Auto merge of #50076 - spastorino:fix_exhaust_iter_in_debug, r=pnkfelix

Fix Iter exhaustion in prove_predicates when debug is on

Fixes the issue noted in this comment https://github.com/rust-lang/rust/pull/49885/files#r182560268

r? @pnkfelix
/cc @nikomatsakis
This commit is contained in:
bors 2018-04-21 11:26:09 +00:00
commit e59f78fb45

View File

@ -275,7 +275,7 @@ impl<'a, 'b, 'gcx, 'tcx> TypeVerifier<'a, 'b, 'gcx, 'tcx> {
tcx.predicates_of(def_id).instantiate(tcx, substs);
let predicates =
type_checker.normalize(&instantiated_predicates.predicates, location);
type_checker.prove_predicates(predicates.iter().cloned(), location);
type_checker.prove_predicates(predicates, location);
}
value.ty
@ -1516,34 +1516,34 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
let predicates = self.normalize(&instantiated_predicates.predicates, location);
debug!("prove_aggregate_predicates: predicates={:?}", predicates);
self.prove_predicates(predicates.iter().cloned(), location);
self.prove_predicates(predicates, location);
}
fn prove_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>, location: Location) {
self.prove_predicates(
[ty::Predicate::Trait(
Some(ty::Predicate::Trait(
trait_ref.to_poly_trait_ref().to_poly_trait_predicate(),
)].iter()
.cloned(),
)),
location,
);
}
fn prove_predicates(
&mut self,
predicates: impl IntoIterator<Item = ty::Predicate<'tcx>>,
location: Location,
) {
let mut predicates_iter = predicates.into_iter();
fn prove_predicates<T>(&mut self, predicates: T, location: Location)
where
T: IntoIterator<Item = ty::Predicate<'tcx>>,
T::IntoIter: Clone,
{
let predicates = predicates.into_iter();
debug!(
"prove_predicates(predicates={:?}, location={:?})",
predicates_iter.by_ref().collect::<Vec<_>>(),
location
predicates.clone().collect::<Vec<_>>(),
location,
);
self.fully_perform_op(location.at_self(), |this| {
let cause = this.misc(this.last_span);
let obligations = predicates_iter
let obligations = predicates
.into_iter()
.map(|p| traits::Obligation::new(cause.clone(), this.param_env, p))
.collect();
Ok(InferOk {