Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 4205 insertions, 0 deletions

diff --git a/xpcom/idl-parser/xpidl/__init__.py b/xpcom/idl-parser/xpidl/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/__init__.py
diff --git a/xpcom/idl-parser/xpidl/header.py b/xpcom/idl-parser/xpidl/header.py
new file mode 100644
index 0000000000..ed179b1bad
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/header.py
@@ -0,0 +1,723 @@
+#!/usr/bin/env python
+# header.py - Generate C++ header files from IDL.
+#
+# 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/.
+
+"""Print a C++ header file for the IDL files specified on the command line"""
+
+import itertools
+import os.path
+import re
+
+from xpidl import xpidl
+
+printdoccomments = False
+
+if printdoccomments:
+
+    def printComments(fd, clist, indent):
+        for c in clist:
+            fd.write("%s%s\n" % (indent, c))
+
+else:
+
+    def printComments(fd, clist, indent):
+        pass
+
+
+def firstCap(str):
+    return str[0].upper() + str[1:]
+
+
+def attributeParamName(a):
+    return "a" + firstCap(a.name)
+
+
+def attributeParamNames(a, getter, return_param=True):
+    if getter and (a.notxpcom or not return_param):
+        l = []
+    else:
+        l = [attributeParamName(a)]
+    if a.implicit_jscontext:
+        l.insert(0, "cx")
+    return ", ".join(l)
+
+
+def attributeNativeName(a, getter):
+    binaryname = a.binaryname is not None and a.binaryname or firstCap(a.name)
+    return "%s%s" % (getter and "Get" or "Set", binaryname)
+
+
+def attributeAttributes(a, getter):
+    ret = ""
+
+    if a.must_use:
+        ret = "[[nodiscard]] " + ret
+
+    # Ideally, we'd set MOZ_CAN_RUN_SCRIPT in the "scriptable and not
+    # builtinclass" case too, so we'd just have memberCanRunScript() check
+    # explicit_setter_can_run_script/explicit_setter_can_run_script and call it
+    # here.  But that would likely require a fair amount of Gecko-side
+    # annotation work.  See bug 1534292.
+    if (a.explicit_getter_can_run_script and getter) or (
+        a.explicit_setter_can_run_script and not getter
+    ):
+        ret = "MOZ_CAN_RUN_SCRIPT " + ret
+
+    return ret
+
+
+def attributeReturnType(a, getter, macro):
+    """macro should be NS_IMETHOD or NS_IMETHODIMP"""
+    # Pick the type to be returned from the getter/setter.
+    if a.notxpcom:
+        ret = a.realtype.nativeType("in").strip() if getter else "void"
+    else:
+        ret = "nsresult"
+
+    # Set calling convention and virtual-ness
+    if a.nostdcall:
+        if macro == "NS_IMETHOD":
+            # This is the declaration.
+            ret = "virtual %s" % ret
+    else:
+        if ret == "nsresult":
+            ret = macro
+        else:
+            ret = "%s_(%s)" % (macro, ret)
+
+    return attributeAttributes(a, getter) + ret
+
+
+def attributeParamlist(a, getter, return_param=True):
+    if getter and (a.notxpcom or not return_param):
+        l = []
+    else:
+        l = [
+            "%s%s"
+            % (a.realtype.nativeType(getter and "out" or "in"), attributeParamName(a))
+        ]
+    if a.implicit_jscontext:
+        l.insert(0, "JSContext* cx")
+
+    return ", ".join(l)
+
+
+def attributeAsNative(a, getter, declType="NS_IMETHOD"):
+    params = {
+        "returntype": attributeReturnType(a, getter, declType),
+        "binaryname": attributeNativeName(a, getter),
+        "paramlist": attributeParamlist(a, getter),
+    }
+    return "%(returntype)s %(binaryname)s(%(paramlist)s)" % params
+
+
+def methodNativeName(m):
+    return m.binaryname is not None and m.binaryname or firstCap(m.name)
+
+
+def methodAttributes(m):
+    ret = ""
+
+    if m.must_use:
+        ret = "[[nodiscard]] " + ret
+
+    # Ideally, we'd set MOZ_CAN_RUN_SCRIPT in the "scriptable and not
+    # builtinclass" case too, so we'd just have memberCanRunScript() check
+    # explicit_can_run_script and call it here.  But that would likely require
+    # a fair amount of Gecko-side annotation work.  See bug 1534292.
+    if m.explicit_can_run_script:
+        ret = "MOZ_CAN_RUN_SCRIPT " + ret
+
+    return ret
+
+
+def methodReturnType(m, macro):
+    """macro should be NS_IMETHOD or NS_IMETHODIMP"""
+    if m.notxpcom:
+        ret = m.realtype.nativeType("in").strip()
+    else:
+        ret = "nsresult"
+
+    # Set calling convention and virtual-ness
+    if m.nostdcall:
+        if macro == "NS_IMETHOD":
+            # This is the declaration
+            ret = "virtual %s" % ret
+    else:
+        if ret == "nsresult":
+            ret = macro
+        else:
+            ret = "%s_(%s)" % (macro, ret)
+
+    return methodAttributes(m) + ret
+
+
+def methodAsNative(m, declType="NS_IMETHOD"):
+    return "%s %s(%s)" % (
+        methodReturnType(m, declType),
+        methodNativeName(m),
+        paramlistAsNative(m),
+    )
+
+
+def paramlistAsNative(m, empty="void", return_param=True):
+    l = [paramAsNative(p) for p in m.params]
+
+    if m.implicit_jscontext:
+        l.append("JSContext* cx")
+
+    if m.optional_argc:
+        l.append("uint8_t _argc")
+
+    if not m.notxpcom and m.realtype.name != "void" and return_param:
+        l.append(
+            paramAsNative(
+                xpidl.Param(
+                    paramtype="out",
+                    type=None,
+                    name="_retval",
+                    attlist=[],
+                    location=None,
+                    realtype=m.realtype,
+                )
+            )
+        )
+
+    # Set any optional out params to default to nullptr. Skip if we just added
+    # extra non-optional args to l.
+    if len(l) == len(m.params):
+        paramIter = len(m.params) - 1
+        while (
+            paramIter >= 0
+            and m.params[paramIter].optional
+            and "out" in m.params[paramIter].paramtype
+        ):
+            t = m.params[paramIter].type
+            # Strings can't be optional, so this shouldn't happen, but let's make sure:
+            if t == "AString" or t == "ACString" or t == "AUTF8String":
+                break
+            l[paramIter] += " = nullptr"
+            paramIter -= 1
+
+    if len(l) == 0:
+        return empty
+
+    return ", ".join(l)
+
+
+def memberCanRunScript(member):
+    # This can only happen if the member is scriptable and its interface is not builtinclass.
+    return member.isScriptable() and not member.iface.attributes.builtinclass
+
+
+def runScriptAnnotation(member):
+    return "JS_HAZ_CAN_RUN_SCRIPT " if memberCanRunScript(member) else ""
+
+
+def paramAsNative(p):
+    default_spec = ""
+    if p.default_value:
+        default_spec = " = " + p.default_value
+    return "%s%s%s" % (p.nativeType(), p.name, default_spec)
+
+
+def paramlistNames(m, return_param=True):
+    names = [p.name for p in m.params]
+
+    if m.implicit_jscontext:
+        names.append("cx")
+
+    if m.optional_argc:
+        names.append("_argc")
+
+    if not m.notxpcom and m.realtype.name != "void" and return_param:
+        names.append("_retval")
+
+    if len(names) == 0:
+        return ""
+    return ", ".join(names)
+
+
+header = """/*
+ * DO NOT EDIT.  THIS FILE IS GENERATED FROM $SRCDIR/%(relpath)s
+ */
+
+#ifndef __gen_%(basename)s_h__
+#define __gen_%(basename)s_h__
+"""
+
+include = """
+#include "%(basename)s.h"
+"""
+
+jsvalue_include = """
+#include "js/Value.h"
+"""
+
+infallible_includes = """
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/DebugOnly.h"
+"""
+
+can_run_script_includes = """
+#include "js/GCAnnotations.h"
+"""
+
+header_end = """/* For IDL files that don't want to include root IDL files. */
+#ifndef NS_NO_VTABLE
+#define NS_NO_VTABLE
+#endif
+"""
+
+footer = """
+#endif /* __gen_%(basename)s_h__ */
+"""
+
+forward_decl = """class %(name)s; /* forward declaration */
+
+"""
+
+
+def idl_basename(f):
+    """returns the base name of a file with the last extension stripped"""
+    return os.path.basename(f).rpartition(".")[0]
+
+
+def print_header(idl, fd, filename, relpath):
+    fd.write(header % {"relpath": relpath, "basename": idl_basename(filename)})
+
+    foundinc = False
+    for inc in idl.includes():
+        if not foundinc:
+            foundinc = True
+            fd.write("\n")
+        fd.write(include % {"basename": idl_basename(inc.filename)})
+
+    if idl.needsJSTypes():
+        fd.write(jsvalue_include)
+
+    # Include some extra files if any attributes are infallible.
+    interfaces = [p for p in idl.productions if p.kind == "interface"]
+    wroteRunScriptIncludes = False
+    wroteInfallibleIncludes = False
+    for iface in interfaces:
+        for member in iface.members:
+            if not isinstance(member, xpidl.Attribute) and not isinstance(
+                member, xpidl.Method
+            ):
+                continue
+            if not wroteInfallibleIncludes and member.infallible:
+                fd.write(infallible_includes)
+                wroteInfallibleIncludes = True
+            if not wroteRunScriptIncludes and memberCanRunScript(member):
+                fd.write(can_run_script_includes)
+                wroteRunScriptIncludes = True
+        if wroteRunScriptIncludes and wroteInfallibleIncludes:
+            break
+
+    fd.write("\n")
+    fd.write(header_end)
+
+    for p in idl.productions:
+        if p.kind == "include":
+            continue
+        if p.kind == "cdata":
+            fd.write(p.data)
+            continue
+
+        if p.kind == "webidl":
+            write_webidl(p, fd)
+            continue
+        if p.kind == "forward":
+            fd.write(forward_decl % {"name": p.name})
+            continue
+        if p.kind == "interface":
+            write_interface(p, fd)
+            continue
+        if p.kind == "typedef":
+            printComments(fd, p.doccomments, "")
+            fd.write("typedef %s %s;\n\n" % (p.realtype.nativeType("in"), p.name))
+
+    fd.write(footer % {"basename": idl_basename(filename)})
+
+
+def write_webidl(p, fd):
+    path = p.native.split("::")
+    for seg in path[:-1]:
+        fd.write("namespace %s {\n" % seg)
+    fd.write("class %s; /* webidl %s */\n" % (path[-1], p.name))
+    for seg in reversed(path[:-1]):
+        fd.write("} // namespace %s\n" % seg)
+    fd.write("\n")
+
+
+iface_header = r"""
+/* starting interface:    %(name)s */
+#define %(defname)s_IID_STR "%(iid)s"
+
+#define %(defname)s_IID \
+  {0x%(m0)s, 0x%(m1)s, 0x%(m2)s, \
+    { %(m3joined)s }}
+
+"""
+
+uuid_decoder = re.compile(
+    r"""(?P<m0>[a-f0-9]{8})-
+                              (?P<m1>[a-f0-9]{4})-
+                              (?P<m2>[a-f0-9]{4})-
+                              (?P<m3>[a-f0-9]{4})-
+                              (?P<m4>[a-f0-9]{12})$""",
+    re.X,
+)
+
+iface_prolog = """ {
+ public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(%(defname)s_IID)
+
+"""
+
+iface_scriptable = """\
+  /* Used by ToJSValue to check which scriptable interface is implemented. */
+  using ScriptableInterfaceType = %(name)s;
+
+"""
+
+iface_epilog = """};
+
+  NS_DEFINE_STATIC_IID_ACCESSOR(%(name)s, %(defname)s_IID)"""
+
+iface_decl = """
+
+/* Use this macro when declaring classes that implement this interface. */
+#define NS_DECL_%(macroname)s """
+
+iface_nonvirtual = """
+
+/* Use this macro when declaring the members of this interface when the
+   class doesn't implement the interface. This is useful for forwarding. */
+#define NS_DECL_NON_VIRTUAL_%(macroname)s """
+
+iface_forward = """
+
+/* Use this macro to declare functions that forward the behavior of this interface to another object. */
+#define NS_FORWARD_%(macroname)s(_to) """  # NOQA: E501
+
+iface_forward_safe = """
+
+/* Use this macro to declare functions that forward the behavior of this interface to another object in a safe way. */
+#define NS_FORWARD_SAFE_%(macroname)s(_to) """  # NOQA: E501
+
+builtin_infallible_tmpl = """\
+  %(attributes)sinline %(realtype)s %(nativename)s(%(args)s)
+  {
+    %(realtype)sresult;
+    mozilla::DebugOnly<nsresult> rv = %(nativename)s(%(argnames)s&result);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return result;
+  }
+"""
+
+# NOTE: We don't use RefPtr::forget here because we don't want to need the
+# definition of %(realtype)s in scope, which we would need for the
+# AddRef/Release calls.
+refcnt_infallible_tmpl = """\
+  %(attributes)s inline already_AddRefed<%(realtype)s> %(nativename)s(%(args)s)
+  {
+    %(realtype)s* result = nullptr;
+    mozilla::DebugOnly<nsresult> rv = %(nativename)s(%(argnames)s&result);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    return already_AddRefed<%(realtype)s>(result);
+  }
+"""
+
+iface_threadsafe_tmpl = """\
+namespace mozilla::detail {
+template <>
+class InterfaceNeedsThreadSafeRefCnt<%(name)s> : public std::true_type {};
+}
+"""
+
+
+def infallibleDecl(member):
+    isattr = isinstance(member, xpidl.Attribute)
+    ismethod = isinstance(member, xpidl.Method)
+    assert isattr or ismethod
+
+    realtype = member.realtype.nativeType("in")
+    tmpl = builtin_infallible_tmpl
+
+    if member.realtype.kind != "builtin" and member.realtype.kind != "cenum":
+        assert realtype.endswith(" *"), "bad infallible type"
+        tmpl = refcnt_infallible_tmpl
+        realtype = realtype[:-2]  # strip trailing pointer
+
+    if isattr:
+        nativename = attributeNativeName(member, getter=True)
+        args = attributeParamlist(member, getter=True, return_param=False)
+        argnames = attributeParamNames(member, getter=True, return_param=False)
+        attributes = attributeAttributes(member, getter=True)
+    else:
+        nativename = methodNativeName(member)
+        args = paramlistAsNative(member, return_param=False)
+        argnames = paramlistNames(member, return_param=False)
+        attributes = methodAttributes(member)
+
+    return tmpl % {
+        "attributes": attributes,
+        "realtype": realtype,
+        "nativename": nativename,
+        "args": args,
+        "argnames": argnames + ", " if argnames else "",
+    }
+
+
+def write_interface(iface, fd):
+    if iface.namemap is None:
+        raise Exception("Interface was not resolved.")
