rustup https://github.com/rust-lang/rust/pull/67455

[rust.git] / clippy_lints / src / needless_borrowed_ref.rs

diff --git a/clippy_lints/src/needless_borrowed_ref.rs b/clippy_lints/src/needless_borrowed_ref.rs
index 714c746f68d6b2240e9cc921b6a2ee1ac0e0971e..845e5d6425708bea048545dc21b66f15daf9b92c 100644 (file)
--- a/clippy_lints/src/needless_borrowed_ref.rs
+++ b/clippy_lints/src/needless_borrowed_ref.rs
@@ -2,12 +2,13 @@
 //!
 //! This lint is **warn** by default
 
-use crate::utils::{snippet, span_lint_and_then};
+use crate::utils::{snippet_with_applicability, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::hir::{BindingAnnotation, MutImmutable, Pat, PatKind};
+use rustc::declare_lint_pass;
+use rustc::hir::{BindingAnnotation, Mutability, Node, Pat, PatKind};
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
 use rustc_errors::Applicability;
+use rustc_session::declare_tool_lint;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for useless borrowed references.
@@ -61,20 +62,29 @@ fn check_pat(&mut self, cx: &LateContext<'a, 'tcx>, pat: &'tcx Pat) {
 
         if_chain! {
             // Only lint immutable refs, because `&mut ref T` may be useful.
-            if let PatKind::Ref(ref sub_pat, MutImmutable) = pat.node;
+            if let PatKind::Ref(ref sub_pat, Mutability::Immutable) = pat.kind;
 
             // Check sub_pat got a `ref` keyword (excluding `ref mut`).
-            if let PatKind::Binding(BindingAnnotation::Ref, .., spanned_name, _) = sub_pat.node;
+            if let PatKind::Binding(BindingAnnotation::Ref, .., spanned_name, _) = sub_pat.kind;
+            let parent_id = cx.tcx.hir().get_parent_node(pat.hir_id);
+            if let Some(parent_node) = cx.tcx.hir().find(parent_id);
             then {
+                // do not recurse within patterns, as they may have other references
+                // XXXManishearth we can relax this constraint if we only check patterns
+                // with a single ref pattern inside them
+                if let Node::Pat(_) = parent_node {
+                    return;
+                }
+                let mut applicability = Applicability::MachineApplicable;
                 span_lint_and_then(cx, NEEDLESS_BORROWED_REFERENCE, pat.span,
                                    "this pattern takes a reference on something that is being de-referenced",
                                    |db| {
-                                       let hint = snippet(cx, spanned_name.span, "..").into_owned();
+                                       let hint = snippet_with_applicability(cx, spanned_name.span, "..", &mut applicability).into_owned();
                                        db.span_suggestion(
                                            pat.span,
                                            "try removing the `&ref` part and just keep",
                                            hint,
-                                           Applicability::MachineApplicable, // snippet
+                                           applicability,
                                        );
                                    });
             }