Bug 1885914 - Use __slots__ to speedup webidl parsing r=peterv

Per https://wiki.python.org/moin/UsingSlots,

    slots are more efficient in terms of memory space and speed of access

Differential Revision: https://phabricator.services.mozilla.com/D204930

dom/bindings/parser/WebIDL.py

@@ -121,6 +121,8 @@ class Location(object):
 
 
 class BuiltinLocation(object):
+    __slots__ = "msg", "filename"
+
     def __init__(self, text):
         self.msg = text + "\n"
         self.filename = "<builtin>"
@@ -142,9 +144,11 @@ class BuiltinLocation(object):
 
 
 class IDLObject(object):
+    __slots__ = "location", "userData", "filename"
+
     def __init__(self, location):
         self.location = location
-        self.userData = dict()
+        self.userData = {}
         self.filename = location and location.filename
 
     def isInterface(self):
@@ -220,6 +224,8 @@ class IDLObject(object):
 
 
 class IDLScope(IDLObject):
+    __slots__ = "parentScope", "_name", "_dict", "globalNames", "globalNameMapping"
+
     def __init__(self, location, parentScope, identifier):
         IDLObject.__init__(self, location)
 
@@ -349,6 +355,8 @@ class IDLScope(IDLObject):
 
 
 class IDLIdentifier(IDLObject):
+    __slots__ = "name", "scope"
+
     def __init__(self, location, scope, name):
         IDLObject.__init__(self, location)
 
@@ -373,12 +381,14 @@ class IDLIdentifier(IDLObject):
 
 
 class IDLUnresolvedIdentifier(IDLObject):
+    __slots__ = ("name",)
+
     def __init__(
         self, location, name, allowDoubleUnderscore=False, allowForbidden=False
     ):
         IDLObject.__init__(self, location)
 
-        assert len(name) > 0
+        assert name
 
         if name == "__noSuchMethod__":
             raise WebIDLError("__noSuchMethod__ is deprecated", [location])
@@ -417,6 +427,7 @@ class IDLUnresolvedIdentifier(IDLObject):
 
 
 class IDLObjectWithIdentifier(IDLObject):
+    # no slots, incompatible with multiple inheritance
     def __init__(self, location, parentScope, identifier):
         IDLObject.__init__(self, location)
 
@@ -434,6 +445,8 @@ class IDLObjectWithIdentifier(IDLObject):
 
 
 class IDLObjectWithScope(IDLObjectWithIdentifier, IDLScope):
+    __slots__ = ()
+
     def __init__(self, location, parentScope, identifier):
         assert isinstance(identifier, IDLUnresolvedIdentifier)
 
@@ -442,6 +455,8 @@ class IDLObjectWithScope(IDLObjectWithIdentifier, IDLScope):
 
 
 class IDLIdentifierPlaceholder(IDLObjectWithIdentifier):
+    __slots__ = ()
+
     def __init__(self, location, identifier):
         assert isinstance(identifier, IDLUnresolvedIdentifier)
         IDLObjectWithIdentifier.__init__(self, location, None, identifier)
@@ -459,6 +474,7 @@ class IDLIdentifierPlaceholder(IDLObjectWithIdentifier):
 
 
 class IDLExposureMixins:
+    # no slots, incompatible with multiple inheritance
     def __init__(self, location):
         # _exposureGlobalNames are the global names listed in our [Exposed]
         # extended attribute.  exposureSet is the exposure set as defined in the
@@ -541,6 +557,8 @@ class IDLExposureMixins:
 
 
 class IDLExternalInterface(IDLObjectWithIdentifier):
+    __slots__ = ("parent",)
+
     def __init__(self, location, parentScope, identifier):
         assert isinstance(identifier, IDLUnresolvedIdentifier)
         assert isinstance(parentScope, IDLScope)
@@ -591,6 +609,8 @@ class IDLExternalInterface(IDLObjectWithIdentifier):
 
 
 class IDLPartialDictionary(IDLObject):
+    __slots__ = "identifier", "members", "_nonPartialDictionary", "_finished"
+
     def __init__(self, location, name, members, nonPartialDictionary):
         assert isinstance(name, IDLUnresolvedIdentifier)
 
@@ -619,6 +639,15 @@ class IDLPartialDictionary(IDLObject):
 
 
 class IDLPartialInterfaceOrNamespace(IDLObject):
+    __slots__ = (
+        "identifier",
+        "members",
+        "propagatedExtendedAttrs",
+        "_haveSecureContextExtendedAttribute",
+        "_nonPartialInterfaceOrNamespace",
+        "_finished",
+    )
+
     def __init__(self, location, name, members, nonPartialInterfaceOrNamespace):
         assert isinstance(name, IDLUnresolvedIdentifier)
 
