reduce diversity in linting methods

src/librustc/traits/object_safety.rs

@@ -179,7 +179,7 @@ fn object_safety_violations_for_trait(
             {
                 // Using `CRATE_NODE_ID` is wrong, but it's hard to get a more precise id.
                 // It's also hard to get a use site span, so we use the method definition span.
-                tcx.lint_node_note(
+                tcx.struct_span_lint_hir(
                     WHERE_CLAUSES_OBJECT_SAFETY,
                     hir::CRATE_HIR_ID,
                     *span,
@@ -187,8 +187,9 @@ fn object_safety_violations_for_trait(
                         "the trait `{}` cannot be made into an object",
                         tcx.def_path_str(trait_def_id)
                     ),
-                    &violation.error_msg(),
+                )
-                );
+                .note(&violation.error_msg())
+                .emit();
                 false
             } else {
                 true

src/librustc/ty/context.rs

@@ -2562,32 +2562,6 @@ impl<'tcx> TyCtxt<'tcx> {
         self.struct_span_lint_hir(lint, hir_id, span.into(), msg).emit()
     }
 
-    pub fn lint_hir_note(
-        self,
-        lint: &'static Lint,
-        hir_id: HirId,
-        span: impl Into<MultiSpan>,
-        msg: &str,
-        note: &str,
-    ) {
-        let mut err = self.struct_span_lint_hir(lint, hir_id, span.into(), msg);
-        err.note(note);
-        err.emit()
-    }
-
-    pub fn lint_node_note(
-        self,
-        lint: &'static Lint,
-        id: hir::HirId,
-        span: impl Into<MultiSpan>,
-        msg: &str,
-        note: &str,
-    ) {
-        let mut err = self.struct_span_lint_hir(lint, id, span.into(), msg);
-        err.note(note);
-        err.emit()
-    }
-
     /// Walks upwards from `id` to find a node which might change lint levels with attributes.
     /// It stops at `bound` and just returns it if reached.
     pub fn maybe_lint_level_root_bounded(

src/librustc_mir/transform/check_unsafety.rs

@@ -648,17 +648,17 @@ pub fn check_unsafety(tcx: TyCtxt<'_>, def_id: DefId) {
                 if let Some(impl_def_id) = builtin_derive_def_id(tcx, def_id) {
                     tcx.unsafe_derive_on_repr_packed(impl_def_id);
                 } else {
-                    tcx.lint_node_note(
+                    tcx.struct_span_lint_hir(
                         SAFE_PACKED_BORROWS,
                         lint_hir_id,
                         source_info.span,
                         &format!(
-                            "{} is unsafe and requires unsafe function or block \
+                            "{} is unsafe and requires unsafe function or block (error E0133)",
-                                            (error E0133)",
                             description
                         ),
-                        &details.as_str(),
+                    )
-                    );
+                    .note(&details.as_str())
+                    .emit();
                 }
             }
         }

src/librustc_passes/liveness.rs

@@ -1513,13 +1513,16 @@ impl<'tcx> Liveness<'_, 'tcx> {
                 if ln == self.s.exit_ln { false } else { self.assigned_on_exit(ln, var).is_some() };
 
             if is_assigned {
-                self.ir.tcx.lint_hir_note(
+                self.ir
-                    lint::builtin::UNUSED_VARIABLES,
+                    .tcx
-                    hir_id,
+                    .struct_span_lint_hir(
-                    spans,
+                        lint::builtin::UNUSED_VARIABLES,
-                    &format!("variable `{}` is assigned to, but never used", name),
+                        hir_id,
-                    &format!("consider using `_{}` instead", name),
+                        spans,
-                );
+                        &format!("variable `{}` is assigned to, but never used", name),
+                    )
+                    .note(&format!("consider using `_{}` instead", name))
+                    .emit();
             } else {
                 let mut err = self.ir.tcx.struct_span_lint_hir(
                     lint::builtin::UNUSED_VARIABLES,