Auto merge of #97853 - TaKO8Ki:emit-only-one-note-per-unused-struct-field, r=estebank

Collapse multiple dead code warnings into a single diagnostic

closes #97643

Cargo.lock

@@ -4287,6 +4287,7 @@ dependencies = [
 name = "rustc_passes"
 version = "0.0.0"
 dependencies = [
+ "itertools",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_attr",

compiler/rustc_passes/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 tracing = "0.1"
+itertools = "0.10.1"
 rustc_middle = { path = "../rustc_middle" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_passes/src/dead.rs

@@ -2,8 +2,9 @@
 // closely. The idea is that all reachable symbols are live, codes called
 // from live codes are live, and everything else is dead.
 
+use itertools::Itertools;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_errors::pluralize;
+use rustc_errors::{pluralize, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -183,10 +184,10 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
             }
         }
 
-        if let hir::ExprKind::Assign(lhs, rhs, _) = assign.kind {
+        if let hir::ExprKind::Assign(lhs, rhs, _) = assign.kind
-            if check_for_self_assign_helper(self.typeck_results(), lhs, rhs)
+            && check_for_self_assign_helper(self.typeck_results(), lhs, rhs)
                 && !assign.span.from_expansion()
-            {
+        {
                 let is_field_assign = matches!(lhs.kind, hir::ExprKind::Field(..));
                 self.tcx.struct_span_lint_hir(
                     lint::builtin::DEAD_CODE,
@@ -201,7 +202,6 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                         .emit();
                     },
                 )
-            }
         }
     }
 
@@ -251,19 +251,19 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 return false;
             }
 
-            if let Some(trait_of) = self.tcx.trait_id_of_impl(impl_of) {
+            if let Some(trait_of) = self.tcx.trait_id_of_impl(impl_of)
-                if self.tcx.has_attr(trait_of, sym::rustc_trivial_field_reads) {
+                && self.tcx.has_attr(trait_of, sym::rustc_trivial_field_reads)
-                    let trait_ref = self.tcx.impl_trait_ref(impl_of).unwrap();
+            {
-                    if let ty::Adt(adt_def, _) = trait_ref.self_ty().kind() {
+                let trait_ref = self.tcx.impl_trait_ref(impl_of).unwrap();
-                        if let Some(adt_def_id) = adt_def.did().as_local() {
+                if let ty::Adt(adt_def, _) = trait_ref.self_ty().kind()
-                            self.ignored_derived_traits
+                    && let Some(adt_def_id) = adt_def.did().as_local()
-                                .entry(adt_def_id)
+                {
-                                .or_default()
+                    self.ignored_derived_traits
-                                .push((trait_of, impl_of));
+                        .entry(adt_def_id)
-                        }
+                        .or_default()
-                    }
+                        .push((trait_of, impl_of));
-                    return true;
                 }
+                return true;
             }
         }
 
@@ -271,13 +271,10 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
     }
 
     fn visit_node(&mut self, node: Node<'tcx>) {
-        if let Some(item_def_id) = match node {
+        if let Node::ImplItem(hir::ImplItem { def_id, .. }) = node
-            Node::ImplItem(hir::ImplItem { def_id, .. }) => Some(def_id.to_def_id()),
+            && self.should_ignore_item(def_id.to_def_id())
-            _ => None,
+        {
-        } {
+            return;
-            if self.should_ignore_item(item_def_id) {
-                return;
-            }
         }
 
         let had_repr_c = self.repr_has_repr_c;
@@ -534,10 +531,10 @@ fn check_item<'tcx>(
         }
         DefKind::Struct => {
             let item = tcx.hir().item(id);
-            if let hir::ItemKind::Struct(ref variant_data, _) = item.kind {
+            if let hir::ItemKind::Struct(ref variant_data, _) = item.kind
-                if let Some(ctor_hir_id) = variant_data.ctor_hir_id() {
+                && let Some(ctor_hir_id) = variant_data.ctor_hir_id()
-                    struct_constructors.insert(tcx.hir().local_def_id(ctor_hir_id), item.def_id);
+            {
-                }
+                struct_constructors.insert(tcx.hir().local_def_id(ctor_hir_id), item.def_id);
             }
         }
         DefKind::GlobalAsm => {
@@ -626,6 +623,13 @@ fn live_symbols_and_ignored_derived_traits<'tcx>(
     (symbol_visitor.live_symbols, symbol_visitor.ignored_derived_traits)
 }
 
+struct DeadVariant {
+    hir_id: hir::HirId,
+    span: Span,
+    name: Symbol,
+    level: lint::Level,
+}
+
 struct DeadVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
     live_symbols: &'tcx FxHashSet<LocalDefId>,
@@ -677,16 +681,121 @@ impl<'tcx> DeadVisitor<'tcx> {
         let inherent_impls = self.tcx.inherent_impls(def_id);
         for &impl_did in inherent_impls.iter() {
             for item_did in self.tcx.associated_item_def_ids(impl_did) {
-                if let Some(def_id) = item_did.as_local() {
+                if let Some(def_id) = item_did.as_local()
-                    if self.live_symbols.contains(&def_id) {
+                    && self.live_symbols.contains(&def_id)
-                        return true;
+                {
-                    }
+                    return true;
                 }
             }
         }
         false
     }
 
+    fn warn_multiple_dead_codes(
+        &self,
+        dead_codes: &[(hir::HirId, Span, Symbol)],
+        participle: &str,
+        parent_hir_id: Option<hir::HirId>,
+    ) {
+        if let Some((id, _, name)) = dead_codes.first()
+            && !name.as_str().starts_with('_')
+        {
+            self.tcx.struct_span_lint_hir(
+                lint::builtin::DEAD_CODE,
+                *id,
+                MultiSpan::from_spans(
+                    dead_codes.iter().map(|(_, span, _)| *span).collect(),
+                ),
+                |lint| {
+                    let def_id = self.tcx.hir().local_def_id(*id);
+                    let descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
+                    let span_len = dead_codes.len();
+                    let names = match &dead_codes.iter().map(|(_, _, n)| n.to_string()).collect::<Vec<_>>()[..]
+                    {
+                        _ if span_len > 6 => String::new(),
+                        [name] => format!("`{name}` "),
+                        [names @ .., last] => {
+                            format!("{} and `{last}` ", names.iter().map(|name| format!("`{name}`")).join(", "))
+                        }
+                        [] => unreachable!(),
+                    };
+                    let mut err = lint.build(&format!(
+                        "{these}{descr}{s} {names}{are} never {participle}",
+                        these = if span_len > 6 { "multiple " } else { "" },
+                        s = pluralize!(span_len),
+                        are = pluralize!("is", span_len),
+                    ));
+                    let hir = self.tcx.hir();
+                    if let Some(parent_hir_id) = parent_hir_id
+                        && let Some(parent_node) = hir.find(parent_hir_id)
+                        && let Node::Item(item) = parent_node
+                    {
+                        let def_id = self.tcx.hir().local_def_id(parent_hir_id);
+                        let parent_descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
+                        err.span_label(
+                            item.ident.span,
+                            format!(
+                                "{descr}{s} in this {parent_descr}",
+                                s = pluralize!(span_len)
+                            ),
+                        );
+                    }
+                    if let Some(encl_scope) = hir.get_enclosing_scope(*id)
+                        && let Some(encl_def_id) = hir.opt_local_def_id(encl_scope)
+                        && let Some(ign_traits) = self.ignored_derived_traits.get(&encl_def_id)
+                    {
+                        let traits_str = ign_traits
+                            .iter()
+                            .map(|(trait_id, _)| format!("`{}`", self.tcx.item_name(*trait_id)))
+                            .collect::<Vec<_>>()
+                            .join(" and ");
+                        let plural_s = pluralize!(ign_traits.len());
+                        let article = if ign_traits.len() > 1 { "" } else { "a " };
+                        let is_are = if ign_traits.len() > 1 { "these are" } else { "this is" };
+                        let msg = format!(
+                            "`{}` has {}derived impl{} for the trait{} {}, but {} \
+                            intentionally ignored during dead code analysis",
+                            self.tcx.item_name(encl_def_id.to_def_id()),
+                            article,
+                            plural_s,
+                            plural_s,
+                            traits_str,
+                            is_are
+                        );
+                        err.note(&msg);
+                    }
+                        err.emit();
+                    },
+            );
+        }
+    }
+
+    fn warn_dead_fields_and_variants(
+        &self,
+        hir_id: hir::HirId,
+        participle: &str,
+        dead_codes: Vec<DeadVariant>,
+    ) {
+        let mut dead_codes = dead_codes
+            .iter()
+            .filter(|v| !v.name.as_str().starts_with('_'))
+            .map(|v| v)
+            .collect::<Vec<&DeadVariant>>();
+        if dead_codes.is_empty() {
+            return;
+        }
+        dead_codes.sort_by_key(|v| v.level);
+        for (_, group) in &dead_codes.into_iter().group_by(|v| v.level) {
+            self.warn_multiple_dead_codes(
+                &group
+                    .map(|v| (v.hir_id, v.span, v.name))
+                    .collect::<Vec<(hir::HirId, Span, Symbol)>>(),
+                participle,
+                Some(hir_id),
+            );
+        }
+    }
+
     fn warn_dead_code(
         &mut self,
         id: hir::HirId,
@@ -694,39 +803,7 @@ impl<'tcx> DeadVisitor<'tcx> {
         name: Symbol,
         participle: &str,
     ) {
-        if !name.as_str().starts_with('_') {
+        self.warn_multiple_dead_codes(&[(id, span, name)], participle, None);
-            self.tcx.struct_span_lint_hir(lint::builtin::DEAD_CODE, id, span, |lint| {
-                let def_id = self.tcx.hir().local_def_id(id);
-                let descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
-                let mut err = lint.build(&format!("{} is never {}: `{}`", descr, participle, name));
-                let hir = self.tcx.hir();
-                if let Some(encl_scope) = hir.get_enclosing_scope(id)
-                    && let Some(encl_def_id) = hir.opt_local_def_id(encl_scope)
-                    && let Some(ign_traits) = self.ignored_derived_traits.get(&encl_def_id)
-                {
-                    let traits_str = ign_traits
-                        .iter()
-                        .map(|(trait_id, _)| format!("`{}`", self.tcx.item_name(*trait_id)))
-                        .collect::<Vec<_>>()
-                        .join(" and ");
-                    let plural_s = pluralize!(ign_traits.len());
-                    let article = if ign_traits.len() > 1 { "" } else { "a " };
-                    let is_are = if ign_traits.len() > 1 { "these are" } else { "this is" };
-                    let msg = format!(
-                        "`{}` has {}derived impl{} for the trait{} {}, but {} \
-                        intentionally ignored during dead code analysis",
-                        self.tcx.item_name(encl_def_id.to_def_id()),
-                        article,
-                        plural_s,
-                        plural_s,
-                        traits_str,
-                        is_are
-                    );
-                    err.note(&msg);
-                }
-                err.emit();
-            });
-        }
     }
 }
 
