webidl binder

2 files changed, 5032 insertions, 0 deletions

diff --git a/third_party/WebIDL.py b/third_party/WebIDL.py
new file mode 100644
index 00000000..867a7cbc
--- /dev/null
+++ b/third_party/WebIDL.py
@@ -0,0 +1,5030 @@
+# from http://mxr.mozilla.org/mozilla-central/source/dom/bindings/parser/WebIDL.py
+# rev 501baeb3a034
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+""" A WebIDL parser. """
+
+from ply import lex, yacc
+import re
+import os
+import traceback
+import math
+
+# Machinery
+
+def parseInt(literal):
+    string = literal
+    sign = 0
+    base = 0
+
+    if string[0] == '-':
+        sign = -1
+        string = string[1:]
+    else:
+        sign = 1
+
+    if string[0] == '0' and len(string) > 1:
+        if string[1] == 'x' or string[1] == 'X':
+            base = 16
+            string = string[2:]
+        else:
+            base = 8
+            string = string[1:]
+    else:
+        base = 10
+
+    value = int(string, base)
+    return value * sign
+
+# Magic for creating enums
+def M_add_class_attribs(attribs, start):
+    def foo(name, bases, dict_):
+        for v, k in enumerate(attribs):
+            dict_[k] = start + v
+        assert 'length' not in dict_
+        dict_['length'] = start + len(attribs)
+        return type(name, bases, dict_)
+    return foo
+
+def enum(*names, **kw):
+    if len(kw) == 1:
+        base = kw['base'].__class__
+        start = base.length
+    else:
+        assert len(kw) == 0
+        base = object
+        start = 0
+    class Foo(base):
+        __metaclass__ = M_add_class_attribs(names, start)
+        def __setattr__(self, name, value):  # this makes it read-only
+            raise NotImplementedError
+    return Foo()
+
+class WebIDLError(Exception):
+    def __init__(self, message, locations, warning=False):
+        self.message = message
+        self.locations = [str(loc) for loc in locations]
+        self.warning = warning
+
+    def __str__(self):
+        return "%s: %s%s%s" % (self.warning and 'warning' or 'error',
+                                 self.message,
+                                 ", " if len(self.locations) != 0 else "",
+                                 "\n".join(self.locations))
+
+class Location(object):
+    def __init__(self, lexer, lineno, lexpos, filename):
+        self._line = None
+        self._lineno = lineno
+        self._lexpos = lexpos
+        self._lexdata = lexer.lexdata
+        self._file = filename if filename else "<unknown>"
+
+    def __eq__(self, other):
+        return self._lexpos == other._lexpos and \
+               self._file == other._file
+
+    def filename(self):
+        return self._file
+
+    def resolve(self):
+        if self._line:
+            return
+
+        startofline = self._lexdata.rfind('\n', 0, self._lexpos) + 1
+        endofline = self._lexdata.find('\n', self._lexpos, self._lexpos + 80)
+        if endofline != -1:
+            self._line = self._lexdata[startofline:endofline]
+        else:
+            self._line = self._lexdata[startofline:]
+        self._colno = self._lexpos - startofline
+
+        # Our line number seems to point to the start of self._lexdata
+        self._lineno += self._lexdata.count('\n', 0, startofline)
+
+    def get(self):
+        self.resolve()
+        return "%s line %s:%s" % (self._file, self._lineno, self._colno)
+
+    def _pointerline(self):
+        return " " * self._colno + "^"
+
+    def __str__(self):
+        self.resolve()
+        return "%s line %s:%s\n%s\n%s" % (self._file, self._lineno, self._colno,
+                                          self._line, self._pointerline())
+
+class BuiltinLocation(object):
+    def __init__(self, text):
+        self.msg = text + "\n"
+
+    def __eq__(self, other):
+        return isinstance(other, BuiltinLocation) and \
+               self.msg == other.msg
+
+    def filename(self):
+        return '<builtin>'
+
+    def resolve(self):
+        pass
+
+    def get(self):
+        return self.msg
+
+    def __str__(self):
+        return self.get()
+
+
+# Data Model
+
+class IDLObject(object):
+    def __init__(self, location):
+        self.location = location
+        self.userData = dict()
+
+    def filename(self):
+        return self.location.filename()
+
+    def isInterface(self):
+        return False
+
+    def isEnum(self):
+        return False
+
+    def isCallback(self):
+        return False
+
+    def isType(self):
+        return False
+
+    def isDictionary(self):
+        return False;
+
+    def isUnion(self):
+        return False
+
+    def getUserData(self, key, default):
+        return self.userData.get(key, default)
+
+    def setUserData(self, key, value):
+        self.userData[key] = value
+
+    def addExtendedAttributes(self, attrs):
+        assert False # Override me!
