use crate::utils::span_lint;
-use rustc::declare_lint_pass;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::ty::subst::Subst;
-use rustc::ty::{self, Ty};
-use rustc_session::declare_tool_lint;
+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,
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>, arguments: &[Expr], type_definition: Ty<'tcx>, name: &str) {
- match type_definition.kind {
+fn check_arguments<'tcx>(
+ cx: &LateContext<'tcx>,
+ arguments: &[Expr<'_>],
+ type_definition: Ty<'tcx>,
+ name: &str,
+ fn_kind: &str,
+) {
+ 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 {
- ty::Ref(_, _, Mutability::Immutable)
+ match parameter.kind() {
+ ty::Ref(_, _, Mutability::Not)
| ty::RawPtr(ty::TypeAndMut {
- mutbl: Mutability::Immutable,
- ..
+ mutbl: Mutability::Not, ..
}) => {
- if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mutable, _) = argument.kind {
+ if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Mut, _) = argument.kind {
span_lint(
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),
);
}
},