gecko-dev/xpcom/idl-parser/xpidl/xpidl.py

#!/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 sys
import os.path
import re
from ply import lex
from ply import yacc

"""A type conforms to the following pattern:

    def isScriptable(self):
        'returns True or False'

    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 rustBlacklistedForward(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."""
    blacklisted = [
        "nsIFrame",
        "nsIObjectFrame",
        "nsSubDocumentFrame",
    ]
    return s in blacklisted


def attlistToIDL(attlist):
    if len(attlist) == 0:
        return ''

    attlist = list(attlist)
    attlist.sort(cmp=lambda a, b: cmp(a[0], b[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 isScriptable(self):
        return True

    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 const:
            print >>sys.stderr, IDLError(
                "[const] doesn't make sense on builtin types.", self.location, warning=True)
            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 (calltype == 'in' and self.isPointer()) or shared
        rustname = self.rustname
        if const and self.isPointer():
            rustname = self.rustname.replace("*mut", "*const")

        return "%s%s" % (calltype != 'in' and '*mut ' or '', rustname)


builtinNames = [
    Builtin('boolean', 'bool', 'bool'),
    Builtin('void', 'void', 'libc::c_void'),
    Builtin('octet', 'uint8_t', 'libc::uint8_t'),
    Builtin('short', 'int16_t', 'libc::int16_t', True, True),
    Builtin('long', 'int32_t', 'libc::int32_t', True, True),
    Builtin('long long', 'int64_t', 'libc::int64_t', True, False),
    Builtin('unsigned short', 'uint16_t', 'libc::uint16_t', False, True),
    Builtin('unsigned long', 'uint32_t', 'libc::uint32_t', False, True),
    Builtin('unsigned long long', 'uint64_t', 'libc::uint64_t', False, False),
    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', 'libc::int16_t', False, False),
    Builtin('wstring', 'char16_t *', '*const libc::int16_t', False, False),
]

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 xrange(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 self._d.itervalues()

    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("Name '%s' 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):
        self.message = message
        self.location = location
        self.warning = warning

    def __str__(self):
        return "%s: %s, %s" % (self.warning and 'warning' or 'error',
                               self.message, self.location)


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

            self.IDL = parent.parser.parse(open(file).read(), filename=file)
            self.IDL.resolve(parent.incdirs, parent.parser, parent.webidlconfig)
            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.productions = productions
        self.deps = []

    def setName(self, object):
        self.namemap.set(object)

    def getName(self, id, location):
        try:
            return self.namemap[id]
        except KeyError:
            raise IDLError("type '%s' not found" % id, 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):
        self.namemap = NameMap()
        self.incdirs = incdirs
        self.parser = parser
        self.webidlconfig = webidlconfig
        for p in self.productions:
            p.resolve(self)

    def includes(self):
        for p in self.productions:
            if p.kind == 'include':
                yield p

    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):
        pass

    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)

    def isScriptable(self):
        return self.realtype.isScriptable()

    def nativeType(self, calltype):
        return "%s %s" % (self.name, '*' if 'out' in calltype else '')

    def rustType(self, calltype):
        return "%s%s" % (calltype != 'in' and '*mut ' or '',
                         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 xrange(0, len(parent.productions)):
                if parent.productions[i] is self:
                    break
            for i in xrange(i + 1, len(parent.productions)):
                if hasattr(parent.productions[i], 'doccomments'):
                    parent.productions[i].doccomments[0:0] = self.doccomments
                    break

        parent.setName(self)

    def isScriptable(self):
        return True

    def nativeType(self, calltype):
        return "%s *%s" % (self.name, '*' if 'out' in calltype else '')

    def rustType(self, calltype):
        if rustBlacklistedForward(self.name):
            raise RustNoncompat("forward declaration %s is unsupported" % self.name)
        return "%s*const %s" % (calltype != 'in' and '*mut ' or '',
                                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,
        'domstring': ('const nsAString&', 'nsAString&', 'nsString'),
        'utf8string': ('const nsACString&', 'nsACString&', 'nsCString'),
        'cstring': ('const nsACString&', 'nsACString&', 'nsCString'),
        'astring': ('const nsAString&', 'nsAString&', 'nsString'),
        'jsval': ('JS::HandleValue', 'JS::MutableHandleValue', '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 isScriptable(self):
        if self.specialtype is None:
            return False

        if self.specialtype == 'promise':
            return self.modifier == 'ptr'

        if self.specialtype == 'nsid':
            return self.modifier is not None

        return self.modifier == 'ref'

