Beispiel #1
0
 def testSuperType(self):
     supercls = special_builtins.Super(self._vm)
     self.assertListEqual(supercls.get_class().data,
                          [self._vm.convert.type_type])
Beispiel #2
0
    def _constant_to_value(self, pyval, subst, get_node):
        """Create a AtomicAbstractValue that represents a python constant.

    This supports both constant from code constant pools and PyTD constants such
    as classes. This also supports builtin python objects such as int and float.

    Args:
      pyval: The python or PyTD value to convert.
      subst: The current type parameters.
      get_node: A getter function for the current node.
    Returns:
      A Value that represents the constant, or None if we couldn't convert.
    Raises:
      NotImplementedError: If we don't know how to convert a value.
      TypeParameterError: If we can't find a substitution for a type parameter.
    """
        if pyval.__class__ is str:
            # We use a subclass of str, compat.BytesPy3, to mark Python 3
            # bytestrings, which are converted to abstract bytes instances.
            # compat.BytesType dispatches to this when appropriate.
            return abstract.AbstractOrConcreteValue(pyval, self.str_type,
                                                    self.vm)
        elif isinstance(pyval, compat.UnicodeType):
            return abstract.AbstractOrConcreteValue(pyval, self.unicode_type,
                                                    self.vm)
        elif isinstance(pyval, compat.BytesType):
            return abstract.AbstractOrConcreteValue(pyval, self.bytes_type,
                                                    self.vm)
        elif isinstance(pyval, bool):
            return self.true if pyval is True else self.false
        elif isinstance(pyval, int) and -1 <= pyval <= MAX_IMPORT_DEPTH:
            # For small integers, preserve the actual value (for things like the
            # level in IMPORT_NAME).
            return abstract.AbstractOrConcreteValue(pyval, self.int_type,
                                                    self.vm)
        elif isinstance(pyval, compat.LongType):
            # long is aliased to int
            return self.primitive_class_instances[int]
        elif pyval.__class__ in self.primitive_classes:
            return self.primitive_class_instances[pyval.__class__]
        elif isinstance(pyval, (loadmarshal.CodeType, blocks.OrderedCode)):
            return abstract.AbstractOrConcreteValue(
                pyval, self.primitive_classes[types.CodeType], self.vm)
        elif pyval is super:
            return special_builtins.Super(self.vm)
        elif pyval is object:
            return special_builtins.Object(self.vm)
        elif pyval.__class__ is type:
            try:
                return self.name_to_value(self._type_to_name(pyval), subst)
            except (KeyError, AttributeError):
                log.debug("Failed to find pytd", exc_info=True)
                raise
        elif isinstance(pyval, pytd.LateType):
            actual = self._load_late_type(pyval)
            return self._constant_to_value(actual, subst, get_node)
        elif isinstance(pyval, pytd.TypeDeclUnit):
            return self._create_module(pyval)
        elif isinstance(pyval, pytd.Module):
            mod = self.vm.loader.import_name(pyval.module_name)
            return self._create_module(mod)
        elif isinstance(pyval, pytd.Class):
            if pyval.name == "__builtin__.super":
                return self.vm.special_builtins["super"]
            elif pyval.name == "__builtin__.object":
                return self.object_type
            elif pyval.name == "types.ModuleType":
                return self.module_type
            elif pyval.name == "_importlib_modulespec.ModuleType":
                # Python 3's typeshed uses a stub file indirection to define ModuleType
                # even though it is exported via types.pyi.
                return self.module_type
            else:
                module, dot, base_name = pyval.name.rpartition(".")
                try:
                    cls = abstract.PyTDClass(base_name, pyval, self.vm)
                except mro.MROError as e:
                    self.vm.errorlog.mro_error(self.vm.frames, base_name,
                                               e.mro_seqs)
                    cls = self.unsolvable
                else:
                    if dot:
                        cls.module = module
                return cls
        elif isinstance(pyval, pytd.Function):
            signatures = [
                abstract.PyTDSignature(pyval.name, sig, self.vm)
                for sig in pyval.signatures
            ]
            type_new = self.vm.lookup_builtin("__builtin__.type").Lookup(
                "__new__")
            if pyval is type_new:
                f_cls = special_builtins.TypeNew
            else:
                f_cls = abstract.PyTDFunction
            f = f_cls(pyval.name, signatures, pyval.kind, self.vm)
            f.is_abstract = pyval.is_abstract
            return f
        elif isinstance(pyval, pytd.ClassType):
            assert pyval.cls
            return self.constant_to_value(pyval.cls, subst,
                                          self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.NothingType):
            return self.empty
        elif isinstance(pyval, pytd.AnythingType):
            return self.unsolvable
        elif (isinstance(pyval, pytd.Constant)
              and isinstance(pyval.type, pytd.AnythingType)):
