Rollup merge of rust-lang#122839 - compiler-errors:predicate-polarity, r=lcnr

Split out `PredicatePolarity` from `ImplPolarity`

Because having to deal with a third `Reservation` level in all the trait solver code is kind of weird.

r? `@lcnr` or `@oli-obk`

Author: matthiaskrgr

compiler/rustc_borrowck/src/type_check/canonical.rs

@@ -82,7 +82,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     ) {
         self.prove_predicate(
             ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::Trait(
-                ty::TraitPredicate { trait_ref, polarity: ty::ImplPolarity::Positive },
+                ty::TraitPredicate { trait_ref, polarity: ty::PredicatePolarity::Positive },
             ))),
             locations,
             category,

compiler/rustc_hir_analysis/src/astconv/bounds.rs

@@ -132,16 +132,16 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                 hir::GenericBound::Trait(poly_trait_ref, modifier) => {
                     let (constness, polarity) = match modifier {
                         hir::TraitBoundModifier::Const => {
-                            (ty::BoundConstness::Const, ty::ImplPolarity::Positive)
+                            (ty::BoundConstness::Const, ty::PredicatePolarity::Positive)
                         }
                         hir::TraitBoundModifier::MaybeConst => {
-                            (ty::BoundConstness::ConstIfConst, ty::ImplPolarity::Positive)
+                            (ty::BoundConstness::ConstIfConst, ty::PredicatePolarity::Positive)
                         }
                         hir::TraitBoundModifier::None => {
-                            (ty::BoundConstness::NotConst, ty::ImplPolarity::Positive)
+                            (ty::BoundConstness::NotConst, ty::PredicatePolarity::Positive)
                         }
                         hir::TraitBoundModifier::Negative => {
-                            (ty::BoundConstness::NotConst, ty::ImplPolarity::Negative)
+                            (ty::BoundConstness::NotConst, ty::PredicatePolarity::Negative)
                         }
                         hir::TraitBoundModifier::Maybe => continue,
                     };

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -645,7 +645,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
         trait_ref: &hir::TraitRef<'tcx>,
         span: Span,
         constness: ty::BoundConstness,
-        polarity: ty::ImplPolarity,
+        polarity: ty::PredicatePolarity,
         self_ty: Ty<'tcx>,
         bounds: &mut Bounds<'tcx>,
         only_self_bounds: OnlySelfBounds,
@@ -682,7 +682,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             // Don't register additional associated type bounds for negative bounds,
             // since we should have emitten an error for them earlier, and they will
             // not be well-formed!
-            if polarity == ty::ImplPolarity::Negative {
+            if polarity != ty::PredicatePolarity::Positive {
                 assert!(
                     self.tcx().dcx().has_errors().is_some(),
                     "negative trait bounds should not have bindings",

compiler/rustc_hir_analysis/src/astconv/object_safety.rs

@@ -41,7 +41,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                 &trait_bound.trait_ref,
                 trait_bound.span,
                 ty::BoundConstness::NotConst,
-                ty::ImplPolarity::Positive,
+                ty::PredicatePolarity::Positive,
                 dummy_self,
                 &mut bounds,
                 // True so we don't populate `bounds` with associated type bounds, even
@@ -58,7 +58,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             let bound_pred = pred.kind();
             match bound_pred.skip_binder() {
                 ty::ClauseKind::Trait(trait_pred) => {
-                    assert_eq!(trait_pred.polarity, ty::ImplPolarity::Positive);
+                    assert_eq!(trait_pred.polarity, ty::PredicatePolarity::Positive);
                     trait_bounds.push((bound_pred.rebind(trait_pred.trait_ref), span));
                 }
                 ty::ClauseKind::Projection(proj) => {

compiler/rustc_hir_analysis/src/bounds.rs

@@ -42,7 +42,7 @@ impl<'tcx> Bounds<'tcx> {
         tcx: TyCtxt<'tcx>,
         trait_ref: ty::PolyTraitRef<'tcx>,
         span: Span,
-        polarity: ty::ImplPolarity,
+        polarity: ty::PredicatePolarity,
     ) {
         self.push_trait_bound_inner(tcx, trait_ref, span, polarity);
     }
@@ -52,7 +52,7 @@ impl<'tcx> Bounds<'tcx> {
         tcx: TyCtxt<'tcx>,
         trait_ref: ty::PolyTraitRef<'tcx>,
         span: Span,
-        polarity: ty::ImplPolarity,
+        polarity: ty::PredicatePolarity,
     ) {
         self.clauses.push((
             trait_ref

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1322,7 +1322,7 @@ fn check_impl<'tcx>(
                     trait_ref,
                 );
                 let trait_pred =
-                    ty::TraitPredicate { trait_ref, polarity: ty::ImplPolarity::Positive };
+                    ty::TraitPredicate { trait_ref, polarity: ty::PredicatePolarity::Positive };
                 let mut obligations = traits::wf::trait_obligations(
                     wfcx.infcx,
                     wfcx.param_env,

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -551,7 +551,7 @@ fn infringing_fields_error(
                     }
                     if let ty::PredicateKind::Clause(ty::ClauseKind::Trait(ty::TraitPredicate {
                         trait_ref,
-                        polarity: ty::ImplPolarity::Positive,
+                        polarity: ty::PredicatePolarity::Positive,
                         ..
                     })) = error_predicate.kind().skip_binder()
                     {

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -624,7 +624,7 @@ pub(super) fn implied_predicates_with_filter(
             for &(pred, span) in implied_bounds {
                 debug!("superbound: {:?}", pred);
                 if let ty::ClauseKind::Trait(bound) = pred.kind().skip_binder()
-                    && bound.polarity == ty::ImplPolarity::Positive
+                    && bound.polarity == ty::PredicatePolarity::Positive
                 {
                     tcx.at(span).super_predicates_of(bound.def_id());
                 }
@@ -634,7 +634,7 @@ pub(super) fn implied_predicates_with_filter(
             for &(pred, span) in implied_bounds {
                 debug!("superbound: {:?}", pred);
                 if let ty::ClauseKind::Trait(bound) = pred.kind().skip_binder()
-                    && bound.polarity == ty::ImplPolarity::Positive
+                    && bound.polarity == ty::PredicatePolarity::Positive
                 {
                     tcx.at(span).implied_predicates_of(bound.def_id());
                 }

compiler/rustc_hir_typeck/src/expr.rs

@@ -3100,7 +3100,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     cause.clone().derived_cause(
                         ty::Binder::dummy(ty::TraitPredicate {
                             trait_ref: impl_trait_ref,
-                            polarity: ty::ImplPolarity::Positive,
+                            polarity: ty::PredicatePolarity::Positive,
                         }),
                         |derived| {
                             traits::ImplDerivedObligation(Box::new(

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -875,7 +875,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 match pred.kind().skip_binder() {
                                     ty::PredicateKind::Clause(ty::ClauseKind::Trait(pred)) => {
                                         Some(pred.def_id()) == self.tcx.lang_items().sized_trait()
-                                            && pred.polarity == ty::ImplPolarity::Positive
+                                            && pred.polarity == ty::PredicatePolarity::Positive
                                     }
                                     _ => false,
                                 }
@@ -3367,7 +3367,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 "inherent impls can't be candidates, only trait impls can be",
                             )
                         })
-                        .filter(|header| header.polarity == ty::ImplPolarity::Negative)
+                        .filter(|header| header.polarity != ty::ImplPolarity::Positive)
                         .any(|header| {
                             let imp = header.trait_ref.instantiate_identity();
                             let imp_simp =