split out AliasTy -> AliasTerm

10 files changed, 39 insertions, 32 deletions

diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index db223f9d80f..0a6aa751ed7 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -2205,7 +2205,7 @@ fn param_env_with_gat_bounds<'tcx>(
             _ => predicates.push(
                 ty::Binder::bind_with_vars(
                     ty::ProjectionPredicate {
-                        projection_ty: ty::AliasTy::new(tcx, trait_ty.def_id, rebased_args),
+                        projection_term: ty::AliasTerm::new(tcx, trait_ty.def_id, rebased_args),
                         term: normalize_impl_ty.into(),
                     },
                     bound_vars,
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index eb0ffc19d45..c7462a6ee49 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -343,9 +343,10 @@ fn bounds_from_generic_predicates<'tcx>(
                 let mut projections_str = vec![];
                 for projection in &projections {
                     let p = projection.skip_binder();
-                    let alias_ty = p.projection_ty;
-                    if bound == tcx.parent(alias_ty.def_id) && alias_ty.self_ty() == ty {
-                        let name = tcx.item_name(alias_ty.def_id);
+                    if bound == tcx.parent(p.projection_term.def_id)
+                        && p.projection_term.self_ty() == ty
+                    {
+                        let name = tcx.item_name(p.projection_term.def_id);
                         projections_str.push(format!("{} = {}", name, p.term));
                     }
                 }
diff --git a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
index 02291cc603e..67f578373e0 100644
--- a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
+++ b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
@@ -39,7 +39,7 @@ fn associated_type_bounds<'tcx>(
     let bounds_from_parent = trait_predicates.predicates.iter().copied().filter(|(pred, _)| {
         match pred.kind().skip_binder() {
             ty::ClauseKind::Trait(tr) => tr.self_ty() == item_ty,
-            ty::ClauseKind::Projection(proj) => proj.projection_ty.self_ty() == item_ty,
+            ty::ClauseKind::Projection(proj) => proj.projection_term.self_ty() == item_ty,
             ty::ClauseKind::TypeOutlives(outlives) => outlives.0 == item_ty,
             _ => false,
         }
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 7e82571d172..8948e60b6dc 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -445,7 +445,9 @@ pub(super) fn explicit_predicates_of<'tcx>(
             .copied()
             .filter(|(pred, _)| match pred.kind().skip_binder() {
                 ty::ClauseKind::Trait(tr) => !is_assoc_item_ty(tr.self_ty()),
-                ty::ClauseKind::Projection(proj) => !is_assoc_item_ty(proj.projection_ty.self_ty()),
+                ty::ClauseKind::Projection(proj) => {
+                    !is_assoc_item_ty(proj.projection_term.self_ty())
+                }
                 ty::ClauseKind::TypeOutlives(outlives) => !is_assoc_item_ty(outlives.0),
                 _ => true,
             })
diff --git a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
index 3b8bb0731fb..ccf0c7bf2c1 100644
--- a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
+++ b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
@@ -197,7 +197,7 @@ pub fn setup_constraining_predicates<'tcx>(
                 // Special case: watch out for some kind of sneaky attempt
                 // to project out an associated type defined by this very
                 // trait.
-                let unbound_trait_ref = projection.projection_ty.trait_ref(tcx);
+                let unbound_trait_ref = projection.projection_term.trait_ref(tcx);
                 if Some(unbound_trait_ref) == impl_trait_ref {
                     continue;
                 }
@@ -207,7 +207,7 @@ pub fn setup_constraining_predicates<'tcx>(
                 //     `<<T as Bar>::Baz as Iterator>::Output = <U as Iterator>::Output`
                 // Then the projection only applies if `T` is known, but it still
                 // does not determine `U`.
-                let inputs = parameters_for(tcx, projection.projection_ty, true);
+                let inputs = parameters_for(tcx, projection.projection_term, true);
                 let relies_only_on_inputs = inputs.iter().all(|p| input_parameters.contains(p));
                 if !relies_only_on_inputs {
                     continue;
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
index de12475678c..41e3abd7451 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs
@@ -326,7 +326,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             })
             .or_insert(binding.span);
 
