X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fneedless_borrow.rs;h=3adbbfb8e89647b0ef43062f5ef37b9ef38ce03f;hb=6e03a306ac44c6670064c68197df8813fe1cac06;hp=b71d5496a37a3e27b610ac5da97cf01279f0fe13;hpb=23646e658326503720742c556d73230a4e96f0bf;p=rust.git

diff --git a/clippy_lints/src/needless_borrow.rs b/clippy_lints/src/needless_borrow.rs
index b71d5496a37..3adbbfb8e89 100644
--- a/clippy_lints/src/needless_borrow.rs
+++ b/clippy_lints/src/needless_borrow.rs
@@ -2,10 +2,11 @@
 //!
 //! This lint is **warn** by default
 
-use crate::utils::{snippet_opt, span_lint_and_then};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::snippet_opt;
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, HirId, Item, Mutability, Pat, PatKind};
+use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, Mutability, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment};
@@ -34,19 +35,17 @@
 }
 
 #[derive(Default)]
-pub struct NeedlessBorrow {
-    derived_item: Option<HirId>,
-}
+pub struct NeedlessBorrow;
 
 impl_lint_pass!(NeedlessBorrow => [NEEDLESS_BORROW]);
 
 impl<'tcx> LateLintPass<'tcx> for NeedlessBorrow {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
-        if e.span.from_expansion() || self.derived_item.is_some() {
+        if e.span.from_expansion() {
             return;
         }
-        if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, ref inner) = e.kind {
-            if let ty::Ref(..) = cx.typeck_results().expr_ty(inner).kind() {
+        if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, inner) = e.kind {
+            if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty(inner).kind() {
                 for adj3 in cx.typeck_results().expr_adjustments(e).windows(3) {
                     if let [Adjustment {
                         kind: Adjust::Deref(_), ..
@@ -61,8 +60,11 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
                             cx,
                             NEEDLESS_BORROW,
                             e.span,
-                            "this expression borrows a reference that is immediately dereferenced \
+                            &format!(
+                                "this expression borrows a reference (`&{}`) that is immediately dereferenced \
                              by the compiler",
+                                ty
+                            ),
                             |diag| {
                                 if let Some(snippet) = snippet_opt(cx, inner.span) {
                                     diag.span_suggestion(
@@ -80,7 +82,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         }
     }
     fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
-        if pat.span.from_expansion() || self.derived_item.is_some() {
+        if pat.span.from_expansion() {
             return;
         }
         if_chain! {
@@ -110,19 +112,4 @@ fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
             }
         }
     }
-
-    fn check_item(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if item.attrs.iter().any(|a| a.has_name(sym!(automatically_derived))) {
-            debug_assert!(self.derived_item.is_none());
-            self.derived_item = Some(item.hir_id);
-        }
-    }
-
-    fn check_item_post(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let Some(id) = self.derived_item {
-            if item.hir_id == id {
-                self.derived_item = None;
-            }
-        }
-    }
 }