            # We allow "X = ... # type: Any" to declare X as a type.
            return self.unsolvable
        elif isinstance(pyval, pytd.FunctionType):
            return self.constant_to_value(pyval.function, subst,
                                          self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.UnionType):
            options = [
                self.constant_to_value(t, subst, self.vm.root_cfg_node)
                for t in pyval.type_list
            ]
            if len(options) > 1:
                return abstract.Union(options, self.vm)
            else:
                return options[0]
        elif isinstance(pyval, pytd.TypeParameter):
            constraints = tuple(
                self.constant_to_value(c, {}, self.vm.root_cfg_node)
                for c in pyval.constraints)
            bound = (pyval.bound and self.constant_to_value(
                pyval.bound, {}, self.vm.root_cfg_node))
            return abstract.TypeParameter(pyval.name,
                                          self.vm,
                                          constraints=constraints,
                                          bound=bound)
        elif isinstance(pyval, abstract.AsInstance):
            cls = pyval.cls
            if isinstance(cls, pytd.LateType):
                actual = self._load_late_type(cls)
                if not isinstance(actual, pytd.ClassType):
                    return self.unsolvable
                cls = actual.cls
            if isinstance(cls, pytd.ClassType):
                cls = cls.cls
            if (isinstance(cls, pytd.GenericType)
                    and cls.base_type.name == "typing.ClassVar"):
                param, = cls.parameters
                return self.constant_to_value(abstract.AsInstance(param),
                                              subst, self.vm.root_cfg_node)
            elif isinstance(cls,
                            pytd.GenericType) or (isinstance(cls, pytd.Class)
                                                  and cls.template):
                # If we're converting a generic Class, need to create a new instance of
                # it. See test_classes.testGenericReinstantiated.
                if isinstance(cls, pytd.Class):
                    params = tuple(t.type_param.upper_value
                                   for t in cls.template)
                    cls = pytd.GenericType(base_type=pytd.ClassType(
                        cls.name, cls),
                                           parameters=params)
                if isinstance(cls.base_type, pytd.LateType):
                    actual = self._load_late_type(cls.base_type)
                    if not isinstance(actual, pytd.ClassType):
                        return self.unsolvable
                    base_cls = actual.cls
                else:
                    assert isinstance(cls.base_type, pytd.ClassType)
                    base_cls = cls.base_type.cls
                assert isinstance(base_cls, pytd.Class), base_cls
                if base_cls.name == "__builtin__.type":
                    c, = cls.parameters
                    if isinstance(c, pytd.TypeParameter):
                        if not subst or c.name not in subst:
                            raise self.TypeParameterError(c.name)
                        return self.merge_classes(get_node(),
                                                  subst[c.name].data)
                    else:
                        return self.constant_to_value(c, subst,
                                                      self.vm.root_cfg_node)
                elif isinstance(cls, pytd.TupleType):
                    content = tuple(
                        self.constant_to_var(abstract.AsInstance(p), subst,
                                             get_node())
                        for p in cls.parameters)
                    return abstract.Tuple(content, self.vm)
                elif isinstance(cls, pytd.CallableType):
                    clsval = self.constant_to_value(cls, subst,
                                                    self.vm.root_cfg_node)
                    return abstract.Instance(clsval, self.vm)
                else:
                    clsval = self.constant_to_value(base_cls, subst,
                                                    self.vm.root_cfg_node)
                    instance = abstract.Instance(clsval, self.vm)
                    num_params = len(cls.parameters)
                    assert num_params <= len(base_cls.template)
                    for i, formal in enumerate(base_cls.template):
                        if i < num_params:
                            node = get_node()
                            p = self.constant_to_var(
                                abstract.AsInstance(cls.parameters[i]), subst,
                                node)
                        else:
                            # An omitted type parameter implies `Any`.
                            node = self.vm.root_cfg_node
                            p = self.unsolvable.to_variable(node)
                        instance.merge_type_parameter(node, formal.name, p)
                    return instance
            elif isinstance(cls, pytd.Class):
                assert not cls.template
                # This key is also used in __init__
                key = (abstract.Instance, cls)
                if key not in self._convert_cache:
                    if cls.name in [
                            "__builtin__.type", "__builtin__.property"
                    ]:
