType):
return handle_partial_attribute_type(typ, is_lvalue, msg, var)
t = expand_type_by_instance(typ, itype)
if is_lvalue and var.is_property and not var.is_settable_property:
# TODO allow setting attributes in subclass (although it is probably an error)
msg.read_only_property(name, info, node)
if var.is_initialized_in_class and isinstance(t, FunctionLike):
if is_lvalue:
if var.is_property:
if not var.is_settable_property:
msg.read_only_property(name, info, node)
else:
msg.cant_assign_to_method(node)
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 = t
check_method_type(functype, itype, var.is_classmethod, node, msg)
signature = method_type(functype)
if var.is_property:
# A property cannot have an overloaded type => the cast
# is fine.
return cast(CallableType, signature).ret_type
else:
return signature
return t
else:
if not var.is_ready:
not_ready_callback(var.name(), node)
# Implicit 'Any' type.
return AnyType()
def analyse_lvalue(self, lval, nested=False, add_defs=False):
if isinstance(lval, NameExpr):
n = lval
nested_global = not self.locals and self.block_depth > 0 and not self.type
if (add_defs or nested_global) and n.name not in self.globals:
# Define new global name.
v = Var(n.name)
v._full_name = self.qualified_name(n.name)
v.is_ready = False # Type not inferred yet
n.node = v
n.is_def = True
n.kind = GDEF
n.full_name = v._full_name
self.globals[n.name] = SymbolTableNode(GDEF, v, self.cur_mod_id)
elif isinstance(n.node, Var) and n.is_def:
v = n.node
self.module_names[v.name()] = SymbolTableNode(GDEF, v, self.cur_mod_id)
elif self.locals and n.name not in self.locals[-1] and n.name not in self.global_decls[-1]:
# Define new local name.
v = Var(n.name)
n.node = v
n.is_def = True
n.kind = LDEF
self.add_local(v, n)
elif not self.locals and (self.type and n.name not in self.type.vars):
# Define a new attribute.
v = Var(n.name)
v.info = self.type
v.is_initialized_in_class = True
n.node = v
n.is_def = True
self.type.vars[n.name] = v
else:
# Bind to an existing name.
lval.accept(self)
elif isinstance(lval, MemberExpr):
if not add_defs:
self.analyse_member_lvalue(lval)
elif isinstance(lval, IndexExpr):
if not add_defs:
lval.accept(self)
elif isinstance(lval, ParenExpr):
self.analyse_lvalue((lval).expr, nested, add_defs)
elif (isinstance(lval, TupleExpr) or isinstance(lval, ListExpr)) and not nested:
items = (lval).items
for i in items:
self.analyse_lvalue(i, True, add_defs)
else:
self.fail("Invalid assignment target", lval)
def visit_var(self, node: Var) -> Var:
# Note that a Var must be transformed to a Var.
if node in self.var_map:
return self.var_map[node]
new = Var(node.name(), self.optional_type(node.type))
new.line = node.line
new._fullname = node._fullname
new.info = node.info
new.is_self = node.is_self
new.is_ready = node.is_ready
new.is_initialized_in_class = node.is_initialized_in_class
new.is_staticmethod = node.is_staticmethod
new.is_property = node.is_property
new.set_line(node.line)
self.var_map[node] = new
return new
def analyze_var(
name: str, var: Var, itype: Instance, info: TypeInfo, node: Context, is_lvalue: bool, msg: MessageBuilder
) -> Type:
"""Analyze access to an attribute via a Var node.
This is conceptually part of analyze_member_access and the arguments are similar.
"""
# Found a member variable.
itype = map_instance_to_supertype(itype, var.info)
if var.type:
t = expand_type_by_instance(var.type, itype)
if var.is_initialized_in_class and isinstance(t, FunctionLike):
if is_lvalue:
if var.is_property:
if not var.is_settable_property:
msg.read_only_property(name, info, node)
else:
msg.cant_assign_to_method(node)
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 = cast(FunctionLike, t)
check_method_type(functype, itype, node, msg)
signature = method_type(functype)
if var.is_property:
# A property cannot have an overloaded type => the cast
# is fine.
return cast(CallableType, signature).ret_type
else:
return signature
return t
else:
if not var.is_ready:
msg.cannot_determine_type(var.name(), node)
# Implicit 'Any' type.
return AnyType()
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)
t = expand_type_by_instance(typ, itype)
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)
result = t
if var.is_initialized_in_class and isinstance(t, FunctionLike) and not t.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 = t
# 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)
check_self_arg(functype, dispatched_type, var.is_classmethod, mx.context, name,
mx.msg)
signature = bind_self(functype, mx.original_type, var.is_classmethod)
if var.is_property:
# A property cannot have an overloaded type => the cast is fine.
assert isinstance(signature, CallableType)
result = signature.ret_type
else:
result = 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(mx.original_type, result, mx.context, mx.chk))
return result
def make_init_arg(var: Var) -> Argument:
default = default_items.get(var.name(), None)
kind = ARG_POS if default is None else ARG_OPT
return Argument(var, var.type, default, kind)
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)
t = expand_type_by_instance(typ, itype)
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)
result = t
if var.is_initialized_in_class and isinstance(
t, FunctionLike) and not t.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 = t
# 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)
check_self_arg(functype, dispatched_type, var.is_classmethod,
mx.context, name, mx.msg)
signature = bind_self(functype, mx.self_type,
var.is_classmethod)
if var.is_property:
# A property cannot have an overloaded type => the cast is fine.
assert isinstance(signature, CallableType)
result = signature.ret_type
else:
result = 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(mx.original_type, result, mx.context, mx.chk))
return result
def make_init_arg(var: Var) -> Argument:
default = default_items.get(var.name(), None)
kind = ARG_POS if default is None else ARG_OPT
return Argument(var, var.type, default, kind)