+
+    def handleExtendedAttribute(self, attr):
+        assert False # Override me!
+
+    def _getDependentObjects(self):
+        assert False # Override me!
+
+    def getDeps(self, visited=None):
+        """ Return a set of files that this object depends on.  If any of
+            these files are changed the parser needs to be rerun to regenerate
+            a new IDLObject.
+
+            The visited argument is a set of all the objects already visited.
+            We must test to see if we are in it, and if so, do nothing.  This
+            prevents infinite recursion."""
+
+        # NB: We can't use visited=set() above because the default value is
+        # evaluated when the def statement is evaluated, not when the function
+        # is executed, so there would be one set for all invocations.
+        if visited == None:
+            visited = set()
+
+        if self in visited:
+            return set()
+
+        visited.add(self)
+
+        deps = set()
+        if self.filename() != "<builtin>":
+            deps.add(self.filename())
+
+        for d in self._getDependentObjects():
+            deps = deps.union(d.getDeps(visited))
+
+        return deps
+
+class IDLScope(IDLObject):
+    def __init__(self, location, parentScope, identifier):
+        IDLObject.__init__(self, location)
+
+        self.parentScope = parentScope
+        if identifier:
+            assert isinstance(identifier, IDLIdentifier)
+            self._name = identifier
+        else:
+            self._name = None
+
+        self._dict = {}
+
+    def __str__(self):
+        return self.QName()
+
+    def QName(self):
+        if self._name:
+            return self._name.QName() + "::"
+        return "::"
+
+    def ensureUnique(self, identifier, object):
+        """
+            Ensure that there is at most one 'identifier' in scope ('self').
+            Note that object can be None.  This occurs if we end up here for an
+            interface type we haven't seen yet.
+        """
+        assert isinstance(identifier, IDLUnresolvedIdentifier)
+        assert not object or isinstance(object, IDLObjectWithIdentifier)
+        assert not object or object.identifier == identifier
+
+        if identifier.name in self._dict:
+            if not object:
+                return
+
+            # ensureUnique twice with the same object is not allowed
+            assert id(object) != id(self._dict[identifier.name])
+
+            replacement = self.resolveIdentifierConflict(self, identifier,
+                                                         self._dict[identifier.name],
+                                                         object)
+            self._dict[identifier.name] = replacement
+            return
+
+        assert object
+
+        self._dict[identifier.name] = object
+
+    def resolveIdentifierConflict(self, scope, identifier, originalObject, newObject):
+        if isinstance(originalObject, IDLExternalInterface) and \
+           isinstance(newObject, IDLExternalInterface) and \
+           originalObject.identifier.name == newObject.identifier.name:
+            return originalObject
+
+        if (isinstance(originalObject, IDLExternalInterface) or
+            isinstance(newObject, IDLExternalInterface)):
+            raise WebIDLError(
+                "Name collision between "
+                "interface declarations for identifier '%s' at '%s' and '%s'"
+                % (identifier.name,
+                    originalObject.location, newObject.location), [])
+
+        # We do the merging of overloads here as opposed to in IDLInterface
+        # because we need to merge overloads of NamedConstructors and we need to
+        # detect conflicts in those across interfaces. See also the comment in
+        # IDLInterface.addExtendedAttributes for "NamedConstructor".