                        # An instance of "type" or of an anonymous property can be anything.
                        instance = self._create_new_unknown_value("type")
                    else:
                        mycls = self.constant_to_value(cls, subst,
                                                       self.vm.root_cfg_node)
                        instance = abstract.Instance(mycls, self.vm)
                    log.info("New pytd instance for %s: %r", cls.name,
                             instance)
                    self._convert_cache[key] = instance
                return self._convert_cache[key]
            else:
                return self.constant_to_value(cls, subst,
                                              self.vm.root_cfg_node)
        elif (isinstance(pyval, pytd.GenericType)
              and pyval.base_type.name == "typing.ClassVar"):
            param, = pyval.parameters
            return self.constant_to_value(param, subst, self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.GenericType):
            if isinstance(pyval.base_type, pytd.LateType):
                actual = self._load_late_type(pyval.base_type)
                if not isinstance(actual, pytd.ClassType):
                    return self.unsolvable
                base = actual.cls
            else:
                assert isinstance(pyval.base_type, pytd.ClassType)
                base = pyval.base_type.cls
            assert isinstance(base, pytd.Class), base
            base_cls = self.constant_to_value(base, subst,
                                              self.vm.root_cfg_node)
            if not isinstance(base_cls, abstract.Class):
                # base_cls can be, e.g., an unsolvable due to an mro error.
                return self.unsolvable
            if isinstance(pyval, pytd.TupleType):
                abstract_class = abstract.TupleClass
                template = list(range(len(pyval.parameters))) + [abstract.T]
                parameters = pyval.parameters + (pytd.UnionType(
                    pyval.parameters), )
            elif isinstance(pyval, pytd.CallableType):
                abstract_class = abstract.Callable
                template = list(range(len(
                    pyval.args))) + [abstract.ARGS, abstract.RET]
                parameters = pyval.args + (pytd_utils.JoinTypes(
                    pyval.args), pyval.ret)
            else:
                abstract_class = abstract.ParameterizedClass
                template = tuple(t.name for t in base.template)
                parameters = pyval.parameters
            assert (pyval.base_type.name == "typing.Generic"
                    or len(parameters) <= len(template))
            type_parameters = datatypes.LazyDict()
            for i, name in enumerate(template):
                if i < len(parameters):
                    type_parameters.add_lazy_item(name, self.constant_to_value,
                                                  parameters[i], subst,
                                                  self.vm.root_cfg_node)
                else:
                    type_parameters[name] = self.unsolvable
            return abstract_class(base_cls, type_parameters, self.vm)
        elif pyval.__class__ is tuple:  # only match raw tuple, not namedtuple/Node
            return self.tuple_to_value([
                self.constant_to_var(item, subst, self.vm.root_cfg_node)
                for i, item in enumerate(pyval)
            ])
        else:
            raise NotImplementedError("Can't convert constant %s %r" %
                                      (type(pyval), pyval))
Beispiel #3
0
 def test_super_type(self):
   supercls = special_builtins.Super(self._vm)
   self.assertEqual(supercls.get_class(), self._vm.convert.type_type)
Beispiel #4
0
    def _constant_to_value(self, pyval, subst, get_node):
        """Create a AtomicAbstractValue that represents a python constant.

    This supports both constant from code constant pools and PyTD constants such
    as classes. This also supports builtin python objects such as int and float.

    Args:
      pyval: The python or PyTD value to convert.
      subst: The current type parameters.
      get_node: A getter function for the current node.
    Returns:
      A Value that represents the constant, or None if we couldn't convert.
    Raises:
      NotImplementedError: If we don't know how to convert a value.
      TypeParameterError: If we can't find a substitution for a type parameter.