@@ -780,15 +857,40 @@ impl<'tcx> Visitor<'tcx> for DeadVisitor<'tcx> {
     // This visitor should only visit a single module at a time.
     fn visit_mod(&mut self, _: &'tcx hir::Mod<'tcx>, _: Span, _: hir::HirId) {}
 
+    fn visit_enum_def(
+        &mut self,
+        enum_definition: &'tcx hir::EnumDef<'tcx>,
+        generics: &'tcx hir::Generics<'tcx>,
+        item_id: hir::HirId,
+        _: Span,
+    ) {
+        intravisit::walk_enum_def(self, enum_definition, generics, item_id);
+        let dead_variants = enum_definition
+            .variants
+            .iter()
+            .filter_map(|variant| {
+                if self.should_warn_about_variant(&variant) {
+                    Some(DeadVariant {
+                        hir_id: variant.id,
+                        span: variant.span,
+                        name: variant.ident.name,
+                        level: self.tcx.lint_level_at_node(lint::builtin::DEAD_CODE, variant.id).0,
+                    })
+                } else {
+                    None
+                }
+            })
+            .collect();
+        self.warn_dead_fields_and_variants(item_id, "constructed", dead_variants)
+    }
+
     fn visit_variant(
         &mut self,
         variant: &'tcx hir::Variant<'tcx>,
         g: &'tcx hir::Generics<'tcx>,
         id: hir::HirId,
     ) {
-        if self.should_warn_about_variant(&variant) {
+        if !self.should_warn_about_variant(&variant) {
-            self.warn_dead_code(variant.id, variant.span, variant.ident.name, "constructed");
-        } else {
             intravisit::walk_variant(self, variant, g, id);
         }
     }
@@ -800,11 +902,35 @@ impl<'tcx> Visitor<'tcx> for DeadVisitor<'tcx> {
         intravisit::walk_foreign_item(self, fi);
     }
 
-    fn visit_field_def(&mut self, field: &'tcx hir::FieldDef<'tcx>) {
+    fn visit_variant_data(
-        if self.should_warn_about_field(&field) {
+        &mut self,
-            self.warn_dead_code(field.hir_id, field.span, field.ident.name, "read");
+        def: &'tcx hir::VariantData<'tcx>,
-        }
+        _: Symbol,
-        intravisit::walk_field_def(self, field);
+        _: &hir::Generics<'_>,
+        id: hir::HirId,
+        _: rustc_span::Span,
+    ) {
+        intravisit::walk_struct_def(self, def);
+        let dead_fields = def
+            .fields()
+            .iter()
+            .filter_map(|field| {
+                if self.should_warn_about_field(&field) {
+                    Some(DeadVariant {
+                        hir_id: field.hir_id,
+                        span: field.span,
+                        name: field.ident.name,
+                        level: self
+                            .tcx
+                            .lint_level_at_node(lint::builtin::DEAD_CODE, field.hir_id)
+                            .0,
+                    })
+                } else {
+                    None
+                }
+            })
+            .collect();
+        self.warn_dead_fields_and_variants(id, "read", dead_fields)
     }
 
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {

src/test/rustdoc-ui/display-output.stdout

@@ -24,7 +24,7 @@ warning: unused variable: `x`
 LL | fn foo(x: &dyn std::fmt::Display) {}
    |        ^ help: if this is intentional, prefix it with an underscore: `_x`
 
-warning: function is never used: `foo`
+warning: function `foo` is never used
   --> $DIR/display-output.rs:13:4
    |
 LL | fn foo(x: &dyn std::fmt::Display) {}

src/test/ui/associated-consts/associated-const-dead-code.rs

@@ -4,7 +4,7 @@ struct MyFoo;
 
 impl MyFoo {
     const BAR: u32 = 1;
-    //~^ ERROR associated constant is never used: `BAR`
+    //~^ ERROR associated constant `BAR` is never used
 }
 
 fn main() {

src/test/ui/associated-consts/associated-const-dead-code.stderr

@@ -1,4 +1,4 @@
-error: associated constant is never used: `BAR`
+error: associated constant `BAR` is never used
   --> $DIR/associated-const-dead-code.rs:6:5
    |
 LL |     const BAR: u32 = 1;

src/test/ui/closures/2229_closure_analysis/issue-87987.rs

@@ -2,16 +2,13 @@
 // edition:2021
 
 struct Props {
-    field_1: u32, //~ WARNING: field is never read: `field_1`
+    field_1: u32, //~ WARNING: fields `field_1` and `field_2` are never read
-    field_2: u32, //~ WARNING: field is never read: `field_2`
+    field_2: u32,
 }
 
 fn main() {
     // Test 1
-    let props_2 = Props {
+    let props_2 = Props { field_1: 1, field_2: 1 };
-        field_1: 1,
-        field_2: 1,
-    };
 
     let _ = || {
         let _: Props = props_2;
@@ -23,7 +20,7 @@ fn main() {
     let mref = &mut arr;
 
     let _c = || match arr {
-        [_, _, _, _] => println!("A")
+        [_, _, _, _] => println!("A"),
     };
 
     println!("{:#?}", mref);

src/test/ui/closures/2229_closure_analysis/issue-87987.stderr

@@ -1,16 +1,14 @@
-warning: field is never read: `field_1`
+warning: fields `field_1` and `field_2` are never read
   --> $DIR/issue-87987.rs:5:5
    |
+LL | struct Props {
+   |        ----- fields in this struct
 LL |     field_1: u32,
    |     ^^^^^^^^^^^^
+LL |     field_2: u32,
+   |     ^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default
 