+        if originalObject.tag == IDLInterfaceMember.Tags.Method and \
+           newObject.tag == IDLInterfaceMember.Tags.Method:
+            return originalObject.addOverload(newObject)
+
+        # Default to throwing, derived classes can override.
+        conflictdesc = "\n\t%s at %s\n\t%s at %s" % \
+          (originalObject, originalObject.location, newObject, newObject.location)
+
+        raise WebIDLError(
+            "Multiple unresolvable definitions of identifier '%s' in scope '%s%s"
+            % (identifier.name, str(self), conflictdesc), [])
+
+    def _lookupIdentifier(self, identifier):
+        return self._dict[identifier.name]
+
+    def lookupIdentifier(self, identifier):
+        assert isinstance(identifier, IDLIdentifier)
+        assert identifier.scope == self
+        return self._lookupIdentifier(identifier)
+
+class IDLIdentifier(IDLObject):
+    def __init__(self, location, scope, name):
+        IDLObject.__init__(self, location)
+
+        self.name = name
+        assert isinstance(scope, IDLScope)
+        self.scope = scope
+
+    def __str__(self):
+        return self.QName()
+
+    def QName(self):
+        return self.scope.QName() + self.name
+
+    def __hash__(self):
+        return self.QName().__hash__()
+
+    def __eq__(self, other):
+        return self.QName() == other.QName()
+
+    def object(self):
+        return self.scope.lookupIdentifier(self)
+
+class IDLUnresolvedIdentifier(IDLObject):
+    def __init__(self, location, name, allowDoubleUnderscore = False,
+                 allowForbidden = False):
+        IDLObject.__init__(self, location)
+
+        assert len(name) > 0
+
+        if name[:2] == "__" and name != "__content" and name != "___noSuchMethod__"  and not allowDoubleUnderscore:
+            raise WebIDLError("Identifiers beginning with __ are reserved",
+                              [location])
+        if name[0] == '_' and not allowDoubleUnderscore:
+            name = name[1:]
+        # TODO: Bug 872377, Restore "toJSON" to below list.
+        # We sometimes need custom serialization, so allow toJSON for now.
+        if (name in ["constructor", "toString"] and
+            not allowForbidden):
+            raise WebIDLError("Cannot use reserved identifier '%s'" % (name),
+                              [location])
+
+        self.name = name
+
+    def __str__(self):
+        return self.QName()
+
+    def QName(self):
+        return "<unresolved scope>::" + self.name
+
+    def resolve(self, scope, object):
+        assert isinstance(scope, IDLScope)
+        assert not object or isinstance(object, IDLObjectWithIdentifier)
+        assert not object or object.identifier == self
+
+        scope.ensureUnique(self, object)
+
+        identifier = IDLIdentifier(self.location, scope, self.name)
+        if object:
+            object.identifier = identifier
+        return identifier
+
+    def finish(self):
+        assert False # Should replace with a resolved identifier first.
+
+class IDLObjectWithIdentifier(IDLObject):
+    def __init__(self, location, parentScope, identifier):
+        IDLObject.__init__(self, location)
+
+        assert isinstance(identifier, IDLUnresolvedIdentifier)
+
+        self.identifier = identifier
+
+        if parentScope:
+            self.resolve(parentScope)
+
+        self.treatNullAs = "Default"
+
+    def resolve(self, parentScope):
+        assert isinstance(parentScope, IDLScope)
+        assert isinstance(self.identifier, IDLUnresolvedIdentifier)
+        self.identifier.resolve(parentScope, self)
+
+    def checkForStringHandlingExtendedAttributes(self, attrs,
+                                                 isDictionaryMember=False,
+                                                 isOptional=False):
+        """
+        A helper function to deal with TreatNullAs.  Returns the list
+        of attrs it didn't handle itself.
