Feed parent hir id for Node::Synthetic

Author: compiler-errors

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -112,7 +112,7 @@ fn intern_as_new_static<'tcx>(
     feed.def_ident_span(tcx.def_ident_span(static_id));
     feed.explicit_predicates_of(tcx.explicit_predicates_of(static_id));
 
-    feed.feed_hir()
+    feed.feed_hir(None);
 }
 
 /// How a constant value should be interned.

compiler/rustc_middle/src/query/mod.rs

@@ -186,6 +186,7 @@ rustc_queries! {
     /// Avoid calling this query directly.
     query hir_owner_parent(key: hir::OwnerId) -> hir::HirId {
         desc { |tcx| "getting HIR parent of `{}`", tcx.def_path_str(key) }
+        feedable
     }
 
     /// Gives access to the HIR nodes and bodies inside `key` if it's a HIR owner.

compiler/rustc_middle/src/ty/context.rs

@@ -599,7 +599,7 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
     }
 
     // Fills in all the important parts needed by HIR queries
-    pub fn feed_hir(&self) {
+    pub fn feed_hir(&self, parent_hir_id: Option<HirId>) {
         self.local_def_id_to_hir_id(HirId::make_owner(self.def_id()));
 
         let node = hir::OwnerNode::Synthetic;
@@ -616,7 +616,11 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
             ),
             bodies,
         })));
+
         self.feed_owner_id().hir_attrs(attrs);
+        if let Some(parent) = parent_hir_id {
+            self.feed_owner_id().hir_owner_parent(parent);
+        }
     }
 }
 

compiler/rustc_ty_utils/src/assoc.rs

@@ -258,7 +258,9 @@ fn associated_type_for_impl_trait_in_trait(
     let local_def_id = trait_assoc_ty.def_id();
     let def_id = local_def_id.to_def_id();
 
-    trait_assoc_ty.feed_hir();
+    // Set the parent HIR for this item to be the `Node::Ty` of the `impl Trait` in trait.
+    let parent_ty = tcx.parent_hir_id(tcx.local_def_id_to_hir_id(opaque_ty_def_id));
+    trait_assoc_ty.feed_hir(Some(parent_ty));
 
     // Copy span of the opaque.
     trait_assoc_ty.def_ident_span(Some(span));
@@ -312,7 +314,7 @@ fn associated_type_for_impl_trait_in_impl(
     let local_def_id = impl_assoc_ty.def_id();
     let def_id = local_def_id.to_def_id();
 
-    impl_assoc_ty.feed_hir();
+    impl_assoc_ty.feed_hir(None);
 
     // Copy span of the opaque.
     impl_assoc_ty.def_ident_span(Some(span));

tests/ui/impl-trait/in-trait/synthetic-hir-has-parent.rs

@@ -0,0 +1,14 @@
+// Don't panic when iterating through the `hir::Map::parent_iter` of an RPITIT.
+
+pub trait Foo<'a> {
+    type Assoc;
+
+    fn demo() -> impl Foo
+    //~^ ERROR missing lifetime specifier
+    //~| ERROR the trait bound `String: Copy` is not satisfied
+    where
+        String: Copy;
+    //~^ ERROR the trait bound `String: Copy` is not satisfied
+}
+
+fn main() {}

tests/ui/impl-trait/in-trait/synthetic-hir-has-parent.stderr

@@ -0,0 +1,40 @@
+error[E0106]: missing lifetime specifier
+  --> $DIR/synthetic-hir-has-parent.rs:6:23
+   |
+LL |     fn demo() -> impl Foo
+   |                       ^^^ expected named lifetime parameter
+   |
+   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
+help: consider using the `'a` lifetime
+   |
+LL |     fn demo() -> impl Foo<'a>
+   |                          ++++
+
+error[E0277]: the trait bound `String: Copy` is not satisfied
+  --> $DIR/synthetic-hir-has-parent.rs:10:9
+   |
+LL |         String: Copy;
+   |         ^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |
+   = help: see issue #48214
+help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   |
+LL + #![feature(trivial_bounds)]
+   |
+
+error[E0277]: the trait bound `String: Copy` is not satisfied
+  --> $DIR/synthetic-hir-has-parent.rs:6:18
+   |
+LL |     fn demo() -> impl Foo
+   |                  ^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |
+   = help: see issue #48214
+help: add `#![feature(trivial_bounds)]` to the crate attributes to enable
+   |
+LL + #![feature(trivial_bounds)]
+   |
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0106, E0277.
+For more information about an error, try `rustc --explain E0106`.