-warning: field is never read: `field_2`
+warning: 1 warning emitted
-  --> $DIR/issue-87987.rs:6:5
-   |
-LL |     field_2: u32,
-   |     ^^^^^^^^^^^^
-
-warning: 2 warnings emitted
 

src/test/ui/closures/2229_closure_analysis/match/issue-87097.rs

@@ -3,7 +3,7 @@
 
 enum Variant {
     A,
-    B, //~ WARNING: variant is never constructed: `B`
+    B, //~ WARNING: variant `B` is never constructed
 }
 
 struct A {

src/test/ui/closures/2229_closure_analysis/match/issue-87097.stderr

@@ -1,6 +1,9 @@
-warning: variant is never constructed: `B`
+warning: variant `B` is never constructed
   --> $DIR/issue-87097.rs:6:5
    |
+LL | enum Variant {
+   |      ------- variant in this enum
+LL |     A,
 LL |     B,
    |     ^
    |

src/test/ui/derive-uninhabited-enum-38885.rs

@@ -10,7 +10,7 @@ enum Void {}
 #[derive(Debug)]
 enum Foo {
     Bar(u8),
-    Void(Void), //~ WARN never constructed
+    Void(Void), //~ WARN variant `Void` is never constructed
 }
 
 fn main() {

src/test/ui/derive-uninhabited-enum-38885.stderr

@@ -1,6 +1,9 @@
-warning: variant is never constructed: `Void`
+warning: variant `Void` is never constructed
   --> $DIR/derive-uninhabited-enum-38885.rs:13:5
    |
+LL | enum Foo {
+   |      --- variant in this enum
+LL |     Bar(u8),
 LL |     Void(Void),
    |     ^^^^^^^^^^
    |

src/test/ui/derives/clone-debug-dead-code-in-the-same-struct.rs

@@ -0,0 +1,12 @@
+#![forbid(dead_code)]
+
+#[derive(Debug)]
+pub struct Whatever {
+    pub field0: (),
+    field1: (), //~ ERROR fields `field1`, `field2`, `field3` and `field4` are never read
+    field2: (),
+    field3: (),
+    field4: (),
+}
+
+fn main() {}

src/test/ui/derives/clone-debug-dead-code-in-the-same-struct.stderr

@@ -0,0 +1,24 @@
+error: fields `field1`, `field2`, `field3` and `field4` are never read
+  --> $DIR/clone-debug-dead-code-in-the-same-struct.rs:6:5
+   |
+LL | pub struct Whatever {
+   |            -------- fields in this struct
+LL |     pub field0: (),
+LL |     field1: (),
+   |     ^^^^^^^^^^
+LL |     field2: (),
+   |     ^^^^^^^^^^
+LL |     field3: (),
+   |     ^^^^^^^^^^
+LL |     field4: (),
+   |     ^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/clone-debug-dead-code-in-the-same-struct.rs:1:11
+   |
+LL | #![forbid(dead_code)]
+   |           ^^^^^^^^^
+   = note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
+
+error: aborting due to previous error
+

src/test/ui/derives/clone-debug-dead-code.rs

@@ -4,22 +4,22 @@
 #![forbid(dead_code)]
 
 struct A { f: () }
-//~^ ERROR: field is never read: `f`
+//~^ ERROR: field `f` is never read
 
 #[derive(Clone)]
 struct B { f: () }
-//~^ ERROR: field is never read: `f`
+//~^ ERROR: field `f` is never read
 
 #[derive(Debug)]
 struct C { f: () }
-//~^ ERROR: field is never read: `f`
+//~^ ERROR: field `f` is never read
 
 #[derive(Debug,Clone)]
 struct D { f: () }
-//~^ ERROR: field is never read: `f`
+//~^ ERROR: field `f` is never read
 
 struct E { f: () }
-//~^ ERROR: field is never read: `f`
+//~^ ERROR: field `f` is never read
 // Custom impl, still doesn't read f
 impl Clone for E {
     fn clone(&self) -> Self {

src/test/ui/derives/clone-debug-dead-code.stderr

@@ -1,8 +1,10 @@
-error: field is never read: `f`
+error: field `f` is never read
   --> $DIR/clone-debug-dead-code.rs:6:12
    |
 LL | struct A { f: () }
-   |            ^^^^^
+   |        -   ^^^^^
+   |        |
+   |        field in this struct
    |
 note: the lint level is defined here
   --> $DIR/clone-debug-dead-code.rs:4:11
@@ -10,35 +12,43 @@ note: the lint level is defined here
 LL | #![forbid(dead_code)]
    |           ^^^^^^^^^
 
-error: field is never read: `f`
+error: field `f` is never read
   --> $DIR/clone-debug-dead-code.rs:10:12
    |
 LL | struct B { f: () }
-   |            ^^^^^
+   |        -   ^^^^^
+   |        |
+   |        field in this struct
    |
    = note: `B` has a derived impl for the trait `Clone`, but this is intentionally ignored during dead code analysis
 
-error: field is never read: `f`
+error: field `f` is never read
   --> $DIR/clone-debug-dead-code.rs:14:12
    |
 LL | struct C { f: () }
-   |            ^^^^^
+   |        -   ^^^^^
+   |        |
+   |        field in this struct
    |
    = note: `C` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
 
-error: field is never read: `f`
+error: field `f` is never read
   --> $DIR/clone-debug-dead-code.rs:18:12
    |
 LL | struct D { f: () }
-   |            ^^^^^
+   |        -   ^^^^^
+   |        |
+   |        field in this struct
    |
    = note: `D` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
 
-error: field is never read: `f`
+error: field `f` is never read
   --> $DIR/clone-debug-dead-code.rs:21:12
    |
 LL | struct E { f: () }
-   |            ^^^^^
+   |        -   ^^^^^
+   |        |
+   |        field in this struct
 
 error: aborting due to 5 previous errors
 

src/test/ui/issues/issue-37515.rs

@@ -3,6 +3,6 @@
 #![warn(unused)]
 
 type Z = dyn for<'x> Send;
-//~^ WARN type alias is never used
+//~^ WARN type alias `Z` is never used
 
 fn main() {}

src/test/ui/issues/issue-37515.stderr

@@ -1,4 +1,4 @@
-warning: type alias is never used: `Z`
+warning: type alias `Z` is never used
   --> $DIR/issue-37515.rs:5:1
    |
 LL | type Z = dyn for<'x> Send;

src/test/ui/lint/dead-code/basic.rs

@@ -1,7 +1,7 @@
 #![deny(dead_code)]
 #![allow(unreachable_code)]
 
-fn foo() { //~ ERROR function is never used
+fn foo() { //~ ERROR function `foo` is never used
 
     // none of these should have any dead_code exposed to the user
     panic!();

src/test/ui/lint/dead-code/basic.stderr

@@ -1,4 +1,4 @@
-error: function is never used: `foo`
+error: function `foo` is never used
   --> $DIR/basic.rs:4:4
    |
 LL | fn foo() {

src/test/ui/lint/dead-code/const-and-self.rs

@@ -30,8 +30,8 @@ impl Foo<Y> for X {
 
 enum E {
     A,
-    B, //~ WARN variant is never constructed: `B`
+    B, //~ WARN variants `B` and `C` are never constructed
-    C, //~ WARN variant is never constructed: `C`
+    C,
 }
 
 type F = E;

src/test/ui/lint/dead-code/const-and-self.stderr

@@ -1,8 +1,13 @@
-warning: variant is never constructed: `B`
+warning: variants `B` and `C` are never constructed
   --> $DIR/const-and-self.rs:33:5
    |
+LL | enum E {
+   |      - variants in this enum
+LL |     A,
 LL |     B,
    |     ^
+LL |     C,
+   |     ^
    |
 note: the lint level is defined here
   --> $DIR/const-and-self.rs:3:9
@@ -10,11 +15,5 @@ note: the lint level is defined here
 LL | #![warn(dead_code)]
    |         ^^^^^^^^^
 
-warning: variant is never constructed: `C`
+warning: 1 warning emitted
-  --> $DIR/const-and-self.rs:34:5
-   |
-LL |     C,
-   |     ^
-
-warning: 2 warnings emitted
 

src/test/ui/lint/dead-code/empty-unused-enum.rs

@@ -1,5 +1,5 @@
 #![deny(unused)]
 
