Merge commit '4911ab124c481430672a3833b37075e6435ec34d' into clippyup

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

diff --git a/clippy_lints/src/mut_reference.rs b/clippy_lints/src/mut_reference.rs
index 2d70b65bb1ee597a76816c6f2cd4184802dee019..3f0b765df1561dc9543984506ea475dca498299a 100644 (file)
--- a/clippy_lints/src/mut_reference.rs
+++ b/clippy_lints/src/mut_reference.rs
@@ -1,22 +1,26 @@
 use crate::utils::span_lint;
-use rustc::ty::subst::Subst;
-use rustc::ty::{self, Ty};
-use rustc_hir::*;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::subst::Subst;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
-    /// **What it does:** Detects giving a mutable reference to a function that only
+    /// **What it does:** Detects passing a mutable reference to a function that only
     /// requires an immutable reference.
     ///
-    /// **Why is this bad?** The immutable reference rules out all other references
-    /// to the value. Also the code misleads about the intent of the call site.
+    /// **Why is this bad?** The mutable reference rules out all other references to
+    /// the value. Also the code misleads about the intent of the call site.
     ///
     /// **Known problems:** None.
     ///
     /// **Example:**
     /// ```ignore
+    /// // Bad
     /// my_vec.push(&mut value)
+    ///
+    /// // Good
+    /// my_vec.push(&value)
     /// ```
     pub UNNECESSARY_MUT_PASSED,
     style,
@@ -25,41 +29,43 @@
 
 declare_lint_pass!(UnnecessaryMutPassed => [UNNECESSARY_MUT_PASSED]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnecessaryMutPassed {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for UnnecessaryMutPassed {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         match e.kind {
             ExprKind::Call(ref fn_expr, ref arguments) => {
                 if let ExprKind::Path(ref path) = fn_expr.kind {
                     check_arguments(
                         cx,
                         arguments,
-                        cx.tables.expr_ty(fn_expr),
-                        &print::to_string(print::NO_ANN, |s| s.print_qpath(path, false)),
+                        cx.typeck_results().expr_ty(fn_expr),
+                        &rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false)),
+                        "function",
                     );
                 }
             },
-            ExprKind::MethodCall(ref path, _, ref arguments) => {
-                let def_id = cx.tables.type_dependent_def_id(e.hir_id).unwrap();
-                let substs = cx.tables.node_substs(e.hir_id);
+            ExprKind::MethodCall(ref path, _, ref arguments, _) => {
+                let def_id = cx.typeck_results().type_dependent_def_id(e.hir_id).unwrap();
+                let substs = cx.typeck_results().node_substs(e.hir_id);
                 let method_type = cx.tcx.type_of(def_id).subst(cx.tcx, substs);
-                check_arguments(cx, arguments, method_type, &path.ident.as_str())
+                check_arguments(cx, arguments, method_type, &path.ident.as_str(), "method")
             },
             _ => (),
         }
     }
 }
 
-fn check_arguments<'a, 'tcx>(
-    cx: &LateContext<'a, 'tcx>,
+fn check_arguments<'tcx>(
+    cx: &LateContext<'tcx>,
     arguments: &[Expr<'_>],
     type_definition: Ty<'tcx>,
     name: &str,
+    fn_kind: &str,
 ) {
-    match type_definition.kind {
+    match type_definition.kind() {
         ty::FnDef(..) | ty::FnPtr(_) => {
             let parameters = type_definition.fn_sig(cx.tcx).skip_binder().inputs();
             for (argument, parameter) in arguments.iter().zip(parameters.iter()) {
-                match parameter.kind {
+                match parameter.kind() {
                     ty::Ref(_, _, Mutability::Not)
                     | ty::RawPtr(ty::TypeAndMut {
                         mutbl: Mutability::Not, ..
@@ -69,7 +75,7 @@ fn check_arguments<'a, 'tcx>(
                                 cx,
                                 UNNECESSARY_MUT_PASSED,
                                 argument.span,
-                                &format!("The function/method `{}` doesn't need a mutable reference", name),
+                                &format!("the {} `{}` doesn't need a mutable reference", fn_kind, name),
                             );
                         }
                     },