5 files changed, 34 insertions, 49 deletions
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 363a75911ad..74daad08394 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1181,11 +1181,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         } {
             let in_module_is_extern = !in_module.def_id().is_local();
             in_module.for_each_child(self, |this, ident, ns, name_binding| {
-                // avoid non-importable candidates
-                if !name_binding.is_importable()
-                    // FIXME(import_trait_associated_functions): remove this when `import_trait_associated_functions` is stable
-                    || name_binding.is_assoc_const_or_fn()
-                        && !this.tcx.features().import_trait_associated_functions()
+                // Avoid non-importable candidates.
+                if name_binding.is_assoc_item()
+                    && !this.tcx.features().import_trait_associated_functions()
                 {
                     return;
                 }
diff --git a/compiler/rustc_resolve/src/errors.rs b/compiler/rustc_resolve/src/errors.rs
index e26b300f13e..7fe74378b67 100644
--- a/compiler/rustc_resolve/src/errors.rs
+++ b/compiler/rustc_resolve/src/errors.rs
@@ -781,22 +781,6 @@ pub(crate) struct CannotGlobImportAllCrates {
     pub(crate) span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(resolve_items_in_traits_are_not_importable)]
-pub(crate) struct ItemsInTraitsAreNotImportable {
-    #[primary_span]
-    pub(crate) span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(resolve_is_not_directly_importable, code = E0253)]
-pub(crate) struct IsNotDirectlyImportable {
-    #[primary_span]
-    #[label]
-    pub(crate) span: Span,
-    pub(crate) target: Ident,
-}
-
 #[derive(Subdiagnostic)]
 #[suggestion(
     resolve_unexpected_res_change_ty_to_const_param_sugg,
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 762e08b2be5..816efd0d5fa 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -30,8 +30,7 @@ use crate::diagnostics::{DiagMode, Suggestion, import_candidates};
 use crate::errors::{
     CannotBeReexportedCratePublic, CannotBeReexportedCratePublicNS, CannotBeReexportedPrivate,
     CannotBeReexportedPrivateNS, CannotDetermineImportResolution, CannotGlobImportAllCrates,
-    ConsiderAddingMacroExport, ConsiderMarkingAsPub, IsNotDirectlyImportable,
-    ItemsInTraitsAreNotImportable,
+    ConsiderAddingMacroExport, ConsiderMarkingAsPub,
 };
 use crate::{
     AmbiguityError, AmbiguityKind, BindingKey, Finalize, ImportSuggestion, Module,
@@ -835,11 +834,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
                 let parent = import.parent_scope.module;
                 match source_bindings[ns].get() {
-                    Err(Undetermined) => indeterminate_count += 1,
-                    // Don't update the resolution, because it was never added.
-                    Err(Determined) if target.name == kw::Underscore => {}
-                    Ok(binding) if binding.is_importable() => {
-                        if binding.is_assoc_const_or_fn()
+                    Ok(binding) => {
+                        if binding.is_assoc_item()
                             && !this.tcx.features().import_trait_associated_functions()
                         {
                             feature_err(
@@ -850,21 +846,21 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             )
                             .emit();
                         }
+
                         let imported_binding = this.import(binding, import);
                         target_bindings[ns].set(Some(imported_binding));
                         this.define(parent, target, ns, imported_binding);
                     }
-                    source_binding @ (Ok(..) | Err(Determined)) => {
-                        if source_binding.is_ok() {
-                            this.dcx()
-                                .create_err(IsNotDirectlyImportable { span: import.span, target })
-                                .emit();
+                    Err(Determined) => {
+                        // Don't update the resolution for underscores, because it was never added.
+                        if target.name != kw::Underscore {
+                            let key = BindingKey::new(target, ns);
+                            this.update_resolution(parent, key, false, |_, resolution| {
+                                resolution.single_imports.swap_remove(&import);
+                            });
                         }
-                        let key = BindingKey::new(target, ns);
-                        this.update_resolution(parent, key, false, |_, resolution| {
-                            resolution.single_imports.swap_remove(&import);
-                        });
                     }
+                    Err(Undetermined) => indeterminate_count += 1,
                 }
             }
         });
@@ -1428,10 +1424,17 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             return;
         };
 
-        if module.is_trait() {
-            self.dcx().emit_err(ItemsInTraitsAreNotImportable { span: import.span });
-            return;
-        } else if module == import.parent_scope.module {
+        if module.is_trait() && !self.tcx.features().import_trait_associated_functions() {
+            feature_err(
+                self.tcx.sess,
+                sym::import_trait_associated_functions,
+                import.span,
+                "`use` associated items of traits is unstable",
+            )
+            .emit();
+        }
+
+        if module == import.parent_scope.module {
             return;
         } else if is_prelude {
             self.prelude = Some(module);
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index bae2fdeecaf..faee0e7dd5f 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -958,6 +958,11 @@ impl<'ra: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'r
                     self.resolve_anon_const(end, AnonConstKind::ConstArg(IsRepeatExpr::No));
                 }
             }
+            TyPatKind::Or(patterns) => {
+                for pat in patterns {
+                    self.visit_ty_pat(pat)
+                }
+            }
             TyPatKind::Err(_) => {}
         }
     }
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index bb8d7b76371..d0549bae614 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -19,6 +19,7 @@
 #![feature(iter_intersperse)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
+#![recursion_limit = "256"]
 // tidy-alphabetical-end
 
 use std::cell::{Cell, RefCell};
@@ -949,14 +950,8 @@ impl<'ra> NameBindingData<'ra> {
         }
     }
 
-    fn is_importable(&self) -> bool {
-        !matches!(self.res(), Res::Def(DefKind::AssocTy, _))
-    }
-
-    // FIXME(import_trait_associated_functions): associate `const` or `fn` are not importable unless
-    // the feature `import_trait_associated_functions` is enable
-    fn is_assoc_const_or_fn(&self) -> bool {
-        matches!(self.res(), Res::Def(DefKind::AssocConst | DefKind::AssocFn, _))
+    fn is_assoc_item(&self) -> bool {
+        matches!(self.res(), Res::Def(DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy, _))
     }
 
     fn macro_kind(&self) -> Option<MacroKind> {