@@ -726,12 +755,22 @@ def globalNameSetToExposureSet(globalScope, nameSet, exposureSet):
 # we use a special class to be able to store them both in the scope for the
 # same identifier.
 class IDLOperations:
+    __slots__ = "static", "regular"
+
     def __init__(self, static=None, regular=None):
         self.static = static
         self.regular = regular
 
 
 class IDLInterfaceOrInterfaceMixinOrNamespace(IDLObjectWithScope, IDLExposureMixins):
+    __slots__ = (
+        "_finished",
+        "members",
+        "_partials",
+        "_extendedAttrDict",
+        "_isKnownNonPartial",
+    )
+
     def __init__(self, location, parentScope, name):
         assert isinstance(parentScope, IDLScope)
         assert isinstance(name, IDLUnresolvedIdentifier)
@@ -897,10 +936,12 @@ class IDLInterfaceOrInterfaceMixinOrNamespace(IDLObjectWithScope, IDLExposureMix
 
 
 class IDLInterfaceMixin(IDLInterfaceOrInterfaceMixinOrNamespace):
+    __slots__ = ("actualExposureGlobalNames",)
+
     def __init__(self, location, parentScope, name, members, isKnownNonPartial):
         self.actualExposureGlobalNames = set()
 
-        assert isKnownNonPartial or len(members) == 0
+        assert isKnownNonPartial or not members
         IDLInterfaceOrInterfaceMixinOrNamespace.__init__(
             self, location, parentScope, name
         )
@@ -1001,9 +1042,27 @@ class IDLInterfaceMixin(IDLInterfaceOrInterfaceMixinOrNamespace):
 
 
 class IDLInterfaceOrNamespace(IDLInterfaceOrInterfaceMixinOrNamespace):
+    __slots__ = (
+        "parent",
+        "_callback",
+        "maplikeOrSetlikeOrIterable",
+        "legacyFactoryFunctions",
+        "legacyWindowAliases",
+        "includedMixins",
+        "interfacesBasedOnSelf",
+        "_hasChildInterfaces",
+        "_isOnGlobalProtoChain",
+        "totalMembersInSlots",
+        "_ownMembersInSlots",
+        "iterableInterface",
+        "asyncIterableInterface",
+        "hasCrossOriginMembers",
+        "hasDescendantWithCrossOriginMembers",
+    )
+
     def __init__(self, location, parentScope, name, parent, members, isKnownNonPartial):
         assert isKnownNonPartial or not parent
-        assert isKnownNonPartial or len(members) == 0
+        assert isKnownNonPartial or not members
 
         self.parent = None
         self._callback = False
@@ -1011,13 +1070,13 @@ class IDLInterfaceOrNamespace(IDLInterfaceOrInterfaceMixinOrNamespace):
         # legacyFactoryFunctions needs deterministic ordering because bindings code
         # outputs the constructs in the order that legacyFactoryFunctions enumerates
         # them.
-        self.legacyFactoryFunctions = list()
+        self.legacyFactoryFunctions = []
         self.legacyWindowAliases = []
         self.includedMixins = set()
         # self.interfacesBasedOnSelf is the set of interfaces that inherit from
         # self, including self itself.
         # Used for distinguishability checking.
-        self.interfacesBasedOnSelf = set([self])
+        self.interfacesBasedOnSelf = {self}
         self._hasChildInterfaces = False
         self._isOnGlobalProtoChain = False
 
@@ -1885,6 +1944,8 @@ class IDLInterfaceOrNamespace(IDLInterfaceOrInterfaceMixinOrNamespace):
 
 
 class IDLInterface(IDLInterfaceOrNamespace):
+    __slots__ = ("classNameOverride",)
+
     def __init__(
         self,
         location,
@@ -2103,6 +2164,8 @@ class IDLInterface(IDLInterfaceOrNamespace):
 
 
 class IDLNamespace(IDLInterfaceOrNamespace):
+    __slots__ = ()
+
     def __init__(self, location, parentScope, name, members, isKnownNonPartial):
         IDLInterfaceOrNamespace.__init__(
             self, location, parentScope, name, None, members, isKnownNonPartial
@@ -2161,6 +2224,16 @@ class IDLNamespace(IDLInterfaceOrNamespace):
 