+
+    # Confirm that no names of methods will overload in this interface
+    names = set()
+
+    def record_name(name):
+        if name in names:
+            raise Exception(
+                "Unexpected overloaded virtual method %s in interface %s"
+                % (name, iface.name)
+            )
+        names.add(name)
+
+    for m in iface.members:
+        if type(m) == xpidl.Attribute:
+            record_name(attributeNativeName(m, getter=True))
+            if not m.readonly:
+                record_name(attributeNativeName(m, getter=False))
+        elif type(m) == xpidl.Method:
+            record_name(methodNativeName(m))
+
+    def write_const_decls(g):
+        fd.write("  enum {\n")
+        enums = []
+        for c in g:
+            printComments(fd, c.doccomments, "  ")
+            basetype = c.basetype
+            value = c.getValue()
+            enums.append(
+                "    %(name)s = %(value)s%(signed)s"
+                % {
+                    "name": c.name,
+                    "value": value,
+                    "signed": (not basetype.signed) and "U" or "",
+                }
+            )
+        fd.write(",\n".join(enums))
+        fd.write("\n  };\n\n")
+
+    def write_cenum_decl(b):
+        fd.write("  enum %s : uint%d_t {\n" % (b.basename, b.width))
+        for var in b.variants:
+            fd.write("    %s = %s,\n" % (var.name, var.value))
+        fd.write("  };\n\n")
+
+    def write_method_decl(m):
+        printComments(fd, m.doccomments, "  ")
+
+        fd.write("  /* %s */\n" % m.toIDL())
+        fd.write("  %s%s = 0;\n\n" % (runScriptAnnotation(m), methodAsNative(m)))
+
+        if m.infallible:
+            fd.write(infallibleDecl(m))
+
+    def write_attr_decl(a):
+        printComments(fd, a.doccomments, "  ")
+
+        fd.write("  /* %s */\n" % a.toIDL())
+
+        fd.write("  %s%s = 0;\n" % (runScriptAnnotation(a), attributeAsNative(a, True)))
+        if a.infallible:
+            fd.write(infallibleDecl(a))
+
+        if not a.readonly:
+            fd.write(
+                "  %s%s = 0;\n" % (runScriptAnnotation(a), attributeAsNative(a, False))
+            )
+        fd.write("\n")
+
+    defname = iface.name.upper()
+    if iface.name[0:2] == "ns":
+        defname = "NS_" + defname[2:]
+
+    names = uuid_decoder.match(iface.attributes.uuid).groupdict()
+    m3str = names["m3"] + names["m4"]
+    names["m3joined"] = ", ".join(["0x%s" % m3str[i : i + 2] for i in range(0, 16, 2)])
+
+    if iface.name[2] == "I":
+        implclass = iface.name[:2] + iface.name[3:]
+    else:
+        implclass = "_MYCLASS_"
+
+    names.update(
+        {
+            "defname": defname,
+            "macroname": iface.name.upper(),
+            "name": iface.name,
+            "iid": iface.attributes.uuid,
+            "implclass": implclass,
+        }
+    )
+
+    fd.write(iface_header % names)
+
+    printComments(fd, iface.doccomments, "")
+
+    fd.write("class ")
+    foundcdata = False
+    for m in iface.members:
+        if isinstance(m, xpidl.CDATA):
+            foundcdata = True
+
+    if not foundcdata:
+        fd.write("NS_NO_VTABLE ")
+
+    fd.write(iface.name)
+    if iface.base:
+        fd.write(" : public %s" % iface.base)
+    fd.write(iface_prolog % names)
+
+    if iface.attributes.scriptable:
+        fd.write(iface_scriptable % names)
+
+    for key, group in itertools.groupby(iface.members, key=type):
+        if key == xpidl.ConstMember:
+            write_const_decls(group)  # iterator of all the consts
+        else:
+            for member in group:
+                if key == xpidl.Attribute:
+                    write_attr_decl(member)
+                elif key == xpidl.Method:
+                    write_method_decl(member)
+                elif key == xpidl.CDATA:
+                    fd.write(" %s" % member.data)
+                elif key == xpidl.CEnum:
+                    write_cenum_decl(member)
+                else:
+                    raise Exception("Unexpected interface member: %s" % member)
+
+    fd.write(iface_epilog % names)
+
+    if iface.attributes.rust_sync:
+        fd.write(iface_threadsafe_tmpl % names)
+
+    fd.write(iface_decl % names)
+
+    def writeDeclaration(fd, iface, virtual):
+        declType = "NS_IMETHOD" if virtual else "nsresult"
+        suffix = " override" if virtual else ""
+        for member in iface.members:
+            if isinstance(member, xpidl.Attribute):
+                if member.infallible:
+                    fd.write(
+                        "\\\n  using %s::%s; "
+                        % (iface.name, attributeNativeName(member, True))
+                    )
+                fd.write(
+                    "\\\n  %s%s; " % (attributeAsNative(member, True, declType), suffix)
+                )
+                if not member.readonly:
+                    fd.write(
+                        "\\\n  %s%s; "
+                        % (attributeAsNative(member, False, declType), suffix)
+                    )
+            elif isinstance(member, xpidl.Method):
+                fd.write("\\\n  %s%s; " % (methodAsNative(member, declType), suffix))
+        if len(iface.members) == 0:
+            fd.write("\\\n  /* no methods! */")
+        elif member.kind not in ("attribute", "method"):
+            fd.write("\\")
+
+    writeDeclaration(fd, iface, True)
+    fd.write(iface_nonvirtual % names)
+    writeDeclaration(fd, iface, False)
+    fd.write(iface_forward % names)
+
+    def emitTemplate(forward_infallible, tmpl, tmpl_notxpcom=None):
+        if tmpl_notxpcom is None:
+            tmpl_notxpcom = tmpl
+        for member in iface.members:
+            if isinstance(member, xpidl.Attribute):
+                if forward_infallible and member.infallible:
+                    fd.write(
+                        "\\\n  using %s::%s; "
+                        % (iface.name, attributeNativeName(member, True))
+                    )
+                attr_tmpl = tmpl_notxpcom if member.notxpcom else tmpl
+                fd.write(
+                    attr_tmpl
+                    % {
+                        "asNative": attributeAsNative(member, True),
+                        "nativeName": attributeNativeName(member, True),
+                        "paramList": attributeParamNames(member, True),
+                    }
+                )
+                if not member.readonly:
+                    fd.write(
+                        attr_tmpl
+                        % {
+                            "asNative": attributeAsNative(member, False),
+                            "nativeName": attributeNativeName(member, False),
+                            "paramList": attributeParamNames(member, False),
+                        }
+                    )
+            elif isinstance(member, xpidl.Method):
+                if member.notxpcom:
+                    fd.write(
+                        tmpl_notxpcom
+                        % {
+                            "asNative": methodAsNative(member),
+                            "nativeName": methodNativeName(member),
+                            "paramList": paramlistNames(member),
+                        }
+                    )
+                else:
+                    fd.write(
+                        tmpl
+                        % {
+                            "asNative": methodAsNative(member),
+                            "nativeName": methodNativeName(member),
+                            "paramList": paramlistNames(member),
+                        }
+                    )
+        if len(iface.members) == 0:
+            fd.write("\\\n  /* no methods! */")
+        elif member.kind not in ("attribute", "method"):
+            fd.write("\\")
+
+    emitTemplate(
+        True,
+        "\\\n  %(asNative)s override { return _to %(nativeName)s(%(paramList)s); } ",
+    )
+
+    fd.write(iface_forward_safe % names)
+
+    # Don't try to safely forward notxpcom functions, because we have no
+    # sensible default error return.  Instead, the caller will have to
+    # implement them.
+    emitTemplate(
+        False,
+        "\\\n  %(asNative)s override { return !_to ? NS_ERROR_NULL_POINTER : _to->%(nativeName)s(%(paramList)s); } ",  # NOQA: E501
+        "\\\n  %(asNative)s override; ",
+    )
+
+    fd.write("\n\n")
+
+
+def main(outputfile):
+    xpidl.IDLParser()
+
+
+if __name__ == "__main__":
+    main(None)
diff --git a/xpcom/idl-parser/xpidl/jsonxpt.py b/xpcom/idl-parser/xpidl/jsonxpt.py
new file mode 100644
index 0000000000..342188f645
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/jsonxpt.py
@@ -0,0 +1,282 @@
+#!/usr/bin/env python
+# jsonxpt.py - Generate json XPT typelib files from IDL.
+#
+# 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/.
+
+"""Generate a json XPT typelib for an IDL file"""
+
+import itertools
+import json
+
+from xpidl import xpidl
+
+# A map of xpidl.py types to xpt enum variants
+TypeMap = {
+    # builtins
+    "boolean": "TD_BOOL",
+    "void": "TD_VOID",
+    "int16_t": "TD_INT16",
+    "int32_t": "TD_INT32",
+    "int64_t": "TD_INT64",
+    "uint8_t": "TD_UINT8",
+    "uint16_t": "TD_UINT16",
+    "uint32_t": "TD_UINT32",
+    "uint64_t": "TD_UINT64",
+    "octet": "TD_UINT8",
+    "short": "TD_INT16",
+    "long": "TD_INT32",
+    "long long": "TD_INT64",
+    "unsigned short": "TD_UINT16",
+    "unsigned long": "TD_UINT32",
+    "unsigned long long": "TD_UINT64",
+    "float": "TD_FLOAT",
+    "double": "TD_DOUBLE",
+    "char": "TD_CHAR",
+    "string": "TD_PSTRING",
+    "wchar": "TD_WCHAR",
+    "wstring": "TD_PWSTRING",
+    # special types
+    "nsid": "TD_NSID",
+    "astring": "TD_ASTRING",
+    "utf8string": "TD_UTF8STRING",
+    "cstring": "TD_CSTRING",
+    "jsval": "TD_JSVAL",
+    "promise": "TD_PROMISE",
+}
+
+
+def flags(*flags):
+    return [flag for flag, cond in flags if cond]
+
+
+def get_type(type, calltype, iid_is=None, size_is=None):
+    while isinstance(type, xpidl.Typedef):
+        type = type.realtype
+
+    if isinstance(type, xpidl.Builtin):
+        ret = {"tag": TypeMap[type.name]}
+        if type.name in ["string", "wstring"] and size_is is not None:
+            ret["tag"] += "_SIZE_IS"
+            ret["size_is"] = size_is
+        return ret
+
+    if isinstance(type, xpidl.Array):
+        # NB: For a Array<T> we pass down the iid_is to get the type of T.
+        #     This allows Arrays of InterfaceIs types to work.
+        return {
+            "tag": "TD_ARRAY",
+            "element": get_type(type.type, calltype, iid_is),
+        }
+
+    if isinstance(type, xpidl.LegacyArray):
+        # NB: For a Legacy [array] T we pass down iid_is to get the type of T.
+        #     This allows [array] of InterfaceIs types to work.
+        return {
+            "tag": "TD_LEGACY_ARRAY",
+            "size_is": size_is,
+            "element": get_type(type.type, calltype, iid_is),
+        }
+
+    if isinstance(type, xpidl.Interface) or isinstance(type, xpidl.Forward):
+        return {
+            "tag": "TD_INTERFACE_TYPE",
+            "name": type.name,
+        }
+
+    if isinstance(type, xpidl.WebIDL):
+        return {
+            "tag": "TD_DOMOBJECT",
+            "name": type.name,
+            "native": type.native,
+            "headerFile": type.headerFile,
+        }
+
+    if isinstance(type, xpidl.Native):
+        if type.specialtype == "nsid" and type.isPtr(calltype):
+            return {"tag": "TD_NSIDPTR"}
+        elif type.specialtype:
+            return {"tag": TypeMap[type.specialtype]}
+        elif iid_is is not None:
+            return {
+                "tag": "TD_INTERFACE_IS_TYPE",
+                "iid_is": iid_is,
+            }
+        else:
+            return {"tag": "TD_VOID"}
+
+    if isinstance(type, xpidl.CEnum):
+        # As far as XPConnect is concerned, cenums are just unsigned integers.
+        return {"tag": "TD_UINT%d" % type.width}
+
+    raise Exception("Unknown type!")
+
+
+def mk_param(type, in_=0, out=0, optional=0):
+    return {
+        "type": type,
+        "flags": flags(
+            ("in", in_),
+            ("out", out),
+            ("optional", optional),
+        ),
+    }
+
+
+def mk_method(method, params, getter=0, setter=0, optargc=0, hasretval=0, symbol=0):
+    return {
+        "name": method.name,
+        # NOTE: We don't include any return value information here, as we'll
+        # never call the methods if they're marked notxpcom, and all xpcom
+        # methods return the same type (nsresult).
+        # XXX: If we ever use these files for other purposes than xptcodegen we
+        # may want to write that info.
+        "params": params,
+        "flags": flags(
+            ("getter", getter),
+            ("setter", setter),
+            ("hidden", method.noscript or method.notxpcom),
+            ("optargc", optargc),
+            ("jscontext", method.implicit_jscontext),
+            ("hasretval", hasretval),
+            ("symbol", method.symbol),
+        ),
+    }
+
+
+def attr_param_idx(p, m, attr):
+    attr_val = getattr(p, attr, None)
+    if not attr_val:
+        return None
+    for i, param in enumerate(m.params):
+        if param.name == attr_val:
+            return i
+    raise Exception(f"Need parameter named '{attr_val}' for attribute '{attr}'")
+
+
+def build_interface(iface):
+    if iface.namemap is None:
+        raise Exception("Interface was not resolved.")
+
+    assert (
+        iface.attributes.scriptable
+    ), "Don't generate XPT info for non-scriptable interfaces"
+
+    # State used while building an interface
+    consts = []
+    methods = []
+
+    def build_const(c):
+        consts.append(
+            {
+                "name": c.name,
+                "type": get_type(c.basetype, ""),
+                "value": c.getValue(),  # All of our consts are numbers
+            }
+        )
+
+    def build_cenum(b):
+        for var in b.variants:
+            consts.append(
+                {
+                    "name": var.name,
+                    "type": get_type(b, "in"),
+                    "value": var.value,
+                }
+            )
+
+    def build_method(m):
+        params = []
+        for p in m.params:
+            params.append(
+                mk_param(
+                    get_type(
+                        p.realtype,
+                        p.paramtype,
+                        iid_is=attr_param_idx(p, m, "iid_is"),
+                        size_is=attr_param_idx(p, m, "size_is"),
+                    ),
+                    in_=p.paramtype.count("in"),
+                    out=p.paramtype.count("out"),
+                    optional=p.optional,
+                )
+            )
+
+        hasretval = len(m.params) > 0 and m.params[-1].retval
+        if not m.notxpcom and m.realtype.name != "void":
+            hasretval = True
+            params.append(mk_param(get_type(m.realtype, "out"), out=1))
+
+        methods.append(
+            mk_method(m, params, optargc=m.optional_argc, hasretval=hasretval)
+        )
+
+    def build_attr(a):
+        assert a.realtype.name != "void"
+        # Write the getter
+        getter_params = []
+        if not a.notxpcom:
+            getter_params.append(mk_param(get_type(a.realtype, "out"), out=1))
+
+        methods.append(mk_method(a, getter_params, getter=1, hasretval=1))
+
+        # And maybe the setter
+        if not a.readonly:
+            param = mk_param(get_type(a.realtype, "in"), in_=1)
+            methods.append(mk_method(a, [param], setter=1))
+
+    for member in iface.members:
+        if isinstance(member, xpidl.ConstMember):
+            build_const(member)
+        elif isinstance(member, xpidl.Attribute):
+            build_attr(member)
+        elif isinstance(member, xpidl.Method):
+            build_method(member)
+        elif isinstance(member, xpidl.CEnum):
+            build_cenum(member)
+        elif isinstance(member, xpidl.CDATA):
+            pass
+        else:
+            raise Exception("Unexpected interface member: %s" % member)
+
+    return {
+        "name": iface.name,
+        "uuid": iface.attributes.uuid,
+        "methods": methods,
+        "consts": consts,
+        "parent": iface.base,
+        "flags": flags(
+            ("function", iface.attributes.function),
+            ("builtinclass", iface.attributes.builtinclass),
+            ("main_process_only", iface.attributes.main_process_scriptable_only),
+        ),
+    }
+
+
+# These functions are the public interface of this module. They are very simple
+# functions, but are exported so that if we need to do something more
+# complex in them in the future we can.
+
+
+def build_typelib(idl):
+    """Given a parsed IDL file, generate and return the typelib"""
+    return [
+        build_interface(p)
+        for p in idl.productions
+        if p.kind == "interface" and p.attributes.scriptable
+    ]
+
+
+def link(typelibs):
+    """Link a list of typelibs together into a single typelib"""
+    linked = list(itertools.chain.from_iterable(typelibs))
+    assert len(set(iface["name"] for iface in linked)) == len(
+        linked
+    ), "Multiple typelibs containing the same interface were linked together"
+    return linked
+
+
+def write(typelib, fd):
+    """Write typelib into fd"""
+    json.dump(typelib, fd, indent=2, sort_keys=True)
diff --git a/xpcom/idl-parser/xpidl/moz.build b/xpcom/idl-parser/xpidl/moz.build
new file mode 100644
index 0000000000..60252a0b81
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/moz.build
@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+PYTHON_UNITTEST_MANIFESTS += [
+    "python.toml",
+]
+
+GeneratedFile("xpidl.stub", script="header.py", entry_point="main")
diff --git a/xpcom/idl-parser/xpidl/python.toml b/xpcom/idl-parser/xpidl/python.toml
new file mode 100644
index 0000000000..577127329e
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/python.toml
@@ -0,0 +1,4 @@
+[DEFAULT]
+subsuite = "xpcom"
+
+["runtests.py"]
diff --git a/xpcom/idl-parser/xpidl/runtests.py b/xpcom/idl-parser/xpidl/runtests.py
new file mode 100755
index 0000000000..2dd269dfd9
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/runtests.py
@@ -0,0 +1,257 @@
+#!/usr/bin/env python
+#
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+#
+# Unit tests for xpidl.py
+
+import sys
+
+# Hack: the first entry in sys.path is the directory containing the script.