-        let projection_ty = if let ty::AssocKind::Fn = assoc_kind {
+        let projection_term = if let ty::AssocKind::Fn = assoc_kind {
             let mut emitted_bad_param_err = None;
             // If we have an method return type bound, then we need to instantiate
             // the method's early bound params with suitable late-bound params.
@@ -380,7 +380,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             let output = if let ty::Alias(ty::Projection, alias_ty) = *output.skip_binder().kind()
                 && tcx.is_impl_trait_in_trait(alias_ty.def_id)
             {
-                alias_ty
+                alias_ty.into()
             } else {
                 return Err(tcx.dcx().emit_err(crate::errors::ReturnTypeNotationOnNonRpitit {
                     span: binding.span,
@@ -424,7 +424,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 // Note that we're indeed also using `AliasTy` (alias *type*) for associated
                 // *constants* to represent *const projections*. Alias *term* would be a more
                 // appropriate name but alas.
-                ty::AliasTy::new(tcx, assoc_item.def_id, alias_args)
+                ty::AliasTerm::new(tcx, assoc_item.def_id, alias_args)
             });
 
             // Provide the resolved type of the associated constant to `type_of(AnonConst)`.
@@ -461,7 +461,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 //     for<'a> <T as Iterator>::Item = &'a str // <-- 'a is bad
                 //     for<'a> <T as FnMut<(&'a u32,)>>::Output = &'a str // <-- 'a is ok
                 let late_bound_in_projection_ty =
-                    tcx.collect_constrained_late_bound_regions(projection_ty);
+                    tcx.collect_constrained_late_bound_regions(projection_term);
                 let late_bound_in_term =
                     tcx.collect_referenced_late_bound_regions(trait_ref.rebind(term));
                 debug!(?late_bound_in_projection_ty);
@@ -490,8 +490,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
                 bounds.push_projection_bound(
                     tcx,
-                    projection_ty
-                        .map_bound(|projection_ty| ty::ProjectionPredicate { projection_ty, term }),
+                    projection_term.map_bound(|projection_term| ty::ProjectionPredicate {
+                        projection_term,
+                        term,
+                    }),
                     binding.span,
                 );
             }
@@ -501,6 +503,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 // NOTE: If `only_self_bounds` is true, do NOT expand this associated type bound into
                 // a trait predicate, since we only want to add predicates for the `Self` type.
                 if !only_self_bounds.0 {
+                    let projection_ty = projection_term
+                        .map_bound(|projection_term| projection_term.expect_ty(self.tcx()));
                     // Calling `skip_binder` is okay, because `lower_bounds` expects the `param_ty`
                     // parameter to have a skipped binder.
                     let param_ty = Ty::new_alias(tcx, ty::Projection, projection_ty.skip_binder());
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
index 38dfa8d57d3..8f68a670d01 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs
@@ -627,23 +627,23 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 ty::PredicateKind::Clause(ty::ClauseKind::Projection(pred)) => {
                     let pred = bound_predicate.rebind(pred);
                     // `<Foo as Iterator>::Item = String`.
-                    let projection_ty = pred.skip_binder().projection_ty;
+                    let projection_term = pred.skip_binder().projection_term;
 
                     let args_with_infer_self = tcx.mk_args_from_iter(
                         std::iter::once(Ty::new_var(tcx, ty::TyVid::ZERO).into())
-                            .chain(projection_ty.args.iter().skip(1)),
+                            .chain(projection_term.args.iter().skip(1)),
                     );
 
                     let quiet_projection_ty =
-                        ty::AliasTy::new(tcx, projection_ty.def_id, args_with_infer_self);
+                        ty::AliasTerm::new(tcx, projection_term.def_id, args_with_infer_self);
 
                     let term = pred.skip_binder().term;
 
-                    let obligation = format!("{projection_ty} = {term}");
+                    let obligation = format!("{projection_term} = {term}");
                     let quiet = format!("{quiet_projection_ty} = {term}");
 
