Skip to content

Make negative_impl and negative_impl_exists take the right types #104674

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Nov 22, 2022
+10 −16
Merged

Make negative_impl and negative_impl_exists take the right types #104674

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2faad3b
negative_impl should take a TyCtxt
spastorino Nov 21, 2022
16c9e39
negative_impl_exists should take an InferCtxt
spastorino Nov 21, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 10 additions & 16 deletions compiler/rustc_trait_selection/src/traits/coherence.rs
View file
Open in desktop
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