+        """
+        assert isinstance(self, IDLArgument) or isinstance(self, IDLAttribute)
+        unhandledAttrs = list()
+        for attr in attrs:
+            if not attr.hasValue():
+                unhandledAttrs.append(attr)
+                continue
+
+            identifier = attr.identifier()
+            value = attr.value()
+            if identifier == "TreatNullAs":
+                if not self.type.isDOMString() or self.type.nullable():
+                    raise WebIDLError("[TreatNullAs] is only allowed on "
+                                      "arguments or attributes whose type is "
+                                      "DOMString",
+                                      [self.location])
+                if isDictionaryMember:
+                    raise WebIDLError("[TreatNullAs] is not allowed for "
+                                      "dictionary members", [self.location])
+                if value != 'EmptyString':
+                    raise WebIDLError("[TreatNullAs] must take the identifier "
+                                      "'EmptyString', not '%s'" % value,
+                                      [self.location])
+                self.treatNullAs = value
+            else:
+                unhandledAttrs.append(attr)
+
+        return unhandledAttrs
+
+class IDLObjectWithScope(IDLObjectWithIdentifier, IDLScope):
+    def __init__(self, location, parentScope, identifier):
+        assert isinstance(identifier, IDLUnresolvedIdentifier)
+
+        IDLObjectWithIdentifier.__init__(self, location, parentScope, identifier)
+        IDLScope.__init__(self, location, parentScope, self.identifier)
+
+class IDLIdentifierPlaceholder(IDLObjectWithIdentifier):
+    def __init__(self, location, identifier):
+        assert isinstance(identifier, IDLUnresolvedIdentifier)
+        IDLObjectWithIdentifier.__init__(self, location, None, identifier)
+
+    def finish(self, scope):
+        try:
+            scope._lookupIdentifier(self.identifier)
+        except:
+            raise WebIDLError("Unresolved type '%s'." % self.identifier,
+                              [self.location])
+
+        obj = self.identifier.resolve(scope, None)
+        return scope.lookupIdentifier(obj)
+
+class IDLExternalInterface(IDLObjectWithIdentifier):
+    def __init__(self, location, parentScope, identifier):
+        assert isinstance(identifier, IDLUnresolvedIdentifier)
+        assert isinstance(parentScope, IDLScope)
+        self.parent = None
+        IDLObjectWithIdentifier.__init__(self, location, parentScope, identifier)
+        IDLObjectWithIdentifier.resolve(self, parentScope)
+
+    def finish(self, scope):
+        pass
+
+    def validate(self):
+        pass
+
+    def isExternal(self):
+        return True
+
+    def isInterface(self):
+        return True
+
+    def isConsequential(self):
+        return False
+
+    def addExtendedAttributes(self, attrs):
+        assert len(attrs) == 0
+
+    def resolve(self, parentScope):
+        pass
+
+    def getJSImplementation(self):
+        return None
+
+    def isJSImplemented(self):
+        return False
+
+    def getNavigatorProperty(self):
+        return None
+
+    def _getDependentObjects(self):
+        return set()
+
+class IDLInterface(IDLObjectWithScope):
+    def __init__(self, location, parentScope, name, parent, members,
+                 isPartial):
+        assert isinstance(parentScope, IDLScope)
+        assert isinstance(name, IDLUnresolvedIdentifier)
+        assert not isPartial or not parent
+
+        self.parent = None
+        self._callback = False
+        self._finished = False
+        self.members = []
+        # namedConstructors needs deterministic ordering because bindings code
+        # outputs the constructs in the order that namedConstructors enumerates
+        # them.
+        self.namedConstructors = list()
+        self.implementedInterfaces = set()
+        self._consequential = False
+        self._isPartial = True
+        # self.interfacesBasedOnSelf is the set of interfaces that inherit from
+        # self or have self as a consequential interface, including self itself.
+        # Used for distinguishability checking.
+        self.interfacesBasedOnSelf = set([self])
+        # self.interfacesImplementingSelf is the set of interfaces that directly
+        # have self as a consequential interface
+        self.interfacesImplementingSelf = set()
+        self._hasChildInterfaces = False
+        self._isOnGlobalProtoChain = False
+        # Tracking of the number of reserved slots we need for our
+        # members and those of ancestor interfaces.