 
 class IDLDictionary(IDLObjectWithScope):
+    __slots__ = (
+        "parent",
+        "_finished",
+        "members",
+        "_partialDictionaries",
+        "_extendedAttrDict",
+        "needsConversionToJS",
+        "needsConversionFromJS",
+    )
+
     def __init__(self, location, parentScope, name, parent, members):
         assert isinstance(parentScope, IDLScope)
         assert isinstance(name, IDLUnresolvedIdentifier)
@@ -2388,6 +2461,8 @@ class IDLDictionary(IDLObjectWithScope):
 
 
 class IDLEnum(IDLObjectWithIdentifier):
+    __slots__ = ("_values",)
+
     def __init__(self, location, parentScope, name, values):
         assert isinstance(parentScope, IDLScope)
         assert isinstance(name, IDLUnresolvedIdentifier)
@@ -2462,6 +2537,16 @@ class IDLType(IDLObject):
         "observablearray",
     )
 
+    __slots__ = (
+        "name",
+        "builtin",
+        "legacyNullToEmptyString",
+        "_clamp",
+        "_enforceRange",
+        "_allowShared",
+        "_extendedAttrDict",
+    )
+
     def __init__(self, location, name):
         IDLObject.__init__(self, location)
         self.name = name
@@ -2662,6 +2747,8 @@ class IDLUnresolvedType(IDLType):
     Unresolved types are interface types
     """
 
+    __slots__ = ("extraTypeAttributes",)
+
     def __init__(self, location, name, attrs=[]):
         IDLType.__init__(self, location, name)
         self.extraTypeAttributes = attrs
@@ -2702,6 +2789,8 @@ class IDLUnresolvedType(IDLType):
 
 
 class IDLParametrizedType(IDLType):
+    __slots__ = "builtin", "inner"
+
     def __init__(self, location, name, innerType):
         IDLType.__init__(self, location, name)
         self.builtin = False
@@ -2725,6 +2814,8 @@ class IDLParametrizedType(IDLType):
 
 
 class IDLNullableType(IDLParametrizedType):
+    __slots__ = ()
+
     def __init__(self, location, innerType):
         assert not innerType == BuiltinTypes[IDLBuiltinType.Types.any]
 
@@ -2900,6 +2991,8 @@ class IDLNullableType(IDLParametrizedType):
 
 
 class IDLSequenceType(IDLParametrizedType):
+    __slots__ = ("name",)
+
     def __init__(self, location, parameterType):
         assert not parameterType.isUndefined()
 
@@ -2960,6 +3053,8 @@ class IDLSequenceType(IDLParametrizedType):
 
 
 class IDLRecordType(IDLParametrizedType):
+    __slots__ = "keyType", "name"
+
     def __init__(self, location, keyType, valueType):
         assert keyType.isString()
         assert keyType.isComplete()
@@ -3038,6 +3133,8 @@ class IDLRecordType(IDLParametrizedType):
 
 
 class IDLObservableArrayType(IDLParametrizedType):
+    __slots__ = ()
+
     def __init__(self, location, innerType):
         assert not innerType.isUndefined()
         IDLParametrizedType.__init__(self, location, None, innerType)
@@ -3104,6 +3201,14 @@ class IDLObservableArrayType(IDLParametrizedType):
 
 
 class IDLUnionType(IDLType):
+    __slots__ = (
+        "memberTypes",
+        "hasNullableType",
+        "_dictionaryType",
+        "flatMemberTypes",
+        "builtin",
+    )
+
     def __init__(self, location, memberTypes):
         IDLType.__init__(self, location, "")
         self.memberTypes = memberTypes
@@ -3247,6 +3352,8 @@ class IDLUnionType(IDLType):
 
 
 class IDLTypedefType(IDLType):
+    __slots__ = "inner", "builtin"
+
     def __init__(self, location, innerType, name):
         IDLType.__init__(self, location, name)
         self.inner = innerType
@@ -3354,6 +3461,8 @@ class IDLTypedefType(IDLType):
 
 
 class IDLTypedef(IDLObjectWithIdentifier):
+    __slots__ = ("innerType",)
+
     def __init__(self, location, parentScope, innerType, name):
         # Set self.innerType first, because IDLObjectWithIdentifier.__init__
         # will call our __str__, which wants to use it.
@@ -3386,6 +3495,8 @@ class IDLTypedef(IDLObjectWithIdentifier):
 
 
 class IDLWrapperType(IDLType):
+    __slots__ = "inner", "_identifier", "builtin"
+
     def __init__(self, location, inner):
         IDLType.__init__(self, location, inner.identifier.name)
         self.inner = inner
@@ -3582,6 +3693,8 @@ class IDLWrapperType(IDLType):
 
 
 class IDLPromiseType(IDLParametrizedType):
+    __slots__ = ()
+
     def __init__(self, location, innerType):
         IDLParametrizedType.__init__(self, location, "Promise", innerType)
 
