mojom/generate/module.py

# Copyright 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# This module's classes provide an interface to mojo modules. Modules are
# collections of interfaces and structs to be used by mojo ipc clients and
# servers.
#
# A simple interface would be created this way:
# module = mojom.generate.module.Module('Foo')
# interface = module.AddInterface('Bar')
# method = interface.AddMethod('Tat', 0)
# method.AddParameter('baz', 0, mojom.INT32)


# We use our own version of __repr__ when displaying the AST, as the
# AST currently doesn't capture which nodes are reference (e.g. to
# types) and which nodes are definitions. This allows us to e.g. print
# the definition of a struct when it's defined inside a module, but
# only print its name when it's referenced in e.g. a method parameter.
def Repr(obj, as_ref=True):
  """A version of __repr__ that can distinguish references.

  Sometimes we like to print an object's full representation
  (e.g. with its fields) and sometimes we just want to reference an
  object that was printed in full elsewhere. This function allows us
  to make that distinction.

  Args:
    obj: The object whose string representation we compute.
    as_ref: If True, use the short reference representation.

  Returns:
    A str representation of |obj|.
  """
  if hasattr(obj, 'Repr'):
    return obj.Repr(as_ref=as_ref)
  # Since we cannot implement Repr for existing container types, we
  # handle them here.
  elif isinstance(obj, list):
    if not obj:
      return '[]'
    else:
      return ('[\n%s\n]' % (',\n'.join('    %s' % Repr(elem, as_ref).replace(
          '\n', '\n    ') for elem in obj)))
  elif isinstance(obj, dict):
    if not obj:
      return '{}'
    else:
      return ('{\n%s\n}' % (',\n'.join('    %s: %s' % (
          Repr(key, as_ref).replace('\n', '\n    '),
          Repr(val, as_ref).replace('\n', '\n    '))
          for key, val in obj.iteritems())))
  else:
    return repr(obj)


def GenericRepr(obj, names):
  """Compute generic Repr for |obj| based on the attributes in |names|.

  Args:
    obj: The object to compute a Repr for.
    names: A dict from attribute names to include, to booleans
        specifying whether those attributes should be shown as
        references or not.

  Returns:
    A str representation of |obj|.
  """
  def ReprIndent(name, as_ref):
    return '    %s=%s' % (name, Repr(getattr(obj, name), as_ref).replace(
        '\n', '\n    '))

  return '%s(\n%s\n)' % (
      obj.__class__.__name__,
      ',\n'.join(ReprIndent(name, as_ref)
                 for (name, as_ref) in names.iteritems()))


class Kind(object):
  """Kind represents a type (e.g. int8, string).

  Attributes:
    spec: A string uniquely identifying the type. May be None.
    parent_kind: The enclosing type. For example, a struct defined
        inside an interface has that interface as its parent. May be None.
  """
  def __init__(self, spec=None):
    self.spec = spec
    self.parent_kind = None

  def Repr(self, as_ref=True):
    return '<%s spec=%r>' % (self.__class__.__name__, self.spec)

  def __repr__(self):
    # Gives us a decent __repr__ for all kinds.
    return self.Repr()


class ReferenceKind(Kind):
  """ReferenceKind represents pointer and handle types.

  A type is nullable if null (for pointer types) or invalid handle (for handle
  types) is a legal value for the type.

  Attributes:
    is_nullable: True if the type is nullable.
  """

  def __init__(self, spec=None, is_nullable=False):
    assert spec is None or is_nullable == spec.startswith('?')
    Kind.__init__(self, spec)
    self.is_nullable = is_nullable
    self.shared_definition = {}

  def Repr(self, as_ref=True):
    return '<%s spec=%r is_nullable=%r>' % (self.__class__.__name__, self.spec,
                                            self.is_nullable)

  def MakeNullableKind(self):
    assert not self.is_nullable

    if self == STRING:
      return NULLABLE_STRING
    if self == HANDLE:
      return NULLABLE_HANDLE
    if self == DCPIPE:
      return NULLABLE_DCPIPE
    if self == DPPIPE:
      return NULLABLE_DPPIPE
    if self == MSGPIPE:
      return NULLABLE_MSGPIPE
    if self == SHAREDBUFFER:
      return NULLABLE_SHAREDBUFFER

    nullable_kind = type(self)()
    nullable_kind.shared_definition = self.shared_definition
    if self.spec is not None:
      nullable_kind.spec = '?' + self.spec
    nullable_kind.is_nullable = True

    return nullable_kind

  @classmethod
  def AddSharedProperty(cls, name):
    """Adds a property |name| to |cls|, which accesses the corresponding item in
       |shared_definition|.