+        self.totalMembersInSlots = 0
+        # Tracking of the number of own own members we have in slots
+        self._ownMembersInSlots = 0
+
+        IDLObjectWithScope.__init__(self, location, parentScope, name)
+
+        if not isPartial:
+            self.setNonPartial(location, parent, members)
+        else:
+            # Just remember our members for now
+            self.members = members
+
+    def __str__(self):
+        return "Interface '%s'" % self.identifier.name
+
+    def ctor(self):
+        identifier = IDLUnresolvedIdentifier(self.location, "constructor",
+                                             allowForbidden=True)
+        try:
+            return self._lookupIdentifier(identifier)
+        except:
+            return None
+
+    def resolveIdentifierConflict(self, scope, identifier, originalObject, newObject):
+        assert isinstance(scope, IDLScope)
+        assert isinstance(originalObject, IDLInterfaceMember)
+        assert isinstance(newObject, IDLInterfaceMember)
+
+        retval = IDLScope.resolveIdentifierConflict(self, scope, identifier,
+                                                    originalObject, newObject)
+
+        # Might be a ctor, which isn't in self.members
+        if newObject in self.members:
+            self.members.remove(newObject)
+        return retval
+
+    def finish(self, scope):
+        if self._finished:
+            return
+
+        self._finished = True
+
+        if self._isPartial:
+            raise WebIDLError("Interface %s does not have a non-partial "
+                              "declaration" % self.identifier.name,
+                              [self.location])
+
+        assert not self.parent or isinstance(self.parent, IDLIdentifierPlaceholder)
+        parent = self.parent.finish(scope) if self.parent else None
+        if parent and isinstance(parent, IDLExternalInterface):
+            raise WebIDLError("%s inherits from %s which does not have "
+                              "a definition" %
+                              (self.identifier.name,
+                               self.parent.identifier.name),
+                              [self.location])
+        assert not parent or isinstance(parent, IDLInterface)
+
+        self.parent = parent
+
+        assert iter(self.members)
+
+        if self.parent:
+            self.parent.finish(scope)
+
+            self.parent._hasChildInterfaces = True
+
+            self.totalMembersInSlots = self.parent.totalMembersInSlots
+
+            # Interfaces with [Global] must not have anything inherit from them
+            if self.parent.getExtendedAttribute("Global"):
+                # Note: This is not a self.parent.isOnGlobalProtoChain() check
+                # because ancestors of a [Global] interface can have other
+                # descendants.
+                raise WebIDLError("[Global] interface has another interface "
+                                  "inheriting from it",
+                                  [self.location, self.parent.location])
+
+            # Callbacks must not inherit from non-callbacks or inherit from
+            # anything that has consequential interfaces.
+            # XXXbz Can non-callbacks inherit from callbacks?  Spec issue pending.
+            # XXXbz Can callbacks have consequential interfaces?  Spec issue pending
+            if self.isCallback():
+                if not self.parent.isCallback():
+                    raise WebIDLError("Callback interface %s inheriting from "
+                                      "non-callback interface %s" %
+                                      (self.identifier.name,
+                                       self.parent.identifier.name),
+                                      [self.location, self.parent.location])
+            elif self.parent.isCallback():
+                raise WebIDLError("Non-callback interface %s inheriting from "
+                                  "callback interface %s" %
+                                  (self.identifier.name,
+                                   self.parent.identifier.name),
+                                  [self.location, self.parent.location])
+
+        for iface in self.implementedInterfaces:
+            iface.finish(scope)
+
+        cycleInGraph = self.findInterfaceLoopPoint(self)
+        if cycleInGraph:
+            raise WebIDLError("Interface %s has itself as ancestor or "
+                              "implemented interface" % self.identifier.name,
+                              [self.location, cycleInGraph.location])
+
+        if self.isCallback():
+            # "implements" should have made sure we have no
+            # consequential interfaces.
+            assert len(self.getConsequentialInterfaces()) == 0
+            # And that we're not consequential.
+            assert not self.isConsequential()
+
+        # Now resolve() and finish() our members before importing the
+        # ones from our implemented interfaces.
+
+        # resolve() will modify self.members, so we need to iterate
+        # over a copy of the member list here.