-enum E {} //~ ERROR enum is never used
+enum E {} //~ ERROR enum `E` is never used
 
 fn main() {}

src/test/ui/lint/dead-code/empty-unused-enum.stderr

@@ -1,4 +1,4 @@
-error: enum is never used: `E`
+error: enum `E` is never used
   --> $DIR/empty-unused-enum.rs:3:6
    |
 LL | enum E {}

src/test/ui/lint/dead-code/impl-trait.rs

@@ -9,7 +9,7 @@ impl Trait for () {
 }
 
 type Used = ();
-type Unused = (); //~ ERROR type alias is never used
+type Unused = (); //~ ERROR type alias `Unused` is never used
 
 fn foo() -> impl Trait<Type = Used> {}
 

src/test/ui/lint/dead-code/impl-trait.stderr

@@ -1,4 +1,4 @@
-error: type alias is never used: `Unused`
+error: type alias `Unused` is never used
   --> $DIR/impl-trait.rs:12:1
    |
 LL | type Unused = ();

src/test/ui/lint/dead-code/issue-85255.rs

@@ -4,39 +4,39 @@
 #![warn(dead_code)]
 
 struct Foo {
-    a: i32, //~ WARNING: field is never read
+    a: i32, //~ WARNING: fields `a` and `b` are never read
-    pub b: i32, //~ WARNING: field is never read
+    pub b: i32,
 }
 
 struct Bar;
 
 impl Bar {
-    fn a(&self) -> i32 { 5 } //~ WARNING: associated function is never used
+    fn a(&self) -> i32 { 5 } //~ WARNING: associated function `a` is never used
-    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function is never used
+    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function `b` is never used
 }
 
 pub(crate) struct Foo1 {
-    a: i32, //~ WARNING: field is never read
+    a: i32, //~ WARNING: fields `a` and `b` are never read
-    pub b: i32, //~ WARNING: field is never read
+    pub b: i32,
 }
 
 pub(crate) struct Bar1;
 
 impl Bar1 {
-    fn a(&self) -> i32 { 5 } //~ WARNING: associated function is never used
+    fn a(&self) -> i32 { 5 } //~ WARNING: associated function `a` is never used
-    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function is never used
+    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function `b` is never used
 }
 
 pub(crate) struct Foo2 {
-    a: i32, //~ WARNING: field is never read
+    a: i32, //~ WARNING: fields `a` and `b` are never read
-    pub b: i32, //~ WARNING: field is never read
+    pub b: i32,
 }
 
 pub(crate) struct Bar2;
 
 impl Bar2 {
-    fn a(&self) -> i32 { 5 } //~ WARNING: associated function is never used
+    fn a(&self) -> i32 { 5 } //~ WARNING: associated function `a` is never used
-    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function is never used
+    pub fn b(&self) -> i32 { 6 } //~ WARNING: associated function `b` is never used
 }
 
 

src/test/ui/lint/dead-code/issue-85255.stderr

@@ -1,8 +1,12 @@
-warning: field is never read: `a`
+warning: fields `a` and `b` are never read
   --> $DIR/issue-85255.rs:7:5
    |
+LL | struct Foo {
+   |        --- fields in this struct
 LL |     a: i32,
    |     ^^^^^^
+LL |     pub b: i32,
+   |     ^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/issue-85255.rs:4:9
@@ -10,71 +14,61 @@ note: the lint level is defined here
 LL | #![warn(dead_code)]
    |         ^^^^^^^^^
 
-warning: field is never read: `b`
+warning: associated function `a` is never used
-  --> $DIR/issue-85255.rs:8:5
-   |
-LL |     pub b: i32,
-   |     ^^^^^^^^^^
-
-warning: associated function is never used: `a`
   --> $DIR/issue-85255.rs:14:8
    |
 LL |     fn a(&self) -> i32 { 5 }
    |        ^
 
-warning: associated function is never used: `b`
+warning: associated function `b` is never used
   --> $DIR/issue-85255.rs:15:12
    |
 LL |     pub fn b(&self) -> i32 { 6 }
    |            ^
 
-warning: field is never read: `a`
+warning: fields `a` and `b` are never read
   --> $DIR/issue-85255.rs:19:5
    |
+LL | pub(crate) struct Foo1 {
+   |                   ---- fields in this struct
 LL |     a: i32,
    |     ^^^^^^
-
-warning: field is never read: `b`
-  --> $DIR/issue-85255.rs:20:5
-   |
 LL |     pub b: i32,
    |     ^^^^^^^^^^
 
-warning: associated function is never used: `a`
+warning: associated function `a` is never used
   --> $DIR/issue-85255.rs:26:8
    |
 LL |     fn a(&self) -> i32 { 5 }
    |        ^
 
-warning: associated function is never used: `b`
+warning: associated function `b` is never used
   --> $DIR/issue-85255.rs:27:12
    |
 LL |     pub fn b(&self) -> i32 { 6 }
    |            ^
 
-warning: field is never read: `a`
+warning: fields `a` and `b` are never read
   --> $DIR/issue-85255.rs:31:5
    |
+LL | pub(crate) struct Foo2 {
+   |                   ---- fields in this struct
 LL |     a: i32,
    |     ^^^^^^
-
-warning: field is never read: `b`
-  --> $DIR/issue-85255.rs:32:5
-   |
 LL |     pub b: i32,
    |     ^^^^^^^^^^
 
-warning: associated function is never used: `a`
+warning: associated function `a` is never used
   --> $DIR/issue-85255.rs:38:8
    |
 LL |     fn a(&self) -> i32 { 5 }
    |        ^
 
-warning: associated function is never used: `b`
+warning: associated function `b` is never used
   --> $DIR/issue-85255.rs:39:12
    |
 LL |     pub fn b(&self) -> i32 { 6 }
    |            ^
 
-warning: 12 warnings emitted
+warning: 9 warnings emitted
 

src/test/ui/lint/dead-code/lint-dead-code-1.rs

@@ -9,7 +9,7 @@
 pub use foo2::Bar2;
 
 mod foo {
-    pub struct Bar; //~ ERROR: struct is never constructed
+    pub struct Bar; //~ ERROR: struct `Bar` is never constructed
 }
 
 mod foo2 {
@@ -17,14 +17,14 @@ mod foo2 {
 }
 
 pub static pub_static: isize = 0;
-static priv_static: isize = 0; //~ ERROR: static is never used
+static priv_static: isize = 0; //~ ERROR: static `priv_static` is never used
 const used_static: isize = 0;
 pub static used_static2: isize = used_static;
 const USED_STATIC: isize = 0;
 const STATIC_USED_IN_ENUM_DISCRIMINANT: isize = 10;
 
 pub const pub_const: isize = 0;
-const priv_const: isize = 0; //~ ERROR: constant is never used
+const priv_const: isize = 0; //~ ERROR: constant `priv_const` is never used
 const used_const: isize = 0;
 pub const used_const2: isize = used_const;
 const USED_CONST: isize = 1;
@@ -32,7 +32,7 @@ const CONST_USED_IN_ENUM_DISCRIMINANT: isize = 11;
 
 pub type typ = *const UsedStruct4;
 pub struct PubStruct;
-struct PrivStruct; //~ ERROR: struct is never constructed
+struct PrivStruct; //~ ERROR: struct `PrivStruct` is never constructed
 struct UsedStruct1 {
     #[allow(dead_code)]
     x: isize
@@ -61,10 +61,10 @@ pub enum pub_enum3 {
     Bar = CONST_USED_IN_ENUM_DISCRIMINANT,
 }
 
-enum priv_enum { foo2, bar2 } //~ ERROR: enum is never used
+enum priv_enum { foo2, bar2 } //~ ERROR: enum `priv_enum` is never used
 enum used_enum {
     foo3,
-    bar3 //~ ERROR variant is never constructed
+    bar3 //~ ERROR variant `bar3` is never constructed
 }
 
 fn f<T>() {}
@@ -85,21 +85,21 @@ pub fn pub_fn() {
     }
     f::<StructUsedInGeneric>();
 }
-fn priv_fn() { //~ ERROR: function is never used
+fn priv_fn() { //~ ERROR: function `priv_fn` is never used
     let unused_struct = PrivStruct;
 }
 fn used_fn() {}
 