@@ -3745,6 +3858,14 @@ class IDLBuiltinType(IDLType):
         Types.Float64Array: "Float64Array",
     }
 
+    __slots__ = (
+        "_typeTag",
+        "_clamped",
+        "_rangeEnforced",
+        "_withLegacyNullToEmptyString",
+        "_withAllowShared",
+    )
+
     def __init__(
         self,
         location,
@@ -4242,6 +4363,11 @@ class NoCoercionFoundError(WebIDLError):
 
 
 class IDLValue(IDLObject):
+    __slots__ = (
+        "type",
+        "value",
+    )
+
     def __init__(self, location, type, value):
         IDLObject.__init__(self, location)
         self.type = type
@@ -4374,6 +4500,8 @@ class IDLValue(IDLObject):
 
 
 class IDLNullValue(IDLObject):
+    __slots__ = "type", "value"
+
     def __init__(self, location):
         IDLObject.__init__(self, location)
         self.type = None
@@ -4403,6 +4531,8 @@ class IDLNullValue(IDLObject):
 
 
 class IDLEmptySequenceValue(IDLObject):
+    __slots__ = "type", "value"
+
     def __init__(self, location):
         IDLObject.__init__(self, location)
         self.type = None
@@ -4433,6 +4563,8 @@ class IDLEmptySequenceValue(IDLObject):
 
 
 class IDLDefaultDictionaryValue(IDLObject):
+    __slots__ = "type", "value"
+
     def __init__(self, location):
         IDLObject.__init__(self, location)
         self.type = None
@@ -4463,6 +4595,8 @@ class IDLDefaultDictionaryValue(IDLObject):
 
 
 class IDLUndefinedValue(IDLObject):
+    __slots__ = "type", "value"
+
     def __init__(self, location):
         IDLObject.__init__(self, location)
         self.type = None
@@ -4492,6 +4626,7 @@ class IDLInterfaceMember(IDLObjectWithIdentifier, IDLExposureMixins):
     AffectsValues = ("Nothing", "Everything")
     DependsOnValues = ("Nothing", "DOMState", "DeviceState", "Everything")
 
+    # no slots : multiple inheritance
     def __init__(self, location, identifier, tag, extendedAttrDict=None):
         IDLObjectWithIdentifier.__init__(self, location, None, identifier)
         IDLExposureMixins.__init__(self, location)
@@ -4611,6 +4746,14 @@ class IDLInterfaceMember(IDLObjectWithIdentifier, IDLExposureMixins):
 
 
 class IDLMaplikeOrSetlikeOrIterableBase(IDLInterfaceMember):
+    __slots__ = (
+        "keyType",
+        "valueType",
+        "maplikeOrSetlikeOrIterableType",
+        "disallowedMemberNames",
+        "disallowedNonMethodNames",
+    )
+
     def __init__(self, location, identifier, ifaceType, keyType, valueType, ifaceKind):
         IDLInterfaceMember.__init__(self, location, identifier, ifaceKind)
         if keyType is not None:
@@ -4827,6 +4970,8 @@ class IDLMaplikeOrSetlikeOrIterableBase(IDLInterfaceMember):
 # Iterable adds ES6 iterator style functions and traits
 # (keys/values/entries/@@iterator) to an interface.
 class IDLIterable(IDLMaplikeOrSetlikeOrIterableBase):
+    __slots__ = ("iteratorType",)
+
     def __init__(self, location, identifier, keyType, valueType, scope):
         IDLMaplikeOrSetlikeOrIterableBase.__init__(
             self,
@@ -4902,6 +5047,8 @@ class IDLIterable(IDLMaplikeOrSetlikeOrIterableBase):
 
 
 class IDLAsyncIterable(IDLMaplikeOrSetlikeOrIterableBase):
+    __slots__ = "iteratorType", "argList"
+
     def __init__(self, location, identifier, keyType, valueType, argList, scope):
         for arg in argList:
             if not arg.optional:
@@ -4986,6 +5133,8 @@ class IDLAsyncIterable(IDLMaplikeOrSetlikeOrIterableBase):
 