       The reason of adding such indirection is to enable sharing definition
       between a reference kind and its nullable variation. For example:
         a = Struct('test_struct_1')
         b = a.MakeNullableKind()
         a.name = 'test_struct_2'
         print b.name  # Outputs 'test_struct_2'.
    """
    def Get(self):
      return self.shared_definition[name]

    def Set(self, value):
      self.shared_definition[name] = value

    setattr(cls, name, property(Get, Set))


# Initialize the set of primitive types. These can be accessed by clients.
BOOL                  = Kind('b')
INT8                  = Kind('i8')
INT16                 = Kind('i16')
INT32                 = Kind('i32')
INT64                 = Kind('i64')
UINT8                 = Kind('u8')
UINT16                = Kind('u16')
UINT32                = Kind('u32')
UINT64                = Kind('u64')
FLOAT                 = Kind('f')
DOUBLE                = Kind('d')
STRING                = ReferenceKind('s')
HANDLE                = ReferenceKind('h')
DCPIPE                = ReferenceKind('h:d:c')
DPPIPE                = ReferenceKind('h:d:p')
MSGPIPE               = ReferenceKind('h:m')
SHAREDBUFFER          = ReferenceKind('h:s')
NULLABLE_STRING       = ReferenceKind('?s', True)
NULLABLE_HANDLE       = ReferenceKind('?h', True)
NULLABLE_DCPIPE       = ReferenceKind('?h:d:c', True)
NULLABLE_DPPIPE       = ReferenceKind('?h:d:p', True)
NULLABLE_MSGPIPE      = ReferenceKind('?h:m', True)
NULLABLE_SHAREDBUFFER = ReferenceKind('?h:s', True)


# Collection of all Primitive types
PRIMITIVES = (
  BOOL,
  INT8,
  INT16,
  INT32,
  INT64,
  UINT8,
  UINT16,
  UINT32,
  UINT64,
  FLOAT,
  DOUBLE,
  STRING,
  HANDLE,
  DCPIPE,
  DPPIPE,
  MSGPIPE,
  SHAREDBUFFER,
  NULLABLE_STRING,
  NULLABLE_HANDLE,
  NULLABLE_DCPIPE,
  NULLABLE_DPPIPE,
  NULLABLE_MSGPIPE,
  NULLABLE_SHAREDBUFFER
)


ATTRIBUTE_MIN_VERSION = 'MinVersion'
ATTRIBUTE_EXTENSIBLE = 'Extensible'
ATTRIBUTE_SYNC = 'Sync'


class NamedValue(object):
  def __init__(self, module, parent_kind, name):
    self.module = module
    self.namespace = module.namespace
    self.parent_kind = parent_kind
    self.name = name
    self.imported_from = None

  def GetSpec(self):
    return (self.namespace + '.' +
        (self.parent_kind and (self.parent_kind.name + '.') or "") +
        self.name)


class BuiltinValue(object):
  def __init__(self, value):
    self.value = value


class ConstantValue(NamedValue):
  def __init__(self, module, parent_kind, constant):
    NamedValue.__init__(self, module, parent_kind, constant.name)
    self.constant = constant


class EnumValue(NamedValue):
  def __init__(self, module, enum, field):
    NamedValue.__init__(self, module, enum.parent_kind, field.name)
    self.enum = enum

  def GetSpec(self):
    return (self.namespace + '.' +
        (self.parent_kind and (self.parent_kind.name + '.') or "") +
        self.enum.name + '.' + self.name)


class Constant(object):
  def __init__(self, name=None, kind=None, value=None, parent_kind=None):
    self.name = name
    self.kind = kind
    self.value = value
    self.parent_kind = parent_kind


class Field(object):
  def __init__(self, name=None, kind=None, ordinal=None, default=None,
               attributes=None):
    if self.__class__.__name__ == 'Field':
      raise Exception()
    self.name = name
    self.kind = kind
    self.ordinal = ordinal
    self.default = default
    self.attributes = attributes

  def Repr(self, as_ref=True):
    # Fields are only referenced by objects which define them and thus
    # they are always displayed as non-references.
    return GenericRepr(self, {'name': False, 'kind': True})

  @property
  def min_version(self):
    return self.attributes.get(ATTRIBUTE_MIN_VERSION) \
        if self.attributes else None


class StructField(Field): pass


class UnionField(Field): pass


class Struct(ReferenceKind):
  """A struct with typed fields.