-fn foo() { //~ ERROR: function is never used
+fn foo() { //~ ERROR: function `foo` is never used
     bar();
     let unused_enum = priv_enum::foo2;
 }
 
-fn bar() { //~ ERROR: function is never used
+fn bar() { //~ ERROR: function `bar` is never used
     foo();
 }
 
-fn baz() -> impl Copy { //~ ERROR: function is never used
+fn baz() -> impl Copy { //~ ERROR: function `baz` is never used
     "I'm unused, too"
 }
 

src/test/ui/lint/dead-code/lint-dead-code-1.stderr

@@ -1,4 +1,4 @@
-error: static is never used: `priv_static`
+error: static `priv_static` is never used
   --> $DIR/lint-dead-code-1.rs:20:1
    |
 LL | static priv_static: isize = 0;
@@ -10,55 +10,58 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: constant is never used: `priv_const`
+error: constant `priv_const` is never used
   --> $DIR/lint-dead-code-1.rs:27:1
    |
 LL | const priv_const: isize = 0;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: struct is never constructed: `PrivStruct`
+error: struct `PrivStruct` is never constructed
   --> $DIR/lint-dead-code-1.rs:35:8
    |
 LL | struct PrivStruct;
    |        ^^^^^^^^^^
 
-error: enum is never used: `priv_enum`
+error: enum `priv_enum` is never used
   --> $DIR/lint-dead-code-1.rs:64:6
    |
 LL | enum priv_enum { foo2, bar2 }
    |      ^^^^^^^^^
 
-error: variant is never constructed: `bar3`
+error: variant `bar3` is never constructed
   --> $DIR/lint-dead-code-1.rs:67:5
    |
+LL | enum used_enum {
+   |      --------- variant in this enum
+LL |     foo3,
 LL |     bar3
    |     ^^^^
 
-error: function is never used: `priv_fn`
+error: function `priv_fn` is never used
   --> $DIR/lint-dead-code-1.rs:88:4
    |
 LL | fn priv_fn() {
    |    ^^^^^^^
 
-error: function is never used: `foo`
+error: function `foo` is never used
   --> $DIR/lint-dead-code-1.rs:93:4
    |
 LL | fn foo() {
    |    ^^^
 
-error: function is never used: `bar`
+error: function `bar` is never used
   --> $DIR/lint-dead-code-1.rs:98:4
    |
 LL | fn bar() {
    |    ^^^
 
-error: function is never used: `baz`
+error: function `baz` is never used
   --> $DIR/lint-dead-code-1.rs:102:4
    |
 LL | fn baz() -> impl Copy {
    |    ^^^
 
-error: struct is never constructed: `Bar`
+error: struct `Bar` is never constructed
   --> $DIR/lint-dead-code-1.rs:12:16
    |
 LL |     pub struct Bar;

src/test/ui/lint/dead-code/lint-dead-code-2.rs

@@ -19,10 +19,10 @@ impl Bar for Foo {
 
 fn live_fn() {}
 
-fn dead_fn() {} //~ ERROR: function is never used
+fn dead_fn() {} //~ ERROR: function `dead_fn` is never used
 
 #[rustc_main]
-fn dead_fn2() {} //~ ERROR: function is never used
+fn dead_fn2() {} //~ ERROR: function `dead_fn2` is never used
 
 fn used_fn() {}
 
@@ -35,7 +35,7 @@ fn start(_: isize, _: *const *const u8) -> isize {
 }
 
 // this is not main
-fn main() { //~ ERROR: function is never used
+fn main() { //~ ERROR: function `main` is never used
     dead_fn();
     dead_fn2();
 }

src/test/ui/lint/dead-code/lint-dead-code-2.stderr

@@ -1,4 +1,4 @@
-error: function is never used: `dead_fn`
+error: function `dead_fn` is never used
   --> $DIR/lint-dead-code-2.rs:22:4
    |
 LL | fn dead_fn() {}
@@ -10,13 +10,13 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: function is never used: `dead_fn2`
+error: function `dead_fn2` is never used
   --> $DIR/lint-dead-code-2.rs:25:4
    |
 LL | fn dead_fn2() {}
    |    ^^^^^^^^
 
-error: function is never used: `main`
+error: function `main` is never used
   --> $DIR/lint-dead-code-2.rs:38:4
    |
 LL | fn main() {

src/test/ui/lint/dead-code/lint-dead-code-3.rs

@@ -11,14 +11,14 @@ extern "C" {
     pub fn extern_foo();
 }
 
-struct Foo; //~ ERROR: struct is never constructed
+struct Foo; //~ ERROR: struct `Foo` is never constructed
 impl Foo {
-    fn foo(&self) { //~ ERROR: associated function is never used
+    fn foo(&self) { //~ ERROR: associated function `foo` is never used
         bar()
     }
 }
 
-fn bar() { //~ ERROR: function is never used
+fn bar() { //~ ERROR: function `bar` is never used
     fn baz() {}
 
     Foo.foo();
@@ -57,9 +57,9 @@ mod blah {
     }
 }
 
-enum c_void {} //~ ERROR: enum is never used
+enum c_void {} //~ ERROR: enum `c_void` is never used
 extern "C" {
-    fn free(p: *const c_void); //~ ERROR: function is never used
+    fn free(p: *const c_void); //~ ERROR: function `free` is never used
 }
 
 // Check provided method

src/test/ui/lint/dead-code/lint-dead-code-3.stderr

@@ -1,4 +1,4 @@
-error: struct is never constructed: `Foo`
+error: struct `Foo` is never constructed
   --> $DIR/lint-dead-code-3.rs:14:8
    |
 LL | struct Foo;
@@ -10,25 +10,25 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: associated function is never used: `foo`
+error: associated function `foo` is never used
   --> $DIR/lint-dead-code-3.rs:16:8
    |
 LL |     fn foo(&self) {
    |        ^^^
 
-error: function is never used: `bar`
+error: function `bar` is never used
   --> $DIR/lint-dead-code-3.rs:21:4
    |
 LL | fn bar() {
    |    ^^^
 
-error: enum is never used: `c_void`
+error: enum `c_void` is never used
   --> $DIR/lint-dead-code-3.rs:60:6
    |
 LL | enum c_void {}
    |      ^^^^^^
 
-error: function is never used: `free`
+error: function `free` is never used
   --> $DIR/lint-dead-code-3.rs:62:5
    |
 LL |     fn free(p: *const c_void);

src/test/ui/lint/dead-code/lint-dead-code-4.rs

@@ -4,7 +4,7 @@
 
 struct Foo {
     x: usize,
-    b: bool, //~ ERROR: field is never read
+    b: bool, //~ ERROR: field `b` is never read
 }
 
 fn field_read(f: Foo) -> usize {
@@ -12,8 +12,8 @@ fn field_read(f: Foo) -> usize {
 }
 
 enum XYZ {
-    X, //~ ERROR variant is never constructed
+    X, //~ ERROR variants `X` and `Y` are never constructed
-    Y { //~ ERROR variant is never constructed
+    Y {
         a: String,
         b: i32,
         c: i32,
@@ -21,7 +21,7 @@ enum XYZ {
     Z
 }
 
-enum ABC { //~ ERROR enum is never used
+enum ABC { //~ ERROR enum `ABC` is never used
     A,
     B {
         a: String,
@@ -33,13 +33,13 @@ enum ABC { //~ ERROR enum is never used
 
 // ensure struct variants get warning for their fields
 enum IJK {
-    I, //~ ERROR variant is never constructed
+    I, //~ ERROR variants `I` and `K` are never constructed
     J {
         a: String,
-        b: i32, //~ ERROR field is never read
+        b: i32, //~ ERROR fields `b` and `c` are never read
-        c: i32, //~ ERROR field is never read
+        c: i32,
     },
-    K //~ ERROR variant is never constructed
+    K
 
