Call `type_of` for opaque types later in compilation

This ensures that various wf checks have already been done before we
typeck item bodies.

3 files changed, 10 insertions, 3 deletions

diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs
index 2daa0354acb..0647be2dfde 100644
--- a/compiler/rustc_typeck/src/check/check.rs
+++ b/compiler/rustc_typeck/src/check/check.rs
@@ -385,6 +385,7 @@ pub(super) fn check_opaque<'tcx>(
     origin: &hir::OpaqueTyOrigin,
 ) {
     check_opaque_for_inheriting_lifetimes(tcx, def_id, span);
+    tcx.ensure().type_of(def_id);
     check_opaque_for_cycles(tcx, def_id, substs, span, origin);
 }
 
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index a571bd58abc..d6985f3bd4d 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -693,8 +693,14 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::HirId) {
         // Desugared from `impl Trait`, so visited by the function's return type.
         hir::ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn: Some(_), .. }) => {}
 
-        hir::ItemKind::OpaqueTy(..)
-        | hir::ItemKind::TyAlias(..)
+        // Don't call `type_of` on opaque types, since that depends on type
+        // checking function bodies. `check_item_type` ensures that it's called
+        // instead.
+        hir::ItemKind::OpaqueTy(..) => {
+            tcx.ensure().generics_of(def_id);
+            tcx.ensure().predicates_of(def_id);
+        }
+        hir::ItemKind::TyAlias(..)
         | hir::ItemKind::Static(..)
         | hir::ItemKind::Const(..)
         | hir::ItemKind::Fn(..) => {
diff --git a/compiler/rustc_typeck/src/lib.rs b/compiler/rustc_typeck/src/lib.rs
index 84efb92582e..dd6621a3f11 100644
--- a/compiler/rustc_typeck/src/lib.rs
+++ b/compiler/rustc_typeck/src/lib.rs
@@ -360,7 +360,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorReported> {
 
     // this ensures that later parts of type checking can assume that items
     // have valid types and not error
-    // FIXME(matthewjasper) We shouldn't need to do this.
+    // FIXME(matthewjasper) We shouldn't need to use `track_errors`.
     tcx.sess.track_errors(|| {
         tcx.sess.time("type_collecting", || {
             for &module in tcx.hir().krate().modules.keys() {