Ensure define_opaque attrs are accounted for in HIR hash

compiler/rustc_ast_lowering/src/lib.rs

@@ -625,7 +625,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         // Don't hash unless necessary, because it's expensive.
         let (opt_hash_including_bodies, attrs_hash) =
-            self.tcx.hash_owner_nodes(node, &bodies, &attrs);
+            self.tcx.hash_owner_nodes(node, &bodies, &attrs, define_opaque);
         let num_nodes = self.item_local_id_counter.as_usize();
         let (nodes, parenting) = index::index_hir(self.tcx, node, &bodies, num_nodes);
         let nodes = hir::OwnerNodes { opt_hash_including_bodies, nodes, bodies };

compiler/rustc_middle/src/hir/mod.rs

@@ -14,7 +14,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
 use rustc_hir::*;
 use rustc_macros::{Decodable, Encodable, HashStable};
-use rustc_span::{ErrorGuaranteed, ExpnId};
+use rustc_span::{ErrorGuaranteed, ExpnId, Span};
 
 use crate::query::Providers;
 use crate::ty::{EarlyBinder, ImplSubject, TyCtxt};
@@ -157,6 +157,7 @@ impl<'tcx> TyCtxt<'tcx> {
         node: OwnerNode<'_>,
         bodies: &SortedMap<ItemLocalId, &Body<'_>>,
         attrs: &SortedMap<ItemLocalId, &[Attribute]>,
+        define_opaque: Option<&[(Span, LocalDefId)]>,
     ) -> (Option<Fingerprint>, Option<Fingerprint>) {
         if self.needs_crate_hash() {
             self.with_stable_hashing_context(|mut hcx| {
@@ -168,6 +169,10 @@ impl<'tcx> TyCtxt<'tcx> {
 
                 let mut stable_hasher = StableHasher::new();
                 attrs.hash_stable(&mut hcx, &mut stable_hasher);
+
+                // Hash the defined opaque types, which are not present in the attrs.
+                define_opaque.hash_stable(&mut hcx, &mut stable_hasher);
+
                 let h2 = stable_hasher.finish();
                 (Some(h1), Some(h2))
             })

compiler/rustc_middle/src/ty/context.rs

@@ -1288,7 +1288,8 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
         let bodies = Default::default();
         let attrs = hir::AttributeMap::EMPTY;
 
-        let (opt_hash_including_bodies, _) = self.tcx.hash_owner_nodes(node, &bodies, &attrs.map);
+        let (opt_hash_including_bodies, _) =
+            self.tcx.hash_owner_nodes(node, &bodies, &attrs.map, attrs.define_opaque);
         let node = node.into();
         self.opt_hir_owner_nodes(Some(self.tcx.arena.alloc(hir::OwnerNodes {
             opt_hash_including_bodies,

tests/incremental/define-opaques.rs

@@ -0,0 +1,19 @@
+//@ revisions: rpass1 cfail2
+
+#![feature(type_alias_impl_trait)]
+
+pub type Foo = impl Sized;
+
+#[cfg_attr(rpass1, define_opaque())]
+#[cfg_attr(cfail2, define_opaque(Foo))]
+fn a() {
+    //[cfail2]~^ ERROR item does not constrain `Foo::{opaque#0}`
+    let _: Foo = b();
+}
+
+#[define_opaque(Foo)]
+fn b() -> Foo {
+    ()
+}
+
+fn main() {}