 # MaplikeOrSetlike adds ES6 map-or-set-like traits to an interface.
 class IDLMaplikeOrSetlike(IDLMaplikeOrSetlikeOrIterableBase):
+    __slots__ = "readonly", "slotIndices", "prefix"
+
     def __init__(
         self, location, identifier, maplikeOrSetlikeType, readonly, keyType, valueType
     ):
@@ -5153,6 +5302,8 @@ class IDLMaplikeOrSetlike(IDLMaplikeOrSetlikeOrIterableBase):
 
 
 class IDLConst(IDLInterfaceMember):
+    __slots__ = "type", "value"
+
     def __init__(self, location, identifier, type, value):
         IDLInterfaceMember.__init__(
             self, location, identifier, IDLInterfaceMember.Tags.Const
@@ -5225,6 +5376,21 @@ class IDLConst(IDLInterfaceMember):
 
 
 class IDLAttribute(IDLInterfaceMember):
+    __slots__ = (
+        "type",
+        "readonly",
+        "inherit",
+        "_static",
+        "legacyLenientThis",
+        "_legacyUnforgeable",
+        "stringifier",
+        "slotIndices",
+        "maplikeOrSetlike",
+        "dependsOn",
+        "affects",
+        "bindingAliases",
+    )
+
     def __init__(
         self,
         location,
@@ -5827,6 +5993,18 @@ class IDLAttribute(IDLInterfaceMember):
 
 
 class IDLArgument(IDLObjectWithIdentifier):
+    __slots__ = (
+        "type",
+        "optional",
+        "defaultValue",
+        "variadic",
+        "dictionaryMember",
+        "_isComplete",
+        "_allowTreatNonCallableAsNull",
+        "_extendedAttrDict",
+        "allowTypeAttributes",
+    )
+
     def __init__(
         self,
         location,
@@ -5970,6 +6148,15 @@ class IDLArgument(IDLObjectWithIdentifier):
 
 
 class IDLCallback(IDLObjectWithScope):
+    __slots__ = (
+        "_returnType",
+        "_arguments",
+        "_treatNonCallableAsNull",
+        "_treatNonObjectAsNull",
+        "_isRunScriptBoundary",
+        "_isConstructor",
+    )
+
     def __init__(
         self, location, parentScope, identifier, returnType, arguments, isConstructor
     ):
@@ -6067,6 +6254,8 @@ class IDLCallback(IDLObjectWithScope):
 
 
 class IDLCallbackType(IDLType):
+    __slots__ = ("callback",)
+
     def __init__(self, location, callback):
         IDLType.__init__(self, location, callback.identifier.name)
         self.callback = callback
@@ -6109,6 +6298,8 @@ class IDLMethodOverload:
     the full set of overloads.
     """
 
+    __slots__ = "returnType", "arguments", "location"
+
     def __init__(self, returnType, arguments, location):
         self.returnType = returnType
         # Clone the list of arguments, just in case
@@ -6131,6 +6322,25 @@ class IDLMethod(IDLInterfaceMember, IDLScope):
 
     NamedOrIndexed = enum("Neither", "Named", "Indexed")
 
+    __slots__ = (
+        "_hasOverloads",
+        "_overloads",
+        "_static",
+        "_getter",
+        "_setter",
+        "_deleter",
+        "_legacycaller",
+        "_stringifier",
+        "maplikeOrSetlikeOrIterable",
+        "_htmlConstructor",
+        "underlyingAttr",
+        "_specialType",
+        "_legacyUnforgeable",
+        "dependsOn",
+        "affects",
+        "aliases",
+    )
+
     def __init__(
         self,
         location,
@@ -6797,6 +7007,14 @@ class IDLMethod(IDLInterfaceMember, IDLScope):
 
 
 class IDLConstructor(IDLMethod):
+    __slots__ = (
+        "_initLocation",
+        "_initArgs",
+        "_initName",
+        "_inited",
+        "_initExtendedAttrs",
+    )
+
     def __init__(self, location, args, name):
         # We can't actually init our IDLMethod yet, because we do not know the
         # return type yet.  Just save the info we have for now and we will init
@@ -6866,6 +7084,8 @@ class IDLConstructor(IDLMethod):
 
 
 class IDLIncludesStatement(IDLObject):
+    __slots__ = ("interface", "mixin", "_finished")
+
     def __init__(self, location, interface, mixin):
         IDLObject.__init__(self, location)
         self.interface = interface
@@ -6922,6 +7142,8 @@ class IDLExtendedAttribute(IDLObject):
     A class to represent IDL extended attributes so we can give them locations
     """
 
+    __slots__ = ("_tuple",)
+
     def __init__(self, location, tuple):
         IDLObject.__init__(self, location)
         self._tuple = tuple