non_local_defs: use labels to indicate what may need to be moved

3 files changed, 19 insertions, 3 deletions

diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index 52d8def425f..8582148e26c 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -544,7 +544,7 @@ lint_non_local_definitions_deprecation = this lint may become deny-by-default in
 
 lint_non_local_definitions_impl = non-local `impl` definition, `impl` blocks should be written at the same level as their item
     .help =
-        move this `impl` block outside the of the current {$body_kind_descr} {$depth ->
+        move this `impl` block outside of the current {$body_kind_descr} {$depth ->
             [one] `{$body_name}`
            *[other] `{$body_name}` and up {$depth} bodies
         }
@@ -565,6 +565,8 @@ lint_non_local_definitions_macro_rules = non-local `macro_rules!` definition, `#
     .non_local = a `macro_rules!` definition is non-local if it is nested inside an item and has a `#[macro_export]` attribute
     .exception = one exception to the rule are anon-const (`const _: () = {"{"} ... {"}"}`) at top-level module
 
+lint_non_local_definitions_may_move = may need to be moved as well
+
 lint_non_snake_case = {$sort} `{$name}` should have a snake case name
     .rename_or_convert_suggestion = rename the identifier or convert it to a snake case raw identifier
     .cannot_convert_note = `{$sc}` cannot be used as a raw identifier
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index d3c409bb6e5..305cc67c1ee 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -6,7 +6,7 @@ use crate::errors::RequestedLevel;
 use crate::fluent_generated as fluent;
 use rustc_errors::{
     codes::*, Applicability, Diag, DiagArgValue, DiagMessage, DiagStyledString,
-    ElidedLifetimeInPathSubdiag, EmissionGuarantee, LintDiagnostic, SubdiagMessageOp,
+    ElidedLifetimeInPathSubdiag, EmissionGuarantee, LintDiagnostic, MultiSpan, SubdiagMessageOp,
     Subdiagnostic, SuggestionStyle,
 };
 use rustc_hir::{def::Namespace, def_id::DefId};
@@ -1336,6 +1336,9 @@ pub enum NonLocalDefinitionsDiag {
         body_name: String,
         cargo_update: Option<NonLocalDefinitionsCargoUpdateNote>,
         const_anon: Option<Option<Span>>,
+        move_help: Span,
+        self_ty: Span,
+        of_trait: Option<Span>,
         has_trait: bool,
     },
     MacroRules {
@@ -1357,6 +1360,9 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                 body_name,
                 cargo_update,
                 const_anon,
+                move_help,
+                self_ty,
+                of_trait,
                 has_trait,
             } => {
                 diag.primary_message(fluent::lint_non_local_definitions_impl);
@@ -1364,13 +1370,18 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                 diag.arg("body_kind_descr", body_kind_descr);
                 diag.arg("body_name", body_name);
 
-                diag.help(fluent::lint_help);
                 if has_trait {
                     diag.note(fluent::lint_bounds);
                     diag.note(fluent::lint_with_trait);
                 } else {
                     diag.note(fluent::lint_without_trait);
                 }
+                let mut ms = MultiSpan::from_span(move_help);
+                ms.push_span_label(self_ty, fluent::lint_non_local_definitions_may_move);
+                if let Some(of_trait) = of_trait {
+                    ms.push_span_label(of_trait, fluent::lint_non_local_definitions_may_move);
+                }
+                diag.span_help(ms, fluent::lint_help);
 
                 if let Some(cargo_update) = cargo_update {
                     diag.subdiagnostic(&diag.dcx, cargo_update);
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index d4d3afcce3b..6b75e546a66 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -222,6 +222,9 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                     item.span.shrink_to_lo().to(impl_.self_ty.span),
                     NonLocalDefinitionsDiag::Impl {
                         depth: self.body_depth,
+                        move_help: item.span,
+                        self_ty: impl_.self_ty.span,
+                        of_trait: impl_.of_trait.map(|t| t.path.span),
                         body_kind_descr: cx.tcx.def_kind_descr(parent_def_kind, parent),
                         body_name: parent_opt_item_name
                             .map(|s| s.to_ident_string())