3 files changed, 17 insertions, 0 deletions
diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index d2b1f50d79c..28f75a8193b 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -550,6 +550,7 @@ lint_non_local_definitions_impl = non-local `impl` definition, `impl` blocks sho
     .bounds = `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
     .exception = items in an anonymous const item (`const _: () = {"{"} ... {"}"}`) are treated as in the same scope as the anonymous const's declaration
     .const_anon = use a const-anon item to suppress this lint
+    .macro_to_change = the {$macro_kind} `{$macro_to_change}` defines the non-local `impl`, and may need to be changed
 
 lint_non_local_definitions_impl_move_help =
     move the `impl` block outside of this {$body_kind_descr} {$depth ->
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index c365e68ba44..91a600e754f 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -1355,6 +1355,7 @@ pub enum NonLocalDefinitionsDiag {
         has_trait: bool,
         self_ty_str: String,
         of_trait_str: Option<String>,
+        macro_to_change: Option<(String, &'static str)>,
     },
     MacroRules {
         depth: u32,
@@ -1380,6 +1381,7 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                 has_trait,
                 self_ty_str,
                 of_trait_str,
+                macro_to_change,
             } => {
                 diag.primary_message(fluent::lint_non_local_definitions_impl);
                 diag.arg("depth", depth);
@@ -1390,6 +1392,12 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                     diag.arg("of_trait_str", of_trait_str);
                 }
 
+                if let Some((macro_to_change, macro_kind)) = macro_to_change {
+                    diag.arg("macro_to_change", macro_to_change);
+                    diag.arg("macro_kind", macro_kind);
+                    diag.note(fluent::lint_macro_to_change);
+                }
+
                 if has_trait {
                     diag.note(fluent::lint_bounds);
                     diag.note(fluent::lint_with_trait);
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index 42b03f47a5b..ac5ed9d2190 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -258,6 +258,13 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                     Some((cx.tcx.def_span(parent), may_move))
                 };
 
+                let macro_to_change =
+                    if let ExpnKind::Macro(kind, name) = item.span.ctxt().outer_expn_data().kind {
+                        Some((name.to_string(), kind.descr()))
+                    } else {
+                        None
+                    };
+
                 cx.emit_span_lint(
                     NON_LOCAL_DEFINITIONS,
                     ms,
@@ -274,6 +281,7 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                         move_to,
                         may_remove,
                         has_trait: impl_.of_trait.is_some(),
+                        macro_to_change,
                     },
                 )
             }