6 files changed, 36 insertions, 28 deletions
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index aeaa862f5fd..a6a61ffc5da 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -310,7 +310,7 @@ impl CheckAttrVisitor<'tcx> {
                 .sess
                 .struct_span_err(
                     meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
-                    &format!("{:?} character isn't allowed in `#[doc(alias = \"...\")]`", c,),
+                    &format!("{:?} character isn't allowed in `#[doc(alias = \"...\")]`", c),
                 )
                 .emit();
             return false;
@@ -358,6 +358,17 @@ impl CheckAttrVisitor<'tcx> {
                 .emit();
             return false;
         }
+        let item_name = self.tcx.hir().name(hir_id);
+        if &*item_name.as_str() == doc_alias {
+            self.tcx
+                .sess
+                .struct_span_err(
+                    meta.span(),
+                    &format!("`#[doc(alias = \"...\")]` is the same as the item's name"),
+                )
+                .emit();
+            return false;
+        }
         true
     }
 
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 00152878d6d..c4fb0cf5b28 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -23,18 +23,18 @@ use rustc_span::symbol::{sym, Symbol};
 // function, then we should explore its block to check for codes that
 // may need to be marked as live.
 fn should_explore(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
-    match tcx.hir().find(hir_id) {
+    matches!(
+        tcx.hir().find(hir_id),
         Some(
             Node::Item(..)
-            | Node::ImplItem(..)
-            | Node::ForeignItem(..)
-            | Node::TraitItem(..)
-            | Node::Variant(..)
-            | Node::AnonConst(..)
-            | Node::Pat(..),
-        ) => true,
-        _ => false,
-    }
+                | Node::ImplItem(..)
+                | Node::ForeignItem(..)
+                | Node::TraitItem(..)
+                | Node::Variant(..)
+                | Node::AnonConst(..)
+                | Node::Pat(..),
+        )
+    )
 }
 
 struct MarkSymbolVisitor<'tcx> {
@@ -500,16 +500,16 @@ struct DeadVisitor<'tcx> {
 
 impl DeadVisitor<'tcx> {
     fn should_warn_about_item(&mut self, item: &hir::Item<'_>) -> bool {
-        let should_warn = match item.kind {
+        let should_warn = matches!(
+            item.kind,
             hir::ItemKind::Static(..)
-            | hir::ItemKind::Const(..)
-            | hir::ItemKind::Fn(..)
-            | hir::ItemKind::TyAlias(..)
-            | hir::ItemKind::Enum(..)
-            | hir::ItemKind::Struct(..)
-            | hir::ItemKind::Union(..) => true,
-            _ => false,
-        };
+                | hir::ItemKind::Const(..)
+                | hir::ItemKind::Fn(..)
+                | hir::ItemKind::TyAlias(..)
+                | hir::ItemKind::Enum(..)
+                | hir::ItemKind::Struct(..)
+                | hir::ItemKind::Union(..)
+        );
         should_warn && !self.symbol_is_live(item.hir_id)
     }
 
diff --git a/compiler/rustc_passes/src/intrinsicck.rs b/compiler/rustc_passes/src/intrinsicck.rs
index 711e8e87c6c..ee90e9c54f6 100644
--- a/compiler/rustc_passes/src/intrinsicck.rs
+++ b/compiler/rustc_passes/src/intrinsicck.rs
@@ -78,7 +78,7 @@ impl ExprVisitor<'tcx> {
                 return;
             }
 
-            // Special-case transmutting from `typeof(function)` and
+            // Special-case transmuting from `typeof(function)` and
             // `Option<typeof(function)>` to present a clearer error.
             let from = unpack_option_like(self.tcx, from);
             if let (&ty::FnDef(..), SizeSkeleton::Known(size_to)) = (from.kind(), sk_to) {
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 86ce35c6d99..fcea1b29ec3 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -367,10 +367,7 @@ impl<'tcx> Visitor<'tcx> for IrMaps<'tcx> {
     }
 
     fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
-        let is_shorthand = match param.pat.kind {
-            rustc_hir::PatKind::Struct(..) => true,
-            _ => false,
-        };
+        let is_shorthand = matches!(param.pat.kind, rustc_hir::PatKind::Struct(..));
         param.pat.each_binding(|_bm, hir_id, _x, ident| {
             let var = if is_shorthand {
                 Local(LocalInfo { id: hir_id, name: ident.name, is_shorthand: true })
@@ -1385,7 +1382,7 @@ impl<'tcx> Liveness<'_, 'tcx> {
 
     fn should_warn(&self, var: Variable) -> Option<String> {
         let name = self.ir.variable_name(var);
-        if name == kw::Invalid {
+        if name == kw::Empty {
             return None;
         }
         let name: &str = &name.as_str();
diff --git a/compiler/rustc_passes/src/naked_functions.rs b/compiler/rustc_passes/src/naked_functions.rs
index 5b50ef8627b..788f1df328c 100644
--- a/compiler/rustc_passes/src/naked_functions.rs
+++ b/compiler/rustc_passes/src/naked_functions.rs
@@ -149,7 +149,7 @@ impl<'tcx> Visitor<'tcx> for CheckParameters<'tcx> {
 fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, hir_id: HirId, body: &'tcx hir::Body<'tcx>, fn_span: Span) {
     let mut this = CheckInlineAssembly { tcx, items: Vec::new() };
     this.visit_body(body);
-    if let &[(ItemKind::Asm, _)] = &this.items[..] {
+    if let [(ItemKind::Asm, _)] = this.items[..] {
         // Ok.
     } else {
         tcx.struct_span_lint_hir(UNSUPPORTED_NAKED_FUNCTIONS, hir_id, fn_span, |lint| {
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index 3c2462aab26..def2a501cf4 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -443,7 +443,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
 
     fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam<'tcx>) {
         let kind = match &p.kind {
-            // FIXME(const_generics:defaults)
+            // FIXME(const_generics_defaults)
             hir::GenericParamKind::Type { default, .. } if default.is_some() => {
                 AnnotationKind::Container
             }