+# This messes things up because that directory is the xpidl module, and that
+# which conflicts with the xpidl submodule in the imports further below.
+sys.path.pop(0)
+
+import unittest
+
+import mozunit
+
+from xpidl import header, xpidl
+
+
+class TestParser(unittest.TestCase):
+    def setUp(self):
+        self.p = xpidl.IDLParser()
+
+    def testEmpty(self):
+        i = self.p.parse("", filename="f")
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertEqual([], i.productions)
+
+    def testForwardInterface(self):
+        i = self.p.parse("interface foo;", filename="f")
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Forward))
+        self.assertEqual("foo", i.productions[0].name)
+
+    def testInterface(self):
+        i = self.p.parse("[uuid(abc)] interface foo {};", filename="f")
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Interface))
+        self.assertEqual("foo", i.productions[0].name)
+
+    def testAttributes(self):
+        i = self.p.parse(
+            "[scriptable, builtinclass, function, uuid(abc)] interface foo {};",
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Interface))
+        iface = i.productions[0]
+        self.assertEqual("foo", iface.name)
+        self.assertTrue(iface.attributes.scriptable)
+        self.assertTrue(iface.attributes.builtinclass)
+        self.assertTrue(iface.attributes.function)
+
+        i = self.p.parse("[uuid(abc)] interface foo {};", filename="f")
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Interface))
+        iface = i.productions[0]
+        self.assertEqual("foo", iface.name)
+        self.assertFalse(iface.attributes.scriptable)
+
+    def testMethod(self):
+        i = self.p.parse(
+            """[uuid(abc)] interface foo {
+void bar();
+};""",
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Interface))
+        iface = i.productions[0]
+        m = iface.members[0]
+        self.assertTrue(isinstance(m, xpidl.Method))
+        self.assertEqual("bar", m.name)
+        self.assertEqual(xpidl.TypeId("void"), m.type)
+
+    def testMethodParams(self):
+        i = self.p.parse(
+            """
+        [scriptable, uuid(aaa)] interface nsISupports {};
+        [uuid(abc)] interface foo : nsISupports {
+          long bar(in long a, in float b, [array] in long c);
+        };""",
+            filename="f",
+        )
+        i.resolve([], self.p, {})
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[1], xpidl.Interface))
+        iface = i.productions[1]
+        m = iface.members[0]
+        self.assertTrue(isinstance(m, xpidl.Method))
+        self.assertEqual("bar", m.name)
+        self.assertEqual(xpidl.TypeId("long"), m.type)
+        self.assertEqual(3, len(m.params))
+        self.assertEqual(xpidl.TypeId("long"), m.params[0].type)
+        self.assertEqual("in", m.params[0].paramtype)
+        self.assertEqual(xpidl.TypeId("float"), m.params[1].type)
+        self.assertEqual("in", m.params[1].paramtype)
+        self.assertEqual(xpidl.TypeId("long"), m.params[2].type)
+        self.assertEqual("in", m.params[2].paramtype)
+        self.assertTrue(isinstance(m.params[2].realtype, xpidl.LegacyArray))
+        self.assertEqual("long", m.params[2].realtype.type.name)
+
+    def testAttribute(self):
+        i = self.p.parse(
+            """[uuid(abc)] interface foo {
+attribute long bar;
+};""",
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        self.assertTrue(isinstance(i.productions[0], xpidl.Interface))
+        iface = i.productions[0]
+        a = iface.members[0]
+        self.assertTrue(isinstance(a, xpidl.Attribute))
+        self.assertEqual("bar", a.name)
+        self.assertEqual(xpidl.TypeId("long"), a.type)
+
+    def testOverloadedVirtual(self):
+        i = self.p.parse(
+            """
+        [scriptable, uuid(00000000-0000-0000-0000-000000000000)] interface nsISupports {};
+        [uuid(abc)] interface foo : nsISupports {
+          attribute long bar;
+          void getBar();
+        };""",
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        i.resolve([], self.p, {})
+
+        class FdMock:
+            def write(self, s):
+                pass
+
+        try:
+            header.print_header(i, FdMock(), filename="f", relpath="f")
+            self.assertTrue(False, "Header printing failed to fail")
+        except Exception as e:
+            self.assertEqual(
+                e.args[0],
+                "Unexpected overloaded virtual method GetBar in interface foo",
+            )
+
+    def testNotISupports(self):
+        i = self.p.parse(
+            """
+        [uuid(abc)] interface foo {};
+        """,
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        try:
+            i.resolve([], self.p, {})
+            self.assertTrue(
+                False, "Must check that interfaces inherit from nsISupports"
+            )
+        except xpidl.IDLError as e:
+            self.assertEqual(e.args[0], "Interface 'foo' must inherit from nsISupports")
+
+    def testBuiltinClassParent(self):
+        i = self.p.parse(
+            """
+        [scriptable, uuid(aaa)] interface nsISupports {};
+        [scriptable, builtinclass, uuid(abc)] interface foo : nsISupports {};
+        [scriptable, uuid(def)] interface bar : foo {};
+        """,
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        try:
+            i.resolve([], self.p, {})
+            self.assertTrue(
+                False, "non-builtinclasses can't inherit from builtinclasses"
+            )
+        except xpidl.IDLError as e:
+            self.assertEqual(
+                e.args[0],
+                "interface 'bar' is not builtinclass but derives from builtinclass 'foo'",
+            )
+
+    def testScriptableNotXPCOM(self):
+        # notxpcom method requires builtinclass on the interface
+        i = self.p.parse(
+            """
+        [scriptable, uuid(aaa)] interface nsISupports {};
+        [scriptable, uuid(abc)] interface nsIScriptableWithNotXPCOM : nsISupports {
+          [notxpcom] void method2();
+        };
+        """,
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        try:
+            i.resolve([], self.p, {})
+            self.assertTrue(
+                False,
+                "Resolve should fail for non-builtinclasses with notxpcom methods",
+            )
+        except xpidl.IDLError as e:
+            self.assertEqual(
+                e.args[0],
+                (
+                    "scriptable interface 'nsIScriptableWithNotXPCOM' "
+                    "must be marked [builtinclass] because it contains a [notxpcom] "
+                    "method 'method2'"
+                ),
+            )
+
+        # notxpcom attribute requires builtinclass on the interface
+        i = self.p.parse(
+            """
+        interface nsISomeInterface;
+        [scriptable, uuid(aaa)] interface nsISupports {};
+        [scriptable, uuid(abc)] interface nsIScriptableWithNotXPCOM : nsISupports {
+          [notxpcom] attribute nsISomeInterface attrib;
+        };
+        """,
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        try:
+            i.resolve([], self.p, {})
+            self.assertTrue(
+                False,
+                "Resolve should fail for non-builtinclasses with notxpcom attributes",
+            )
+        except xpidl.IDLError as e:
+            self.assertEqual(
+                e.args[0],
+                (
+                    "scriptable interface 'nsIScriptableWithNotXPCOM' must be marked "
+                    "[builtinclass] because it contains a [notxpcom] attribute 'attrib'"
+                ),
+            )
+
+    def testUndefinedConst(self):
+        i = self.p.parse(
+            """
+        [scriptable, uuid(aaa)] interface nsISupports {};
+        [scriptable, uuid(abc)] interface foo : nsISupports {
+          const unsigned long X = Y + 1;
+        };
+        """,
+            filename="f",
+        )
+        self.assertTrue(isinstance(i, xpidl.IDL))
+        try:
+            i.resolve([], self.p, {})
+            self.assertTrue(False, "Must detect undefined symbols")
+        except xpidl.IDLError as e:
+            self.assertEqual(e.args[0], ("cannot find symbol 'Y'"))
+
+
+if __name__ == "__main__":
+    mozunit.main(runwith="unittest")
diff --git a/xpcom/idl-parser/xpidl/rust.py b/xpcom/idl-parser/xpidl/rust.py
new file mode 100644
index 0000000000..b9fc6627fb
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/rust.py
@@ -0,0 +1,693 @@
+# rust.py - Generate rust bindings from IDL.
+#
+# 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/.
+
+"""Print a runtime Rust bindings file for the IDL file specified"""
+
+# --- Safety Hazards ---
+
+# We currently don't generate some bindings for some IDL methods in rust code,
+# due to there being ABI safety hazards if we were to do so. This is the
+# documentation for the reasons why we don't generate certain types of bindings,
+# so that we don't accidentally start generating them in the future.
+
+# notxpcom methods and attributes return their results directly by value. The x86
+# windows stdcall ABI returns aggregates by value differently for methods than
+# functions, and rust only exposes the function ABI, so that's the one we're
+# using. The correct ABI can be emulated for notxpcom methods returning aggregates
+# by passing an &mut ReturnType parameter as the second parameter.  This strategy
+# is used by the winapi-rs crate.
+# https://github.com/retep998/winapi-rs/blob/7338a5216a6a7abeefcc6bb1bc34381c81d3e247/src/macros.rs#L220-L231
+#
+# Right now we can generate code for notxpcom methods and attributes, as we don't
+# support passing aggregates by value over these APIs ever (the types which are
+# allowed in xpidl.py shouldn't include any aggregates), so the code is
+# correct. In the future if we want to start supporting returning aggregates by
+# value, we will need to use a workaround such as the one used by winapi.rs.
+
+# nostdcall methods on x86 windows will use the thiscall ABI, which is not
+# stable in rust right now, so we cannot generate bindings to them.
+
+# In general, passing C++ objects by value over the C ABI is not a good idea,
+# and when possible we should avoid doing so. We don't generate bindings for
+# these methods here currently.
+
+import os.path
+import re
+
+from xpidl import xpidl
+
+
+class AutoIndent(object):
+    """A small autoindenting wrapper around a fd.
+    Used to make the code output more readable."""
+
+    def __init__(self, fd):
+        self.fd = fd
+        self.indent = 0
+
+    def write(self, string):
+        """A smart write function which automatically adjusts the
+        indentation of each line as it is written by counting braces"""
+        for s in string.split("\n"):
+            s = s.strip()
+            indent = self.indent
+            if len(s) == 0:
+                indent = 0
+            elif s[0] == "}":
+                indent -= 1
+
+            self.fd.write("    " * indent + s + "\n")
+            for c in s:
+                if c == "(" or c == "{" or c == "[":
+                    self.indent += 1
+                elif c == ")" or c == "}" or c == "]":
+                    self.indent -= 1
+
+
+def rustSanitize(s):
+    keywords = [
+        "abstract",
+        "alignof",
+        "as",
+        "become",
+        "box",
+        "break",
+        "const",
+        "continue",
+        "crate",
+        "do",
+        "else",
+        "enum",
+        "extern",
+        "false",
+        "final",
+        "fn",
+        "for",
+        "if",
+        "impl",
+        "in",
+        "let",
+        "loop",
+        "macro",
+        "match",
+        "mod",
+        "move",
+        "mut",
+        "offsetof",
+        "override",
+        "priv",
+        "proc",
+        "pub",
+        "pure",
+        "ref",
+        "return",
+        "Self",
+        "self",
+        "sizeof",
+        "static",
+        "struct",
+        "super",
+        "trait",
+        "true",
+        "type",
+        "typeof",
+        "unsafe",
+        "unsized",
+        "use",
+        "virtual",
+        "where",
+        "while",
+        "yield",
+    ]
+    if s in keywords:
+        return s + "_"
+    return s
+
+
+# printdoccomments = False
+printdoccomments = True
+
+if printdoccomments:
+
+    def printComments(fd, clist, indent):
+        fd.write("%s%s" % (indent, doccomments(clist)))
+
+    def doccomments(clist):
+        if len(clist) == 0:
+            return ""
+        s = "/// ```text"
+        for c in clist:
+            for cc in c.splitlines():
+                s += "\n/// " + cc
+        s += "\n/// ```\n///\n"
+        return s
+
+else:
+
+    def printComments(fd, clist, indent):
+        pass
+
+    def doccomments(clist):
+        return ""
+
+
+def firstCap(str):
+    return str[0].upper() + str[1:]
+
+
+# Attribute VTable Methods
+def attributeNativeName(a, getter):
+    binaryname = rustSanitize(a.binaryname if a.binaryname else firstCap(a.name))
+    return "%s%s" % ("Get" if getter else "Set", binaryname)
+
+
+def attributeReturnType(a, getter):
+    if a.notxpcom:
+        if getter:
+            return a.realtype.rustType("in").strip()
+        return "::libc::c_void"
+    return "::nserror::nsresult"
+
+
+def attributeParamName(a):
+    return "a" + firstCap(a.name)
+
+
+def attributeRawParamList(iface, a, getter):
+    if getter and a.notxpcom:
+        l = []
+    else:
+        l = [(attributeParamName(a), a.realtype.rustType("out" if getter else "in"))]
+    if a.implicit_jscontext:
+        raise xpidl.RustNoncompat("jscontext is unsupported")
+    if a.nostdcall:
+        raise xpidl.RustNoncompat("nostdcall is unsupported")
+    return l
+
+
+def attributeParamList(iface, a, getter):
+    l = ["this: *const " + iface.name]
+    l += ["%s: %s" % x for x in attributeRawParamList(iface, a, getter)]
+    return ", ".join(l)
+
+
+def attrAsVTableEntry(iface, m, getter):
+    try:
+        return 'pub %s: unsafe extern "system" fn (%s) -> %s' % (
+            attributeNativeName(m, getter),
+            attributeParamList(iface, m, getter),
+            attributeReturnType(m, getter),
+        )
+    except xpidl.RustNoncompat as reason:
+        return """\
+/// Unable to generate binding because `%s`
+pub %s: *const ::libc::c_void""" % (
+            reason,
+            attributeNativeName(m, getter),
+        )
+
+
+# Method VTable generation functions
+def methodNativeName(m):
+    binaryname = m.binaryname is not None and m.binaryname or firstCap(m.name)
+    return rustSanitize(binaryname)
+
+
+def methodReturnType(m):
+    if m.notxpcom:
+        return m.realtype.rustType("in").strip()
+    return "::nserror::nsresult"
+
+
+def methodRawParamList(iface, m):
+    l = [(rustSanitize(p.name), p.rustType()) for p in m.params]
+
+    if m.implicit_jscontext:
+        raise xpidl.RustNoncompat("jscontext is unsupported")
+
+    if m.optional_argc:
+        raise xpidl.RustNoncompat("optional_argc is unsupported")
+
+    if m.nostdcall:
+        raise xpidl.RustNoncompat("nostdcall is unsupported")
+
+    if not m.notxpcom and m.realtype.name != "void":
+        l.append(("_retval", m.realtype.rustType("out")))
+
+    return l
+
+
+def methodParamList(iface, m):
+    l = ["this: *const %s" % iface.name]
+    l += ["%s: %s" % x for x in methodRawParamList(iface, m)]
+    return ", ".join(l)
+
+
+def methodAsVTableEntry(iface, m):
+    try:
+        return 'pub %s: unsafe extern "system" fn (%s) -> %s' % (
+            methodNativeName(m),
+            methodParamList(iface, m),
+            methodReturnType(m),
+        )
+    except xpidl.RustNoncompat as reason:
+        return """\
+/// Unable to generate binding because `%s`
+pub %s: *const ::libc::c_void""" % (
+            reason,
+            methodNativeName(m),
+        )
+
+
+method_impl_tmpl = """\
+#[inline]
+pub unsafe fn %(name)s(&self, %(params)s) -> %(ret_ty)s {
+    ((*self.vtable).%(name)s)(self, %(args)s)
+}
+"""
+
+
+def methodAsWrapper(iface, m):
+    try:
+        param_list = methodRawParamList(iface, m)
+        params = ["%s: %s" % x for x in param_list]
+        args = [x[0] for x in param_list]
+
+        return method_impl_tmpl % {
+            "name": methodNativeName(m),
+            "params": ", ".join(params),
+            "ret_ty": methodReturnType(m),
+            "args": ", ".join(args),
+        }
+    except xpidl.RustNoncompat:
+        # Dummy field for the doc comments to attach to.