    """
        if isinstance(pyval, str):
            return abstract.AbstractOrConcreteValue(pyval, self.str_type,
                                                    self.vm)
        elif isinstance(pyval, int) and -1 <= pyval <= MAX_IMPORT_DEPTH:
            # For small integers, preserve the actual value (for things like the
            # level in IMPORT_NAME).
            return abstract.AbstractOrConcreteValue(pyval, self.int_type,
                                                    self.vm)
        elif isinstance(pyval, long):
            # long is aliased to int
            return self.primitive_class_instances[int]
        elif pyval.__class__ in self.primitive_classes:
            return self.primitive_class_instances[pyval.__class__]
        elif isinstance(pyval, (loadmarshal.CodeType, blocks.OrderedCode)):
            return abstract.AbstractOrConcreteValue(
                pyval, self.primitive_classes[types.CodeType], self.vm)
        elif pyval is super:
            return special_builtins.Super(self.vm)
        elif pyval is object:
            return special_builtins.Object(self.vm)
        elif pyval.__class__ is type:
            if pyval is types.FunctionType:
                classname = "typing.Callable"
            else:
                classname = "__builtin__." + pyval.__name__
            try:
                return self.name_to_value(classname, subst)
            except (KeyError, AttributeError):
                log.debug("Failed to find pytd", exc_info=True)
                raise
        elif isinstance(pyval, pytd.TypeDeclUnit):
            data = (pyval.constants + pyval.type_params + pyval.classes +
                    pyval.functions + pyval.aliases)
            members = {val.name.rsplit(".")[-1]: val for val in data}
            return abstract.Module(self.vm, pyval.name, members, pyval)
        elif isinstance(pyval,
                        pytd.Class) and pyval.name == "__builtin__.super":
            return self.vm.special_builtins["super"]
        elif isinstance(pyval,
                        pytd.Class) and pyval.name == "__builtin__.object":
            return self.object_type
        elif isinstance(pyval,
                        pytd.Class) and pyval.name == "types.ModuleType":
            return self.module_type
        elif isinstance(pyval, pytd.Class):
            module, dot, base_name = pyval.name.rpartition(".")
            try:
                cls = abstract.PyTDClass(base_name, pyval, self.vm)
            except mro.MROError as e:
                self.vm.errorlog.mro_error(self.vm.frames, base_name,
                                           e.mro_seqs)
                cls = self.unsolvable
            else:
                if dot:
                    cls.module = module
            return cls
        elif isinstance(pyval, pytd.ExternalFunction):
            module, _, name = pyval.name.partition(".")
            assert module == "__builtin__", "PYTHONCODE allowed only in __builtin__"
            return abstract.merge_values(
                self.vm.frame.f_globals.members[name].data, self.vm)
        elif isinstance(pyval, pytd.Function):
            signatures = [
                abstract.PyTDSignature(pyval.name, sig, self.vm)
                for sig in pyval.signatures
            ]
            type_new = self.vm.lookup_builtin("__builtin__.type").Lookup(
                "__new__")
            if pyval is type_new:
                f_cls = special_builtins.TypeNew
            else:
                f_cls = abstract.PyTDFunction
            f = f_cls(pyval.name, signatures, pyval.kind, self.vm)
            f.is_abstract = pyval.is_abstract
            return f
        elif isinstance(pyval, pytd.ClassType):
            assert pyval.cls
            return self.constant_to_value(pyval.cls, subst,
                                          self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.NothingType):
            return self.nothing
        elif isinstance(pyval, pytd.AnythingType):
            return self.unsolvable
        elif isinstance(pyval, pytd.FunctionType):
            return self.constant_to_value(pyval.function, subst,
                                          self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.UnionType):
            options = [
                self.constant_to_value(t, subst, self.vm.root_cfg_node)
                for t in pyval.type_list
            ]
            if len(options) > 1:
                return abstract.Union(options, self.vm)
            else:
                return options[0]
        elif isinstance(pyval, pytd.TypeParameter):
            constraints = tuple(
                self.constant_to_value(c, {}, self.vm.root_cfg_node)
                for c in pyval.constraints)
            bound = (pyval.bound and self.constant_to_value(
                pyval.bound, {}, self.vm.root_cfg_node))
            return abstract.TypeParameter(pyval.name,
                                          self.vm,
                                          constraints=constraints,
                                          bound=bound)
        elif isinstance(pyval, abstract.AsInstance):
            cls = pyval.cls
            if isinstance(cls, pytd.ClassType):
                cls = cls.cls
            if isinstance(cls, pytd.Class):
                # This key is also used in __init__
                key = (abstract.Instance, cls)
                if key not in self._convert_cache:
                    if cls.name in [
                            "__builtin__.type", "__builtin__.property"
                    ]:
