1 files changed, 50 insertions, 26 deletions

diff --git a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
index 9cf3ff65a..2e56d2463 100644
--- a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
+++ b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
@@ -3,8 +3,8 @@ use crate::astconv::AstConv;
 use rustc_hir as hir;
 use rustc_infer::traits::util;
 use rustc_middle::ty::subst::InternalSubsts;
-use rustc_middle::ty::{self, DefIdTree, TyCtxt};
-use rustc_span::def_id::DefId;
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::Span;
 
 /// For associated types we include both bounds written on the type
@@ -16,12 +16,12 @@ use rustc_span::Span;
 /// `hr-associated-type-bound-1.rs`.
 fn associated_type_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
-    assoc_item_def_id: DefId,
+    assoc_item_def_id: LocalDefId,
     ast_bounds: &'tcx [hir::GenericBound<'tcx>],
     span: Span,
 ) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
     let item_ty = tcx.mk_projection(
-        assoc_item_def_id,
+        assoc_item_def_id.to_def_id(),
         InternalSubsts::identity_for_item(tcx, assoc_item_def_id),
     );
 
@@ -30,8 +30,8 @@ fn associated_type_bounds<'tcx>(
     // Associated types are implicitly sized unless a `?Sized` bound is found
     icx.astconv().add_implicitly_sized(&mut bounds, item_ty, ast_bounds, None, span);
 
-    let trait_def_id = tcx.parent(assoc_item_def_id);
-    let trait_predicates = tcx.trait_explicit_predicates_and_bounds(trait_def_id.expect_local());
+    let trait_def_id = tcx.local_parent(assoc_item_def_id);
+    let trait_predicates = tcx.trait_explicit_predicates_and_bounds(trait_def_id);
 
     let bounds_from_parent = trait_predicates.predicates.iter().copied().filter(|(pred, _)| {
         match pred.kind().skip_binder() {
@@ -45,7 +45,11 @@ fn associated_type_bounds<'tcx>(
     });
 
     let all_bounds = tcx.arena.alloc_from_iter(bounds.predicates().chain(bounds_from_parent));
-    debug!("associated_type_bounds({}) = {:?}", tcx.def_path_str(assoc_item_def_id), all_bounds);
+    debug!(
+        "associated_type_bounds({}) = {:?}",
+        tcx.def_path_str(assoc_item_def_id.to_def_id()),
+        all_bounds
+    );
     all_bounds
 }
 
@@ -56,19 +60,12 @@ fn associated_type_bounds<'tcx>(
 #[instrument(level = "trace", skip(tcx), ret)]
 fn opaque_type_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
-    opaque_def_id: DefId,
+    opaque_def_id: LocalDefId,
     ast_bounds: &'tcx [hir::GenericBound<'tcx>],
+    item_ty: Ty<'tcx>,
     span: Span,
-    in_trait: bool,
 ) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
     ty::print::with_no_queries!({
-        let substs = InternalSubsts::identity_for_item(tcx, opaque_def_id);
-        let item_ty = if in_trait {
-            tcx.mk_projection(opaque_def_id, substs)
-        } else {
-            tcx.mk_opaque(opaque_def_id, substs)
-        };
-
         let icx = ItemCtxt::new(tcx, opaque_def_id);
         let mut bounds = icx.astconv().compute_bounds(item_ty, ast_bounds);
         // Opaque types are implicitly sized unless a `?Sized` bound is found
@@ -81,9 +78,31 @@ fn opaque_type_bounds<'tcx>(
 
 pub(super) fn explicit_item_bounds(
     tcx: TyCtxt<'_>,
-    def_id: DefId,
+    def_id: LocalDefId,
 ) -> &'_ [(ty::Predicate<'_>, Span)] {
-    let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
+    match tcx.opt_rpitit_info(def_id.to_def_id()) {
+        // RPITIT's bounds are the same as opaque type bounds, but with
+        // a projection self type.
+        Some(ty::ImplTraitInTraitData::Trait { opaque_def_id, .. }) => {
+            let item = tcx.hir().get_by_def_id(opaque_def_id.expect_local()).expect_item();
+            let opaque_ty = item.expect_opaque_ty();
+            return opaque_type_bounds(
+                tcx,
+                opaque_def_id.expect_local(),
+                opaque_ty.bounds,
+                tcx.mk_projection(
+                    def_id.to_def_id(),
+                    ty::InternalSubsts::identity_for_item(tcx, def_id),
+                ),
+                item.span,
+            );
+        }
+        // These should have been fed!
+        Some(ty::ImplTraitInTraitData::Impl { .. }) => unreachable!(),
+        None => {}
+    }
+
+    let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
     match tcx.hir().get(hir_id) {
         hir::Node::TraitItem(hir::TraitItem {
             kind: hir::TraitItemKind::Type(bounds, _),
@@ -94,7 +113,15 @@ pub(super) fn explicit_item_bounds(
             kind: hir::ItemKind::OpaqueTy(hir::OpaqueTy { bounds, in_trait, .. }),
             span,
             ..
-        }) => opaque_type_bounds(tcx, def_id, bounds, *span, *in_trait),
+        }) => {
+            let substs = InternalSubsts::identity_for_item(tcx, def_id);
+            let item_ty = if *in_trait && !tcx.lower_impl_trait_in_trait_to_assoc_ty() {
+                tcx.mk_projection(def_id.to_def_id(), substs)
+            } else {
+                tcx.mk_opaque(def_id.to_def_id(), substs)
+            };
+            opaque_type_bounds(tcx, def_id, bounds, item_ty, *span)
+        }
         _ => bug!("item_bounds called on {:?}", def_id),
     }
 }
@@ -103,12 +130,9 @@ pub(super) fn item_bounds(
     tcx: TyCtxt<'_>,
     def_id: DefId,
 ) -> ty::EarlyBinder<&'_ ty::List<ty::Predicate<'_>>> {
-    let bounds = tcx.mk_predicates_from_iter(
-        util::elaborate_predicates(
-            tcx,
-            tcx.explicit_item_bounds(def_id).iter().map(|&(bound, _span)| bound),
-        )
-        .map(|obligation| obligation.predicate),
-    );
+    let bounds = tcx.mk_predicates_from_iter(util::elaborate(
+        tcx,
+        tcx.explicit_item_bounds(def_id).iter().map(|&(bound, _span)| bound),
+    ));
     ty::EarlyBinder(bounds)
 }