def visit_raise(self, node):
"""visit raise possibly inferring value"""
# ignore empty raise
if node.exc is None:
return
expr = node.exc
if self._check_raise_value(node, expr):
return
else:
try:
value = unpack_infer(expr).next()
except astng.InferenceError:
return
self._check_raise_value(node, value)
def visit_tryexcept(self, node):
"""check for empty except"""
exceptions_classes = []
nb_handlers = len(node.handlers)
for index, handler in enumerate(node.handlers):
# single except doing nothing but "pass" without else clause
if nb_handlers == 1 and is_empty(handler.body) and not node.orelse:
self.add_message('W0704', node=handler.type or handler.body[0])
if handler.type is None:
if nb_handlers == 1 and not is_raising(handler.body):
self.add_message('W0702', node=handler)
# check if a "except:" is followed by some other
# except
elif index < (nb_handlers - 1):
msg = 'empty except clause should always appear last'
self.add_message('E0701', node=node, args=msg)
else:
try:
excs = list(unpack_infer(handler.type))
except astng.InferenceError:
continue
for exc in excs:
# XXX skip other non class nodes
if exc is YES or not isinstance(exc, astng.Class):
continue
exc_ancestors = [
anc for anc in exc.ancestors()
if isinstance(anc, astng.Class)
]
for previous_exc in exceptions_classes:
if previous_exc in exc_ancestors:
msg = '%s is an ancestor class of %s' % (
previous_exc.name, exc.name)
self.add_message('E0701',
node=handler.type,
args=msg)
if (exc.name in self.config.overgeneral_exceptions
and exc.root().name == EXCEPTIONS_MODULE
and nb_handlers == 1
and not is_raising(handler.body)):
self.add_message('W0703',
args=exc.name,
node=handler.type)
exceptions_classes += excs
def visit_tryexcept(self, node):
"""check for empty except"""
exceptions_classes = []
nb_handlers = len(node.handlers)
for index, handler in enumerate(node.handlers):
# single except doing nothing but "pass" without else clause
if nb_handlers == 1 and is_empty(handler.body) and not node.orelse:
self.add_message('W0704', node=handler.type or handler.body[0])
if handler.type is None:
if nb_handlers == 1 and not is_raising(handler.body):
self.add_message('W0702', node=handler)
# check if a "except:" is followed by some other
# except
elif index < (nb_handlers - 1):
msg = 'empty except clause should always appear last'
self.add_message('E0701', node=node, args=msg)
elif isinstance(handler.type, astng.BoolOp):
self.add_message('W0711', node=handler, args=handler.type.op)
else:
try:
excs = list(unpack_infer(handler.type))
except astng.InferenceError:
continue
for exc in excs:
# XXX skip other non class nodes
if exc is YES or not isinstance(exc, astng.Class):
continue
exc_ancestors = [anc for anc in exc.ancestors()
if isinstance(anc, astng.Class)]
for previous_exc in exceptions_classes:
if previous_exc in exc_ancestors:
msg = '%s is an ancestor class of %s' % (
previous_exc.name, exc.name)
self.add_message('E0701', node=handler.type, args=msg)
if (exc.name in self.config.overgeneral_exceptions
and exc.root().name == EXCEPTIONS_MODULE
and nb_handlers == 1 and not is_raising(handler.body)):
self.add_message('W0703', args=exc.name, node=handler.type)
exceptions_classes += excs
