Commit 4fca21c1 authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Markus Armbruster
Browse files

qapi: leave the ifcond attribute undefined until check() 



We commonly initialize attributes to None in .init(), then set their
real value in .check().  Accessing the attribute before .check()
yields None.  If we're lucky, the code that accesses the attribute
prematurely chokes on None.

It won't for .ifcond, because None is a legitimate value.

Leave the ifcond attribute undefined until check().

Suggested-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-4-marcandre.lureau@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent 2cbc9437

scripts/qapi/common.py

+17 −4
Original line number Diff line number Diff line
@@ -1021,13 +1021,19 @@ class QAPISchemaEntity(object): 
        # such place).

        self.info = info

        self.doc = doc

        self.ifcond = listify_cond(ifcond)

        self._ifcond = ifcond  # self.ifcond is set only after .check()



    def c_name(self):

        return c_name(self.name)



    def check(self, schema):

        pass

        if isinstance(self._ifcond, QAPISchemaType):

            # inherit the condition from a type

            typ = self._ifcond

            typ.check(schema)

            self.ifcond = typ.ifcond

        else:

            self.ifcond = listify_cond(self._ifcond)



    def is_implicit(self):

        return not self.info
@@ -1164,6 +1170,7 @@ class QAPISchemaEnumType(QAPISchemaType): 
        self.prefix = prefix



    def check(self, schema):

        QAPISchemaType.check(self, schema)

        seen = {}

        for v in self.values:

            v.check_clash(self.info, seen)
@@ -1196,8 +1203,10 @@ class QAPISchemaArrayType(QAPISchemaType): 
        self.element_type = None



    def check(self, schema):

        QAPISchemaType.check(self, schema)

        self.element_type = schema.lookup_type(self._element_type_name)

        assert self.element_type

        self.element_type.check(schema)

        self.ifcond = self.element_type.ifcond



    def is_implicit(self):
@@ -1240,6 +1249,7 @@ class QAPISchemaObjectType(QAPISchemaType): 
        self.members = None



    def check(self, schema):

        QAPISchemaType.check(self, schema)

        if self.members is False:               # check for cycles

            raise QAPISemError(self.info,

                               "Object %s contains itself" % self.name)
@@ -1430,6 +1440,7 @@ class QAPISchemaAlternateType(QAPISchemaType): 
        self.variants = variants



    def check(self, schema):

        QAPISchemaType.check(self, schema)

        self.variants.tag_member.check(schema)

        # Not calling self.variants.check_clash(), because there's nothing

        # to clash with
@@ -1474,6 +1485,7 @@ class QAPISchemaCommand(QAPISchemaEntity): 
        self.allow_preconfig = allow_preconfig



    def check(self, schema):

        QAPISchemaEntity.check(self, schema)

        if self._arg_type_name:

            self.arg_type = schema.lookup_type(self._arg_type_name)

            assert (isinstance(self.arg_type, QAPISchemaObjectType) or
@@ -1509,6 +1521,7 @@ class QAPISchemaEvent(QAPISchemaEntity): 
        self.boxed = boxed



    def check(self, schema):

        QAPISchemaEntity.check(self, schema)

        if self._arg_type_name:

            self.arg_type = schema.lookup_type(self._arg_type_name)

            assert (isinstance(self.arg_type, QAPISchemaObjectType) or
@@ -1642,7 +1655,7 @@ class QAPISchema(object): 
            # But it's not tight: the disjunction need not imply it.  We

            # may end up compiling useless wrapper types.

            # TODO kill simple unions or implement the disjunction

            assert ifcond == typ.ifcond

            assert ifcond == typ._ifcond # pylint: disable=protected-access

        else:

            self._def_entity(QAPISchemaObjectType(name, info, doc, ifcond,

                                                  None, members, None))
@@ -1688,7 +1701,7 @@ class QAPISchema(object): 
            assert len(typ) == 1

            typ = self._make_array_type(typ[0], info)

        typ = self._make_implicit_object_type(

            typ, info, None, self.lookup_type(typ).ifcond,

            typ, info, None, self.lookup_type(typ),

            'wrapper', [self._make_member('data', typ, info)])

        return QAPISchemaObjectTypeVariant(case, typ)