+        for member in list(self.members):
+            member.resolve(self)
+
+        for member in self.members:
+            member.finish(scope)
+
+        ctor = self.ctor()
+        if ctor is not None:
+            ctor.finish(scope)
+
+        for ctor in self.namedConstructors:
+            ctor.finish(scope)
+
+        # Make a copy of our member list, so things that implement us
+        # can get those without all the stuff we implement ourselves
+        # admixed.
+        self.originalMembers = list(self.members)
+
+        # Import everything from our consequential interfaces into
+        # self.members.  Sort our consequential interfaces by name
+        # just so we have a consistent order.
+        for iface in sorted(self.getConsequentialInterfaces(),
+                            cmp=cmp,
+                            key=lambda x: x.identifier.name):
+            # Flag the interface as being someone's consequential interface
+            iface.setIsConsequentialInterfaceOf(self)
+            additionalMembers = iface.originalMembers;
+            for additionalMember in additionalMembers:
+                for member in self.members:
+                    if additionalMember.identifier.name == member.identifier.name:
+                        raise WebIDLError(
+                            "Multiple definitions of %s on %s coming from 'implements' statements" %
+                            (member.identifier.name, self),
+                            [additionalMember.location, member.location])
+            self.members.extend(additionalMembers)
+            iface.interfacesImplementingSelf.add(self)
+
+        for ancestor in self.getInheritedInterfaces():
+            ancestor.interfacesBasedOnSelf.add(self)
+            for ancestorConsequential in ancestor.getConsequentialInterfaces():
+                ancestorConsequential.interfacesBasedOnSelf.add(self)
+
+        for member in self.members:
+            if (member.isAttr() and member.isUnforgeable() and
+                not hasattr(member, "originatingInterface")):
+                member.originatingInterface = self
+
+        # Compute slot indices for our members before we pull in
+        # unforgeable members from our parent.
+        for member in self.members:
+            if (member.isAttr() and
+                (member.getExtendedAttribute("StoreInSlot") or
+                 member.getExtendedAttribute("Cached"))):
+                member.slotIndex = self.totalMembersInSlots
+                self.totalMembersInSlots += 1
+                if member.getExtendedAttribute("StoreInSlot"):
+                    self._ownMembersInSlots += 1
+
+        if self.parent:
+            # Make sure we don't shadow any of the [Unforgeable] attributes on
+            # our ancestor interfaces.  We don't have to worry about
+            # consequential interfaces here, because those have already been
+            # imported into the relevant .members lists.  And we don't have to
+            # worry about anything other than our parent, because it has already
+            # imported its ancestors unforgeable attributes into its member
+            # list.
+            for unforgeableAttr in (attr for attr in self.parent.members if
+                                    attr.isAttr() and not attr.isStatic() and
+                                    attr.isUnforgeable()):
+                shadows = [ m for m in self.members if
+                            (m.isAttr() or m.isMethod()) and
+                            not m.isStatic() and
+                            m.identifier.name == unforgeableAttr.identifier.name ]
+                if len(shadows) != 0:
+                    locs = [unforgeableAttr.location] + [ s.location for s
+                                                          in shadows ]
+                    raise WebIDLError("Interface %s shadows [Unforgeable] "
+                                      "members of %s" %
+                                      (self.identifier.name,
+                                       ancestor.identifier.name),
+                                      locs)
+                # And now just stick it in our members, since we won't be
+                # inheriting this down the proto chain.  If we really cared we
+                # could try to do something where we set up the unforgeable
+                # attributes of ancestor interfaces, with their corresponding
+                # getters, on our interface, but that gets pretty complicated
+                # and seems unnecessary.
+                self.members.append(unforgeableAttr)
+
+        # Ensure that there's at most one of each {named,indexed}
+        # {getter,setter,creator,deleter}, at most one stringifier,
+        # and at most one legacycaller.  Note that this last is not
+        # quite per spec, but in practice no one overloads
+        # legacycallers.