    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.")
            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 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.
        #
        # 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')

        prefix = '*mut ' if 'out' in calltype else '*const '
        if 'out' in calltype and self.modifier == 'ptr':
            prefix += '*mut '

        if self.specialtype == 'nsid':
            return prefix + self.nativename
        if self.specialtype in ['cstring', 'utf8string']:
            if calltype == 'element':
                return '::nsstring::nsCString'
            return prefix + '::nsstring::nsACString'
        if self.specialtype in ['astring', 'domstring']:
            if calltype == 'element':
                return '::nsstring::nsString'
            return prefix + '::nsstring::nsAString'
        if self.nativename == 'void':
            return prefix + 'libc::c_void'

        if self.specialtype:
            raise RustNoncompat("specialtype %s unsupported" % self.specialtype)
        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 isScriptable(self):
        return True  # All DOM objects are script exposed.

    def nativeType(self, calltype):
        return "%s *%s" % (self.native, '*' if 'out' in calltype else '')

    def rustType(self, calltype):
        # 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
        self.implicit_builtinclass = False

        for m in members:
            if not isinstance(m, CDATA):
                self.namemap.set(m)

            if m.kind == 'method' and m.notxpcom and name != 'nsISupports':
                # An interface cannot be implemented by JS if it has a
                # notxpcom method. Such a type is an "implicit builtinclass".
                #
                # XXX(nika): Why does nostdcall not imply builtinclass?
                # It could screw up the shims as well...
                self.implicit_builtinclass = True

    def __eq__(self, other):
        return self.name == other.name and self.location == other.location

    def resolve(self, parent):
        self.idl = parent

        # 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(self.name, None).doccomments

        if self.attributes.function:
            has_method = False
            for member in self.members:
                if member.kind is '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(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.implicit_builtinclass:
                self.implicit_builtinclass = True  # Inherit implicit builtinclass from base

        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 isScriptable(self):
        # NOTE: this is not whether *this* interface is scriptable... it's
        # whether, when used as a type, it's scriptable, which is true of all
        # interfaces.
        return True

    def nativeType(self, calltype, const=False):
        return "%s%s *%s" % ('const ' if const else '', self.name,
                             '*' if 'out' in calltype else '')

    def rustType(self, calltype, const=False):
        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 is not None:
            iface = self.idl.getName(self.base, self.location)
        if iface is None:
            raise IDLError("cannot find symbol '%s'" % name)
        c = iface.namemap.get(name, location)
        if c.kind != 'const':
            raise IDLError("symbol '%s' is not a constant", c.location)

        return c.getValue()

    def needsJSTypes(self):
        for m in self.members:
            if m.kind == "attribute" and m.type == "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(self.base, self.location)
            total += realbase.countEntries()
        return total


class InterfaceAttributes(object):
    uuid = None
    scriptable = False
    builtinclass = False
    function = False
    noscript = False
    main_process_scriptable_only = False
    shim = None
    shimfile = None

    def setuuid(self, value):
        self.uuid = value.lower()

    def setscriptable(self):
        self.scriptable = True

    def setfunction(self):
        self.function = True

    def setnoscript(self):
        self.noscript = True

    def setbuiltinclass(self):
        self.builtinclass = True

    def setmain_process_scriptable_only(self):
        self.main_process_scriptable_only = True

    def setshim(self, value):
        self.shim = value

    def setshimfile(self, value):
        self.shimfile = value

    actions = {
        'uuid':       (True, setuuid),
        'scriptable': (False, setscriptable),
        'builtinclass': (False, setbuiltinclass),
        'function':   (False, setfunction),
        'noscript':   (False, setnoscript),
        'object':     (False, lambda self: True),
        'main_process_scriptable_only': (False, setmain_process_scriptable_only),
        'shim':    (True, setshim),
        'shimfile': (True, setshimfile),
    }

    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.shim:
            l.append("\tshim: %s\n" % self.shim)
        if self.shimfile:
            l.append("\tshimfile: %s\n" % self.shimfile)
        return "".join(l)


class ConstMember(object):
    kind = 'const'

    def __init__(self, type, name, value, location, doccomments):
        self.type = type
        self.name = name
        self.value = 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

    def getValue(self):
        return self.value(self.iface)

    def __str__(self):
        return "\tconst %s %s = %s\n" % (self.type, self.name, self.getValue())

    def count(self):
        return 0


class Attribute(object):
    kind = 'attribute'
    noscript = False
    readonly = False
    implicit_jscontext = False
    nostdcall = False
    must_use = False
    binaryname = None
    null = None
    undefined = None
    infallible = 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 name == 'Null':
                if value is None:
                    raise IDLError("'Null' attribute requires a value", aloc)
                if readonly:
                    raise IDLError("'Null' attribute only makes sense for setters",
                                   aloc)
                if value not in ('Empty', 'Null', 'Stringify'):
                    raise IDLError("'Null' attribute value must be 'Empty', 'Null' or 'Stringify'",
                                   aloc)
                self.null = value
            elif name == 'Undefined':
                if value is None:
                    raise IDLError("'Undefined' attribute requires a value", aloc)
                if readonly:
                    raise IDLError("'Undefined' attribute only makes sense for setters",
                                   aloc)
                if value not in ('Empty', 'Null'):
                    raise IDLError("'Undefined' attribute value must be 'Empty' or 'Null'",
                                   aloc)
                self.undefined = value
            else:
                if value is not None:
                    raise IDLError("Unexpected attribute value", aloc)