                        # An instance of "type" or of an anonymous property can be anything.
                        instance = self._create_new_unknown_value("type")
                    else:
                        mycls = self.constant_to_value(cls, subst,
                                                       self.vm.root_cfg_node)
                        instance = abstract.Instance(mycls, self.vm)
                        instance.make_template_unsolvable(
                            cls.template, self.vm.root_cfg_node)
                    log.info("New pytd instance for %s: %r", cls.name,
                             instance)
                    self._convert_cache[key] = instance
                return self._convert_cache[key]
            elif isinstance(cls, pytd.GenericType):
                assert isinstance(cls.base_type, pytd.ClassType)
                base_cls = cls.base_type.cls
                if base_cls.name == "__builtin__.type":
                    c, = cls.parameters
                    if isinstance(c, pytd.TypeParameter):
                        if not subst or c.name not in subst:
                            raise self.TypeParameterError(c.name)
                        return self.merge_classes(get_node(),
                                                  subst[c.name].data)
                    else:
                        return self.constant_to_value(c, subst,
                                                      self.vm.root_cfg_node)
                elif isinstance(cls, pytd.TupleType):
                    content = tuple(
                        self.constant_to_var(abstract.AsInstance(p), subst,
                                             get_node())
                        for p in cls.parameters)
                    return abstract.Tuple(content, self.vm)
                elif isinstance(cls, pytd.CallableType):
                    clsval = self.constant_to_value(cls, subst,
                                                    self.vm.root_cfg_node)
                    return abstract.Instance(clsval, self.vm)
                else:
                    clsval = self.constant_to_value(base_cls, subst,
                                                    self.vm.root_cfg_node)
                    instance = abstract.Instance(clsval, self.vm)
                    assert len(cls.parameters) <= len(base_cls.template)
                    for formal, actual in zip(base_cls.template,
                                              cls.parameters):
                        p = self.constant_to_var(abstract.AsInstance(actual),
                                                 subst, self.vm.root_cfg_node)
                        instance.initialize_type_parameter(
                            get_node(), formal.name, p)
                    return instance
            else:
                return self.constant_to_value(cls, subst,
                                              self.vm.root_cfg_node)
        elif isinstance(pyval, pytd.GenericType):
            assert isinstance(pyval.base_type, pytd.ClassType)
            base_cls = self.constant_to_value(pyval.base_type.cls, subst,
                                              self.vm.root_cfg_node)
            if not isinstance(base_cls, abstract.Class):
                # base_cls can be, e.g., an unsolvable due to an mro error.
                return self.unsolvable
            if isinstance(pyval, pytd.TupleType):
                abstract_class = abstract.TupleClass
                template = range(len(pyval.parameters)) + [abstract.T]
                parameters = pyval.parameters + (pytd.UnionType(
                    pyval.parameters), )
            elif isinstance(pyval, pytd.CallableType):
                abstract_class = abstract.Callable
                template = range(len(
                    pyval.args)) + [abstract.ARGS, abstract.RET]
                parameters = pyval.args + (pytd_utils.JoinTypes(
                    pyval.args), pyval.ret)
            else:
                abstract_class = abstract.ParameterizedClass
                template = tuple(t.name for t in pyval.base_type.cls.template)
                parameters = pyval.parameters
            assert (pyval.base_type.name == "typing.Generic"
                    or len(parameters) <= len(template))
            type_parameters = utils.LazyDict()
            for i, name in enumerate(template):
                if i < len(parameters):
                    type_parameters.add_lazy_item(name, self.constant_to_value,
                                                  parameters[i], subst,
                                                  self.vm.root_cfg_node)
                else:
                    type_parameters[name] = self.unsolvable
            return abstract_class(base_cls, type_parameters, self.vm)
        elif pyval.__class__ is tuple:  # only match raw tuple, not namedtuple/Node
            return self.tuple_to_value([
                self.constant_to_var(item, subst, self.vm.root_cfg_node)
                for i, item in enumerate(pyval)
            ])
        else:
            raise NotImplementedError("Can't convert constant %s %r" %
                                      (type(pyval), pyval))
Beispiel #5
0
 def test_super_type(self):
   supercls = special_builtins.Super(self._ctx)
   self.assertEqual(supercls.cls, self._ctx.convert.type_type)
Beispiel #6
0
  def _constant_to_value(self, pyval, subst, get_node):
    """Create a BaseValue that represents a python constant.

    This supports both constant from code constant pools and PyTD constants such
    as classes. This also supports builtin python objects such as int and float.

    Args:
      pyval: The python or PyTD value to convert.
      subst: The current type parameters.
      get_node: A getter function for the current node.

    Returns:
      A Value that represents the constant, or None if we couldn't convert.
    Raises:
      NotImplementedError: If we don't know how to convert a value.