+        specialMembersSeen = {}
+        for member in self.members:
+            if not member.isMethod():
+                continue
+
+            if member.isGetter():
+                memberType = "getters"
+            elif member.isSetter():
+                memberType = "setters"
+            elif member.isCreator():
+                memberType = "creators"
+            elif member.isDeleter():
+                memberType = "deleters"
+            elif member.isStringifier():
+                memberType = "stringifiers"
+            elif member.isJsonifier():
+                memberType = "jsonifiers"
+            elif member.isLegacycaller():
+                memberType = "legacycallers"
+            else:
+                continue
+
+            if (memberType != "stringifiers" and memberType != "legacycallers" and
+                memberType != "jsonifiers"):
+                if member.isNamed():
+                    memberType = "named " + memberType
+                else:
+                    assert member.isIndexed()
+                    memberType = "indexed " + memberType
+
+            if memberType in specialMembersSeen:
+                raise WebIDLError("Multiple " + memberType + " on %s" % (self),
+                                   [self.location,
+                                    specialMembersSeen[memberType].location,
+                                    member.location])
+
+            specialMembersSeen[memberType] = member
+
+        if self._isOnGlobalProtoChain:
+            # Make sure we have no named setters, creators, or deleters
+            for memberType in ["setter", "creator", "deleter"]:
+                memberId = "named " + memberType + "s"
+                if memberId in specialMembersSeen:
+                    raise WebIDLError("Interface with [Global] has a named %s" %
+                                      memberType,
+                                      [self.location,
+                                       specialMembersSeen[memberId].location])
+            # Make sure we're not [OverrideBuiltins]
+            if self.getExtendedAttribute("OverrideBuiltins"):
+                raise WebIDLError("Interface with [Global] also has "
+                                  "[OverrideBuiltins]",
+                                  [self.location])
+            # Mark all of our ancestors as being on the global's proto chain too
+            parent = self.parent
+            while parent:
+                # Must not inherit from an interface with [OverrideBuiltins]
+                if parent.getExtendedAttribute("OverrideBuiltins"):
+                    raise WebIDLError("Interface with [Global] inherits from "
+                                      "interface with [OverrideBuiltins]",
+                                      [self.location, parent.location])
+                parent._isOnGlobalProtoChain = True
+                parent = parent.parent
+
+    def validate(self):
+        for member in self.members:
+            member.validate()
+
+            # Check that PutForwards refers to another attribute and that no
+            # cycles exist in forwarded assignments.
+            if member.isAttr():
+                iface = self
+                attr = member
+                putForwards = attr.getExtendedAttribute("PutForwards")
+                if putForwards and self.isCallback():
+                    raise WebIDLError("[PutForwards] used on an attribute "
+                                      "on interface %s which is a callback "
+                                      "interface" % self.identifier.name,
+                                      [self.location, member.location])
+
+                while putForwards is not None:
+                    forwardIface = attr.type.unroll().inner
+                    fowardAttr = None
+
+                    for forwardedMember in forwardIface.members:
+                        if (not forwardedMember.isAttr() or
+                            forwardedMember.identifier.name != putForwards[0]):
+                            continue
+                        if forwardedMember == member:
+                            raise WebIDLError("Cycle detected in forwarded "
+                                              "assignments for attribute %s on "
+                                              "%s" %
+                                              (member.identifier.name, self),
+                                              [member.location])
+                        fowardAttr = forwardedMember
+                        break
+
+                    if fowardAttr is None:
+                        raise WebIDLError("Attribute %s on %s forwards to "
+                                          "missing attribute %s" %
+                              (attr.identifier.name, iface, putForwards),
+                              [attr.location])
+
+                    iface = forwardIface
+                    attr = fowardAttr
+                    putForwards = attr.getExtendedAttribute("PutForwards")
+
+
+    def isInterface(self):
+        return True
+
+    def isExternal(self):
+        return False
+
+    def setIsConsequentialInterfaceOf(self, other):
+        self._consequential = True
+        self.interfacesBasedOnSelf.add(other)
+
+    def isConsequential(self):
+        return self._consequential
+
+    def setCallback(self, value):
+        self._callback = value
+
+    def isCallback(self):
+        return self._callback
+
+    def isSingleOperationInterface(self):
+        assert self.isCallback() or self.isJSImplemented()
+        return (
+            # JS-implemented things should never need the
+            # this-handling weirdness of single-operation interfaces.
