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Make negative_impl and negative_impl_exists take the right types #104674

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Merged
merged 2 commits into from
Nov 22, 2022
Merged

Make negative_impl and negative_impl_exists take the right types #104674

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2faad3b
negative_impl should take a TyCtxt
spastorino Nov 21, 2022
16c9e39
negative_impl_exists should take an InferCtxt
spastorino Nov 21, 2022
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26 changes: 10 additions & 16 deletions compiler/rustc_trait_selection/src/traits/coherence.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -162,8 +162,8 @@ fn overlap_within_probe<'cx, 'tcx>(
let infcx = selcx.infcx();

if overlap_mode.use_negative_impl() {
if negative_impl(selcx, impl1_def_id, impl2_def_id)
|| negative_impl(selcx, impl2_def_id, impl1_def_id)
if negative_impl(infcx.tcx, impl1_def_id, impl2_def_id)
|| negative_impl(infcx.tcx, impl2_def_id, impl1_def_id)
{
return None;
}
Expand Down Expand Up @@ -279,13 +279,8 @@ fn implicit_negative<'cx, 'tcx>(

/// Given impl1 and impl2 check if both impls are never satisfied by a common type (including
/// where-clauses) If so, return true, they are disjoint and false otherwise.
fn negative_impl<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
impl1_def_id: DefId,
impl2_def_id: DefId,
) -> bool {
fn negative_impl<'tcx>(tcx: TyCtxt<'tcx>, impl1_def_id: DefId, impl2_def_id: DefId) -> bool {
debug!("negative_impl(impl1_def_id={:?}, impl2_def_id={:?})", impl1_def_id, impl2_def_id);
let tcx = selcx.infcx().tcx;

// Create an infcx, taking the predicates of impl1 as assumptions:
let infcx = tcx.infer_ctxt().build();
Expand Down Expand Up @@ -332,11 +327,10 @@ fn equate<'tcx>(
return true;
};

let selcx = &mut SelectionContext::new(&infcx);
let opt_failing_obligation = obligations
.into_iter()
.chain(more_obligations)
.find(|o| negative_impl_exists(selcx, o, body_def_id));
.find(|o| negative_impl_exists(infcx, o, body_def_id));

if let Some(failing_obligation) = opt_failing_obligation {
debug!("overlap: obligation unsatisfiable {:?}", failing_obligation);
Expand All @@ -347,19 +341,19 @@ fn equate<'tcx>(
}

/// Try to prove that a negative impl exist for the given obligation and its super predicates.
#[instrument(level = "debug", skip(selcx))]
fn negative_impl_exists<'cx, 'tcx>(
selcx: &SelectionContext<'cx, 'tcx>,
#[instrument(level = "debug", skip(infcx))]
fn negative_impl_exists<'tcx>(
infcx: &InferCtxt<'tcx>,
o: &PredicateObligation<'tcx>,
body_def_id: DefId,
) -> bool {
if resolve_negative_obligation(selcx.infcx().fork(), o, body_def_id) {
if resolve_negative_obligation(infcx.fork(), o, body_def_id) {
return true;
}

// Try to prove a negative obligation exists for super predicates
for o in util::elaborate_predicates(selcx.tcx(), iter::once(o.predicate)) {
if resolve_negative_obligation(selcx.infcx().fork(), &o, body_def_id) {
for o in util::elaborate_predicates(infcx.tcx, iter::once(o.predicate)) {
if resolve_negative_obligation(infcx.fork(), &o, body_def_id) {
return true;
}
}
Expand Down