+        # Private so that it's not shown in rustdoc.
+        return "const _%s: () = ();" % methodNativeName(m)
+
+
+infallible_impl_tmpl = """\
+#[inline]
+pub unsafe fn %(name)s(&self) -> %(realtype)s {
+    let mut result = <%(realtype)s as ::std::default::Default>::default();
+    let _rv = ((*self.vtable).%(name)s)(self, &mut result);
+    debug_assert!(_rv.succeeded());
+    result
+}
+"""
+
+
+def attrAsWrapper(iface, m, getter):
+    try:
+        if m.implicit_jscontext:
+            raise xpidl.RustNoncompat("jscontext is unsupported")
+
+        if m.nostdcall:
+            raise xpidl.RustNoncompat("nostdcall is unsupported")
+
+        name = attributeParamName(m)
+
+        if getter and m.infallible and m.realtype.kind == "builtin":
+            # NOTE: We don't support non-builtin infallible getters in Rust code.
+            return infallible_impl_tmpl % {
+                "name": attributeNativeName(m, getter),
+                "realtype": m.realtype.rustType("in"),
+            }
+
+        param_list = attributeRawParamList(iface, m, getter)
+        params = ["%s: %s" % x for x in param_list]
+        return method_impl_tmpl % {
+            "name": attributeNativeName(m, getter),
+            "params": ", ".join(params),
+            "ret_ty": attributeReturnType(m, getter),
+            "args": "" if getter and m.notxpcom else name,
+        }
+
+    except xpidl.RustNoncompat:
+        # Dummy field for the doc comments to attach to.
+        # Private so that it's not shown in rustdoc.
+        return "const _%s: () = ();" % attributeNativeName(m, getter)
+
+
+header = """\
+//
+// DO NOT EDIT.  THIS FILE IS GENERATED FROM $SRCDIR/%(relpath)s
+//
+
+"""
+
+
+def idl_basename(f):
+    """returns the base name of a file with the last extension stripped"""
+    return os.path.splitext(os.path.basename(f))[0]
+
+
+def print_rust_bindings(idl, fd, relpath):
+    fd = AutoIndent(fd)
+
+    fd.write(header % {"relpath": relpath})
+
+    # All of the idl files will be included into the same rust module, as we
+    # can't do forward declarations. Because of this, we want to ignore all
+    # import statements
+
+    for p in idl.productions:
+        if p.kind == "include" or p.kind == "cdata" or p.kind == "forward":
+            continue
+
+        if p.kind == "interface":
+            write_interface(p, fd)
+            continue
+
+        if p.kind == "typedef":
+            try:
+                # We have to skip the typedef of bool to bool (it doesn't make any sense anyways)
+                if p.name == "bool":
+                    continue
+
+                if printdoccomments:
+                    fd.write(
+                        "/// `typedef %s %s;`\n///\n"
+                        % (p.realtype.nativeType("in"), p.name)
+                    )
+                    fd.write(doccomments(p.doccomments))
+                fd.write("pub type %s = %s;\n\n" % (p.name, p.realtype.rustType("in")))
+            except xpidl.RustNoncompat as reason:
+                fd.write(
+                    "/* unable to generate %s typedef because `%s` */\n\n"
+                    % (p.name, reason)
+                )
+
+
+base_vtable_tmpl = """
+/// We need to include the members from the base interface's vtable at the start
+/// of the VTable definition.
+pub __base: %sVTable,
+
+"""
+
+
+vtable_tmpl = """\
+// This struct represents the interface's VTable. A pointer to a statically
+// allocated version of this struct is at the beginning of every %(name)s
+// object. It contains one pointer field for each method in the interface. In
+// the case where we can't generate a binding for a method, we include a void
+// pointer.
+#[doc(hidden)]
+#[repr(C)]
+pub struct %(name)sVTable {%(base)s%(entries)s}
+
+"""
+
+
+# NOTE: This template is not generated for nsISupports, as it has no base interfaces.
+deref_tmpl = """\
+// Every interface struct type implements `Deref` to its base interface. This
+// causes methods on the base interfaces to be directly avaliable on the
+// object. For example, you can call `.AddRef` or `.QueryInterface` directly
+// on any interface which inherits from `nsISupports`.
+impl ::std::ops::Deref for %(name)s {
+    type Target = %(base)s;
+    #[inline]
+    fn deref(&self) -> &%(base)s {
+        unsafe {
+            ::std::mem::transmute(self)
+        }
+    }
+}
+
+// Ensure we can use .coerce() to cast to our base types as well. Any type which
+// our base interface can coerce from should be coercable from us as well.
+impl<T: %(base)sCoerce> %(name)sCoerce for T {
+    #[inline]
+    fn coerce_from(v: &%(name)s) -> &Self {
+        T::coerce_from(v)
+    }
+}
+"""
+
+
+struct_tmpl = """\
+// The actual type definition for the interface. This struct has methods
+// declared on it which will call through its vtable. You never want to pass
+// this type around by value, always pass it behind a reference.
+
+#[repr(C)]
+pub struct %(name)s {
+    vtable: &'static %(name)sVTable,
+
+    /// This field is a phantomdata to ensure that the VTable type and any
+    /// struct containing it is not safe to send across threads by default, as
+    /// XPCOM is generally not threadsafe.
+    ///
+    /// If this type is marked as [rust_sync], there will be explicit `Send` and
+    /// `Sync` implementations on this type, which will override the inherited
+    /// negative impls from `Rc`.
+    __nosync: ::std::marker::PhantomData<::std::rc::Rc<u8>>,
+
+    // Make the rust compiler aware that there might be interior mutability
+    // in what actually implements the interface. This works around UB
+    // introduced by https://github.com/llvm/llvm-project/commit/01859da84bad95fd51d6a03b08b60c660e642a4f
+    // that a rust lint would make blatantly obvious, but doesn't exist.
+    // (See https://github.com/rust-lang/rust/issues/111229).
+    // This prevents optimizations, but those optimizations weren't available
+    // before rustc switched to LLVM 16, and they now cause problems because
+    // of the UB.
+    // Until there's a lint available to find all our UB, it's simpler to
+    // avoid the UB in the first place, at the cost of preventing optimizations
+    // in places that don't cause UB. But again, those optimizations weren't
+    // available before.
+    __maybe_interior_mutability: ::std::cell::UnsafeCell<[u8; 0]>,
+}
+
+// Implementing XpCom for an interface exposes its IID, which allows for easy
+// use of the `.query_interface<T>` helper method. This also defines that
+// method for %(name)s.
+unsafe impl XpCom for %(name)s {
+    const IID: nsIID = nsID(0x%(m0)s, 0x%(m1)s, 0x%(m2)s,
+                            [%(m3joined)s]);
+}
+
+// We need to implement the RefCounted trait so we can be used with `RefPtr`.
+// This trait teaches `RefPtr` how to manage our memory.
+unsafe impl RefCounted for %(name)s {
+    #[inline]
+    unsafe fn addref(&self) {
+        self.AddRef();
+    }
+    #[inline]
+    unsafe fn release(&self) {
+        self.Release();
+    }
+}
+
+// This trait is implemented on all types which can be coerced to from %(name)s.
+// It is used in the implementation of `fn coerce<T>`. We hide it from the
+// documentation, because it clutters it up a lot.
+#[doc(hidden)]
+pub trait %(name)sCoerce {
+    /// Cheaply cast a value of this type from a `%(name)s`.
+    fn coerce_from(v: &%(name)s) -> &Self;
+}
+
+// The trivial implementation: We can obviously coerce ourselves to ourselves.
+impl %(name)sCoerce for %(name)s {
+    #[inline]
+    fn coerce_from(v: &%(name)s) -> &Self {
+        v
+    }
+}
+
+impl %(name)s {
+    /// Cast this `%(name)s` to one of its base interfaces.
+    #[inline]
+    pub fn coerce<T: %(name)sCoerce>(&self) -> &T {
+        T::coerce_from(self)
+    }
+}
+"""
+
+
+sendsync_tmpl = """\
+// This interface is marked as [rust_sync], meaning it is safe to be transferred
+// and used from multiple threads silmultaneously.  These override the default
+// from the __nosync marker type allowng the type to be sent between threads.
+unsafe impl Send for %(name)s {}
+unsafe impl Sync for %(name)s {}
+"""
+
+
+wrapper_tmpl = """\
+// The implementations of the function wrappers which are exposed to rust code.
+// Call these methods rather than manually calling through the VTable struct.
+impl %(name)s {
+%(consts)s
+%(methods)s
+}
+
+"""
+
+vtable_entry_tmpl = """\
+/* %(idl)s */
+%(entry)s,
+"""
+
+
+const_wrapper_tmpl = """\
+%(docs)s
+pub const %(name)s: %(type)s = %(val)s;
+"""
+
+
+method_wrapper_tmpl = """\
+%(docs)s
+/// `%(idl)s`
+%(wrapper)s
+"""
+
+
+uuid_decoder = re.compile(
+    r"""(?P<m0>[a-f0-9]{8})-
+                              (?P<m1>[a-f0-9]{4})-
+                              (?P<m2>[a-f0-9]{4})-
+                              (?P<m3>[a-f0-9]{4})-
+                              (?P<m4>[a-f0-9]{12})$""",
+    re.X,
+)
+
+
+def write_interface(iface, fd):
+    if iface.namemap is None:
+        raise Exception("Interface was not resolved.")
+
+    assert iface.base or (iface.name == "nsISupports")
+
+    # Extract the UUID's information so that it can be written into the struct definition
+    names = uuid_decoder.match(iface.attributes.uuid).groupdict()
+    m3str = names["m3"] + names["m4"]
+    names["m3joined"] = ", ".join(["0x%s" % m3str[i : i + 2] for i in range(0, 16, 2)])
+    names["name"] = iface.name
+
+    if printdoccomments:
+        if iface.base is not None:
+            fd.write("/// `interface %s : %s`\n///\n" % (iface.name, iface.base))
+        else:
+            fd.write("/// `interface %s`\n///\n" % iface.name)
+    printComments(fd, iface.doccomments, "")
+    fd.write(struct_tmpl % names)
+
+    if iface.attributes.rust_sync:
+        fd.write(sendsync_tmpl % {"name": iface.name})
+
+    if iface.base is not None:
+        fd.write(
+            deref_tmpl
+            % {
+                "name": iface.name,
+                "base": iface.base,
+            }
+        )
+
+    entries = []
+    for member in iface.members:
+        if type(member) == xpidl.Attribute:
+            entries.append(
+                vtable_entry_tmpl
+                % {
+                    "idl": member.toIDL(),
+                    "entry": attrAsVTableEntry(iface, member, True),
+                }
+            )
+            if not member.readonly:
+                entries.append(
+                    vtable_entry_tmpl
+                    % {
+                        "idl": member.toIDL(),
+                        "entry": attrAsVTableEntry(iface, member, False),
+                    }
+                )
+
+        elif type(member) == xpidl.Method:
+            entries.append(
+                vtable_entry_tmpl
+                % {
+                    "idl": member.toIDL(),
+                    "entry": methodAsVTableEntry(iface, member),
+                }
+            )
+
+    fd.write(
+        vtable_tmpl
+        % {
+            "name": iface.name,
+            "base": base_vtable_tmpl % iface.base if iface.base is not None else "",
+            "entries": "\n".join(entries),
+        }
+    )
+
+    # Get all of the constants
+    consts = []
+    for member in iface.members:
+        if type(member) == xpidl.ConstMember:
+            consts.append(
+                const_wrapper_tmpl
+                % {
+                    "docs": doccomments(member.doccomments),
+                    "type": member.realtype.rustType("in"),
+                    "name": member.name,
+                    "val": member.getValue(),
+                }
+            )
+        if type(member) == xpidl.CEnum:
+            for var in member.variants:
+                consts.append(
+                    const_wrapper_tmpl
+                    % {
+                        "docs": "",
+                        "type": member.rustType("in"),
+                        "name": var.name,
+                        "val": var.getValue(),
+                    }
+                )
+
+    methods = []
+    for member in iface.members:
+        if type(member) == xpidl.Attribute:
+            methods.append(
+                method_wrapper_tmpl
+                % {
+                    "docs": doccomments(member.doccomments),
+                    "idl": member.toIDL(),
+                    "wrapper": attrAsWrapper(iface, member, True),
+                }
+            )
+            if not member.readonly:
+                methods.append(
+                    method_wrapper_tmpl
+                    % {
+                        "docs": doccomments(member.doccomments),
+                        "idl": member.toIDL(),
+                        "wrapper": attrAsWrapper(iface, member, False),
+                    }
+                )
+
+        elif type(member) == xpidl.Method:
+            methods.append(
+                method_wrapper_tmpl
+                % {
+                    "docs": doccomments(member.doccomments),
+                    "idl": member.toIDL(),
+                    "wrapper": methodAsWrapper(iface, member),
+                }
+            )
+
+    fd.write(
+        wrapper_tmpl
+        % {
+            "name": iface.name,
+            "consts": "\n".join(consts),
+            "methods": "\n".join(methods),
+        }
+    )
diff --git a/xpcom/idl-parser/xpidl/rust_macros.py b/xpcom/idl-parser/xpidl/rust_macros.py
new file mode 100644
index 0000000000..bc1788b96c
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/rust_macros.py
@@ -0,0 +1,111 @@
+# rust_macros.py - Generate rust_macros bindings from IDL.
+#
+# 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/.
+
+"""Generate rust bindings information for the IDL file specified"""
+
+from xpidl import rust, xpidl
+
+derive_method_tmpl = """\
+Method {
+    name: "%(name)s",
+    params: &[%(params)s],
+    ret: "%(ret)s",
+}"""
+
+
+def attrAsMethodStruct(iface, m, getter):
+    params = [
+        'Param { name: "%s", ty: "%s" }' % x
+        for x in rust.attributeRawParamList(iface, m, getter)
+    ]
+    return derive_method_tmpl % {
+        "name": rust.attributeNativeName(m, getter),
+        "params": ", ".join(params),
+        "ret": "::nserror::nsresult",
+    }
+
+
+def methodAsMethodStruct(iface, m):
+    params = [
+        'Param { name: "%s", ty: "%s" }' % x for x in rust.methodRawParamList(iface, m)
+    ]
+    return derive_method_tmpl % {
+        "name": rust.methodNativeName(m),
+        "params": ", ".join(params),
+        "ret": rust.methodReturnType(m),
+    }
+
+
+derive_iface_tmpl = """\
+Interface {
+    name: "%(name)s",
+    base: %(base)s,
+    sync: %(sync)s,
+    methods: %(methods)s,
+},
+"""
+
+
+def write_interface(iface, fd):
+    if iface.namemap is None:
+        raise Exception("Interface was not resolved.")
+
+    assert iface.base or (iface.name == "nsISupports")
+
+    base = 'Some("%s")' % iface.base if iface.base is not None else "None"
+    try:
+        methods = ""
+        for member in iface.members:
+            if type(member) == xpidl.Attribute:
+                methods += "/* %s */\n" % member.toIDL()
+                methods += "%s,\n" % attrAsMethodStruct(iface, member, True)
+                if not member.readonly:
+                    methods += "%s,\n" % attrAsMethodStruct(iface, member, False)
+                methods += "\n"
+
+            elif type(member) == xpidl.Method:
+                methods += "/* %s */\n" % member.toIDL()
+                methods += "%s,\n\n" % methodAsMethodStruct(iface, member)
+        fd.write(
+            derive_iface_tmpl
+            % {
+                "name": iface.name,
+                "base": base,
+                "sync": "true" if iface.attributes.rust_sync else "false",
+                "methods": "Ok(&[\n%s])" % methods,
+            }
+        )
+    except xpidl.RustNoncompat as reason:
+        fd.write(
+            derive_iface_tmpl
+            % {
+                "name": iface.name,
+                "base": base,
+                "sync": "false",
+                "methods": 'Err("%s")' % reason,
+            }
+        )
+
+
+header = """\
+//
+// DO NOT EDIT.  THIS FILE IS GENERATED FROM $SRCDIR/%(relpath)s
+//
+
+"""
+
+
+def print_rust_macros_bindings(idl, fd, relpath):
+    fd = rust.AutoIndent(fd)
+
+    fd.write(header % {"relpath": relpath})
+    fd.write("{static D: &[Interface] = &[\n")
+
+    for p in idl.productions:
+        if p.kind == "interface":
+            write_interface(p, fd)
+
+    fd.write("]; D}\n")
diff --git a/xpcom/idl-parser/xpidl/xpidl.py b/xpcom/idl-parser/xpidl/xpidl.py
new file mode 100755
index 0000000000..b95fd14bc5
--- /dev/null
+++ b/xpcom/idl-parser/xpidl/xpidl.py
@@ -0,0 +1,2124 @@
+#!/usr/bin/env python
+# xpidl.py - A parser for cross-platform IDL (XPIDL) files.