 }
 
@@ -58,9 +58,9 @@ fn field_match_in_patterns(b: XYZ) -> String {
 }
 
 struct Bar {
-    x: usize, //~ ERROR: field is never read
+    x: usize, //~ ERROR: fields `x` and `c` are never read
     b: bool,
-    c: bool, //~ ERROR: field is never read
+    c: bool,
     _guard: ()
 }
 

src/test/ui/lint/dead-code/lint-dead-code-4.stderr

@@ -1,6 +1,9 @@
-error: field is never read: `b`
+error: field `b` is never read
   --> $DIR/lint-dead-code-4.rs:7:5
    |
+LL | struct Foo {
+   |        --- field in this struct
+LL |     x: usize,
 LL |     b: bool,
    |     ^^^^^^^
    |
@@ -10,15 +13,13 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: variant is never constructed: `X`
+error: variants `X` and `Y` are never constructed
   --> $DIR/lint-dead-code-4.rs:15:5
    |
-LL |     X,
+LL |   enum XYZ {
-   |     ^
+   |        --- variants in this enum
-
+LL |       X,
-error: variant is never constructed: `Y`
+   |       ^
-  --> $DIR/lint-dead-code-4.rs:16:5
-   |
 LL | /     Y {
 LL | |         a: String,
 LL | |         b: i32,
@@ -26,47 +27,44 @@ LL | |         c: i32,
 LL | |     },
    | |_____^
 
-error: enum is never used: `ABC`
+error: enum `ABC` is never used
   --> $DIR/lint-dead-code-4.rs:24:6
    |
 LL | enum ABC {
    |      ^^^
 
-error: variant is never constructed: `I`
+error: fields `b` and `c` are never read
-  --> $DIR/lint-dead-code-4.rs:36:5
-   |
-LL |     I,
-   |     ^
-
-error: field is never read: `b`
   --> $DIR/lint-dead-code-4.rs:39:9
    |
+LL | enum IJK {
+   |      --- fields in this enum
+...
 LL |         b: i32,
    |         ^^^^^^
-
-error: field is never read: `c`
-  --> $DIR/lint-dead-code-4.rs:40:9
-   |
 LL |         c: i32,
    |         ^^^^^^
 
-error: variant is never constructed: `K`
+error: variants `I` and `K` are never constructed
-  --> $DIR/lint-dead-code-4.rs:42:5
+  --> $DIR/lint-dead-code-4.rs:36:5
    |
+LL | enum IJK {
+   |      --- variants in this enum
+LL |     I,
+   |     ^
+...
 LL |     K
    |     ^
 
-error: field is never read: `x`
+error: fields `x` and `c` are never read
   --> $DIR/lint-dead-code-4.rs:61:5
    |
+LL | struct Bar {
+   |        --- fields in this struct
 LL |     x: usize,
    |     ^^^^^^^^
-
+LL |     b: bool,
-error: field is never read: `c`
-  --> $DIR/lint-dead-code-4.rs:63:5
-   |
 LL |     c: bool,
    |     ^^^^^^^
 
-error: aborting due to 10 previous errors
+error: aborting due to 6 previous errors
 

src/test/ui/lint/dead-code/lint-dead-code-5.rs

@@ -3,15 +3,15 @@
 
 enum Enum1 {
     Variant1(isize),
-    Variant2 //~ ERROR: variant is never constructed
+    Variant2 //~ ERROR: variant `Variant2` is never constructed
 }
 
 enum Enum2 {
     Variant3(bool),
     #[allow(dead_code)]
     Variant4(isize),
-    Variant5 { _x: isize }, //~ ERROR: variant is never constructed: `Variant5`
+    Variant5 { _x: isize }, //~ ERROR: variants `Variant5` and `Variant6` are never constructed
-    Variant6(isize), //~ ERROR: variant is never constructed: `Variant6`
+    Variant6(isize),
     _Variant7,
     Variant8 { _field: bool },
     Variant9,
@@ -32,7 +32,7 @@ impl Enum2 {
     }
 }
 
-enum Enum3 { //~ ERROR: enum is never used
+enum Enum3 { //~ ERROR: enum `Enum3` is never used
     Variant8,
     Variant9
 }

src/test/ui/lint/dead-code/lint-dead-code-5.stderr

@@ -1,6 +1,9 @@
-error: variant is never constructed: `Variant2`
+error: variant `Variant2` is never constructed
   --> $DIR/lint-dead-code-5.rs:6:5
    |
+LL | enum Enum1 {
+   |      ----- variant in this enum
+LL |     Variant1(isize),
 LL |     Variant2
    |     ^^^^^^^^
    |
@@ -10,23 +13,22 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: variant is never constructed: `Variant5`
+error: variants `Variant5` and `Variant6` are never constructed
   --> $DIR/lint-dead-code-5.rs:13:5
    |
+LL | enum Enum2 {
+   |      ----- variants in this enum
+...
 LL |     Variant5 { _x: isize },
    |     ^^^^^^^^^^^^^^^^^^^^^^
-
-error: variant is never constructed: `Variant6`
-  --> $DIR/lint-dead-code-5.rs:14:5
-   |
 LL |     Variant6(isize),
    |     ^^^^^^^^^^^^^^^
 
-error: enum is never used: `Enum3`
+error: enum `Enum3` is never used
   --> $DIR/lint-dead-code-5.rs:35:6
    |
 LL | enum Enum3 {
    |      ^^^^^
 
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 

src/test/ui/lint/dead-code/lint-dead-code-6.rs

@@ -1,16 +1,16 @@
 #![deny(dead_code)]
 
-struct UnusedStruct; //~ ERROR struct is never constructed: `UnusedStruct`
+struct UnusedStruct; //~ ERROR struct `UnusedStruct` is never constructed
 impl UnusedStruct {
-    fn unused_impl_fn_1() { //~ ERROR associated function is never used: `unused_impl_fn_1`
+    fn unused_impl_fn_1() { //~ ERROR associated function `unused_impl_fn_1` is never used
         println!("blah");
     }
 
-    fn unused_impl_fn_2(var: i32) { //~ ERROR associated function is never used: `unused_impl_fn_2`
+    fn unused_impl_fn_2(var: i32) { //~ ERROR associated function `unused_impl_fn_2` is never used
         println!("foo {}", var);
     }
 
-    fn unused_impl_fn_3( //~ ERROR associated function is never used: `unused_impl_fn_3`
+    fn unused_impl_fn_3( //~ ERROR associated function `unused_impl_fn_3` is never used
         var: i32,
     ) {
         println!("bar {}", var);

src/test/ui/lint/dead-code/lint-dead-code-6.stderr

@@ -1,4 +1,4 @@
-error: struct is never constructed: `UnusedStruct`
+error: struct `UnusedStruct` is never constructed
   --> $DIR/lint-dead-code-6.rs:3:8
    |
 LL | struct UnusedStruct;
@@ -10,19 +10,19 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: associated function is never used: `unused_impl_fn_1`
+error: associated function `unused_impl_fn_1` is never used
   --> $DIR/lint-dead-code-6.rs:5:8
    |
 LL |     fn unused_impl_fn_1() {
    |        ^^^^^^^^^^^^^^^^
 
-error: associated function is never used: `unused_impl_fn_2`
+error: associated function `unused_impl_fn_2` is never used
   --> $DIR/lint-dead-code-6.rs:9:8
    |
 LL |     fn unused_impl_fn_2(var: i32) {
    |        ^^^^^^^^^^^^^^^^
 
-error: associated function is never used: `unused_impl_fn_3`
+error: associated function `unused_impl_fn_3` is never used
   --> $DIR/lint-dead-code-6.rs:13:8
    |
 LL |     fn unused_impl_fn_3(

src/test/ui/lint/dead-code/multiple-dead-codes-in-the-same-struct.rs

@@ -0,0 +1,29 @@
+#![warn(dead_code)]
+
+struct Bar {
+    #[allow(dead_code)]
+    a: usize,
+    #[forbid(dead_code)]
+    b: usize, //~ ERROR field `b` is never read
+    #[deny(dead_code)]
+    c: usize, //~ ERROR fields `c` and `e` are never read
+    d: usize, //~ WARN fields `d`, `f` and `g` are never read
+    #[deny(dead_code)]
+    e: usize,
+    f: usize,
+    g: usize,
+    _h: usize,
+}
+
+fn main() {
+    Bar {
+        a: 1,
+        b: 1,
+        c: 1,
+        d: 1,
+        e: 1,
+        f: 1,
+        g: 1,
+        _h: 1,
+    };
+}