      TypeParameterError: If we can't find a substitution for a type parameter.
    """
    if isinstance(pyval, str):
      return abstract.ConcreteValue(pyval, self.str_type, self.ctx)
    elif isinstance(pyval, bytes):
      return abstract.ConcreteValue(pyval, self.bytes_type, self.ctx)
    elif isinstance(pyval, bool):
      return self.true if pyval else self.false
    elif isinstance(pyval, int) and -1 <= pyval <= _MAX_IMPORT_DEPTH:
      # For small integers, preserve the actual value (for things like the
      # level in IMPORT_NAME).
      return abstract.ConcreteValue(pyval, self.int_type, self.ctx)
    elif pyval.__class__ in self.primitive_classes:
      return self.primitive_class_instances[pyval.__class__]
    elif pyval.__class__ is frozenset:
      instance = abstract.Instance(self.frozenset_type, self.ctx)
      for element in pyval:
        instance.merge_instance_type_parameter(
            self.ctx.root_node, abstract_utils.T,
            self.constant_to_var(element, subst, self.ctx.root_node))
      return instance
    elif isinstance(pyval, (loadmarshal.CodeType, blocks.OrderedCode)):
      return abstract.ConcreteValue(pyval,
                                    self.primitive_classes[types.CodeType],
                                    self.ctx)
    elif pyval is super:
      return special_builtins.Super(self.ctx)
    elif pyval is object:
      return special_builtins.Object(self.ctx)
    elif pyval.__class__ is type:
      try:
        return self.name_to_value(self._type_to_name(pyval), subst)
      except (KeyError, AttributeError):
        log.debug("Failed to find pytd", exc_info=True)
        raise
    elif isinstance(pyval, pytd.LateType):
      actual = self._load_late_type(pyval)
      return self._constant_to_value(actual, subst, get_node)
    elif isinstance(pyval, pytd.TypeDeclUnit):
      return self._create_module(pyval)
    elif isinstance(pyval, pytd.Module):
      mod = self.ctx.loader.import_name(pyval.module_name)
      return self._create_module(mod)
    elif isinstance(pyval, pytd.Class):
      if pyval.name == "builtins.super":
        return self.ctx.special_builtins["super"]
      elif pyval.name == "builtins.object":
        return self.object_type
      elif pyval.name == "types.ModuleType":
        return self.module_type
      elif pyval.name == "_importlib_modulespec.ModuleType":
        # Python 3's typeshed uses a stub file indirection to define ModuleType
        # even though it is exported via types.pyi.
        return self.module_type
      elif pyval.name == "types.FunctionType":
        return self.function_type
      else:
        module, dot, base_name = pyval.name.rpartition(".")
        # typing.TypingContainer intentionally loads the underlying pytd types.
        if (module not in ("typing", "typing_extensions") and
            module in overlay_dict.overlays):
          overlay = self.ctx.vm.import_module(module, module, 0)
          if overlay.get_module(base_name) is overlay:
            overlay.load_lazy_attribute(base_name)
            return abstract_utils.get_atomic_value(overlay.members[base_name])
        try:
          cls = abstract.PyTDClass.make(base_name, pyval, self.ctx)
        except mro.MROError as e:
          self.ctx.errorlog.mro_error(self.ctx.vm.frames, base_name, e.mro_seqs)
          cls = self.unsolvable
        else:
          if dot:
            cls.module = module
          cls.call_metaclass_init(get_node())
        return cls
    elif isinstance(pyval, pytd.Function):
      signatures = [
          abstract.PyTDSignature(pyval.name, sig, self.ctx)
          for sig in pyval.signatures
      ]
      type_new = self.ctx.loader.lookup_builtin("builtins.type").Lookup(
          "__new__")
      if pyval is type_new:
        f_cls = special_builtins.TypeNew
      else:
        f_cls = abstract.PyTDFunction
      f = f_cls(pyval.name, signatures, pyval.kind, self.ctx)
      f.is_abstract = pyval.is_abstract
      return f
    elif isinstance(pyval, pytd.ClassType):
      if pyval.cls:
        cls = pyval.cls
      else:
        # If pyval is a reference to a class in builtins or typing, we can fill
        # in the class ourselves. lookup_builtin raises a KeyError if the name
        # is not found.
        cls = self.ctx.loader.lookup_builtin(pyval.name)
        assert isinstance(cls, pytd.Class)
      return self.constant_to_value(cls, subst, self.ctx.root_node)
    elif isinstance(pyval, pytd.NothingType):
      return self.empty
    elif isinstance(pyval, pytd.AnythingType):
      return self.unsolvable
    elif (isinstance(pyval, pytd.Constant) and
          isinstance(pyval.type, pytd.AnythingType)):
      # We allow "X = ... # type: Any" to declare X as a type.
      return self.unsolvable
    elif (isinstance(pyval, pytd.Constant) and
          isinstance(pyval.type, pytd.GenericType) and
          pyval.type.name == "builtins.type"):
      # `X: Type[other_mod.X]` is equivalent to `X = other_mod.X`.
      param, = pyval.type.parameters
      return self.constant_to_value(param, subst, self.ctx.root_node)
    elif isinstance(pyval, pytd.UnionType):
      options = [
          self.constant_to_value(t, subst, self.ctx.root_node)
          for t in pyval.type_list
      ]
      if len(options) > 1:
        return abstract.Union(options, self.ctx)
      else:
        return options[0]
    elif isinstance(pyval, pytd.TypeParameter):
      constraints = tuple(
          self.constant_to_value(c, {}, self.ctx.root_node)
          for c in pyval.constraints)
      bound = (
          pyval.bound and
          self.constant_to_value(pyval.bound, {}, self.ctx.root_node))
      return abstract.TypeParameter(
          pyval.name,
          self.ctx,
          constraints=constraints,
          bound=bound,
          module=pyval.scope)
    elif isinstance(pyval, abstract_utils.AsInstance):
      cls = pyval.cls
      if isinstance(cls, pytd.LateType):
        actual = self._load_late_type(cls)
        if not isinstance(actual, pytd.ClassType):
          return self.unsolvable
        cls = actual.cls
      if isinstance(cls, pytd.ClassType):
        cls = cls.cls
      if isinstance(cls, pytd.GenericType) and cls.name == "typing.ClassVar":
        param, = cls.parameters
        return self.constant_to_value(
            abstract_utils.AsInstance(param), subst, self.ctx.root_node)
      elif isinstance(cls, pytd.GenericType) or (isinstance(cls, pytd.Class) and
                                                 cls.template):
        # If we're converting a generic Class, need to create a new instance of
        # it. See test_classes.testGenericReinstantiated.
        if isinstance(cls, pytd.Class):
          params = tuple(t.type_param.upper_value for t in cls.template)
          cls = pytd.GenericType(base_type=pytd.ClassType(cls.name, cls),
                                 parameters=params)
        if isinstance(cls.base_type, pytd.LateType):
          actual = self._load_late_type(cls.base_type)
          if not isinstance(actual, pytd.ClassType):
            return self.unsolvable
          base_cls = actual.cls
        else:
          base_type = cls.base_type
          assert isinstance(base_type, pytd.ClassType)
          base_cls = base_type.cls
        assert isinstance(base_cls, pytd.Class), base_cls
        if base_cls.name == "builtins.type":
          c, = cls.parameters
          if isinstance(c, pytd.TypeParameter):
            if not subst or c.full_name not in subst:
              raise self.TypeParameterError(c.full_name)
            # deformalize gets rid of any unexpected TypeVars, which can appear
            # if something is annotated as Type[T].
            return self.ctx.annotation_utils.deformalize(
                self.merge_classes(subst[c.full_name].data))
          else:
            return self.constant_to_value(c, subst, self.ctx.root_node)
        elif isinstance(cls, pytd.TupleType):
          content = tuple(self.constant_to_var(abstract_utils.AsInstance(p),
                                               subst, get_node())
                          for p in cls.parameters)
          return self.tuple_to_value(content)
        elif isinstance(cls, pytd.CallableType):
          clsval = self.constant_to_value(cls, subst, self.ctx.root_node)
          return abstract.Instance(clsval, self.ctx)
        else:
          clsval = self.constant_to_value(base_cls, subst, self.ctx.root_node)
          instance = abstract.Instance(clsval, self.ctx)
          num_params = len(cls.parameters)
          assert num_params <= len(base_cls.template)
          for i, formal in enumerate(base_cls.template):
            if i < num_params:
              node = get_node()
              p = self.constant_to_var(
                  abstract_utils.AsInstance(cls.parameters[i]), subst, node)
            else:
              # An omitted type parameter implies `Any`.
              node = self.ctx.root_node
              p = self.unsolvable.to_variable(node)
            instance.merge_instance_type_parameter(node, formal.name, p)
          return instance
      elif isinstance(cls, pytd.Class):
        assert not cls.template
        # This key is also used in __init__
        key = (abstract.Instance, cls)
        if key not in self._convert_cache:
          if cls.name in ["builtins.type", "builtins.property"]:
            # An instance of "type" or of an anonymous property can be anything.
            instance = self._create_new_unknown_value("type")
          else:
            mycls = self.constant_to_value(cls, subst, self.ctx.root_node)
            instance = abstract.Instance(mycls, self.ctx)
          log.info("New pytd instance for %s: %r", cls.name, instance)
          self._convert_cache[key] = instance
        return self._convert_cache[key]
      elif isinstance(cls, pytd.Literal):
        return self.constant_to_value(
            self._get_literal_value(cls.value), subst, self.ctx.root_node)
      else:
        return self.constant_to_value(cls, subst, self.ctx.root_node)
    elif (isinstance(pyval, pytd.GenericType) and
          pyval.name == "typing.ClassVar"):
      param, = pyval.parameters
      return self.constant_to_value(param, subst, self.ctx.root_node)
    elif isinstance(pyval, pytd.GenericType):
      if isinstance(pyval.base_type, pytd.LateType):
        actual = self._load_late_type(pyval.base_type)
        if not isinstance(actual, pytd.ClassType):
          return self.unsolvable
        base = actual.cls
      else:
        assert isinstance(pyval.base_type, pytd.ClassType), pyval
        base = pyval.base_type.cls
      assert isinstance(base, pytd.Class), base
      base_cls = self.constant_to_value(base, subst, self.ctx.root_node)
      if not isinstance(base_cls, abstract.Class):
        # base_cls can be, e.g., an unsolvable due to an mro error.
        return self.unsolvable
      if isinstance(pyval, pytd.TupleType):
        abstract_class = abstract.TupleClass
        template = list(range(len(pyval.parameters))) + [abstract_utils.T]
        combined_parameter = pytd_utils.JoinTypes(pyval.parameters)
        parameters = pyval.parameters + (combined_parameter,)
      elif isinstance(pyval, pytd.CallableType):
        abstract_class = abstract.CallableClass
        template = list(range(len(pyval.args))) + [abstract_utils.ARGS,
                                                   abstract_utils.RET]
        parameters = pyval.args + (pytd_utils.JoinTypes(pyval.args), pyval.ret)
      else:
        abstract_class = abstract.ParameterizedClass
        if pyval.name == "typing.Generic":
          pyval_template = pyval.parameters
        else:
          pyval_template = base.template
        template = tuple(t.name for t in pyval_template)
        parameters = pyval.parameters
      assert (pyval.name in ("typing.Generic", "typing.Protocol") or
              len(parameters) <= len(template))
      # Delay type parameter loading to handle recursive types.
      # See the ParameterizedClass.formal_type_parameters() property.
      type_parameters = abstract_utils.LazyFormalTypeParameters(
          template, parameters, subst)
      return abstract_class(base_cls, type_parameters, self.ctx)
    elif isinstance(pyval, pytd.Literal):
      value = self.constant_to_value(
          self._get_literal_value(pyval.value), subst, self.ctx.root_node)
      return abstract.LiteralClass(value, self.ctx)
    elif isinstance(pyval, pytd.Annotated):
      typ = self.constant_to_value(pyval.base_type, subst, self.ctx.root_node)
      if pyval.annotations[0] == "'pytype_metadata'":
        try:
          md = metadata.from_string(pyval.annotations[1])
          if md["tag"] == "attr.ib":
            ret = attr_overlay.AttribInstance.from_metadata(
                self.ctx, self.ctx.root_node, typ, md)
            return ret
          elif md["tag"] == "attr.s":
            ret = attr_overlay.Attrs.from_metadata(self.ctx, md)
            return ret
        except (IndexError, ValueError, TypeError, KeyError):
          details = "Wrong format for pytype_metadata."
          self.ctx.errorlog.invalid_annotation(self.ctx.vm.frames,
                                               pyval.annotations[1], details)
          return typ
      else:
        return typ
    elif pyval.__class__ is tuple:  # only match raw tuple, not namedtuple/Node
      return self.tuple_to_value([
          self.constant_to_var(item, subst, self.ctx.root_node)
          for i, item in enumerate(pyval)
      ])
    else:
      raise NotImplementedError("Can't convert constant %s %r" %
                                (type(pyval), pyval))