                if name == 'noscript':
                    self.noscript = 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
                else:
                    raise IDLError("Unexpected attribute '%s'" % name, aloc)

    def resolve(self, iface):
        self.iface = iface
        self.realtype = iface.idl.getName(self.type, self.location)
        if (self.null is not None and
                getBuiltinOrNativeTypeName(self.realtype) != '[domstring]'):
            raise IDLError("'Null' attribute can only be used on DOMString",
                           self.location)
        if (self.undefined is not None and
                getBuiltinOrNativeTypeName(self.realtype) != '[domstring]'):
            raise IDLError("'Undefined' attribute can only be used on DOMString",
                           self.location)
        if self.infallible and self.realtype.kind not in ['builtin',
                                                          'interface',
                                                          'forward',
                                                          'webidl']:
            raise IDLError('[infallible] only works on interfaces, domobjects, and builtin types '
                           '(numbers, booleans, and raw char types)',
                           self.location)
        if self.infallible and not iface.attributes.builtinclass:
            raise IDLError('[infallible] attributes are only allowed on '
                           '[builtinclass] interfaces',
                           self.location)

    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

    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
    binaryname = None
    implicit_jscontext = False
    nostdcall = False
    must_use = False
    optional_argc = 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 == '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
            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)
        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:
                found_size_param = False
                for size_param in self.params:
                    if p.size_is == size_param.name:
                        found_size_param = True
                        if getBuiltinOrNativeTypeName(size_param.realtype) != 'unsigned long':
                            raise IDLError(
                                "is_size parameter must have type 'unsigned long'", self.location)
                if not found_size_param:
                    raise IDLError("could not find is_size parameter '%s'" %
                                   p.size_is, self.location)

    def isScriptable(self):
        if not self.iface.attributes.scriptable:
            return False
        return not (self.noscript or self.notxpcom)

    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 == "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
    null = None
    undefined = None
    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 == 'Null':
                if value is None:
                    raise IDLError("'Null' must specify a parameter", aloc)
                if value not in ('Empty', 'Null', 'Stringify'):
                    raise IDLError("'Null' parameter value must be 'Empty', 'Null', "
                                   "or 'Stringify'",
                                   aloc)
                self.null = value
            elif name == 'Undefined':
                if value is None:
                    raise IDLError("'Undefined' must specify a parameter", aloc)
                if value not in ('Empty', 'Null'):
                    raise IDLError("'Undefined' parameter value must be 'Empty' or 'Null'",
                                   aloc)
                self.undefined = 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 = Array(self.realtype)
        if (self.null is not None and
                getBuiltinOrNativeTypeName(self.realtype) != '[domstring]'):
            raise IDLError("'Null' attribute can only be used on DOMString",
                           self.location)
        if (self.undefined is not None and
                getBuiltinOrNativeTypeName(self.realtype) != '[domstring]'):
            raise IDLError("'Undefined' attribute can only be used on DOMString",
                           self.location)

    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(e.message, self.location)
        except TypeError as e:
            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(e.message, self.location)
        except TypeError as e:
            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 Array(object):
    def __init__(self, basetype):
        self.type = basetype

    def isScriptable(self):
        return self.type.isScriptable()

    def nativeType(self, calltype, const=False):
        # 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('element'),
                            '*' 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('element'))


class IDLParser(object):
    keywords = {
        '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'/\*(?s).*?\*/'
        t.lexer.lineno += t.value.count('\n')
        if t.value.startswith("/**"):
            self._doccomments.append(t.value)

    def t_singlelinecomment(self, t):
        r'(?m)//.*?$'

    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'(?s)%\{[ ]*C\+\+[ ]*\n(?P<cdata>.*?\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):
        r'[^()\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 IDENTIFIER 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",
                               list[0][3])

            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 IDENTIFIER 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_att(self, p):
        """member : attributes optreadonly ATTRIBUTE IDENTIFIER 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 IDENTIFIER 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 IDENTIFIER IDENTIFIER"""
        p[0] = Param(paramtype=p[2],
                     type=p[3],
                     name=p[4],
                     attlist=p[1]['attlist'],
                     location=self.getLocation(p, 3))

    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_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, outputdir=''):
        self._doccomments = []
        self.lexer = lex.lex(object=self,
                             outputdir=outputdir,
                             lextab='xpidllex',
                             optimize=1)
        self.parser = yacc.yacc(module=self,
                                outputdir=outputdir,
                                debug=0,
                                tabmodule='xpidlyacc',
                                optimize=1)

    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).read(), filename=f)