  Attributes:
    name: {str} The name of the struct type.
    native_only: {bool} Does the struct have a body (i.e. any fields) or is it
        purely a native struct.
    module: {Module} The defining module.
    imported_from: {dict} Information about where this union was
        imported from.
    fields: {List[StructField]} The members of the struct.
    attributes: {dict} Additional information about the struct, such as
        if it's a native struct.
  """

  ReferenceKind.AddSharedProperty('name')
  ReferenceKind.AddSharedProperty('native_only')
  ReferenceKind.AddSharedProperty('module')
  ReferenceKind.AddSharedProperty('imported_from')
  ReferenceKind.AddSharedProperty('fields')
  ReferenceKind.AddSharedProperty('attributes')

  def __init__(self, name=None, module=None, attributes=None):
    if name is not None:
      spec = 'x:' + name
    else:
      spec = None
    ReferenceKind.__init__(self, spec)
    self.name = name
    self.native_only = False
    self.module = module
    self.imported_from = None
    self.fields = []
    self.attributes = attributes

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s name=%r imported_from=%s>' % (
          self.__class__.__name__, self.name,
          Repr(self.imported_from, as_ref=True))
    else:
      return GenericRepr(self, {'name': False, 'fields': False,
                                'imported_from': True})

  def AddField(self, name, kind, ordinal=None, default=None, attributes=None):
    field = StructField(name, kind, ordinal, default, attributes)
    self.fields.append(field)
    return field


class Union(ReferenceKind):
  """A union of several kinds.

  Attributes:
    name: {str} The name of the union type.
    module: {Module} The defining module.
    imported_from: {dict} Information about where this union was
        imported from.
    fields: {List[UnionField]} The members of the union.
    attributes: {dict} Additional information about the union, such as
        which Java class name to use to represent it in the generated
        bindings.
  """
  ReferenceKind.AddSharedProperty('name')
  ReferenceKind.AddSharedProperty('module')
  ReferenceKind.AddSharedProperty('imported_from')
  ReferenceKind.AddSharedProperty('fields')
  ReferenceKind.AddSharedProperty('attributes')

  def __init__(self, name=None, module=None, attributes=None):
    if name is not None:
      spec = 'x:' + name
    else:
      spec = None
    ReferenceKind.__init__(self, spec)
    self.name = name
    self.module = module
    self.imported_from = None
    self.fields = []
    self.attributes = attributes

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s spec=%r is_nullable=%r fields=%s>' % (
          self.__class__.__name__, self.spec, self.is_nullable,
          Repr(self.fields))
    else:
      return GenericRepr(self, {'fields': True, 'is_nullable': False})

  def AddField(self, name, kind, ordinal=None, attributes=None):
    field = UnionField(name, kind, ordinal, None, attributes)
    self.fields.append(field)
    return field


class Array(ReferenceKind):
  """An array.

  Attributes:
    kind: {Kind} The type of the elements. May be None.
    length: The number of elements. None if unknown.
  """

  ReferenceKind.AddSharedProperty('kind')
  ReferenceKind.AddSharedProperty('length')

  def __init__(self, kind=None, length=None):
    if kind is not None:
      if length is not None:
        spec = 'a%d:%s' % (length, kind.spec)
      else:
        spec = 'a:%s' % kind.spec

      ReferenceKind.__init__(self, spec)
    else:
      ReferenceKind.__init__(self)
    self.kind = kind
    self.length = length

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s spec=%r is_nullable=%r kind=%s length=%r>' % (
          self.__class__.__name__, self.spec, self.is_nullable, Repr(self.kind),
          self.length)
    else:
      return GenericRepr(self, {'kind': True, 'length': False,
                                'is_nullable': False})


class Map(ReferenceKind):
  """A map.