+#
+# 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 parser for cross-platform IDL (XPIDL) files."""
+
+import os.path
+import re
+import sys
+import textwrap
+from collections import namedtuple
+
+import six
+from ply import lex, yacc
+
+"""A type conforms to the following pattern:
+
+    def nativeType(self, calltype):
+        'returns a string representation of the native type
+        calltype must be 'in', 'out', 'inout', or 'element'
+
+Interface members const/method/attribute conform to the following pattern:
+
+    name = 'string'
+
+    def toIDL(self):
+        'returns the member signature as IDL'
+"""
+
+
+# XXX(nika): Fix the IDL files which do this so we can remove this list?
+def rustPreventForward(s):
+    """These types are foward declared as interfaces, but never actually defined
+    in IDL files. We don't want to generate references to them in rust for that
+    reason."""
+    return s in (
+        "nsIFrame",
+        "nsSubDocumentFrame",
+    )
+
+
+def attlistToIDL(attlist):
+    if len(attlist) == 0:
+        return ""
+
+    attlist = list(attlist)
+    attlist.sort(key=lambda a: a[0])
+
+    return "[%s] " % ",".join(
+        [
+            "%s%s" % (name, value is not None and "(%s)" % value or "")
+            for name, value, aloc in attlist
+        ]
+    )
+
+
+_paramsHardcode = {
+    2: ("array", "shared", "iid_is", "size_is", "retval"),
+    3: ("array", "size_is", "const"),
+}
+
+
+def paramAttlistToIDL(attlist):
+    if len(attlist) == 0:
+        return ""
+
+    # Hack alert: g_hash_table_foreach is pretty much unimitatable... hardcode
+    # quirk
+    attlist = list(attlist)
+    sorted = []
+    if len(attlist) in _paramsHardcode:
+        for p in _paramsHardcode[len(attlist)]:
+            i = 0
+            while i < len(attlist):
+                if attlist[i][0] == p:
+                    sorted.append(attlist[i])
+                    del attlist[i]
+                    continue
+
+                i += 1
+
+    sorted.extend(attlist)
+
+    return "[%s] " % ", ".join(
+        [
+            "%s%s" % (name, value is not None and " (%s)" % value or "")
+            for name, value, aloc in sorted
+        ]
+    )
+
+
+def unaliasType(t):
+    while t.kind == "typedef":
+        t = t.realtype
+    assert t is not None
+    return t
+
+
+def getBuiltinOrNativeTypeName(t):
+    t = unaliasType(t)
+    if t.kind == "builtin":
+        return t.name
+    elif t.kind == "native":
+        assert t.specialtype is not None
+        return "[%s]" % t.specialtype
+    else:
+        return None
+
+
+class BuiltinLocation(object):
+    def get(self):
+        return "<builtin type>"
+
+    def __str__(self):
+        return self.get()
+
+
+class Builtin(object):
+    kind = "builtin"
+    location = BuiltinLocation
+
+    def __init__(self, name, nativename, rustname, signed=False, maybeConst=False):
+        self.name = name
+        self.nativename = nativename
+        self.rustname = rustname
+        self.signed = signed
+        self.maybeConst = maybeConst
+
+    def isPointer(self):
+        """Check if this type is a pointer type - this will control how pointers act"""
+        return self.nativename.endswith("*")
+
+    def nativeType(self, calltype, shared=False, const=False):
+        if self.name in ["string", "wstring"] and calltype == "element":
+            raise IDLError(
+                "Use string class types for string Array elements", self.location
+            )
+
+        if const:
+            print(
+                IDLError(
+                    "[const] doesn't make sense on builtin types.",
+                    self.location,
+                    warning=True,
+                ),
+                file=sys.stderr,
+            )
+            const = "const "
+        elif calltype == "in" and self.isPointer():
+            const = "const "
+        elif shared:
+            if not self.isPointer():
+                raise IDLError(
+                    "[shared] not applicable to non-pointer types.", self.location
+                )
+            const = "const "
+        else:
+            const = ""
+        return "%s%s %s" % (const, self.nativename, "*" if "out" in calltype else "")
+
+    def rustType(self, calltype, shared=False, const=False):
+        # We want to rewrite any *mut pointers to *const pointers if constness
+        # was requested.
+        const = const or ("out" not in calltype and self.isPointer()) or shared
+        rustname = self.rustname
+        if const and self.isPointer():
+            rustname = self.rustname.replace("*mut", "*const")
+
+        return "%s%s" % ("*mut " if "out" in calltype else "", rustname)
+
+
+builtinNames = [
+    Builtin("boolean", "bool", "bool"),
+    Builtin("void", "void", "libc::c_void"),
+    Builtin("octet", "uint8_t", "u8", False, True),
+    Builtin("short", "int16_t", "i16", True, True),
+    Builtin("long", "int32_t", "i32", True, True),
+    Builtin("long long", "int64_t", "i64", True, True),
+    Builtin("unsigned short", "uint16_t", "u16", False, True),
+    Builtin("unsigned long", "uint32_t", "u32", False, True),
+    Builtin("unsigned long long", "uint64_t", "u64", False, True),
+    Builtin("float", "float", "libc::c_float", True, False),
+    Builtin("double", "double", "libc::c_double", True, False),
+    Builtin("char", "char", "libc::c_char", True, False),
+    Builtin("string", "char *", "*const libc::c_char", False, False),
+    Builtin("wchar", "char16_t", "u16", False, False),
+    Builtin("wstring", "char16_t *", "*const u16", False, False),
+    # As seen in mfbt/RefCountType.h, this type has special handling to
+    # maintain binary compatibility with MSCOM's IUnknown that cannot be
+    # expressed in XPIDL.
+    Builtin(
+        "MozExternalRefCountType", "MozExternalRefCountType", "MozExternalRefCountType"
+    ),
+]
+
+builtinMap = {}
+for b in builtinNames:
+    builtinMap[b.name] = b
+
+
+class Location(object):
+    _line = None
+
+    def __init__(self, lexer, lineno, lexpos):
+        self._lineno = lineno
+        self._lexpos = lexpos
+        self._lexdata = lexer.lexdata
+        self._file = getattr(lexer, "filename", "<unknown>")
+
+    def __eq__(self, other):
+        return self._lexpos == other._lexpos and self._file == other._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)
+        self._line = self._lexdata[startofline:endofline]
+        self._colno = self._lexpos - startofline
+
+    def pointerline(self):
+        def i():
+            for i in range(0, self._colno):
+                yield " "
+            yield "^"
+
+        return "".join(i())
+
+    def get(self):
+        self.resolve()
+        return "%s line %s:%s" % (self._file, self._lineno, 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 NameMap(object):
+    """Map of name -> object. Each object must have a .name and .location property.
+    Setting the same name twice throws an error."""
+
+    def __init__(self):
+        self._d = {}
+
+    def __getitem__(self, key):
+        if key in builtinMap:
+            return builtinMap[key]
+        return self._d[key]
+
+    def __iter__(self):
+        return six.itervalues(self._d)
+
+    def __contains__(self, key):
+        return key in builtinMap or key in self._d
+
+    def set(self, object):
+        if object.name in builtinMap:
+            raise IDLError(
+                "name '%s' is a builtin and cannot be redeclared" % (object.name),
+                object.location,
+            )
+        if object.name.startswith("_"):
+            object.name = object.name[1:]
+        if object.name in self._d:
+            old = self._d[object.name]
+            if old == object:
+                return
+            if isinstance(old, Forward) and isinstance(object, Interface):
+                self._d[object.name] = object
+            elif isinstance(old, Interface) and isinstance(object, Forward):
+                pass
+            else:
+                raise IDLError(
+                    "name '%s' specified twice. Previous location: %s"
+                    % (object.name, self._d[object.name].location),
+                    object.location,
+                )
+        else:
+            self._d[object.name] = object
+
+    def get(self, id, location):
+        try:
+            return self[id]
+        except KeyError:
+            raise IDLError(f"Name '{id}' not found", location)
+
+
+class RustNoncompat(Exception):
+    """
+    This exception is raised when a particular type or function cannot be safely exposed to
+    rust code
+    """
+
+    def __init__(self, reason):
+        self.reason = reason
+
+    def __str__(self):
+        return self.reason
+
+
+class IDLError(Exception):
+    def __init__(self, message, location, warning=False, notes=None):
+        self.message = message
+        self.location = location
+        self.warning = warning
+        self.notes = notes
+
+    def __str__(self):
+        error = "%s: %s, %s" % (
+            self.warning and "warning" or "error",
+            self.message,
+            self.location,
+        )
+        if self.notes is not None:
+            error += "\nnote: %s" % self.notes
+        return error
+
+
+class Include(object):
+    kind = "include"
+
+    def __init__(self, filename, location):
+        self.filename = filename
+        self.location = location
+
+    def __str__(self):
+        return "".join(["include '%s'\n" % self.filename])
+
+    def resolve(self, parent):
+        def incfiles():
+            yield self.filename
+            for dir in parent.incdirs:
+                yield os.path.join(dir, self.filename)
+
+        for file in incfiles():
+            if not os.path.exists(file):
+                continue
+
+            if file in parent.includeCache:
+                self.IDL = parent.includeCache[file]
+            else:
+                self.IDL = parent.parser.parse(
+                    open(file, encoding="utf-8").read(), filename=file
+                )
+                self.IDL.resolve(
+                    parent.incdirs,
+                    parent.parser,
+                    parent.webidlconfig,
+                    parent.includeCache,
+                )
+                parent.includeCache[file] = self.IDL
+
+            for type in self.IDL.getNames():
+                parent.setName(type)
+            parent.deps.extend(self.IDL.deps)
+            return
+
+        raise IDLError("File '%s' not found" % self.filename, self.location)
+
+
+class IDL(object):
+    def __init__(self, productions):
+        self.hasSequence = False
+        self.productions = productions
+        self.deps = []
+
+    def setName(self, object):
+        self.namemap.set(object)
+
+    def getName(self, id, location):
+        if id.name == "Array":
+            if id.params is None or len(id.params) != 1:
+                raise IDLError("Array takes exactly 1 parameter", location)
+            self.hasSequence = True
+            return Array(self.getName(id.params[0], location), location)
+
+        if id.params is not None:
+            raise IDLError("Generic type '%s' unrecognized" % id.name, location)
+
+        try:
+            return self.namemap[id.name]
+        except KeyError:
+            raise IDLError("type '%s' not found" % id.name, location)
+
+    def hasName(self, id):
+        return id in self.namemap
+
+    def getNames(self):
+        return iter(self.namemap)
+
+    def __str__(self):
+        return "".join([str(p) for p in self.productions])
+
+    def resolve(self, incdirs, parser, webidlconfig, includeCache=None):
+        self.namemap = NameMap()
+        self.incdirs = incdirs
+        self.parser = parser
+        self.webidlconfig = webidlconfig
+        self.includeCache = {} if includeCache is None else includeCache
+        for p in self.productions:
+            p.resolve(self)
+
+    def includes(self):
+        for p in self.productions:
+            if p.kind == "include":
+                yield p
+        if self.hasSequence:
+            yield Include("nsTArray.h", BuiltinLocation)
+
+    def needsJSTypes(self):
+        for p in self.productions:
+            if p.kind == "interface" and p.needsJSTypes():
+                return True
+        return False
+
+
+class CDATA(object):
+    kind = "cdata"
+    _re = re.compile(r"\n+")
+
+    def __init__(self, data, location):
+        self.data = self._re.sub("\n", data)
+        self.location = location
+
+    def resolve(self, parent):
+        # This can be a false-positive if the word `virtual` is included in a
+        # comment, however this doesn't seem to happen very often.
+        if isinstance(parent, Interface) and re.search(r"\bvirtual\b", self.data):
+            raise IDLError(
+                "cannot declare a C++ `virtual` member in XPIDL interface",
+                self.location,
+                notes=textwrap.fill(
+                    """All virtual members must be declared directly using XPIDL.
+                    Both the Rust bindings and XPConnect rely on the per-platform
+                    vtable layouts generated by the XPIDL compiler to allow
+                    cross-language XPCOM method calls between JS and C++.
+                    Consider using a `[notxpcom, nostdcall]` method instead."""
+                ),
+            )
+
+    def __str__(self):
+        return "cdata: %s\n\t%r\n" % (self.location.get(), self.data)
+
+    def count(self):
+        return 0
+
+
+class Typedef(object):
+    kind = "typedef"
+
+    def __init__(self, type, name, location, doccomments):
+        self.type = type
+        self.name = name
+        self.location = location
+        self.doccomments = doccomments
+
+    def __eq__(self, other):
+        return self.name == other.name and self.type == other.type
+
+    def resolve(self, parent):
+        parent.setName(self)
+        self.realtype = parent.getName(self.type, self.location)
+
+        if not isinstance(self.realtype, (Builtin, CEnum, Native, Typedef)):
+            raise IDLError("Unsupported typedef target type", self.location)
+
+    def nativeType(self, calltype):
+        return "%s %s" % (self.name, "*" if "out" in calltype else "")
+
+    def rustType(self, calltype):
+        if self.name == "nsresult":
+            return "%s::nserror::nsresult" % ("*mut " if "out" in calltype else "")
+
+        return "%s%s" % ("*mut " if "out" in calltype else "", self.name)
+
+    def __str__(self):
+        return "typedef %s %s\n" % (self.type, self.name)
+
+
+class Forward(object):
+    kind = "forward"
+
+    def __init__(self, name, location, doccomments):
+        self.name = name
+        self.location = location
+        self.doccomments = doccomments
+
+    def __eq__(self, other):
+        return other.kind == "forward" and other.name == self.name
+
+    def resolve(self, parent):
+        # Hack alert: if an identifier is already present, move the doccomments
+        # forward.
+        if parent.hasName(self.name):
+            for i in range(0, len(parent.productions)):
+                if parent.productions[i] is self:
+                    break
+            for i in range(i + 1, len(parent.productions)):
+                if hasattr(parent.productions[i], "doccomments"):
+                    parent.productions[i].doccomments[0:0] = self.doccomments
+                    break
+
+        parent.setName(self)
+
+    def nativeType(self, calltype):
+        if calltype == "element":
+            return "RefPtr<%s>" % self.name
+        return "%s *%s" % (self.name, "*" if "out" in calltype else "")
+
+    def rustType(self, calltype):
+        if rustPreventForward(self.name):
+            raise RustNoncompat("forward declaration %s is unsupported" % self.name)
+        if calltype == "element":
+            return "Option<RefPtr<%s>>" % self.name
+        return "%s*const %s" % ("*mut" if "out" in calltype else "", self.name)
+
+    def __str__(self):
+        return "forward-declared %s\n" % self.name
+
+
+class Native(object):
+    kind = "native"
+
+    modifier = None
+    specialtype = None
+
+    # A tuple type here means that a custom value is used for each calltype:
+    #   (in, out/inout, array element) respectively.
+    # A `None` here means that the written type should be used as-is.
