3 files changed, 35 insertions, 0 deletions
diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index fdedf2c2e6d..eac5083ffbf 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -825,6 +825,10 @@ lint_unnameable_test_items = cannot test inner items
 lint_unnecessary_qualification = unnecessary qualification
     .suggestion = remove the unnecessary path segments
 
+lint_unsafe_attr_outside_unsafe = unsafe attribute used without unsafe
+    .label = usage of unsafe attribute
+lint_unsafe_attr_outside_unsafe_suggestion = wrap the attribute in `unsafe(...)`
+
 lint_unsupported_group = `{$lint_group}` lint group is not supported with ´--force-warn´
 
 lint_untranslatable_diag = diagnostics should be created using translatable messages
diff --git a/compiler/rustc_lint/src/context/diagnostics.rs b/compiler/rustc_lint/src/context/diagnostics.rs
index 290bb5173db..adb2a3275c0 100644
--- a/compiler/rustc_lint/src/context/diagnostics.rs
+++ b/compiler/rustc_lint/src/context/diagnostics.rs
@@ -319,6 +319,16 @@ pub(super) fn decorate_lint(sess: &Session, diagnostic: BuiltinLintDiag, diag: &
         BuiltinLintDiag::UnusedQualifications { removal_span } => {
             lints::UnusedQualifications { removal_span }.decorate_lint(diag);
         }
+        BuiltinLintDiag::UnsafeAttrOutsideUnsafe {
+            attribute_name_span,
+            sugg_spans: (left, right),
+        } => {
+            lints::UnsafeAttrOutsideUnsafe {
+                span: attribute_name_span,
+                suggestion: lints::UnsafeAttrOutsideUnsafeSuggestion { left, right },
+            }
+            .decorate_lint(diag);
+        }
         BuiltinLintDiag::AssociatedConstElidedLifetime {
             elided,
             span: lt_span,
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index b26d04d0618..6df3a11deb0 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -2890,3 +2890,24 @@ pub struct RedundantImportVisibility {
     pub import_vis: String,
     pub max_vis: String,
 }
+
+#[derive(LintDiagnostic)]
+#[diag(lint_unsafe_attr_outside_unsafe)]
+pub struct UnsafeAttrOutsideUnsafe {
+    #[label]
+    pub span: Span,
+    #[subdiagnostic]
+    pub suggestion: UnsafeAttrOutsideUnsafeSuggestion,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+    lint_unsafe_attr_outside_unsafe_suggestion,
+    applicability = "machine-applicable"
+)]
+pub struct UnsafeAttrOutsideUnsafeSuggestion {
+    #[suggestion_part(code = "unsafe(")]
+    pub left: Span,
+    #[suggestion_part(code = ")")]
+    pub right: Span,
+}