| use clippy_utils::diagnostics::span_lint_and_sugg; |
| use clippy_utils::expr_custom_deref_adjustment; |
| use clippy_utils::ty::is_type_diagnostic_item; |
| use if_chain::if_chain; |
| use rustc_errors::Applicability; |
| use rustc_hir::{Expr, Mutability}; |
| use rustc_lint::LateContext; |
| use rustc_middle::ty; |
| use rustc_span::{sym, Span}; |
| |
| use super::MUT_MUTEX_LOCK; |
| |
| pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, ex: &'tcx Expr<'tcx>, recv: &'tcx Expr<'tcx>, name_span: Span) { |
| if_chain! { |
| if matches!(expr_custom_deref_adjustment(cx, recv), None | Some(Mutability::Mut)); |
| if let ty::Ref(_, _, Mutability::Mut) = cx.typeck_results().expr_ty(recv).kind(); |
| if let Some(method_id) = cx.typeck_results().type_dependent_def_id(ex.hir_id); |
| if let Some(impl_id) = cx.tcx.impl_of_method(method_id); |
| if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Mutex); |
| then { |
| span_lint_and_sugg( |
| cx, |
| MUT_MUTEX_LOCK, |
| name_span, |
| "calling `&mut Mutex::lock` unnecessarily locks an exclusive (mutable) reference", |
| "change this to", |
| "get_mut".to_owned(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| } |
| } |