+    specialtypes = {
+        "nsid": None,
+        "utf8string": ("const nsACString&", "nsACString&", "nsCString"),
+        "cstring": ("const nsACString&", "nsACString&", "nsCString"),
+        "astring": ("const nsAString&", "nsAString&", "nsString"),
+        "jsval": ("JS::Handle<JS::Value>", "JS::MutableHandle<JS::Value>", "JS::Value"),
+        "promise": "::mozilla::dom::Promise",
+    }
+
+    def __init__(self, name, nativename, attlist, location):
+        self.name = name
+        self.nativename = nativename
+        self.location = location
+
+        for name, value, aloc in attlist:
+            if value is not None:
+                raise IDLError("Unexpected attribute value", aloc)
+            if name in ("ptr", "ref"):
+                if self.modifier is not None:
+                    raise IDLError("More than one ptr/ref modifier", aloc)
+                self.modifier = name
+            elif name in self.specialtypes.keys():
+                if self.specialtype is not None:
+                    raise IDLError("More than one special type", aloc)
+                self.specialtype = name
+                if self.specialtypes[name] is not None:
+                    self.nativename = self.specialtypes[name]
+            else:
+                raise IDLError("Unexpected attribute", aloc)
+
+    def __eq__(self, other):
+        return (
+            self.name == other.name
+            and self.nativename == other.nativename
+            and self.modifier == other.modifier
+            and self.specialtype == other.specialtype
+        )
+
+    def resolve(self, parent):
+        parent.setName(self)
+
+    def isPtr(self, calltype):
+        return self.modifier == "ptr"
+
+    def isRef(self, calltype):
+        return self.modifier == "ref"
+
+    def nativeType(self, calltype, const=False, shared=False):
+        if shared:
+            if calltype != "out":
+                raise IDLError(
+                    "[shared] only applies to out parameters.", self.location
+                )
+            const = True
+
+        if isinstance(self.nativename, tuple):
+            if calltype == "in":
+                return self.nativename[0] + " "
+            elif "out" in calltype:
+                return self.nativename[1] + " "
+            else:
+                return self.nativename[2] + " "
+
+        # 'in' nsid parameters should be made 'const'
+        if self.specialtype == "nsid" and calltype == "in":
+            const = True
+
+        if calltype == "element":
+            if self.specialtype == "nsid":
+                if self.isPtr(calltype):
+                    raise IDLError(
+                        "Array<nsIDPtr> not yet supported. "
+                        "File an XPConnect bug if you need it.",
+                        self.location,
+                    )
+
+                # ns[CI]?IDs should be held directly in Array<T>s
+                return self.nativename
+
+            if self.isRef(calltype):
+                raise IDLError(
+                    "[ref] qualified type unsupported in Array<T>", self.location
+                )
+
+            # Promises should be held in RefPtr<T> in Array<T>s
+            if self.specialtype == "promise":
+                return "RefPtr<mozilla::dom::Promise>"
+
+        if self.isRef(calltype):
+            m = "& "  # [ref] is always passed with a single indirection
+        else:
+            m = "* " if "out" in calltype else ""
+            if self.isPtr(calltype):
+                m += "* "
+        return "%s%s %s" % (const and "const " or "", self.nativename, m)
+
+    def rustType(self, calltype, const=False, shared=False):
+        # For the most part, 'native' types don't make sense in rust, as they
+        # are native C++ types. However, we can support a few types here, as
+        # they're important and can easily be translated.
+        #
+        # NOTE: This code doesn't try to perfectly match C++ constness, as
+        # constness doesn't affect ABI, and raw pointers are already unsafe.
+
+        if self.modifier not in ["ptr", "ref"]:
+            raise RustNoncompat("Rust only supports [ref] / [ptr] native types")
+
+        if shared:
+            if calltype != "out":
+                raise IDLError(
+                    "[shared] only applies to out parameters.", self.location
+                )
+            const = True
+
+        # 'in' nsid parameters should be made 'const'
+        if self.specialtype == "nsid" and calltype == "in":
+            const = True
+
+        prefix = "*const " if const or shared else "*mut "
+        if "out" in calltype and self.isPtr(calltype):
+            prefix = "*mut " + prefix
+
+        if self.specialtype:
+            # The string types are very special, and need to be handled seperately.
+            if self.specialtype in ["cstring", "utf8string"]:
+                if calltype == "in":
+                    return "*const ::nsstring::nsACString"
+                elif "out" in calltype:
+                    return "*mut ::nsstring::nsACString"
+                else:
+                    return "::nsstring::nsCString"
+            if self.specialtype == "astring":
+                if calltype == "in":
+                    return "*const ::nsstring::nsAString"
+                elif "out" in calltype:
+                    return "*mut ::nsstring::nsAString"
+                else:
+                    return "::nsstring::nsString"
+            # nsid has some special handling, but generally re-uses the generic
+            # prefix handling above.
+            if self.specialtype == "nsid":
+                if "element" in calltype:
+                    if self.isPtr(calltype):
+                        raise IDLError(
+                            "Array<nsIDPtr> not yet supported. "
+                            "File an XPConnect bug if you need it.",
+                            self.location,
+                        )
+                    return self.nativename
+                return prefix + self.nativename
+            raise RustNoncompat("special type %s unsupported" % self.specialtype)
+
+        # These 3 special types correspond to native pointer types which can
+        # generally be supported behind pointers. Other types are not supported
+        # for now.
+        if self.nativename == "void":
+            return prefix + "libc::c_void"
+        if self.nativename == "char":
+            return prefix + "libc::c_char"
+        if self.nativename == "char16_t":
+            return prefix + "u16"
+
+        raise RustNoncompat("native type %s unsupported" % self.nativename)
+
+    def __str__(self):
+        return "native %s(%s)\n" % (self.name, self.nativename)
+
+
+class WebIDL(object):
+    kind = "webidl"
+
+    def __init__(self, name, location):
+        self.name = name
+        self.location = location
+
+    def __eq__(self, other):
+        return other.kind == "webidl" and self.name == other.name
+
+    def resolve(self, parent):
+        # XXX(nika): We don't handle _every_ kind of webidl object here (as that
+        # would be hard). For example, we don't support nsIDOM*-defaulting
+        # interfaces.
+        # TODO: More explicit compile-time checks?
+
+        assert (
+            parent.webidlconfig is not None
+        ), "WebIDL declarations require passing webidlconfig to resolve."
+
+        # Resolve our native name according to the WebIDL configs.
+        config = parent.webidlconfig.get(self.name, {})
+        self.native = config.get("nativeType")
+        if self.native is None:
+            self.native = "mozilla::dom::%s" % self.name
+        self.headerFile = config.get("headerFile")
+        if self.headerFile is None:
+            self.headerFile = self.native.replace("::", "/") + ".h"
+
+        parent.setName(self)
+
+    def nativeType(self, calltype, const=False):
+        if calltype == "element":
+            return "RefPtr<%s%s>" % ("const " if const else "", self.native)
+        return "%s%s *%s" % (
+            "const " if const else "",
+            self.native,
+            "*" if "out" in calltype else "",
+        )
+
+    def rustType(self, calltype, const=False):
+        # Just expose the type as a void* - we can't do any better.
+        return "%s*const libc::c_void" % ("*mut " if "out" in calltype else "")
+
+    def __str__(self):
+        return "webidl %s\n" % self.name
+
+
+class Interface(object):
+    kind = "interface"
+
+    def __init__(self, name, attlist, base, members, location, doccomments):
+        self.name = name
+        self.attributes = InterfaceAttributes(attlist, location)
+        self.base = base
+        self.members = members
+        self.location = location
+        self.namemap = NameMap()
+        self.doccomments = doccomments
+        self.nativename = name
+
+        for m in members:
+            if not isinstance(m, CDATA):
+                self.namemap.set(m)
+
+    def __eq__(self, other):
+        return self.name == other.name and self.location == other.location
+
+    def resolve(self, parent):
+        self.idl = parent
+
+        if not self.attributes.scriptable and self.attributes.builtinclass:
+            raise IDLError(
+                "Non-scriptable interface '%s' doesn't need to be marked builtinclass"
+                % self.name,
+                self.location,
+            )
+
+        # Hack alert: if an identifier is already present, libIDL assigns
+        # doc comments incorrectly. This is quirks-mode extraordinaire!
+        if parent.hasName(self.name):
+            for member in self.members:
+                if hasattr(member, "doccomments"):
+                    member.doccomments[0:0] = self.doccomments
+                    break
+            self.doccomments = parent.getName(TypeId(self.name), None).doccomments
+
+        if self.attributes.function:
+            has_method = False
+            for member in self.members:
+                if member.kind == "method":
+                    if has_method:
+                        raise IDLError(
+                            "interface '%s' has multiple methods, but marked 'function'"
+                            % self.name,
+                            self.location,
+                        )
+                    else:
+                        has_method = True
+
+        parent.setName(self)
+        if self.base is not None:
+            realbase = parent.getName(TypeId(self.base), self.location)
+            if realbase.kind != "interface":
+                raise IDLError(
+                    "interface '%s' inherits from non-interface type '%s'"
+                    % (self.name, self.base),
+                    self.location,
+                )
+
+            if self.attributes.scriptable and not realbase.attributes.scriptable:
+                raise IDLError(
+                    "interface '%s' is scriptable but derives from "
+                    "non-scriptable '%s'" % (self.name, self.base),
+                    self.location,
+                    warning=True,
+                )
+
+            if (
+                self.attributes.scriptable
+                and realbase.attributes.builtinclass
+                and not self.attributes.builtinclass
+            ):
+                raise IDLError(
+                    "interface '%s' is not builtinclass but derives from "
+                    "builtinclass '%s'" % (self.name, self.base),
+                    self.location,
+                )
+
+            if realbase.attributes.rust_sync and not self.attributes.rust_sync:
+                raise IDLError(
+                    "interface '%s' is not rust_sync but derives from rust_sync '%s'"
+                    % (self.name, self.base),
+                    self.location,
+                )
+
+            if (
+                self.attributes.rust_sync
+                and self.attributes.scriptable
+                and not self.attributes.builtinclass
+            ):
+                raise IDLError(
+                    "interface '%s' is rust_sync but is not builtinclass" % self.name,
+                    self.location,
+                )
+        elif self.name != "nsISupports":
+            raise IDLError(
+                "Interface '%s' must inherit from nsISupports" % self.name,
+                self.location,
+            )
+
+        for member in self.members:
+            member.resolve(self)
+
+        # The number 250 is NOT arbitrary; this number is the maximum number of
+        # stub entries defined in xpcom/reflect/xptcall/genstubs.pl
+        # Do not increase this value without increasing the number in that
+        # location, or you WILL cause otherwise unknown problems!
+        if self.countEntries() > 250 and not self.attributes.builtinclass:
+            raise IDLError(
+                "interface '%s' has too many entries" % self.name, self.location
+            )
+
+    def nativeType(self, calltype, const=False):
+        if calltype == "element":
+            return "RefPtr<%s>" % self.name
+        return "%s%s *%s" % (
+            "const " if const else "",
+            self.name,
+            "*" if "out" in calltype else "",
+        )
+
+    def rustType(self, calltype, const=False):
+        if calltype == "element":
+            return "Option<RefPtr<%s>>" % self.name
+        return "%s*const %s" % ("*mut " if "out" in calltype else "", self.name)
+
+    def __str__(self):
+        l = ["interface %s\n" % self.name]
+        if self.base is not None:
+            l.append("\tbase %s\n" % self.base)
+        l.append(str(self.attributes))
+        if self.members is None:
+            l.append("\tincomplete type\n")
+        else:
+            for m in self.members:
+                l.append(str(m))
+        return "".join(l)
+
+    def getConst(self, name, location):
+        # The constant may be in a base class
+        iface = self
+        while name not in iface.namemap and iface.base is not None:
+            iface = self.idl.getName(TypeId(iface.base), self.location)
+        if name not in iface.namemap:
+            raise IDLError("cannot find symbol '%s'" % name, location)
+        c = iface.namemap.get(name, location)
+        if c.kind != "const":
+            raise IDLError("symbol '%s' is not a constant" % name, location)
+
+        return c.getValue()
+
+    def needsJSTypes(self):
+        for m in self.members:
+            if m.kind == "attribute" and m.type == TypeId("jsval"):
+                return True
+            if m.kind == "method" and m.needsJSTypes():
+                return True
+        return False
+
+    def countEntries(self):
+        """Returns the number of entries in the vtable for this interface."""
+        total = sum(member.count() for member in self.members)
+        if self.base is not None:
+            realbase = self.idl.getName(TypeId(self.base), self.location)
+            total += realbase.countEntries()
+        return total
+
+
+class InterfaceAttributes(object):
+    uuid = None
+    scriptable = False
+    builtinclass = False
+    function = False
+    main_process_scriptable_only = False
+    rust_sync = False
+
+    def setuuid(self, value):
+        self.uuid = value.lower()
+
+    def setscriptable(self):
+        self.scriptable = True
+
+    def setfunction(self):
+        self.function = True
+
+    def setbuiltinclass(self):
+        self.builtinclass = True
+
+    def setmain_process_scriptable_only(self):
+        self.main_process_scriptable_only = True
+
+    def setrust_sync(self):
+        self.rust_sync = True
+
+    actions = {
+        "uuid": (True, setuuid),
+        "scriptable": (False, setscriptable),
+        "builtinclass": (False, setbuiltinclass),
+        "function": (False, setfunction),
+        "object": (False, lambda self: True),
+        "main_process_scriptable_only": (False, setmain_process_scriptable_only),
+        "rust_sync": (False, setrust_sync),
+    }
+
+    def __init__(self, attlist, location):
+        def badattribute(self):
+            raise IDLError("Unexpected interface attribute '%s'" % name, location)
+
+        for name, val, aloc in attlist:
+            hasval, action = self.actions.get(name, (False, badattribute))
+            if hasval:
+                if val is None:
+                    raise IDLError("Expected value for attribute '%s'" % name, aloc)
+
+                action(self, val)
+            else:
+                if val is not None:
+                    raise IDLError("Unexpected value for attribute '%s'" % name, aloc)
+
+                action(self)
+
+        if self.uuid is None:
+            raise IDLError("interface has no uuid", location)
+
+    def __str__(self):
+        l = []
+        if self.uuid:
+            l.append("\tuuid: %s\n" % self.uuid)
+        if self.scriptable:
+            l.append("\tscriptable\n")
+        if self.builtinclass:
+            l.append("\tbuiltinclass\n")
+        if self.function:
+            l.append("\tfunction\n")
+        if self.main_process_scriptable_only:
+            l.append("\tmain_process_scriptable_only\n")
+        if self.rust_sync:
+            l.append("\trust_sync\n")
+        return "".join(l)
+
+
+class ConstMember(object):
+    kind = "const"
+
+    def __init__(self, type, name, value, location, doccomments):
+        self.type = type
+        self.name = name
+        self.valueFn = value
+        self.location = location
+        self.doccomments = doccomments
+
+    def resolve(self, parent):
+        self.realtype = parent.idl.getName(self.type, self.location)
+        self.iface = parent
+        basetype = self.realtype
+        while isinstance(basetype, Typedef):
+            basetype = basetype.realtype
+        if not isinstance(basetype, Builtin) or not basetype.maybeConst:
+            raise IDLError(
+                "const may only be a short or long type, not %s" % self.type,
+                self.location,
+            )
+
+        self.basetype = basetype
+        # Value is a lambda. Resolve it.
+        self.value = self.valueFn(self.iface)
+
+        min_val = -(2**31) if basetype.signed else 0
+        max_val = 2**31 - 1 if basetype.signed else 2**32 - 1
+        if self.value < min_val or self.value > max_val:
+            raise IDLError(
+                "xpidl constants must fit within %s"
+                % ("int32_t" if basetype.signed else "uint32_t"),
+                self.location,
+            )
+
+    def getValue(self):
+        return self.value
+
+    def __str__(self):
+        return "\tconst %s %s = %s\n" % (self.type, self.name, self.getValue())
+
+    def count(self):
+        return 0
+
+
+# Represents a single name/value pair in a CEnum
+class CEnumVariant(object):
+    # Treat CEnumVariants as consts in terms of value resolution, so we can
+    # do things like binary operation values for enum members.
+    kind = "const"
+
+    def __init__(self, name, value, location):
+        self.name = name
+        self.valueFn = value
+        self.location = location
+
+    def getValue(self):
+        return self.value
+
+
+class CEnum(object):
+    kind = "cenum"
+
+    def __init__(self, width, name, variants, location, doccomments):
+        # We have to set a name here, otherwise we won't pass namemap checks on
+        # the interface. This name will change it in resolve(), in order to
+        # namespace the enum within the interface.
+        self.name = name
+        self.basename = name
+        self.width = width
+        self.location = location
+        self.namemap = NameMap()
+        self.doccomments = doccomments
+        self.variants = variants
+        if self.width not in (8, 16, 32):
+            raise IDLError("Width must be one of {8, 16, 32}", self.location)
+
+    def resolve(self, iface):
+        self.iface = iface
+        # Renaming enum to faux-namespace the enum type to the interface in JS
+        # so we don't collide in the global namespace. Hacky/ugly but it does
+        # the job well enough, and the name will still be interface::variant in
+        # C++.
