Downgrade use of @Lifetime outside stdlib as a warning

meg-gupta · meg-gupta · commit 854ff84365ef · 2025-06-06T21:45:23.000-07:00
diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
@@ -8257,7 +8257,7 @@ ERROR(pack_iteration_where_clause_not_supported, none,
 // MARK: Lifetime Dependence Syntax
 //------------------------------------------------------------------------------
 
-ERROR(use_lifetime_underscored, PointsToFirstBadToken,
+WARNING(use_lifetime_underscored, PointsToFirstBadToken,
       "Unsupported use of @lifetime, use @_lifetime to specify lifetime dependencies", ())
 
 ERROR(lifetime_dependence_invalid_param_name, none,
