1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::{expr_custom_deref_adjustment, ty::is_type_diagnostic_item};
3 use if_chain::if_chain;
4 use rustc_errors::Applicability;
5 use rustc_hir::{Expr, Mutability};
6 use rustc_lint::LateContext;
8 use rustc_span::{sym, Span};
10 use super::MUT_MUTEX_LOCK;
12 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, ex: &'tcx Expr<'tcx>, recv: &'tcx Expr<'tcx>, name_span: Span) {
14 if matches!(expr_custom_deref_adjustment(cx, recv), None | Some(Mutability::Mut));
15 if let ty::Ref(_, _, Mutability::Mut) = cx.typeck_results().expr_ty(recv).kind();
16 if let Some(method_id) = cx.typeck_results().type_dependent_def_id(ex.hir_id);
17 if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
18 if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id), sym::Mutex);
24 "calling `&mut Mutex::lock` unnecessarily locks an exclusive (mutable) reference",
27 Applicability::MaybeIncorrect,