diff --git a/clippy_lints/src/future_not_send.rs b/clippy_lints/src/future_not_send.rs index 3ccfa51ab70b..596047977a9b 100644 --- a/clippy_lints/src/future_not_send.rs +++ b/clippy_lints/src/future_not_send.rs @@ -78,66 +78,65 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend { if let ty::Alias(ty::Opaque, AliasTy { def_id, args, .. }) = *ret_ty.kind() && let Some(future_trait) = cx.tcx.lang_items().future_trait() && let Some(send_trait) = cx.tcx.get_diagnostic_item(sym::Send) + && let preds = cx.tcx.explicit_item_self_bounds(def_id) + // If is a Future + && preds + .iter_instantiated_copied(cx.tcx, args) + .filter_map(|(p, _)| p.as_trait_clause()) + .any(|trait_pred| trait_pred.skip_binder().trait_ref.def_id == future_trait) { - let preds = cx.tcx.explicit_item_self_bounds(def_id); - let is_future = preds.iter_instantiated_copied(cx.tcx, args).any(|(p, _)| { - p.as_trait_clause() - .is_some_and(|trait_pred| trait_pred.skip_binder().trait_ref.def_id == future_trait) - }); - if is_future { - let span = decl.output.span(); - let infcx = cx.tcx.infer_ctxt().build(cx.typing_mode()); - let ocx = ObligationCtxt::new_with_diagnostics(&infcx); - let cause = traits::ObligationCause::misc(span, fn_def_id); - ocx.register_bound(cause, cx.param_env, ret_ty, send_trait); - let send_errors = ocx.select_all_or_error(); + let span = decl.output.span(); + let infcx = cx.tcx.infer_ctxt().build(cx.typing_mode()); + let ocx = ObligationCtxt::new_with_diagnostics(&infcx); + let cause = traits::ObligationCause::misc(span, fn_def_id); + ocx.register_bound(cause, cx.param_env, ret_ty, send_trait); + let send_errors = ocx.select_all_or_error(); - // Allow errors that try to prove `Send` for types that "mention" a generic parameter at the "top - // level". - // For example, allow errors that `T: Send` can't be proven, but reject `Rc: Send` errors, - // which is always unconditionally `!Send` for any possible type `T`. - // - // We also allow associated type projections if the self type is either itself a projection or a - // type parameter. - // This is to prevent emitting warnings for e.g. holding a `::Output` across await - // points, where `Fut` is a type parameter. + // Allow errors that try to prove `Send` for types that "mention" a generic parameter at the "top + // level". + // For example, allow errors that `T: Send` can't be proven, but reject `Rc: Send` errors, + // which is always unconditionally `!Send` for any possible type `T`. + // + // We also allow associated type projections if the self type is either itself a projection or a + // type parameter. + // This is to prevent emitting warnings for e.g. holding a `::Output` across await + // points, where `Fut` is a type parameter. - let is_send = send_errors.iter().all(|err| { - err.obligation - .predicate - .as_trait_clause() - .map(Binder::skip_binder) - .is_some_and(|pred| { - pred.def_id() == send_trait - && pred.self_ty().has_param() - && TyParamAtTopLevelVisitor.visit_ty(pred.self_ty()) == ControlFlow::Break(true) - }) - }); + let is_send = send_errors.iter().all(|err| { + err.obligation + .predicate + .as_trait_clause() + .map(Binder::skip_binder) + .is_some_and(|pred| { + pred.def_id() == send_trait + && pred.self_ty().has_param() + && TyParamAtTopLevelVisitor.visit_ty(pred.self_ty()) == ControlFlow::Break(true) + }) + }); - if !is_send { - span_lint_and_then( - cx, - FUTURE_NOT_SEND, - span, - "future cannot be sent between threads safely", - |db| { - for FulfillmentError { obligation, .. } in send_errors { - infcx - .err_ctxt() - .maybe_note_obligation_cause_for_async_await(db, &obligation); - if let PredicateKind::Clause(ClauseKind::Trait(trait_pred)) = - obligation.predicate.kind().skip_binder() - { - db.note(format!( - "`{}` doesn't implement `{}`", - trait_pred.self_ty(), - trait_pred.trait_ref.print_only_trait_path(), - )); - } + if !is_send { + span_lint_and_then( + cx, + FUTURE_NOT_SEND, + span, + "future cannot be sent between threads safely", + |db| { + for FulfillmentError { obligation, .. } in send_errors { + infcx + .err_ctxt() + .maybe_note_obligation_cause_for_async_await(db, &obligation); + if let PredicateKind::Clause(ClauseKind::Trait(trait_pred)) = + obligation.predicate.kind().skip_binder() + { + db.note(format!( + "`{}` doesn't implement `{}`", + trait_pred.self_ty(), + trait_pred.trait_ref.print_only_trait_path(), + )); } - }, - ); - } + } + }, + ); } } }