+            not self.isJSImplemented() and
+            # Not inheriting from another interface
+            not self.parent and
+            # No consequential interfaces
+            len(self.getConsequentialInterfaces()) == 0 and
+            # No attributes of any kinds
+            not any(m.isAttr() for m in self.members) and
+            # There is at least one regular operation, and all regular
+            # operations have the same identifier
+            len(set(m.identifier.name for m in self.members if
+                    m.isMethod() and not m.isStatic())) == 1)
+
+    def inheritanceDepth(self):
+        depth = 0
+        parent = self.parent
+        while parent:
+            depth = depth + 1
+            parent = parent.parent
+        return depth
+
+    def hasConstants(self):
+        return any(m.isConst() for m in self.members)
+
+    def hasInterfaceObject(self):
+        if self.isCallback():
+            return self.hasConstants()
+        return not hasattr(self, "_noInterfaceObject")
+
+    def hasInterfacePrototypeObject(self):
+        return not self.isCallback() and self.getUserData('hasConcreteDescendant', False)
+
+    def addExtendedAttributes(self, attrs):
+        self._extendedAttrDict = {}
+        for attr in attrs:
+            identifier = attr.identifier()
+
+            # Special cased attrs
+            if identifier == "TreatNonCallableAsNull":
+                raise WebIDLError("TreatNonCallableAsNull cannot be specified on interfaces",
+                                  [attr.location, self.location])
+            if identifier == "TreatNonObjectAsNull":
+                raise WebIDLError("TreatNonObjectAsNull cannot be specified on interfaces",
+                                  [attr.location, self.location])
+            elif identifier == "NoInterfaceObject":
+                if not attr.noArguments():
+                    raise WebIDLError("[NoInterfaceObject] must take no arguments",
+                                      [attr.location])
+
+                if self.ctor():
+                    raise WebIDLError("Constructor and NoInterfaceObject are incompatible",
+                                      [self.location])
+
+                self._noInterfaceObject = True
+            elif identifier == "Constructor" or identifier == "NamedConstructor" or identifier == "ChromeConstructor":
+                if identifier == "Constructor" and not self.hasInterfaceObject():
+                    raise WebIDLError(str(identifier) + " and NoInterfaceObject are incompatible",
+                                      [self.location])
+
+                if identifier == "NamedConstructor" and not attr.hasValue():
+                    raise WebIDLError("NamedConstructor must either take an identifier or take a named argument list",
+                                      [attr.location])
+
+                if identifier == "ChromeConstructor" and not self.hasInterfaceObject():
+                    raise WebIDLError(str(identifier) + " and NoInterfaceObject are incompatible",
+                                      [self.location])
+
+                args = attr.args() if attr.hasArgs() else []
+
+                retType = IDLWrapperType(self.location, self)
+                
+                if identifier == "Constructor" or identifier == "ChromeConstructor":
+                    name = "constructor"
+                    allowForbidden = True
+                else:
+                    name = attr.value()
+                    allowForbidden = False
+
+                methodIdentifier = IDLUnresolvedIdentifier(self.location, name,
+                                                           allowForbidden=allowForbidden)
+
+                method = IDLMethod(self.location, methodIdentifier, retType,
+                                   args, static=True)
+                # Constructors are always NewObject and are always
+                # assumed to be able to throw (since there's no way to
+                # indicate otherwise) and never have any other
+                # extended attributes.
+                method.addExtendedAttributes(
+                    [IDLExtendedAttribute(self.location, ("NewObject",)),
+                     IDLExtendedAttribute(self.location, ("Throws",))])
+                if identifier == "ChromeConstructor":
+                    method.addExtendedAttributes(
+                        [IDLExtendedAttribute(self.location, ("ChromeOnly",))])
+
+                if identifier == "Constructor" or identifier == "ChromeConstructor":
+                    method.resolve(self)
+                else:
+                    # We need to detect conflicts for NamedCon