+        self.name = "%s_%s" % (self.iface.name, self.basename)
+        self.iface.idl.setName(self)
+
+        # Compute the value for each enum variant that doesn't set its own
+        # value
+        next_value = 0
+        for variant in self.variants:
+            # CEnum variants resolve to interface level consts in javascript,
+            # meaning their names could collide with other interface members.
+            # Iterate through all CEnum variants to make sure there are no
+            # collisions.
+            self.iface.namemap.set(variant)
+            # Value may be a lambda. If it is, resolve it.
+            if variant.valueFn:
+                next_value = variant.value = variant.valueFn(self.iface)
+            else:
+                variant.value = next_value
+            next_value += 1
+
+    def count(self):
+        return 0
+
+    def nativeType(self, calltype):
+        if "out" in calltype:
+            return "%s::%s *" % (self.iface.name, self.basename)
+        return "%s::%s " % (self.iface.name, self.basename)
+
+    def rustType(self, calltype):
+        return "%s u%d" % ("*mut" if "out" in calltype else "", self.width)
+
+    def __str__(self):
+        body = ", ".join("%s = %s" % v for v in self.variants)
+        return "\tcenum %s : %d { %s };\n" % (self.name, self.width, body)
+
+
+# Infallible doesn't work for all return types.
+#
+# It also must be implemented on a builtinclass (otherwise it'd be unsound as
+# it could be implemented by JS).
+def ensureInfallibleIsSound(methodOrAttribute):
+    if not methodOrAttribute.infallible:
+        return
+    if methodOrAttribute.realtype.kind not in [
+        "builtin",
+        "interface",
+        "forward",
+        "webidl",
+        "cenum",
+    ]:
+        raise IDLError(
+            "[infallible] only works on interfaces, domobjects, and builtin types "
+            "(numbers, booleans, cenum, and raw char types)",
+            methodOrAttribute.location,
+        )
+    ifaceAttributes = methodOrAttribute.iface.attributes
+    if ifaceAttributes.scriptable and not ifaceAttributes.builtinclass:
+        raise IDLError(
+            "[infallible] attributes and methods are only allowed on "
+            "non-[scriptable] or [builtinclass] interfaces",
+            methodOrAttribute.location,
+        )
+
+    if methodOrAttribute.notxpcom:
+        raise IDLError(
+            "[infallible] does not make sense for a [notxpcom] " "method or attribute",
+            methodOrAttribute.location,
+        )
+
+
+# An interface cannot be implemented by JS if it has a notxpcom or nostdcall
+# method or attribute, so it must be marked as builtinclass.
+def ensureBuiltinClassIfNeeded(methodOrAttribute):
+    iface = methodOrAttribute.iface
+    if not iface.attributes.scriptable or iface.attributes.builtinclass:
+        return
+    if iface.name == "nsISupports":
+        return
+    if methodOrAttribute.notxpcom:
+        raise IDLError(
+            (
+                "scriptable interface '%s' must be marked [builtinclass] because it "
+                "contains a [notxpcom] %s '%s'"
+            )
+            % (iface.name, methodOrAttribute.kind, methodOrAttribute.name),
+            methodOrAttribute.location,
+        )
+    if methodOrAttribute.nostdcall:
+        raise IDLError(
+            (
+                "scriptable interface '%s' must be marked [builtinclass] because it "
+                "contains a [nostdcall] %s '%s'"
+            )
+            % (iface.name, methodOrAttribute.kind, methodOrAttribute.name),
+            methodOrAttribute.location,
+        )
+
+
+class Attribute(object):
+    kind = "attribute"
+    noscript = False
+    notxpcom = False
+    readonly = False
+    symbol = False
+    implicit_jscontext = False
+    nostdcall = False
+    must_use = False
+    binaryname = None
+    infallible = False
+    # explicit_setter_can_run_script is true if the attribute is explicitly
+    # annotated as having a setter that can cause script to run.
+    explicit_setter_can_run_script = False
+    # explicit_getter_can_run_script is true if the attribute is explicitly
+    # annotated as having a getter that can cause script to run.
+    explicit_getter_can_run_script = False
+
+    def __init__(self, type, name, attlist, readonly, location, doccomments):
+        self.type = type
+        self.name = name
+        self.attlist = attlist
+        self.readonly = readonly
+        self.location = location
+        self.doccomments = doccomments
+
+        for name, value, aloc in attlist:
+            if name == "binaryname":
+                if value is None:
+                    raise IDLError("binaryname attribute requires a value", aloc)
+
+                self.binaryname = value
+                continue
+
+            if value is not None:
+                raise IDLError("Unexpected attribute value", aloc)
+
+            if name == "noscript":
+                self.noscript = True
+            elif name == "notxpcom":
+                self.notxpcom = True
+            elif name == "symbol":
+                self.symbol = True
+            elif name == "implicit_jscontext":
+                self.implicit_jscontext = True
+            elif name == "nostdcall":
+                self.nostdcall = True
+            elif name == "must_use":
+                self.must_use = True
+            elif name == "infallible":
+                self.infallible = True
+            elif name == "can_run_script":
+                if (
+                    self.explicit_setter_can_run_script
+                    or self.explicit_getter_can_run_script
+                ):
+                    raise IDLError(
+                        "Redundant getter_can_run_script or "
+                        "setter_can_run_script annotation on "
+                        "attribute",
+                        aloc,
+                    )
+                self.explicit_setter_can_run_script = True
+                self.explicit_getter_can_run_script = True
+            elif name == "setter_can_run_script":
+                if self.explicit_setter_can_run_script:
+                    raise IDLError(
+                        "Redundant setter_can_run_script annotation " "on attribute",
+                        aloc,
+                    )
+                self.explicit_setter_can_run_script = True
+            elif name == "getter_can_run_script":
+                if self.explicit_getter_can_run_script:
+                    raise IDLError(
+                        "Redundant getter_can_run_script annotation " "on attribute",
+                        aloc,
+                    )
+                self.explicit_getter_can_run_script = True
+            else:
+                raise IDLError("Unexpected attribute '%s'" % name, aloc)
+
+    def resolve(self, iface):
+        self.iface = iface
+        self.realtype = iface.idl.getName(self.type, self.location)
+
+        ensureInfallibleIsSound(self)
+        ensureBuiltinClassIfNeeded(self)
+
+    def toIDL(self):
+        attribs = attlistToIDL(self.attlist)
+        readonly = self.readonly and "readonly " or ""
+        return "%s%sattribute %s %s;" % (attribs, readonly, self.type, self.name)
+
+    def isScriptable(self):
+        if not self.iface.attributes.scriptable:
+            return False
+        return not (self.noscript or self.notxpcom or self.nostdcall)
+
+    def __str__(self):
+        return "\t%sattribute %s %s\n" % (
+            self.readonly and "readonly " or "",
+            self.type,
+            self.name,
+        )
+
+    def count(self):
+        return self.readonly and 1 or 2
+
+
+class Method(object):
+    kind = "method"
+    noscript = False
+    notxpcom = False
+    symbol = False
+    binaryname = None
+    implicit_jscontext = False
+    nostdcall = False
+    must_use = False
+    optional_argc = False
+    # explicit_can_run_script is true if the method is explicitly annotated
+    # as being able to cause script to run.
+    explicit_can_run_script = False
+    infallible = False
+
+    def __init__(self, type, name, attlist, paramlist, location, doccomments, raises):
+        self.type = type
+        self.name = name
+        self.attlist = attlist
+        self.params = paramlist
+        self.location = location
+        self.doccomments = doccomments
+        self.raises = raises
+
+        for name, value, aloc in attlist:
+            if name == "binaryname":
+                if value is None:
+                    raise IDLError("binaryname attribute requires a value", aloc)
+
+                self.binaryname = value
+                continue
+
+            if value is not None:
+                raise IDLError("Unexpected attribute value", aloc)
+
+            if name == "noscript":
+                self.noscript = True
+            elif name == "notxpcom":
+                self.notxpcom = True
+            elif name == "symbol":
+                self.symbol = True
+            elif name == "implicit_jscontext":
+                self.implicit_jscontext = True
+            elif name == "optional_argc":
+                self.optional_argc = True
+            elif name == "nostdcall":
+                self.nostdcall = True
+            elif name == "must_use":
+                self.must_use = True
+            elif name == "can_run_script":
+                self.explicit_can_run_script = True
+            elif name == "infallible":
+                self.infallible = True
+            else:
+                raise IDLError("Unexpected attribute '%s'" % name, aloc)
+
+        self.namemap = NameMap()
+        for p in paramlist:
+            self.namemap.set(p)
+
+    def resolve(self, iface):
+        self.iface = iface
+        self.realtype = self.iface.idl.getName(self.type, self.location)
+
+        ensureInfallibleIsSound(self)
+        ensureBuiltinClassIfNeeded(self)
+
+        for p in self.params:
+            p.resolve(self)
+        for p in self.params:
+            if p.retval and p != self.params[-1]:
+                raise IDLError(
+                    "'retval' parameter '%s' is not the last parameter" % p.name,
+                    self.location,
+                )
+            if p.size_is:
+                size_param = self.namemap.get(p.size_is, p.location)
+                if (
+                    p.paramtype.count("in") == 1
+                    and size_param.paramtype.count("in") == 0
+                ):
+                    raise IDLError(
+                        "size_is parameter of an input must also be an input",
+                        p.location,
+                    )
+                if getBuiltinOrNativeTypeName(size_param.realtype) != "unsigned long":
+                    raise IDLError(
+                        "size_is parameter must have type 'unsigned long'",
+                        p.location,
+                    )
+            if p.iid_is:
+                iid_param = self.namemap.get(p.iid_is, p.location)
+                if (
+                    p.paramtype.count("in") == 1
+                    and iid_param.paramtype.count("in") == 0
+                ):
+                    raise IDLError(
+                        "iid_is parameter of an input must also be an input",
+                        p.location,
+                    )
+                if getBuiltinOrNativeTypeName(iid_param.realtype) != "[nsid]":
+                    raise IDLError(
+                        "iid_is parameter must be an nsIID",
+                        self.location,
+                    )
+
+    def isScriptable(self):
+        if not self.iface.attributes.scriptable:
+            return False
+        return not (self.noscript or self.notxpcom or self.nostdcall)
+
+    def __str__(self):
+        return "\t%s %s(%s)\n" % (
+            self.type,
+            self.name,
+            ", ".join([p.name for p in self.params]),
+        )
+
+    def toIDL(self):
+        if len(self.raises):
+            raises = " raises (%s)" % ",".join(self.raises)
+        else:
+            raises = ""
+
+        return "%s%s %s (%s)%s;" % (
+            attlistToIDL(self.attlist),
+            self.type,
+            self.name,
+            ", ".join([p.toIDL() for p in self.params]),
+            raises,
+        )
+
+    def needsJSTypes(self):
+        if self.implicit_jscontext:
+            return True
+        if self.type == TypeId("jsval"):
+            return True
+        for p in self.params:
+            t = p.realtype
+            if isinstance(t, Native) and t.specialtype == "jsval":
+                return True
+        return False
+
+    def count(self):
+        return 1
+
+
+class Param(object):
+    size_is = None
+    iid_is = None
+    const = False
+    array = False
+    retval = False
+    shared = False
+    optional = False
+    default_value = None
+
+    def __init__(self, paramtype, type, name, attlist, location, realtype=None):
+        self.paramtype = paramtype
+        self.type = type
+        self.name = name
+        self.attlist = attlist
+        self.location = location
+        self.realtype = realtype
+
+        for name, value, aloc in attlist:
+            # Put the value-taking attributes first!
+            if name == "size_is":
+                if value is None:
+                    raise IDLError("'size_is' must specify a parameter", aloc)
+                self.size_is = value
+            elif name == "iid_is":
+                if value is None:
+                    raise IDLError("'iid_is' must specify a parameter", aloc)
+                self.iid_is = value
+            elif name == "default":
+                if value is None:
+                    raise IDLError("'default' must specify a default value", aloc)
+                self.default_value = value
+            else:
+                if value is not None:
+                    raise IDLError("Unexpected value for attribute '%s'" % name, aloc)
+
+                if name == "const":
+                    self.const = True
+                elif name == "array":
+                    self.array = True
+                elif name == "retval":
+                    self.retval = True
+                elif name == "shared":
+                    self.shared = True
+                elif name == "optional":
+                    self.optional = True
+                else:
+                    raise IDLError("Unexpected attribute '%s'" % name, aloc)
+
+    def resolve(self, method):
+        self.realtype = method.iface.idl.getName(self.type, self.location)
+        if self.array:
+            self.realtype = LegacyArray(self.realtype)
+
+    def nativeType(self):
+        kwargs = {}
+        if self.shared:
+            kwargs["shared"] = True
+        if self.const:
+            kwargs["const"] = True
+
+        try:
+            return self.realtype.nativeType(self.paramtype, **kwargs)
+        except IDLError as e:
+            raise IDLError(str(e), self.location)
+        except TypeError:
+            raise IDLError("Unexpected parameter attribute", self.location)
+
+    def rustType(self):
+        kwargs = {}
+        if self.shared:
+            kwargs["shared"] = True
+        if self.const:
+            kwargs["const"] = True
+
+        try:
+            return self.realtype.rustType(self.paramtype, **kwargs)
+        except IDLError as e:
+            raise IDLError(str(e), self.location)
+        except TypeError:
+            raise IDLError("Unexpected parameter attribute", self.location)
+
+    def toIDL(self):
+        return "%s%s %s %s" % (
+            paramAttlistToIDL(self.attlist),
+            self.paramtype,
+            self.type,
+            self.name,
+        )
+
+
+class LegacyArray(object):
+    def __init__(self, basetype):
+        self.type = basetype
+        self.location = self.type.location
+
+    def nativeType(self, calltype, const=False):
+        if "element" in calltype:
+            raise IDLError("nested [array] unsupported", self.location)
+
+        # For legacy reasons, we have to add a 'const ' to builtin pointer array
+        # types. (`[array] in string` and `[array] in wstring` parameters)
+        if (
+            calltype == "in"
+            and isinstance(self.type, Builtin)
+            and self.type.isPointer()
+        ):
+            const = True
+
+        return "%s%s*%s" % (
+            "const " if const else "",
+            self.type.nativeType("legacyelement"),
+            "*" if "out" in calltype else "",
+        )
+
+    def rustType(self, calltype, const=False):
+        return "%s%s%s" % (
+            "*mut " if "out" in calltype else "",
+            "*const " if const else "*mut ",
+            self.type.rustType("legacyelement"),
+        )
+
+
+class Array(object):
+    kind = "array"
+
+    def __init__(self, type, location):
+        self.type = type
+        self.location = location
+
+    @property
+    def name(self):
+        return "Array<%s>" % self.type.name
+
+    def resolve(self, idl):
+        idl.getName(self.type, self.location)
+
+    def nativeType(self, calltype):
+        if calltype == "legacyelement":
+            raise IDLError("[array] Array<T> is unsupported", self.location)
+
+        base = "nsTArray<%s>" % self.type.nativeType("element")
+        if "out" in calltype:
+            return "%s& " % base
+        elif "in" == calltype:
+            return "const %s& " % base
+        else:
+            return base
+
+    def rustType(self, calltype):
+        if calltype == "legacyelement":
+            raise IDLError("[array] Array<T> is unsupported", self.location)
+
+        base = "thin_vec::ThinVec<%s>" % self.type.rustType("element")
+        if "out" in calltype:
+            return "*mut %s" % base
+        elif "in" == calltype:
+            return "*const %s" % base
+        else:
+            return base
+
+
+TypeId = namedtuple("TypeId", "name params")
+
+
+# Make str(TypeId) produce a nicer value
+TypeId.__str__ = (
+    lambda self: "%s<%s>" % (self.name, ", ".join(str(p) for p in self.params))
+    if self.params is not None
+    else self.name
+)
+
+
+# Allow skipping 'params' in TypeId(..)
