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assign the correct DefId in nominal_obligations

This commit is contained in:
Bastian Kauschke 2020-09-22 11:36:54 +02:00
parent f8d3f401df
commit b8402d6a6e
3 changed files with 19 additions and 7 deletions

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@ -7,8 +7,9 @@ use rustc_hir::lang_items::LangItem;
use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness};
use rustc_span::Span;
use std::rc::Rc;
use std::iter;
use std::rc::Rc;
/// Returns the set of obligations needed to make `arg` well-formed.
/// If `arg` contains unresolved inference variables, this may include
/// further WF obligations. However, if `arg` IS an unresolved
@ -616,13 +617,24 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
) -> Vec<traits::PredicateObligation<'tcx>> {
let predicates = self.infcx.tcx.predicates_of(def_id).instantiate(self.infcx.tcx, substs);
let predicates = self.infcx.tcx.predicates_of(def_id);
let mut origins = vec![def_id; predicates.predicates.len()];
let mut head = predicates;
while let Some(parent) = head.parent {
head = self.infcx.tcx.predicates_of(parent);
origins.extend(iter::repeat(parent).take(head.predicates.len()));
}
let predicates = predicates.instantiate(self.infcx.tcx, substs);
debug_assert_eq!(predicates.predicates.len(), origins.len());
predicates
.predicates
.into_iter()
.zip(predicates.spans.into_iter())
.map(|(pred, span)| {
let cause = self.cause(traits::BindingObligation(def_id, span));
.zip(origins.into_iter().rev())
.map(|((pred, span), origin_def_id)| {
let cause = self.cause(traits::BindingObligation(origin_def_id, span));
traits::Obligation::new(cause, self.param_env, pred)
})
.filter(|pred| !pred.has_escaping_bound_vars())