-                    bound_span_label(projection_ty.self_ty(), &obligation, &quiet);
-                    Some((obligation, projection_ty.self_ty()))
+                    bound_span_label(projection_term.self_ty(), &obligation, &quiet);
+                    Some((obligation, projection_term.self_ty()))
                 }
                 ty::PredicateKind::Clause(ty::ClauseKind::Trait(poly_trait_ref)) => {
                     let p = poly_trait_ref.trait_ref;
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs
index 37d4d4ec355..a64a7a2e5bd 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs
@@ -280,11 +280,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
         let existential_projections = projection_bounds.iter().map(|(bound, _)| {
             bound.map_bound(|mut b| {
-                assert_eq!(b.projection_ty.self_ty(), dummy_self);
+                assert_eq!(b.projection_term.self_ty(), dummy_self);
 
                 // Like for trait refs, verify that `dummy_self` did not leak inside default type
                 // parameters.
-                let references_self = b.projection_ty.args.iter().skip(1).any(|arg| {
+                let references_self = b.projection_term.args.iter().skip(1).any(|arg| {
                     if arg.walk().any(|arg| arg == dummy_self.into()) {
                         return true;
                     }
@@ -294,7 +294,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     let guar = tcx
                         .dcx()
                         .span_delayed_bug(span, "trait object projection bounds reference `Self`");
-                    b.projection_ty = replace_dummy_self_with_error(tcx, b.projection_ty, guar);
+                    b.projection_term = replace_dummy_self_with_error(tcx, b.projection_term, guar);
                 }
 
                 ty::ExistentialProjection::erase_self_ty(tcx, b)
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index 6dd59a62a7a..61357d6504c 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -258,23 +258,23 @@ fn unconstrained_parent_impl_args<'tcx>(
     // unconstrained parameters.
     for (clause, _) in impl_generic_predicates.predicates.iter() {
         if let ty::ClauseKind::Projection(proj) = clause.kind().skip_binder() {
-            let projection_ty = proj.projection_ty;
-            let projected_ty = proj.term;
+            let projection_term = proj.projection_term;
+            let projected_term = proj.term;
 
-            let unbound_trait_ref = projection_ty.trait_ref(tcx);
+            let unbound_trait_ref = projection_term.trait_ref(tcx);
             if Some(unbound_trait_ref) == impl_trait_ref {
                 continue;
             }
 
-            unconstrained_parameters.extend(cgp::parameters_for(tcx, projection_ty, true));
+            unconstrained_parameters.extend(cgp::parameters_for(tcx, projection_term, true));
 
-            for param in cgp::parameters_for(tcx, projected_ty, false) {
+            for param in cgp::parameters_for(tcx, projected_term, false) {
                 if !unconstrained_parameters.contains(&param) {
                     constrained_params.insert(param.0);
                 }
             }
 
-            unconstrained_parameters.extend(cgp::parameters_for(tcx, projected_ty, true));
+            unconstrained_parameters.extend(cgp::parameters_for(tcx, projected_term, true));
         }
     }
 
@@ -495,11 +495,11 @@ fn check_specialization_on<'tcx>(
                     .emit())
             }
         }
-        ty::ClauseKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => Err(tcx
+        ty::ClauseKind::Projection(ty::ProjectionPredicate { projection_term, term }) => Err(tcx
             .dcx()
             .struct_span_err(
                 span,
-                format!("cannot specialize on associated type `{projection_ty} == {term}`",),
+                format!("cannot specialize on associated type `{projection_term} == {term}`",),
             )
             .emit()),
         ty::ClauseKind::ConstArgHasType(..) => {
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 27fdea01c2b..cfc7ecf8580 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -166,7 +166,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
                 }
             }
             ty::ClauseKind::Projection(ty::ProjectionPredicate {
-                projection_ty: ty::AliasTy { args, .. },
+                projection_term: ty::AliasTerm { args, .. },
                 term,
             }) => {
                 for arg in &args[1..] {