def initialize(
self, obligation_instances: List['GuardedObligationInstance'],
translator: 'AbstractTranslator', ctx: Context,
overriding_check: bool = False) -> List[Stmt]:
"""Construct a list of statements that initialize measure map.
If ``overriding_check`` is ``True``, then adds to measures ``1``
to allow overridden method to have the same measure.
"""
position = translator.no_position(ctx)
info = translator.no_info(ctx)
measures = []
for instance in obligation_instances:
if instance.obligation_instance.is_fresh():
continue
guard_expression = instance.create_guard_expression()
value = instance.obligation_instance.get_measure()
if overriding_check:
value = sil.Inc(value)
measure = self._create_measure(
guard_expression,
instance.obligation_instance.get_target(), value)
measures.append(measure)
assign = sil.Assign(
self._map_var,
sil.PSeq(self._measure_domain.get_type(), measures))
statement = assign.translate(translator, ctx, position, info)
return [statement]
def _set_loop_check_before(self) -> None:
"""Set the variable indicating that we are before loop."""
if obligation_config.disable_all:
return
assign = sil.Assign(self._loop_obligation_info.loop_check_before_var,
sil.TrueLit())
info = self._to_info('We are before loop.')
self._append_statement(assign, info=info)
def _save_must_terminate_amount(
self, amount_var: PythonVar) -> None:
"""Save the current permission amount to a variable."""
if obligation_config.disable_termination_check:
return
predicate = self._get_must_terminate_predicate()
assign = sil.Assign(amount_var, sil.CurrentPerm(predicate))
info = self._to_info('Save current MustTerminate amount.')
self._append_statement(assign, info=info)
def _save_loop_termination(self) -> None:
"""Save if loop promises to terminate into a variable."""
if obligation_config.disable_termination_check:
return
assign = sil.Assign(
self._loop_obligation_info.termination_flag_var,
self._loop_obligation_info.create_termination_check(True))
info = self._to_info('Save loop termination promise.')
self._append_statement(assign, info=info)
def _set_loop_check_after_body(self) -> None:
"""Set the variable indicating that we are after loop body."""
if obligation_config.disable_all:
return
assign = sil.Assign(self._loop_obligation_info.loop_check_before_var,
sil.FalseLit())
info = self._to_info('We are after loop body.')
statement = assign.translate(self._translator, self._ctx,
self._position, info)
self._obligation_loop.append_body(statement)