7 files changed, 78 insertions, 13 deletions
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 4d7ebe3fefe..cbb030958c6 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -878,6 +878,44 @@ impl CheckAttrVisitor<'_> {
         }
     }
 
+    fn check_doc_masked(
+        &self,
+        attr: &Attribute,
+        meta: &NestedMetaItem,
+        hir_id: HirId,
+        target: Target,
+    ) -> bool {
+        if target != Target::ExternCrate {
+            self.tcx.emit_spanned_lint(
+                INVALID_DOC_ATTRIBUTES,
+                hir_id,
+                meta.span(),
+                errors::DocMaskedOnlyExternCrate {
+                    attr_span: meta.span(),
+                    item_span: (attr.style == AttrStyle::Outer)
+                        .then(|| self.tcx.hir().span(hir_id)),
+                },
+            );
+            return false;
+        }
+
+        if self.tcx.extern_mod_stmt_cnum(hir_id.owner).is_none() {
+            self.tcx.emit_spanned_lint(
+                INVALID_DOC_ATTRIBUTES,
+                hir_id,
+                meta.span(),
+                errors::DocMaskedNotExternCrateSelf {
+                    attr_span: meta.span(),
+                    item_span: (attr.style == AttrStyle::Outer)
+                        .then(|| self.tcx.hir().span(hir_id)),
+                },
+            );
+            return false;
+        }
+
+        true
+    }
+
     /// Checks that an attribute is *not* used at the crate level. Returns `true` if valid.
     fn check_attr_not_crate_level(
         &self,
@@ -1048,6 +1086,17 @@ impl CheckAttrVisitor<'_> {
                             is_valid = false;
                         }
 
+                        sym::masked
+                            if !self.check_doc_masked(
+                                attr,
+                                meta,
+                                hir_id,
+                                target,
+                            ) =>
+                        {
+                            is_valid = false;
+                        }
+
                         // no_default_passes: deprecated
                         // passes: deprecated
                         // plugins: removed, but rustdoc warns about it itself
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index fc437c429fb..e70817d7b7c 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -157,10 +157,8 @@ impl<'tcx> CheckConstVisitor<'tcx> {
                 // is a pretty narrow case, however.
                 if tcx.sess.is_nightly_build() {
                     for gate in missing_secondary {
-                        let note = format!(
-                            "add `#![feature({})]` to the crate attributes to enable",
-                            gate,
-                        );
+                        let note =
+                            format!("add `#![feature({gate})]` to the crate attributes to enable",);
                         err.help(note);
                     }
                 }
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index eae13f86049..4f5514372d1 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -267,6 +267,25 @@ pub struct DocInlineOnlyUse {
     pub item_span: Option<Span>,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(passes_doc_masked_only_extern_crate)]
+#[note]
+pub struct DocMaskedOnlyExternCrate {
+    #[label]
+    pub attr_span: Span,
+    #[label(passes_not_an_extern_crate_label)]
+    pub item_span: Option<Span>,
+}
+
+#[derive(LintDiagnostic)]
+#[diag(passes_doc_masked_not_extern_crate_self)]
+pub struct DocMaskedNotExternCrateSelf {
+    #[label]
+    pub attr_span: Span,
+    #[label(passes_extern_crate_self_label)]
+    pub item_span: Option<Span>,
+}
+
 #[derive(Diagnostic)]
 #[diag(passes_doc_attr_not_crate_level)]
 pub struct DocAttrNotCrateLevel<'a> {
diff --git a/compiler/rustc_passes/src/hir_id_validator.rs b/compiler/rustc_passes/src/hir_id_validator.rs
index 363e1743677..f825363ae39 100644
--- a/compiler/rustc_passes/src/hir_id_validator.rs
+++ b/compiler/rustc_passes/src/hir_id_validator.rs
@@ -89,9 +89,8 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
 
             self.error(|| {
                 format!(
-                    "ItemLocalIds not assigned densely in {}. \
-                Max ItemLocalId = {}, missing IDs = {:#?}; seen IDs = {:#?}",
-                    pretty_owner, max, missing_items, seen_items
+                    "ItemLocalIds not assigned densely in {pretty_owner}. \
+                Max ItemLocalId = {max}, missing IDs = {missing_items:#?}; seen IDs = {seen_items:#?}"
                 )
             });
         }
diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index 6c748147abe..5aa8aef6a85 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -126,12 +126,12 @@ impl<'k> StatCollector<'k> {
 
         let total_size = nodes.iter().map(|(_, node)| node.stats.count * node.stats.size).sum();
 
-        eprintln!("{} {}", prefix, title);
+        eprintln!("{prefix} {title}");
         eprintln!(
             "{} {:<18}{:>18}{:>14}{:>14}",
             prefix, "Name", "Accumulated Size", "Count", "Item Size"
         );
-        eprintln!("{} ----------------------------------------------------------------", prefix);
+        eprintln!("{prefix} ----------------------------------------------------------------");
 
         let percent = |m, n| (m * 100) as f64 / n as f64;
 
@@ -163,9 +163,9 @@ impl<'k> StatCollector<'k> {
                 }
             }
         }
-        eprintln!("{} ----------------------------------------------------------------", prefix);
+        eprintln!("{prefix} ----------------------------------------------------------------");
         eprintln!("{} {:<18}{:>10}", prefix, "Total", to_readable_str(total_size));
-        eprintln!("{}", prefix);
+        eprintln!("{prefix}");
     }
 }
 
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 89c6704e416..15757a0f1ad 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -605,7 +605,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
         for var_idx in 0..self.ir.var_kinds.len() {
             let var = Variable::from(var_idx);
             if test(var) {
-                write!(wr, " {:?}", var)?;
+                write!(wr, " {var:?}")?;
             }
         }
         Ok(())
diff --git a/compiler/rustc_passes/src/reachable.rs b/compiler/rustc_passes/src/reachable.rs
index 160528e4074..7dec5b0acc8 100644
--- a/compiler/rustc_passes/src/reachable.rs
+++ b/compiler/rustc_passes/src/reachable.rs
@@ -236,7 +236,7 @@ impl<'tcx> ReachableContext<'tcx> {
                     // Reachable constants will be inlined into other crates
                     // unconditionally, so we need to make sure that their
                     // contents are also reachable.
-                    hir::ItemKind::Const(_, init) | hir::ItemKind::Static(_, _, init) => {
+                    hir::ItemKind::Const(_, _, init) | hir::ItemKind::Static(_, _, init) => {
                         self.visit_nested_body(init);
                     }