+TypeId.__new__.__defaults__ = (None,)
+
+
+class IDLParser(object):
+    keywords = {
+        "cenum": "CENUM",
+        "const": "CONST",
+        "interface": "INTERFACE",
+        "in": "IN",
+        "inout": "INOUT",
+        "out": "OUT",
+        "attribute": "ATTRIBUTE",
+        "raises": "RAISES",
+        "readonly": "READONLY",
+        "native": "NATIVE",
+        "typedef": "TYPEDEF",
+        "webidl": "WEBIDL",
+    }
+
+    tokens = [
+        "IDENTIFIER",
+        "CDATA",
+        "INCLUDE",
+        "IID",
+        "NUMBER",
+        "HEXNUM",
+        "LSHIFT",
+        "RSHIFT",
+        "NATIVEID",
+    ]
+
+    tokens.extend(keywords.values())
+
+    states = (("nativeid", "exclusive"),)
+
+    hexchar = r"[a-fA-F0-9]"
+
+    t_NUMBER = r"-?\d+"
+    t_HEXNUM = r"0x%s+" % hexchar
+    t_LSHIFT = r"<<"
+    t_RSHIFT = r">>"
+
+    literals = '"(){}[]<>,;:=|+-*'
+
+    t_ignore = " \t"
+
+    def t_multilinecomment(self, t):
+        r"/\*(\n|.)*?\*/"
+        t.lexer.lineno += t.value.count("\n")
+        if t.value.startswith("/**"):
+            self._doccomments.append(t.value)
+
+    def t_singlelinecomment(self, t):
+        r"//[^\n]*"
+
+    def t_IID(self, t):
+        return t
+
+    t_IID.__doc__ = r"%(c)s{8}-%(c)s{4}-%(c)s{4}-%(c)s{4}-%(c)s{12}" % {"c": hexchar}
+
+    def t_IDENTIFIER(self, t):
+        r"(unsigned\ long\ long|unsigned\ short|unsigned\ long|long\ long)(?!_?[A-Za-z][A-Za-z_0-9])|_?[A-Za-z][A-Za-z_0-9]*"  # NOQA: E501
+        t.type = self.keywords.get(t.value, "IDENTIFIER")
+        return t
+
+    def t_LCDATA(self, t):
+        r"%\{[ ]*C\+\+[ ]*\n(?P<cdata>(\n|.)*?\n?)%\}[ ]*(C\+\+)?"
+        t.type = "CDATA"
+        t.value = t.lexer.lexmatch.group("cdata")
+        t.lexer.lineno += t.value.count("\n")
+        return t
+
+    def t_INCLUDE(self, t):
+        r'\#include[ \t]+"[^"\n]+"'
+        inc, value, end = t.value.split('"')
+        t.value = value
+        return t
+
+    def t_directive(self, t):
+        r"\#(?P<directive>[a-zA-Z]+)[^\n]+"
+        raise IDLError(
+            "Unrecognized directive %s" % t.lexer.lexmatch.group("directive"),
+            Location(
+                lexer=self.lexer, lineno=self.lexer.lineno, lexpos=self.lexer.lexpos
+            ),
+        )
+
+    def t_newline(self, t):
+        r"\n+"
+        t.lexer.lineno += len(t.value)
+
+    def t_nativeid_NATIVEID(self, t):
+        # Matches non-parenthesis characters, or a single open and closing
+        # parenthesis with at least one non-parenthesis character before,
+        # between and after them (for compatibility with std::function).
+        r"[^()\n]+(?:\([^()\n]+\)[^()\n]+)?(?=\))"
+        t.lexer.begin("INITIAL")
+        return t
+
+    t_nativeid_ignore = ""
+
+    def t_ANY_error(self, t):
+        raise IDLError(
+            "unrecognized input",
+            Location(
+                lexer=self.lexer, lineno=self.lexer.lineno, lexpos=self.lexer.lexpos
+            ),
+        )
+
+    precedence = (
+        ("left", "|"),
+        ("left", "LSHIFT", "RSHIFT"),
+        ("left", "+", "-"),
+        ("left", "*"),
+        ("left", "UMINUS"),
+    )
+
+    def p_idlfile(self, p):
+        """idlfile : productions"""
+        p[0] = IDL(p[1])
+
+    def p_productions_start(self, p):
+        """productions :"""
+        p[0] = []
+
+    def p_productions_cdata(self, p):
+        """productions : CDATA productions"""
+        p[0] = list(p[2])
+        p[0].insert(0, CDATA(p[1], self.getLocation(p, 1)))
+
+    def p_productions_include(self, p):
+        """productions : INCLUDE productions"""
+        p[0] = list(p[2])
+        p[0].insert(0, Include(p[1], self.getLocation(p, 1)))
+
+    def p_productions_interface(self, p):
+        """productions : interface productions
+        | typedef productions
+        | native productions
+        | webidl productions"""
+        p[0] = list(p[2])
+        p[0].insert(0, p[1])
+
+    def p_typedef(self, p):
+        """typedef : TYPEDEF type IDENTIFIER ';'"""
+        p[0] = Typedef(
+            type=p[2],
+            name=p[3],
+            location=self.getLocation(p, 1),
+            doccomments=p.slice[1].doccomments,
+        )
+
+    def p_native(self, p):
+        """native : attributes NATIVE IDENTIFIER afternativeid '(' NATIVEID ')' ';'"""
+        p[0] = Native(
+            name=p[3],
+            nativename=p[6],
+            attlist=p[1]["attlist"],
+            location=self.getLocation(p, 2),
+        )
+
+    def p_afternativeid(self, p):
+        """afternativeid :"""
+        # this is a place marker: we switch the lexer into literal identifier
+        # mode here, to slurp up everything until the closeparen
+        self.lexer.begin("nativeid")
+
+    def p_webidl(self, p):
+        """webidl : WEBIDL IDENTIFIER ';'"""
+        p[0] = WebIDL(name=p[2], location=self.getLocation(p, 2))
+
+    def p_anyident(self, p):
+        """anyident : IDENTIFIER
+        | CONST"""
+        p[0] = {"value": p[1], "location": self.getLocation(p, 1)}
+
+    def p_attributes(self, p):
+        """attributes : '[' attlist ']'
+        |"""
+        if len(p) == 1:
+            p[0] = {"attlist": []}
+        else:
+            p[0] = {"attlist": p[2], "doccomments": p.slice[1].doccomments}
+
+    def p_attlist_start(self, p):
+        """attlist : attribute"""
+        p[0] = [p[1]]
+
+    def p_attlist_continue(self, p):
+        """attlist : attribute ',' attlist"""
+        p[0] = list(p[3])
+        p[0].insert(0, p[1])
+
+    def p_attribute(self, p):
+        """attribute : anyident attributeval"""
+        p[0] = (p[1]["value"], p[2], p[1]["location"])
+
+    def p_attributeval(self, p):
+        """attributeval : '(' IDENTIFIER ')'
+        | '(' IID ')'
+        |"""
+        if len(p) > 1:
+            p[0] = p[2]
+
+    def p_interface(self, p):
+        """interface : attributes INTERFACE IDENTIFIER ifacebase ifacebody ';'"""
+        atts, INTERFACE, name, base, body, SEMI = p[1:]
+        attlist = atts["attlist"]
+        doccomments = []
+        if "doccomments" in atts:
+            doccomments.extend(atts["doccomments"])
+        doccomments.extend(p.slice[2].doccomments)
+
+        def loc():
+            return self.getLocation(p, 2)
+
+        if body is None:
+            # forward-declared interface... must not have attributes!
+            if len(attlist) != 0:
+                raise IDLError(
+                    "Forward-declared interface must not have attributes", loc()
+                )
+
+            if base is not None:
+                raise IDLError("Forward-declared interface must not have a base", loc())
+            p[0] = Forward(name=name, location=loc(), doccomments=doccomments)
+        else:
+            p[0] = Interface(
+                name=name,
+                attlist=attlist,
+                base=base,
+                members=body,
+                location=loc(),
+                doccomments=doccomments,
+            )
+
+    def p_ifacebody(self, p):
+        """ifacebody : '{' members '}'
+        |"""
+        if len(p) > 1:
+            p[0] = p[2]
+
+    def p_ifacebase(self, p):
+        """ifacebase : ':' IDENTIFIER
+        |"""
+        if len(p) == 3:
+            p[0] = p[2]
+
+    def p_members_start(self, p):
+        """members :"""
+        p[0] = []
+
+    def p_members_continue(self, p):
+        """members : member members"""
+        p[0] = list(p[2])
+        p[0].insert(0, p[1])
+
+    def p_member_cdata(self, p):
+        """member : CDATA"""
+        p[0] = CDATA(p[1], self.getLocation(p, 1))
+
+    def p_member_const(self, p):
+        """member : CONST type IDENTIFIER '=' number ';'"""
+        p[0] = ConstMember(
+            type=p[2],
+            name=p[3],
+            value=p[5],
+            location=self.getLocation(p, 1),
+            doccomments=p.slice[1].doccomments,
+        )
+
+    # All "number" products return a function(interface)
+
+    def p_number_decimal(self, p):
+        """number : NUMBER"""
+        n = int(p[1])
+        p[0] = lambda i: n
+
+    def p_number_hex(self, p):
+        """number : HEXNUM"""
+        n = int(p[1], 16)
+        p[0] = lambda i: n
+
+    def p_number_identifier(self, p):
+        """number : IDENTIFIER"""
+        id = p[1]
+        loc = self.getLocation(p, 1)
+        p[0] = lambda i: i.getConst(id, loc)
+
+    def p_number_paren(self, p):
+        """number : '(' number ')'"""
+        p[0] = p[2]
+
+    def p_number_neg(self, p):
+        """number : '-' number %prec UMINUS"""
+        n = p[2]
+        p[0] = lambda i: -n(i)
+
+    def p_number_add(self, p):
+        """number : number '+' number
+        | number '-' number
+        | number '*' number"""
+        n1 = p[1]
+        n2 = p[3]
+        if p[2] == "+":
+            p[0] = lambda i: n1(i) + n2(i)
+        elif p[2] == "-":
+            p[0] = lambda i: n1(i) - n2(i)
+        else:
+            p[0] = lambda i: n1(i) * n2(i)
+
+    def p_number_shift(self, p):
+        """number : number LSHIFT number
+        | number RSHIFT number"""
+        n1 = p[1]
+        n2 = p[3]
+        if p[2] == "<<":
+            p[0] = lambda i: n1(i) << n2(i)
+        else:
+            p[0] = lambda i: n1(i) >> n2(i)
+
+    def p_number_bitor(self, p):
+        """number : number '|' number"""
+        n1 = p[1]
+        n2 = p[3]
+        p[0] = lambda i: n1(i) | n2(i)
+
+    def p_member_cenum(self, p):
+        """member : CENUM IDENTIFIER ':' NUMBER '{' variants '}' ';'"""
+        p[0] = CEnum(
+            name=p[2],
+            width=int(p[4]),
+            variants=p[6],
+            location=self.getLocation(p, 1),
+            doccomments=p.slice[1].doccomments,
+        )
+
+    def p_variants_start(self, p):
+        """variants :"""
+        p[0] = []
+
+    def p_variants_single(self, p):
+        """variants : variant"""
+        p[0] = [p[1]]
+
+    def p_variants_continue(self, p):
+        """variants : variant ',' variants"""
+        p[0] = [p[1]] + p[3]
+
+    def p_variant_implicit(self, p):
+        """variant : IDENTIFIER"""
+        p[0] = CEnumVariant(p[1], None, self.getLocation(p, 1))
+
+    def p_variant_explicit(self, p):
+        """variant : IDENTIFIER '=' number"""
+        p[0] = CEnumVariant(p[1], p[3], self.getLocation(p, 1))
+
+    def p_member_att(self, p):
+        """member : attributes optreadonly ATTRIBUTE type IDENTIFIER ';'"""
+        if "doccomments" in p[1]:
+            doccomments = p[1]["doccomments"]
+        elif p[2] is not None:
+            doccomments = p[2]
+        else:
+            doccomments = p.slice[3].doccomments
+
+        p[0] = Attribute(
+            type=p[4],
+            name=p[5],
+            attlist=p[1]["attlist"],
+            readonly=p[2] is not None,
+            location=self.getLocation(p, 3),
+            doccomments=doccomments,
+        )
+
+    def p_member_method(self, p):
+        """member : attributes type IDENTIFIER '(' paramlist ')' raises ';'"""
+        if "doccomments" in p[1]:
+            doccomments = p[1]["doccomments"]
+        else:
+            doccomments = p.slice[2].doccomments
+
+        p[0] = Method(
+            type=p[2],
+            name=p[3],
+            attlist=p[1]["attlist"],
+            paramlist=p[5],
+            location=self.getLocation(p, 3),
+            doccomments=doccomments,
+            raises=p[7],
+        )
+
+    def p_paramlist(self, p):
+        """paramlist : param moreparams
+        |"""
+        if len(p) == 1:
+            p[0] = []
+        else:
+            p[0] = list(p[2])
+            p[0].insert(0, p[1])
+
+    def p_moreparams_start(self, p):
+        """moreparams :"""
+        p[0] = []
+
+    def p_moreparams_continue(self, p):
+        """moreparams : ',' param moreparams"""
+        p[0] = list(p[3])
+        p[0].insert(0, p[2])
+
+    def p_param(self, p):
+        """param : attributes paramtype type IDENTIFIER"""
+        p[0] = Param(
+            paramtype=p[2],
+            type=p[3],
+            name=p[4],
+            attlist=p[1]["attlist"],
+            location=self.getLocation(p, 4),
+        )
+
+    def p_paramtype(self, p):
+        """paramtype : IN
+        | INOUT
+        | OUT"""
+        p[0] = p[1]
+
+    def p_optreadonly(self, p):
+        """optreadonly : READONLY
+        |"""
+        if len(p) > 1:
+            p[0] = p.slice[1].doccomments
+        else:
+            p[0] = None
+
+    def p_raises(self, p):
+        """raises : RAISES '(' idlist ')'
+        |"""
+        if len(p) == 1:
+            p[0] = []
+        else:
+            p[0] = p[3]
+
+    def p_idlist(self, p):
+        """idlist : IDENTIFIER"""
+        p[0] = [p[1]]
+
+    def p_idlist_continue(self, p):
+        """idlist : IDENTIFIER ',' idlist"""
+        p[0] = list(p[3])
+        p[0].insert(0, p[1])
+
+    def p_type_id(self, p):
+        """type : IDENTIFIER"""
+        p[0] = TypeId(name=p[1])
+        p.slice[0].doccomments = p.slice[1].doccomments
+
+    def p_type_generic(self, p):
+        """type : IDENTIFIER '<' typelist '>'"""
+        p[0] = TypeId(name=p[1], params=p[3])
+        p.slice[0].doccomments = p.slice[1].doccomments
+
+    def p_typelist(self, p):
+        """typelist : type"""
+        p[0] = [p[1]]
+
+    def p_typelist_continue(self, p):
+        """typelist : type ',' typelist"""
+        p[0] = list(p[3])
+        p[0].insert(0, p[1])
+
+    def p_error(self, t):
+        if not t:
+            raise IDLError(
+                "Syntax Error at end of file. Possibly due to missing semicolon(;), braces(}) "
+                "or both",
+                None,
+            )
+        else:
+            location = Location(self.lexer, t.lineno, t.lexpos)
+            raise IDLError("invalid syntax", location)
+
+    def __init__(self):
+        self._doccomments = []
+        self.lexer = lex.lex(object=self, debug=False)
+        self.parser = yacc.yacc(module=self, write_tables=False, debug=False)
+
+    def clearComments(self):
+        self._doccomments = []
+
+    def token(self):
+        t = self.lexer.token()
+        if t is not None and t.type != "CDATA":
+            t.doccomments = self._doccomments
+            self._doccomments = []
+        return t
+
+    def parse(self, data, filename=None):
+        if filename is not None:
+            self.lexer.filename = filename
+        self.lexer.lineno = 1
+        self.lexer.input(data)
+        idl = self.parser.parse(lexer=self)
+        if filename is not None:
+            idl.deps.append(filename)
+        return idl
+
+    def getLocation(self, p, i):
+        return Location(self.lexer, p.lineno(i), p.lexpos(i))
+
+
+if __name__ == "__main__":
+    p = IDLParser()
+    for f in sys.argv[1:]:
+        print("Parsing %s" % f)
+        p.parse(open(f, encoding="utf-8").read(), filename=f)