4 files changed, 40 insertions, 17 deletions
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 2cfde2f62d8..73cd596c076 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1395,7 +1395,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             let head_span = source_map.guess_head_span(span);
             err.subdiagnostic(ConsiderAddingADerive {
                 span: head_span.shrink_to_lo(),
-                suggestion: format!("#[derive(Default)]\n")
+                suggestion: "#[derive(Default)]\n".to_string(),
             });
         }
         for ns in [Namespace::MacroNS, Namespace::TypeNS, Namespace::ValueNS] {
@@ -1718,7 +1718,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             if next_binding.is_none() && let Some(span) = non_exhaustive {
                 note_span.push_span_label(
                     span,
-                    format!("cannot be constructed because it is `#[non_exhaustive]`"),
+                    "cannot be constructed because it is `#[non_exhaustive]`",
                 );
             }
             err.span_note(note_span, msg);
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 526fc9c3aa5..f3cf61c5b93 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -989,14 +989,17 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             initial_binding.res()
                         });
                         let res = binding.res();
+                        if res == Res::Err || !this.ambiguity_errors.is_empty() {
+                            this.tcx
+                                .sess
+                                .delay_span_bug(import.span, "some error happened for an import");
+                            return;
+                        }
                         if let Ok(initial_res) = initial_res {
-                            if res != initial_res && this.ambiguity_errors.is_empty() {
+                            if res != initial_res {
                                 span_bug!(import.span, "inconsistent resolution for an import");
                             }
-                        } else if res != Res::Err
-                            && this.ambiguity_errors.is_empty()
-                            && this.privacy_errors.is_empty()
-                        {
+                        } else if this.privacy_errors.is_empty() {
                             this.tcx
                                 .sess
                                 .create_err(CannotDetermineImportResolution { span: import.span })
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 05128a51016..aab71494fd3 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -549,6 +549,7 @@ enum MaybeExported<'a> {
     Ok(NodeId),
     Impl(Option<DefId>),
     ImplItem(Result<DefId, &'a Visibility>),
+    NestedUse(&'a Visibility),
 }
 
 impl MaybeExported<'_> {
@@ -559,7 +560,9 @@ impl MaybeExported<'_> {
                 trait_def_id.as_local()
             }
             MaybeExported::Impl(None) => return true,
-            MaybeExported::ImplItem(Err(vis)) => return vis.kind.is_pub(),
+            MaybeExported::ImplItem(Err(vis)) | MaybeExported::NestedUse(vis) => {
+                return vis.kind.is_pub();
+            }
         };
         def_id.map_or(true, |def_id| r.effective_visibilities.is_exported(def_id))
     }
@@ -2284,7 +2287,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     fn resolve_item(&mut self, item: &'ast Item) {
         let mod_inner_docs =
             matches!(item.kind, ItemKind::Mod(..)) && rustdoc::inner_docs(&item.attrs);
-        if !mod_inner_docs && !matches!(item.kind, ItemKind::Impl(..)) {
+        if !mod_inner_docs && !matches!(item.kind, ItemKind::Impl(..) | ItemKind::Use(..)) {
             self.resolve_doc_links(&item.attrs, MaybeExported::Ok(item.id));
         }
 
@@ -2428,6 +2431,12 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             }
 
             ItemKind::Use(ref use_tree) => {
+                let maybe_exported = match use_tree.kind {
+                    UseTreeKind::Simple(_) | UseTreeKind::Glob => MaybeExported::Ok(item.id),
+                    UseTreeKind::Nested(_) => MaybeExported::NestedUse(&item.vis),
+                };
+                self.resolve_doc_links(&item.attrs, maybe_exported);
+
                 self.future_proof_import(use_tree);
             }
 
@@ -2569,7 +2578,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             let res = match kind {
                 RibKind::Item(..) | RibKind::AssocItem => Res::Def(def_kind, def_id.to_def_id()),
                 RibKind::Normal => {
-                    if self.r.tcx.sess.features_untracked().non_lifetime_binders {
+                    if self.r.tcx.features().non_lifetime_binders {
                         Res::Def(def_kind, def_id.to_def_id())
                     } else {
                         Res::Err
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index d16b7902f60..d456cc9a9a0 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -24,7 +24,9 @@ use rustc_hir::def_id::{CrateNum, LocalDefId};
 use rustc_middle::middle::stability;
 use rustc_middle::ty::RegisteredTools;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::lint::builtin::{LEGACY_DERIVE_HELPERS, SOFT_UNSTABLE};
+use rustc_session::lint::builtin::{
+    LEGACY_DERIVE_HELPERS, SOFT_UNSTABLE, UNKNOWN_DIAGNOSTIC_ATTRIBUTES,
+};
 use rustc_session::lint::builtin::{UNUSED_MACROS, UNUSED_MACRO_RULES};
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::parse::feature_err;
@@ -140,9 +142,9 @@ pub(crate) fn registered_tools(tcx: TyCtxt<'_>, (): ()) -> RegisteredTools {
             }
         }
     }
-    // We implicitly add `rustfmt` and `clippy` to known tools,
+    // We implicitly add `rustfmt`, `clippy`, `diagnostic` to known tools,
     // but it's not an error to register them explicitly.
-    let predefined_tools = [sym::clippy, sym::rustfmt];
+    let predefined_tools = [sym::clippy, sym::rustfmt, sym::diagnostic];
     registered_tools.extend(predefined_tools.iter().cloned().map(Ident::with_dummy_span));
     registered_tools
 }
@@ -576,10 +578,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
 
         // We are trying to avoid reporting this error if other related errors were reported.
-        if res != Res::Err
-            && inner_attr
-            && !self.tcx.sess.features_untracked().custom_inner_attributes
-        {
+        if res != Res::Err && inner_attr && !self.tcx.features().custom_inner_attributes {
             let msg = match res {
                 Res::Def(..) => "inner macro attributes are unstable",
                 Res::NonMacroAttr(..) => "custom inner attributes are unstable",
@@ -598,6 +597,18 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
         }
 
+        if res == Res::NonMacroAttr(NonMacroAttrKind::Tool)
+            && path.segments.len() >= 2
+            && path.segments[0].ident.name == sym::diagnostic
+        {
+            self.tcx.sess.parse_sess.buffer_lint(
+                UNKNOWN_DIAGNOSTIC_ATTRIBUTES,
+                path.segments[1].span(),
+                node_id,
+                "unknown diagnostic attribute",
+            );
+        }
+
         Ok((ext, res))
     }