src/test/ui/lint/dead-code/multiple-dead-codes-in-the-same-struct.stderr

@@ -0,0 +1,55 @@
+warning: fields `d`, `f` and `g` are never read
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:10:5
+   |
+LL | struct Bar {
+   |        --- fields in this struct
+...
+LL |     d: usize,
+   |     ^^^^^^^^
+...
+LL |     f: usize,
+   |     ^^^^^^^^
+LL |     g: usize,
+   |     ^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:1:9
+   |
+LL | #![warn(dead_code)]
+   |         ^^^^^^^^^
+
+error: fields `c` and `e` are never read
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:9:5
+   |
+LL | struct Bar {
+   |        --- fields in this struct
+...
+LL |     c: usize,
+   |     ^^^^^^^^
+...
+LL |     e: usize,
+   |     ^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:8:12
+   |
+LL |     #[deny(dead_code)]
+   |            ^^^^^^^^^
+
+error: field `b` is never read
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:7:5
+   |
+LL | struct Bar {
+   |        --- field in this struct
+...
+LL |     b: usize,
+   |     ^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/multiple-dead-codes-in-the-same-struct.rs:6:14
+   |
+LL |     #[forbid(dead_code)]
+   |              ^^^^^^^^^
+
+error: aborting due to 2 previous errors; 1 warning emitted
+

src/test/ui/lint/dead-code/newline-span.rs

@@ -1,14 +1,14 @@
 #![deny(dead_code)]
 
-fn unused() { //~ error: function is never used:
+fn unused() { //~ error: function `unused` is never used
     println!("blah");
 }
 
-fn unused2(var: i32) { //~ error: function is never used:
+fn unused2(var: i32) { //~ error: function `unused2` is never used
     println!("foo {}", var);
 }
 
-fn unused3( //~ error: function is never used:
+fn unused3( //~ error: function `unused3` is never used
     var: i32,
 ) {
     println!("bar {}", var);

src/test/ui/lint/dead-code/newline-span.stderr

@@ -1,4 +1,4 @@
-error: function is never used: `unused`
+error: function `unused` is never used
   --> $DIR/newline-span.rs:3:4
    |
 LL | fn unused() {
@@ -10,13 +10,13 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: function is never used: `unused2`
+error: function `unused2` is never used
   --> $DIR/newline-span.rs:7:4
    |
 LL | fn unused2(var: i32) {
    |    ^^^^^^^
 
-error: function is never used: `unused3`
+error: function `unused3` is never used
   --> $DIR/newline-span.rs:11:4
    |
 LL | fn unused3(

src/test/ui/lint/dead-code/type-alias.rs

@@ -1,7 +1,7 @@
 #![deny(dead_code)]
 
 type Used = u8;
-type Unused = u8; //~ ERROR type alias is never used
+type Unused = u8; //~ ERROR type alias `Unused` is never used
 
 fn id(x: Used) -> Used { x }
 

src/test/ui/lint/dead-code/type-alias.stderr

@@ -1,4 +1,4 @@
-error: type alias is never used: `Unused`
+error: type alias `Unused` is never used
   --> $DIR/type-alias.rs:4:1
    |
 LL | type Unused = u8;

src/test/ui/lint/dead-code/unused-enum.rs

@@ -1,9 +1,10 @@
 #![deny(unused)]
 
-struct F; //~ ERROR struct is never constructed
+struct F; //~ ERROR struct `F` is never constructed
-struct B; //~ ERROR struct is never constructed
+struct B; //~ ERROR struct `B` is never constructed
 
-enum E { //~ ERROR enum is never used
+enum E {
+    //~^ ERROR enum `E` is never used
     Foo(F),
     Bar(B),
 }

src/test/ui/lint/dead-code/unused-enum.stderr

@@ -1,4 +1,4 @@
-error: struct is never constructed: `F`
+error: struct `F` is never constructed
   --> $DIR/unused-enum.rs:3:8
    |
 LL | struct F;
@@ -11,13 +11,13 @@ LL | #![deny(unused)]
    |         ^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(unused)]`
 
-error: struct is never constructed: `B`
+error: struct `B` is never constructed
   --> $DIR/unused-enum.rs:4:8
    |
 LL | struct B;
    |        ^
 
-error: enum is never used: `E`
+error: enum `E` is never used
   --> $DIR/unused-enum.rs:6:6
    |
 LL | enum E {

src/test/ui/lint/dead-code/unused-struct-variant.rs

@@ -5,7 +5,7 @@ struct B;
 
 enum E {
     Foo(F),
-    Bar(B), //~ ERROR variant is never constructed
+    Bar(B), //~ ERROR variant `Bar` is never constructed
 }
 
 fn main() {

src/test/ui/lint/dead-code/unused-struct-variant.stderr

@@ -1,6 +1,9 @@
-error: variant is never constructed: `Bar`
+error: variant `Bar` is never constructed
   --> $DIR/unused-struct-variant.rs:8:5
    |
+LL | enum E {
+   |      - variant in this enum
+LL |     Foo(F),
 LL |     Bar(B),
    |     ^^^^^^
    |

src/test/ui/lint/dead-code/unused-variant.rs

@@ -2,7 +2,7 @@
 
 #[derive(Clone)]
 enum Enum {
-    Variant1, //~ ERROR: variant is never constructed
+    Variant1, //~ ERROR: variant `Variant1` is never constructed
     Variant2,
 }
 

src/test/ui/lint/dead-code/unused-variant.stderr

@@ -1,6 +1,8 @@
-error: variant is never constructed: `Variant1`
+error: variant `Variant1` is never constructed
   --> $DIR/unused-variant.rs:5:5
    |
+LL | enum Enum {
+   |      ---- variant in this enum
 LL |     Variant1,
    |     ^^^^^^^^
    |

src/test/ui/lint/dead-code/with-core-crate.rs

@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate core;
 
-fn foo() { //~ ERROR function is never used
+fn foo() { //~ ERROR function `foo` is never used
 
     // none of these should have any dead_code exposed to the user
     panic!();

src/test/ui/lint/dead-code/with-core-crate.stderr

@@ -1,4 +1,4 @@
-error: function is never used: `foo`
+error: function `foo` is never used
   --> $DIR/with-core-crate.rs:7:4
    |
 LL | fn foo() {

src/test/ui/lint/force-warn/allow-warnings.rs

@@ -6,6 +6,6 @@
 #![allow(warnings)]
 
 fn dead_function() {}
-//~^ WARN function is never used
+//~^ WARN function `dead_function` is never used
 
 fn main() {}

src/test/ui/lint/force-warn/allow-warnings.stderr

@@ -1,4 +1,4 @@
-warning: function is never used: `dead_function`
+warning: function `dead_function` is never used
   --> $DIR/allow-warnings.rs:8:4
    |
 LL | fn dead_function() {}

src/test/ui/lint/force-warn/allowed-warn-by-default-lint.rs

@@ -6,6 +6,6 @@
 #![allow(dead_code)]
 
 fn dead_function() {}
-//~^ WARN function is never used
+//~^ WARN function `dead_function` is never used
 
 fn main() {}

src/test/ui/lint/force-warn/allowed-warn-by-default-lint.stderr

@@ -1,4 +1,4 @@
-warning: function is never used: `dead_function`
+warning: function `dead_function` is never used
   --> $DIR/allowed-warn-by-default-lint.rs:8:4
    |
 LL | fn dead_function() {}

src/test/ui/lint/force-warn/warn-by-default-lint-two-modules.rs

@@ -7,12 +7,12 @@ mod one {
     #![allow(dead_code)]
 
     fn dead_function() {}
-    //~^ WARN function is never used
+    //~^ WARN function `dead_function` is never used
 }
 
 mod two {
     fn dead_function() {}
-    //~^ WARN function is never used
+    //~^ WARN function `dead_function` is never used
 }
 
 fn main() {}

src/test/ui/lint/force-warn/warn-by-default-lint-two-modules.stderr

@@ -1,4 +1,4 @@
-warning: function is never used: `dead_function`
+warning: function `dead_function` is never used
   --> $DIR/warn-by-default-lint-two-modules.rs:9:8
    |
 LL |     fn dead_function() {}
@@ -6,7 +6,7 @@ LL |     fn dead_function() {}
    |
    = note: requested on the command line with `--force-warn dead-code`
 
