The AssocOpaqueTy HIR node is not actually needed to differentiate from other hir nodes that were fed

compiler/rustc_ast_lowering/src/index.rs

@@ -55,7 +55,7 @@ pub(super) fn index_hir<'hir>(
         OwnerNode::TraitItem(item) => collector.visit_trait_item(item),
         OwnerNode::ImplItem(item) => collector.visit_impl_item(item),
         OwnerNode::ForeignItem(item) => collector.visit_foreign_item(item),
-        OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+        OwnerNode::Synthetic => unreachable!(),
     };
 
     for (local_id, node) in collector.nodes.iter_enumerated() {

compiler/rustc_hir/src/hir.rs

@@ -2552,11 +2552,6 @@ pub struct OpaqueTy<'hir> {
     pub in_trait: bool,
 }
 
-#[derive(Copy, Clone, Debug, HashStable_Generic)]
-pub struct AssocOpaqueTy {
-    // Add some data if necessary
-}
-
 /// From whence the opaque type came.
 #[derive(Copy, Clone, PartialEq, Eq, Debug, HashStable_Generic)]
 pub enum OpaqueTyOrigin {
@@ -3367,7 +3362,7 @@ pub enum OwnerNode<'hir> {
     TraitItem(&'hir TraitItem<'hir>),
     ImplItem(&'hir ImplItem<'hir>),
     Crate(&'hir Mod<'hir>),
-    AssocOpaqueTy(&'hir AssocOpaqueTy),
+    Synthetic,
 }
 
 impl<'hir> OwnerNode<'hir> {
@@ -3377,7 +3372,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ForeignItem(ForeignItem { ident, .. })
             | OwnerNode::ImplItem(ImplItem { ident, .. })
             | OwnerNode::TraitItem(TraitItem { ident, .. }) => Some(*ident),
-            OwnerNode::Crate(..) | OwnerNode::AssocOpaqueTy(..) => None,
+            OwnerNode::Crate(..) | OwnerNode::Synthetic => None,
         }
     }
 
@@ -3390,7 +3385,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ImplItem(ImplItem { span, .. })
             | OwnerNode::TraitItem(TraitItem { span, .. }) => span,
             OwnerNode::Crate(Mod { spans: ModSpans { inner_span, .. }, .. }) => inner_span,
-            OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+            OwnerNode::Synthetic => unreachable!(),
         }
     }
 
@@ -3449,7 +3444,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ImplItem(ImplItem { owner_id, .. })
             | OwnerNode::ForeignItem(ForeignItem { owner_id, .. }) => *owner_id,
             OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
-            OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+            OwnerNode::Synthetic => unreachable!(),
         }
     }
 
@@ -3493,7 +3488,7 @@ impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
             OwnerNode::ImplItem(n) => Node::ImplItem(n),
             OwnerNode::TraitItem(n) => Node::TraitItem(n),
             OwnerNode::Crate(n) => Node::Crate(n),
-            OwnerNode::AssocOpaqueTy(n) => Node::AssocOpaqueTy(n),
+            OwnerNode::Synthetic => Node::Synthetic,
         }
     }
 }
@@ -3531,7 +3526,8 @@ pub enum Node<'hir> {
     WhereBoundPredicate(&'hir WhereBoundPredicate<'hir>),
     // FIXME: Merge into `Node::Infer`.
     ArrayLenInfer(&'hir InferArg),
-    AssocOpaqueTy(&'hir AssocOpaqueTy),
+    // Created by query feeding
+    Synthetic,
     // Span by reference to minimize `Node`'s size
     #[allow(rustc::pass_by_value)]
     Err(&'hir Span),
@@ -3582,7 +3578,7 @@ impl<'hir> Node<'hir> {
             | Node::Infer(..)
             | Node::WhereBoundPredicate(..)
             | Node::ArrayLenInfer(..)
-            | Node::AssocOpaqueTy(..)
+            | Node::Synthetic
             | Node::Err(..) => None,
         }
     }
@@ -3688,7 +3684,7 @@ impl<'hir> Node<'hir> {
             Node::TraitItem(i) => Some(OwnerNode::TraitItem(i)),
             Node::ImplItem(i) => Some(OwnerNode::ImplItem(i)),
             Node::Crate(i) => Some(OwnerNode::Crate(i)),
-            Node::AssocOpaqueTy(i) => Some(OwnerNode::AssocOpaqueTy(i)),
+            Node::Synthetic => Some(OwnerNode::Synthetic),
             _ => None,
         }
     }

