Updated lint message for rc_mutex

Author: xFrednet

clippy_lints/src/types/rc_mutex.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint;
+use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::is_ty_param_diagnostic_item;
 use if_chain::if_chain;
 use rustc_hir::{self as hir, def_id::DefId, QPath};
@@ -11,13 +11,14 @@ pub(super) fn check(cx: &LateContext<'_>, hir_ty: &hir::Ty<'_>, qpath: &QPath<'_
     if_chain! {
         if cx.tcx.is_diagnostic_item(sym::Rc, def_id) ;
         if let Some(_) = is_ty_param_diagnostic_item(cx, qpath, sym!(mutex_type)) ;
-
-        then{
-            span_lint(
+        then {
+            span_lint_and_help(
                 cx,
                 RC_MUTEX,
                 hir_ty.span,
-                "found `Rc<Mutex<_>>`. Consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead",
+                "usage of `Rc<Mutex<_>>`",
+                None,
+                "consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead",
             );
             return true;
         }

tests/ui/rc_mutex.stderr

@@ -1,28 +1,35 @@
-error: found `Rc<Mutex<_>>`. Consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
+error: usage of `Rc<Mutex<_>>`
   --> $DIR/rc_mutex.rs:8:10
    |
 LL |     foo: Rc<Mutex<i32>>,
    |          ^^^^^^^^^^^^^^
    |
    = note: `-D clippy::rc-mutex` implied by `-D warnings`
+   = help: consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
 
-error: found `Rc<Mutex<_>>`. Consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
+error: usage of `Rc<Mutex<_>>`
   --> $DIR/rc_mutex.rs:20:22
    |
 LL | pub fn test1<T>(foo: Rc<Mutex<T>>) {}
    |                      ^^^^^^^^^^^^
+   |
+   = help: consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
 
-error: found `Rc<Mutex<_>>`. Consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
+error: usage of `Rc<Mutex<_>>`
   --> $DIR/rc_mutex.rs:22:19
    |
 LL | pub fn test2(foo: Rc<Mutex<MyEnum>>) {}
    |                   ^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
 
-error: found `Rc<Mutex<_>>`. Consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
+error: usage of `Rc<Mutex<_>>`
   --> $DIR/rc_mutex.rs:24:19
    |
 LL | pub fn test3(foo: Rc<Mutex<SubT<usize>>>) {}
    |                   ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `Rc<RefCell<_>>` or `Arc<Mutex<_>>` instead
 
 error: aborting due to 4 previous errors