Store relationships on Inherent

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -1,6 +1,5 @@
 use std::mem;
 
-use rustc_data_structures::fx::FxHashMap;
 use rustc_infer::{
     infer::InferCtxt,
     traits::{
@@ -8,7 +7,6 @@ use rustc_infer::{
         SelectionError, TraitEngine,
     },
 };
-use rustc_middle::ty;
 
 use super::{search_graph, Certainty, EvalCtxt};
 
@@ -102,8 +100,4 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.obligations.clone()
     }
-
-    fn relationships(&mut self) -> &mut FxHashMap<ty::TyVid, ty::FoundRelationships> {
-        unimplemented!("Should be moved out of `TraitEngine`")
-    }
 }

compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs

@@ -7,24 +7,18 @@ use crate::traits::{
     ChalkEnvironmentAndGoal, FulfillmentError, FulfillmentErrorCode, PredicateObligation,
     SelectionError, TraitEngine,
 };
-use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
-use rustc_middle::ty::{self, TypeVisitable};
+use rustc_data_structures::fx::FxIndexSet;
+use rustc_middle::ty::TypeVisitable;
 
 pub struct FulfillmentContext<'tcx> {
     obligations: FxIndexSet<PredicateObligation<'tcx>>,
 
-    relationships: FxHashMap<ty::TyVid, ty::FoundRelationships>,
-
     usable_in_snapshot: bool,
 }
 
 impl FulfillmentContext<'_> {
     pub(super) fn new() -> Self {
-        FulfillmentContext {
-            obligations: FxIndexSet::default(),
-            relationships: FxHashMap::default(),
-            usable_in_snapshot: false,
-        }
+        FulfillmentContext { obligations: FxIndexSet::default(), usable_in_snapshot: false }
     }
 
     pub(crate) fn new_in_snapshot() -> Self {
@@ -43,8 +37,6 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         }
         let obligation = infcx.resolve_vars_if_possible(obligation);
 
-        super::relationships::update(self, infcx, &obligation);
-
         self.obligations.insert(obligation);
     }
 
@@ -154,8 +146,4 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.obligations.iter().cloned().collect()
     }
-
-    fn relationships(&mut self) -> &mut FxHashMap<ty::TyVid, ty::FoundRelationships> {
-        &mut self.relationships
-    }
 }

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -1,5 +1,4 @@
 use crate::infer::{InferCtxt, TyOrConstInferVar};
-use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::obligation_forest::ProcessResult;
 use rustc_data_structures::obligation_forest::{Error, ForestObligation, Outcome};
 use rustc_data_structures::obligation_forest::{ObligationForest, ObligationProcessor};
@@ -54,8 +53,6 @@ pub struct FulfillmentContext<'tcx> {
     // fulfillment context.
     predicates: ObligationForest<PendingPredicateObligation<'tcx>>,
 
-    relationships: FxHashMap<ty::TyVid, ty::FoundRelationships>,
-
     // Is it OK to register obligations into this infcx inside
     // an infcx snapshot?
     //
@@ -85,19 +82,11 @@ static_assert_size!(PendingPredicateObligation<'_>, 72);
 impl<'a, 'tcx> FulfillmentContext<'tcx> {
     /// Creates a new fulfillment context.
     pub(super) fn new() -> FulfillmentContext<'tcx> {
-        FulfillmentContext {
-            predicates: ObligationForest::new(),
-            relationships: FxHashMap::default(),
-            usable_in_snapshot: false,
-        }
+        FulfillmentContext { predicates: ObligationForest::new(), usable_in_snapshot: false }
     }
 
     pub(super) fn new_in_snapshot() -> FulfillmentContext<'tcx> {
-        FulfillmentContext {
-            predicates: ObligationForest::new(),
-            relationships: FxHashMap::default(),
-            usable_in_snapshot: true,
-        }
+        FulfillmentContext { predicates: ObligationForest::new(), usable_in_snapshot: true }
     }
 
     /// Attempts to select obligations using `selcx`.
@@ -139,8 +128,6 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
 
         assert!(!infcx.is_in_snapshot() || self.usable_in_snapshot);
 
-        super::relationships::update(self, infcx, &obligation);
-
         self.predicates
             .register_obligation(PendingPredicateObligation { obligation, stalled_on: vec![] });
     }
@@ -164,10 +151,6 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
         self.predicates.map_pending_obligations(|o| o.obligation.clone())
     }
-
-    fn relationships(&mut self) -> &mut FxHashMap<ty::TyVid, ty::FoundRelationships> {
-        &mut self.relationships
-    }
 }
 
 struct FulfillProcessor<'a, 'tcx> {

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -14,7 +14,6 @@ mod object_safety;
 pub mod outlives_bounds;
 mod project;
 pub mod query;
-pub(crate) mod relationships;
 mod select;
 mod specialize;
 mod structural_match;

compiler/rustc_trait_selection/src/traits/relationships.rs

@@ -1,48 +0,0 @@
-use crate::infer::InferCtxt;
-use crate::traits::query::evaluate_obligation::InferCtxtExt;
-use crate::traits::PredicateObligation;
-use rustc_infer::traits::TraitEngine;
-use rustc_middle::ty;
-
-pub(crate) fn update<'tcx, T>(
-    engine: &mut T,
-    infcx: &InferCtxt<'tcx>,
-    obligation: &PredicateObligation<'tcx>,
-) where
-    T: TraitEngine<'tcx>,
-{
-    // (*) binder skipped
-    if let ty::PredicateKind::Clause(ty::Clause::Trait(tpred)) = obligation.predicate.kind().skip_binder()
-        && let Some(ty) = infcx.shallow_resolve(tpred.self_ty()).ty_vid().map(|t| infcx.root_var(t))
-        && infcx.tcx.lang_items().sized_trait().map_or(false, |st| st != tpred.trait_ref.def_id)
-    {
-        let new_self_ty = infcx.tcx.types.unit;
-
-        // Then construct a new obligation with Self = () added
-        // to the ParamEnv, and see if it holds.
-        let o = obligation.with(infcx.tcx,
-            obligation
-                .predicate
-                .kind()
-                .rebind(
-                    // (*) binder moved here
-                    ty::PredicateKind::Clause(ty::Clause::Trait(tpred.with_self_ty(infcx.tcx, new_self_ty)))
-                ),
-        );
-        // Don't report overflow errors. Otherwise equivalent to may_hold.
-        if let Ok(result) = infcx.probe(|_| infcx.evaluate_obligation(&o)) && result.may_apply() {
-            engine.relationships().entry(ty).or_default().self_in_trait = true;
-        }
-    }
-
-    if let ty::PredicateKind::Clause(ty::Clause::Projection(predicate)) =
-        obligation.predicate.kind().skip_binder()
-    {
-        // If the projection predicate (Foo::Bar == X) has X as a non-TyVid,
-        // we need to make it into one.
-        if let Some(vid) = predicate.term.ty().and_then(|ty| ty.ty_vid()) {
-            debug!("relationship: {:?}.output = true", vid);
-            engine.relationships().entry(vid).or_default().output = true;
-        }
-    }
-}