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qapi: leave the ifcond attribute undefined until check()

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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: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-4-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Marc-André Lureau 2018-07-03 17:56:37 +02:00 committed by Markus Armbruster
parent 2cbc94376e
commit 4fca21c1b0
1 changed files with 17 additions and 4 deletions
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21
scripts/qapi/common.py
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@ -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)