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -196,7 +196,7 @@ fn check_well_formed(tcx: TyCtxt<'_>, def_id: hir::OwnerId) -> Result<(), ErrorG
         hir::OwnerNode::TraitItem(item) => check_trait_item(tcx, item),
         hir::OwnerNode::ImplItem(item) => check_impl_item(tcx, item),
         hir::OwnerNode::ForeignItem(item) => check_foreign_item(tcx, item),
-        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+        hir::OwnerNode::Synthetic => unreachable!(),
     };
 
     if let Some(generics) = node.generics() {

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -262,7 +262,7 @@ fn resolve_bound_vars(tcx: TyCtxt<'_>, local_def_id: hir::OwnerId) -> ResolveBou
             visitor.visit_impl_item(item)
         }
         hir::OwnerNode::Crate(_) => {}
-        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+        hir::OwnerNode::Synthetic => unreachable!(),
     }
 
     let mut rl = ResolveBoundVars::default();

compiler/rustc_hir_pretty/src/lib.rs

@@ -121,7 +121,7 @@ impl<'a> State<'a> {
                 self.print_bounds(":", pred.bounds);
             }
             Node::ArrayLenInfer(_) => self.word("_"),
-            Node::AssocOpaqueTy(..) => unreachable!(),
+            Node::Synthetic => unreachable!(),
             Node::Err(_) => self.word("/*ERROR*/"),
         }
     }

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2553,7 +2553,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             hir::OwnerNode::ImplItem(i) => visitor.visit_impl_item(i),
             hir::OwnerNode::TraitItem(i) => visitor.visit_trait_item(i),
             hir::OwnerNode::Crate(_) => bug!("OwnerNode::Crate doesn't not have generics"),
-            hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+            hir::OwnerNode::Synthetic => unreachable!(),
         }
 
         let ast_generics = self.tcx.hir().get_generics(lifetime_scope).unwrap();

compiler/rustc_lint/src/levels.rs

@@ -191,7 +191,7 @@ fn shallow_lint_levels_on(tcx: TyCtxt<'_>, owner: hir::OwnerId) -> ShallowLintLe
                 levels.add_id(hir::CRATE_HIR_ID);
                 levels.visit_mod(mod_, mod_.spans.inner_span, hir::CRATE_HIR_ID)
             }
-            hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
+            hir::OwnerNode::Synthetic => unreachable!(),
         },
     }
 

compiler/rustc_middle/src/hir/map/mod.rs

@@ -954,7 +954,7 @@ impl<'hir> Map<'hir> {
             Node::Crate(item) => item.spans.inner_span,
             Node::WhereBoundPredicate(pred) => pred.span,
             Node::ArrayLenInfer(inf) => inf.span,
-            Node::AssocOpaqueTy(..) => unreachable!(),
+            Node::Synthetic => unreachable!(),
             Node::Err(span) => *span,
         }
     }
@@ -1219,7 +1219,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
         Node::Crate(..) => String::from("(root_crate)"),
         Node::WhereBoundPredicate(_) => node_str("where bound predicate"),
         Node::ArrayLenInfer(_) => node_str("array len infer"),
-        Node::AssocOpaqueTy(..) => unreachable!(),
+        Node::Synthetic => unreachable!(),
         Node::Err(_) => node_str("error"),
     }
 }

compiler/rustc_passes/src/reachable.rs

@@ -247,7 +247,7 @@ impl<'tcx> ReachableContext<'tcx> {
             | Node::Field(_)
             | Node::Ty(_)
             | Node::Crate(_)
-            | Node::AssocOpaqueTy(..) => {}
+            | Node::Synthetic => {}
             _ => {
                 bug!(
                     "found unexpected node kind in worklist: {} ({:?})",

compiler/rustc_ty_utils/src/assoc.rs

@@ -241,18 +241,16 @@ fn associated_types_for_impl_traits_in_associated_fn(
 fn feed_hir(feed: &TyCtxtFeed<'_, LocalDefId>) {
     feed.local_def_id_to_hir_id(HirId::make_owner(feed.def_id()));
 
-    let node = hir::OwnerNode::AssocOpaqueTy(&hir::AssocOpaqueTy {});
+    let node = hir::OwnerNode::Synthetic;
     let bodies = Default::default();
     let attrs = hir::AttributeMap::EMPTY;
 
     let (opt_hash_including_bodies, _) = feed.tcx.hash_owner_nodes(node, &bodies, &attrs.map);
+    let node = node.into();
     feed.opt_hir_owner_nodes(Some(feed.tcx.arena.alloc(hir::OwnerNodes {
         opt_hash_including_bodies,
         nodes: IndexVec::from_elem_n(
-            hir::ParentedNode {
+            hir::ParentedNode { parent: hir::ItemLocalId::INVALID, node },
-                parent: hir::ItemLocalId::INVALID,
-                node: hir::Node::AssocOpaqueTy(&hir::AssocOpaqueTy {}),
-            },
             1,
         ),
         bodies,