  Attributes:
    key_kind: {Kind} The type of the keys. May be None.
    value_kind: {Kind} The type of the elements. May be None.
  """
  ReferenceKind.AddSharedProperty('key_kind')
  ReferenceKind.AddSharedProperty('value_kind')

  def __init__(self, key_kind=None, value_kind=None):
    if (key_kind is not None and value_kind is not None):
      ReferenceKind.__init__(self,
                             'm[' + key_kind.spec + '][' + value_kind.spec +
                             ']')
      if IsNullableKind(key_kind):
        raise Exception("Nullable kinds cannot be keys in maps.")
      if IsAnyHandleKind(key_kind):
        raise Exception("Handles cannot be keys in maps.")
      if IsAnyInterfaceKind(key_kind):
        raise Exception("Interfaces cannot be keys in maps.")
      if IsArrayKind(key_kind):
        raise Exception("Arrays cannot be keys in maps.")
    else:
      ReferenceKind.__init__(self)

    self.key_kind = key_kind
    self.value_kind = value_kind

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s spec=%r is_nullable=%r key_kind=%s value_kind=%s>' % (
          self.__class__.__name__, self.spec, self.is_nullable,
          Repr(self.key_kind), Repr(self.value_kind))
    else:
      return GenericRepr(self, {'key_kind': True, 'value_kind': True})


class InterfaceRequest(ReferenceKind):
  ReferenceKind.AddSharedProperty('kind')

  def __init__(self, kind=None):
    if kind is not None:
      if not isinstance(kind, Interface):
        raise Exception(
            "Interface request requires %r to be an interface." % kind.spec)
      ReferenceKind.__init__(self, 'r:' + kind.spec)
    else:
      ReferenceKind.__init__(self)
    self.kind = kind


class AssociatedInterfaceRequest(ReferenceKind):
  ReferenceKind.AddSharedProperty('kind')

  def __init__(self, kind=None):
    if kind is not None:
      if not isinstance(kind, InterfaceRequest):
        raise Exception(
            "Associated interface request requires %r to be an interface "
            "request." % kind.spec)
      assert not kind.is_nullable
      ReferenceKind.__init__(self, 'asso:' + kind.spec)
    else:
      ReferenceKind.__init__(self)
    self.kind = kind.kind if kind is not None else None


class Parameter(object):
  def __init__(self, name=None, kind=None, ordinal=None, default=None,
               attributes=None):
    self.name = name
    self.ordinal = ordinal
    self.kind = kind
    self.default = default
    self.attributes = attributes

  def Repr(self, as_ref=True):
    return '<%s name=%r kind=%s>' % (self.__class__.__name__, self.name,
                                     self.kind.Repr(as_ref=True))

  @property
  def min_version(self):
    return self.attributes.get(ATTRIBUTE_MIN_VERSION) \
        if self.attributes else None


class Method(object):
  def __init__(self, interface, name, ordinal=None, attributes=None):
    self.interface = interface
    self.name = name
    self.ordinal = ordinal
    self.parameters = []
    self.response_parameters = None
    self.attributes = attributes

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s name=%r>' % (self.__class__.__name__, self.name)
    else:
      return GenericRepr(self, {'name': False, 'parameters': True,
                                'response_parameters': True})

  def AddParameter(self, name, kind, ordinal=None, default=None,
                   attributes=None):
    parameter = Parameter(name, kind, ordinal, default, attributes)
    self.parameters.append(parameter)
    return parameter

  def AddResponseParameter(self, name, kind, ordinal=None, default=None,
                           attributes=None):
    if self.response_parameters == None:
      self.response_parameters = []
    parameter = Parameter(name, kind, ordinal, default, attributes)
    self.response_parameters.append(parameter)
    return parameter

  @property
  def min_version(self):
    return self.attributes.get(ATTRIBUTE_MIN_VERSION) \
        if self.attributes else None

  @property
  def sync(self):
    return self.attributes.get(ATTRIBUTE_SYNC) \
        if self.attributes else None


class Interface(ReferenceKind):
  ReferenceKind.AddSharedProperty('module')
  ReferenceKind.AddSharedProperty('name')
  ReferenceKind.AddSharedProperty('imported_from')
  ReferenceKind.AddSharedProperty('methods')
  ReferenceKind.AddSharedProperty('attributes')

  def __init__(self, name=None, module=None, attributes=None):
    if name is not None:
      spec = 'x:' + name
    else:
      spec = None
    ReferenceKind.__init__(self, spec)
    self.module = module
    self.name = name
    self.imported_from = None
    self.methods = []
    self.attributes = attributes

