rust/clippy_lints/src/methods/waker_clone_wake.rs
2024-09-24 11:58:04 +02:00

32 lines
1.1 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::is_trait_method;
use clippy_utils::source::snippet_with_applicability;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::LateContext;
use rustc_span::sym;
use super::WAKER_CLONE_WAKE;
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, recv: &'tcx Expr<'_>) {
let ty = cx.typeck_results().expr_ty(recv);
if let Some(did) = ty.ty_adt_def()
&& cx.tcx.is_diagnostic_item(sym::Waker, did.did())
&& let ExprKind::MethodCall(_, waker_ref, &[], _) = recv.kind
&& is_trait_method(cx, recv, sym::Clone)
{
let mut applicability = Applicability::MachineApplicable;
let snippet = snippet_with_applicability(cx, waker_ref.span.source_callsite(), "..", &mut applicability);
span_lint_and_sugg(
cx,
WAKER_CLONE_WAKE,
expr.span,
"cloning a `Waker` only to wake it",
"replace with",
format!("{snippet}.wake_by_ref()"),
applicability,
);
}
}