-warning: function is never used: `dead_function`
+warning: function `dead_function` is never used
   --> $DIR/warn-by-default-lint-two-modules.rs:14:8
    |
 LL |     fn dead_function() {}

src/test/ui/lint/issue-17718-const-naming.rs

@@ -3,6 +3,6 @@
 
 const foo: isize = 3;
 //~^ ERROR: should have an upper case name
-//~^^ ERROR: constant is never used
+//~^^ ERROR: constant `foo` is never used
 
 fn main() {}

src/test/ui/lint/issue-17718-const-naming.stderr

@@ -1,4 +1,4 @@
-error: constant is never used: `foo`
+error: constant `foo` is never used
   --> $DIR/issue-17718-const-naming.rs:4:1
    |
 LL | const foo: isize = 3;

src/test/ui/span/macro-span-replacement.rs

@@ -4,7 +4,7 @@
 
 macro_rules! m {
     ($a:tt $b:tt) => {
-        $b $a; //~ WARN struct is never constructed
+        $b $a; //~ WARN struct `S` is never constructed
     }
 }
 

src/test/ui/span/macro-span-replacement.stderr

@@ -1,4 +1,4 @@
-warning: struct is never constructed: `S`
+warning: struct `S` is never constructed
   --> $DIR/macro-span-replacement.rs:7:14
    |
 LL |         $b $a;

src/test/ui/span/unused-warning-point-at-identifier.rs

@@ -2,26 +2,26 @@
 
 #![warn(unused)]
 
-enum Enum { //~ WARN enum is never used
+enum Enum { //~ WARN enum `Enum` is never used
     A,
     B,
     C,
     D,
 }
 
-struct Struct { //~ WARN struct is never constructed
+struct Struct { //~ WARN struct `Struct` is never constructed
     a: usize,
     b: usize,
     c: usize,
     d: usize,
 }
 
-fn func() -> usize { //~ WARN function is never used
+fn func() -> usize { //~ WARN function `func` is never used
     3
 }
 
 fn
-func_complete_span() //~ WARN function is never used
+func_complete_span() //~ WARN function `func_complete_span` is never used
 -> usize
 {
     3

src/test/ui/span/unused-warning-point-at-identifier.stderr

@@ -1,4 +1,4 @@
-warning: enum is never used: `Enum`
+warning: enum `Enum` is never used
   --> $DIR/unused-warning-point-at-identifier.rs:5:6
    |
 LL | enum Enum {
@@ -11,19 +11,19 @@ LL | #![warn(unused)]
    |         ^^^^^^
    = note: `#[warn(dead_code)]` implied by `#[warn(unused)]`
 
-warning: struct is never constructed: `Struct`
+warning: struct `Struct` is never constructed
   --> $DIR/unused-warning-point-at-identifier.rs:12:8
    |
 LL | struct Struct {
    |        ^^^^^^
 
-warning: function is never used: `func`
+warning: function `func` is never used
   --> $DIR/unused-warning-point-at-identifier.rs:19:4
    |
 LL | fn func() -> usize {
    |    ^^^^
 
-warning: function is never used: `func_complete_span`
+warning: function `func_complete_span` is never used
   --> $DIR/unused-warning-point-at-identifier.rs:24:1
    |
 LL | func_complete_span()

src/test/ui/test-attrs/test-warns-dead-code.rs

@@ -2,6 +2,6 @@
 
 #![deny(dead_code)]
 
-fn dead() {} //~ error: function is never used: `dead`
+fn dead() {} //~ error: function `dead` is never used
 
 fn main() {}

src/test/ui/test-attrs/test-warns-dead-code.stderr

@@ -1,4 +1,4 @@
-error: function is never used: `dead`
+error: function `dead` is never used
   --> $DIR/test-warns-dead-code.rs:5:4
    |
 LL | fn dead() {}

src/test/ui/union/union-fields-1.mirunsafeck.stderr

@@ -1,6 +1,9 @@
-error: field is never read: `c`
+error: field `c` is never read
   --> $DIR/union-fields-1.rs:9:5
    |
+LL | union U1 {
+   |       -- field in this union
+...
 LL |     c: u8,
    |     ^^^^^
    |
@@ -10,21 +13,28 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: field is never read: `a`
+error: field `a` is never read
   --> $DIR/union-fields-1.rs:12:5
    |
+LL | union U2 {
+   |       -- field in this union
 LL |     a: u8,
    |     ^^^^^
 
-error: field is never read: `a`
+error: field `a` is never read
   --> $DIR/union-fields-1.rs:16:20
    |
 LL | union NoDropLike { a: u8 }
-   |                    ^^^^^
+   |       ----------   ^^^^^
+   |       |
+   |       field in this union
 
-error: field is never read: `c`
+error: field `c` is never read
   --> $DIR/union-fields-1.rs:21:5
    |
+LL | union U {
+   |       - field in this union
+...
 LL |     c: u8,
    |     ^^^^^
 

src/test/ui/union/union-fields-1.rs

@@ -6,19 +6,19 @@
 union U1 {
     a: u8, // should not be reported
     b: u8, // should not be reported
-    c: u8, //~ ERROR field is never read
+    c: u8, //~ ERROR field `c` is never read
 }
 union U2 {
-    a: u8, //~ ERROR field is never read
+    a: u8, //~ ERROR field `a` is never read
     b: u8, // should not be reported
     c: u8, // should not be reported
 }
-union NoDropLike { a: u8 } //~ ERROR field is never read
+union NoDropLike { a: u8 } //~ ERROR field `a` is never read
 
 union U {
     a: u8, // should not be reported
     b: u8, // should not be reported
-    c: u8, //~ ERROR field is never read
+    c: u8, //~ ERROR field `c` is never read
 }
 type A = U;
 

src/test/ui/union/union-fields-1.thirunsafeck.stderr

@@ -1,6 +1,9 @@
-error: field is never read: `c`
+error: field `c` is never read
   --> $DIR/union-fields-1.rs:9:5
    |
+LL | union U1 {
+   |       -- field in this union
+...
 LL |     c: u8,
    |     ^^^^^
    |
@@ -10,21 +13,28 @@ note: the lint level is defined here
 LL | #![deny(dead_code)]
    |         ^^^^^^^^^
 
-error: field is never read: `a`
+error: field `a` is never read
   --> $DIR/union-fields-1.rs:12:5
    |
+LL | union U2 {
+   |       -- field in this union
 LL |     a: u8,
    |     ^^^^^
 
-error: field is never read: `a`
+error: field `a` is never read
   --> $DIR/union-fields-1.rs:16:20
    |
 LL | union NoDropLike { a: u8 }
-   |                    ^^^^^
+   |       ----------   ^^^^^
+   |       |
+   |       field in this union
 
-error: field is never read: `c`
+error: field `c` is never read
   --> $DIR/union-fields-1.rs:21:5
    |
+LL | union U {
+   |       - field in this union
+...
 LL |     c: u8,
    |     ^^^^^
 

src/test/ui/union/union-lint-dead-code.mirunsafeck.stderr

@@ -1,6 +1,9 @@
-error: field is never read: `b`
+error: field `b` is never read
   --> $DIR/union-lint-dead-code.rs:8:5
    |
+LL | union Foo {
+   |       --- field in this union
+LL |     x: usize,
 LL |     b: bool,
    |     ^^^^^^^
    |

src/test/ui/union/union-lint-dead-code.rs

@@ -5,7 +5,7 @@
 
 union Foo {
     x: usize,
-    b: bool, //~ ERROR: field is never read
+    b: bool, //~ ERROR: field `b` is never read
     _unused: u16,
 }
 

src/test/ui/union/union-lint-dead-code.thirunsafeck.stderr

@@ -1,6 +1,9 @@
-error: field is never read: `b`
+error: field `b` is never read
   --> $DIR/union-lint-dead-code.rs:8:5
    |
+LL | union Foo {
+   |       --- field in this union
+LL |     x: usize,
 LL |     b: bool,
    |     ^^^^^^^
    |

src/tools/cargo

@@ -1 +1 @@
-Subproject commit 8d42b0e8794ce3787c9f7d6d88b02ae80ebe8d19
+Subproject commit 03a849043e25104e8b7ad0d4a96c525787b69379

src/tools/rls

@@ -1 +1 @@
-Subproject commit 7241c6cc45badc0e30cefd6c123a539f82c50cd3
+Subproject commit 27f4044df03d15c7c38a483c3e4635cf4f51807d