def bad_matches(self, var, other_type, node):
"""Match a Variable against a type. Return views that don't match.
Args:
var: A cfg.Variable, containing instances.
other_type: An instance of AtomicAbstractValue.
node: A cfg.CFGNode. The position in the CFG from which we "observe" the
match.
Returns:
A list of all the views of var that didn't match.
"""
bad = []
views = abstract.get_views([var], node, filter_strict=True)
skip_future = None
while True:
try:
view = views.send(skip_future)
except StopIteration:
break
if self.match_var_against_type(var, other_type, {}, node, view) is None:
bad.append(view)
# To get complete error messages, we need to collect all bad views, so
# we can't skip any.
skip_future = False
else:
skip_future = True
return bad
def _instantiate_and_match(self, left, other_type, subst, node, view):
"""Instantiate and match an abstract value."""
instance = left.instantiate(node)
for new_view in abstract.get_views([instance], node):
# When new_view and view have entries in common, we want to use the
# entries from the old view.
new_view.update(view)
new_subst = self.match_var_against_type(instance, other_type,
subst, node, new_view)
if new_subst is not None:
return new_subst
return None
def bad_matches(self, var, other_type, node):
"""Match a Variable against a type. Return views that don't match.
Args:
var: A cfg.Variable, containing instances.
other_type: An instance of AtomicAbstractValue.
node: A cfg.CFGNode. The position in the CFG from which we "observe" the
match.
Returns:
A list of all the views of var that didn't match.
"""
bad = []
for view in abstract.get_views([var], node, filter_strict=True):
if self.match_var_against_type(var, other_type, {}, node, view) is None:
bad.append(view)
return bad
def _instantiate_and_match(self, left, other_type, subst, node, view,
container=None):
"""Instantiate and match an abstract value."""
instance = left.instantiate(node, container=container)
new_substs = []
for new_view in abstract.get_views([instance], node):
# When new_view and view have entries in common, we want to use the
# entries from the old view.
new_view.update(view)
new_subst = self.match_var_against_type(
instance, other_type, subst, node, new_view)
if new_subst is not None:
new_substs.append(new_subst)
if new_substs:
return self._merge_substs(subst, new_substs)
else:
return None
def _match_var(self, left, right):
var = self.vm.program.NewVariable()
var.AddBinding(left, [], self.vm.root_cfg_node)
for view in abstract.get_views([var], self.vm.root_cfg_node):
yield self.vm.matcher.match_var_against_type(
var, right, {}, self.vm.root_cfg_node, view)