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s name=%r>' % (self.__class__.__name__, self.name)
    else:
      return GenericRepr(self, {'name': False, 'attributes': False,
                                'methods': False})

  def AddMethod(self, name, ordinal=None, attributes=None):
    method = Method(self, name, ordinal, attributes)
    self.methods.append(method)
    return method

  # TODO(451323): Remove when the language backends no longer rely on this.
  @property
  def client(self):
    return None


class AssociatedInterface(ReferenceKind):
  ReferenceKind.AddSharedProperty('kind')

  def __init__(self, kind=None):
    if kind is not None:
      if not isinstance(kind, Interface):
        raise Exception(
            "Associated interface requires %r to be an interface." % kind.spec)
      assert not kind.is_nullable
      ReferenceKind.__init__(self, 'asso:' + kind.spec)
    else:
      ReferenceKind.__init__(self)
    self.kind = kind


class EnumField(object):
  def __init__(self, name=None, value=None, attributes=None,
               numeric_value=None):
    self.name = name
    self.value = value
    self.attributes = attributes
    self.numeric_value = numeric_value

  @property
  def min_version(self):
    return self.attributes.get(ATTRIBUTE_MIN_VERSION) \
        if self.attributes else None


class Enum(Kind):
  def __init__(self, name=None, module=None, attributes=None):
    self.module = module
    self.name = name
    self.native_only = False
    self.imported_from = None
    if name is not None:
      spec = 'x:' + name
    else:
      spec = None
    Kind.__init__(self, spec)
    self.fields = []
    self.attributes = attributes

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s name=%r>' % (self.__class__.__name__, self.name)
    else:
      return GenericRepr(self, {'name': False, 'fields': False})

  @property
  def extensible(self):
    return self.attributes.get(ATTRIBUTE_EXTENSIBLE, False) \
        if self.attributes else False


class Module(object):
  def __init__(self, name=None, namespace=None, attributes=None):
    self.name = name
    self.path = name
    self.namespace = namespace
    self.structs = []
    self.unions = []
    self.interfaces = []
    self.kinds = {}
    self.attributes = attributes

  def __repr__(self):
    # Gives us a decent __repr__ for modules.
    return self.Repr()

  def Repr(self, as_ref=True):
    if as_ref:
      return '<%s name=%r namespace=%r>' % (
          self.__class__.__name__, self.name, self.namespace)
    else:
      return GenericRepr(self, {'name': False, 'namespace': False,
                                'attributes': False, 'structs': False,
                                'interfaces': False, 'unions': False})

  def AddInterface(self, name, attributes=None):
    interface = Interface(name, self, attributes)
    self.interfaces.append(interface)
    return interface

  def AddStruct(self, name, attributes=None):
    struct = Struct(name, self, attributes)
    self.structs.append(struct)
    return struct

  def AddUnion(self, name, attributes=None):
    union = Union(name, self, attributes)
    self.unions.append(union)
    return union


def IsBoolKind(kind):
  return kind.spec == BOOL.spec


def IsFloatKind(kind):
  return kind.spec == FLOAT.spec


def IsDoubleKind(kind):
  return kind.spec == DOUBLE.spec


def IsIntegralKind(kind):
  return (kind.spec == BOOL.spec or
          kind.spec == INT8.spec or
          kind.spec == INT16.spec or
          kind.spec == INT32.spec or
          kind.spec == INT64.spec or
          kind.spec == UINT8.spec or
          kind.spec == UINT16.spec or
          kind.spec == UINT32.spec or
          kind.spec == UINT64.spec)


def IsStringKind(kind):
  return kind.spec == STRING.spec or kind.spec == NULLABLE_STRING.spec


def IsGenericHandleKind(kind):
  return kind.spec == HANDLE.spec or kind.spec == NULLABLE_HANDLE.spec


def IsDataPipeConsumerKind(kind):
  return kind.spec == DCPIPE.spec or kind.spec == NULLABLE_DCPIPE.spec


def IsDataPipeProducerKind(kind):
  return kind.spec == DPPIPE.spec or kind.spec == NULLABLE_DPPIPE.spec


def IsMessagePipeKind(kind):
  return kind.spec == MSGPIPE.spec or kind.spec == NULLABLE_MSGPIPE.spec


def IsSharedBufferKind(kind):
  return (kind.spec == SHAREDBUFFER.spec or
          kind.spec == NULLABLE_SHAREDBUFFER.spec)


def IsStructKind(kind):
  return isinstance(kind, Struct)


def IsUnionKind(kind):
  return isinstance(kind, Union)


def IsArrayKind(kind):
  return isinstance(kind, Array)


def IsInterfaceKind(kind):
  return isinstance(kind, Interface)


def IsAssociatedInterfaceKind(kind):
  return isinstance(kind, AssociatedInterface)


def IsInterfaceRequestKind(kind):
  return isinstance(kind, InterfaceRequest)


def IsAssociatedInterfaceRequestKind(kind):
  return isinstance(kind, AssociatedInterfaceRequest)


def IsEnumKind(kind):
  return isinstance(kind, Enum)


def IsReferenceKind(kind):
  return isinstance(kind, ReferenceKind)


def IsNullableKind(kind):
  return IsReferenceKind(kind) and kind.is_nullable


def IsMapKind(kind):
  return isinstance(kind, Map)


def IsObjectKind(kind):
  return IsPointerKind(kind) or IsUnionKind(kind)


def IsPointerKind(kind):
  return (IsStructKind(kind) or IsArrayKind(kind) or IsStringKind(kind) or
          IsMapKind(kind))


# Please note that it doesn't include any interface kind.
def IsAnyHandleKind(kind):
  return (IsGenericHandleKind(kind) or
          IsDataPipeConsumerKind(kind) or
          IsDataPipeProducerKind(kind) or
          IsMessagePipeKind(kind) or
          IsSharedBufferKind(kind))


def IsAnyInterfaceKind(kind):
  return (IsInterfaceKind(kind) or IsInterfaceRequestKind(kind) or
          IsAssociatedKind(kind))


def IsAnyHandleOrInterfaceKind(kind):
  return IsAnyHandleKind(kind) or IsAnyInterfaceKind(kind)


def IsAssociatedKind(kind):
  return (IsAssociatedInterfaceKind(kind) or
          IsAssociatedInterfaceRequestKind(kind))


def HasCallbacks(interface):
  for method in interface.methods:
    if method.response_parameters != None:
      return True
  return False


# Finds out whether an interface passes associated interfaces and associated
# interface requests.
def PassesAssociatedKinds(interface):
  def _ContainsAssociatedKinds(kind, visited_kinds):
    if kind in visited_kinds:
      # No need to examine the kind again.
      return False
    visited_kinds.add(kind)
    if IsAssociatedKind(kind):
      return True
    if IsArrayKind(kind):
      return _ContainsAssociatedKinds(kind.kind, visited_kinds)
    if IsStructKind(kind) or IsUnionKind(kind):
      for field in kind.fields:
        if _ContainsAssociatedKinds(field.kind, visited_kinds):
          return True
    if IsMapKind(kind):
      # No need to examine the key kind, only primitive kinds and non-nullable
      # string are allowed to be key kinds.
      return _ContainsAssociatedKinds(kind.value_kind, visited_kinds)
    return False

  visited_kinds = set()
  for method in interface.methods:
    for param in method.parameters:
      if _ContainsAssociatedKinds(param.kind, visited_kinds):
        return True
    if method.response_parameters != None:
      for param in method.response_parameters:
        if _ContainsAssociatedKinds(param.kind, visited_kinds):
          return True
  return False


def HasSyncMethods(interface):
  for method in interface.methods:
    if method.sync:
      return True
  return False


def ContainsHandlesOrInterfaces(kind):
  """Check if the kind contains any handles.

  This check is recursive so it checks all struct fields, containers elements,
  etc.

  Args:
    struct: {Kind} The kind to check.

  Returns:
    {bool}: True if the kind contains handles.
  """
  # We remember the types we already checked to avoid infinite recursion when
  # checking recursive (or mutually recursive) types:
  checked = set()
  def Check(kind):
    if kind.spec in checked:
      return False
    checked.add(kind.spec)
    if IsStructKind(kind):
      return any(Check(field.kind) for field in kind.fields)
    elif IsUnionKind(kind):
      return any(Check(field.kind) for field in kind.fields)
    elif IsAnyHandleKind(kind):
      return True
    elif IsAnyInterfaceKind(kind):
      return True
    elif IsArrayKind(kind):
      return Check(kind.kind)
    elif IsMapKind(kind):
      return Check(kind.key_kind) or Check(kind.value_kind)
    else:
      return False
  return Check(kind)