diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs')
-rw-r--r-- | compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs | 95 |
1 files changed, 54 insertions, 41 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index c969e5d4975..595f6e0b927 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -1583,55 +1583,68 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } fn suggest_remove_await(&self, obligation: &PredicateObligation<'tcx>, err: &mut Diagnostic) { - let span = obligation.cause.span; - - if let ObligationCauseCode::AwaitableExpr(hir_id) = obligation.cause.code().peel_derives() { - let hir = self.tcx.hir(); - if let Some(hir::Node::Expr(expr)) = hir_id.and_then(|hir_id| hir.find(hir_id)) { - // FIXME: use `obligation.predicate.kind()...trait_ref.self_ty()` to see if we have `()` - // and if not maybe suggest doing something else? If we kept the expression around we - // could also check if it is an fn call (very likely) and suggest changing *that*, if - // it is from the local crate. + let hir = self.tcx.hir(); + if let ObligationCauseCode::AwaitableExpr(Some(hir_id)) = obligation.cause.code().peel_derives() + && let hir::Node::Expr(expr) = hir.get(*hir_id) + { + // FIXME: use `obligation.predicate.kind()...trait_ref.self_ty()` to see if we have `()` + // and if not maybe suggest doing something else? If we kept the expression around we + // could also check if it is an fn call (very likely) and suggest changing *that*, if + // it is from the local crate. + + // use nth(1) to skip one layer of desugaring from `IntoIter::into_iter` + if let Some((_, hir::Node::Expr(await_expr))) = hir.parent_iter(*hir_id).nth(1) + && let Some(expr_span) = expr.span.find_ancestor_inside(await_expr.span) + { + let removal_span = self.tcx + .sess + .source_map() + .span_extend_while(expr_span, char::is_whitespace) + .unwrap_or(expr_span) + .shrink_to_hi() + .to(await_expr.span.shrink_to_hi()); err.span_suggestion( - span, + removal_span, "remove the `.await`", "", Applicability::MachineApplicable, ); - // FIXME: account for associated `async fn`s. - if let hir::Expr { span, kind: hir::ExprKind::Call(base, _), .. } = expr { - if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = - obligation.predicate.kind().skip_binder() + } else { + err.span_label(obligation.cause.span, "remove the `.await`"); + } + // FIXME: account for associated `async fn`s. + if let hir::Expr { span, kind: hir::ExprKind::Call(base, _), .. } = expr { + if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = + obligation.predicate.kind().skip_binder() + { + err.span_label(*span, &format!("this call returns `{}`", pred.self_ty())); + } + if let Some(typeck_results) = &self.typeck_results + && let ty = typeck_results.expr_ty_adjusted(base) + && let ty::FnDef(def_id, _substs) = ty.kind() + && let Some(hir::Node::Item(hir::Item { ident, span, vis_span, .. })) = + hir.get_if_local(*def_id) { - err.span_label(*span, &format!("this call returns `{}`", pred.self_ty())); - } - if let Some(typeck_results) = &self.typeck_results - && let ty = typeck_results.expr_ty_adjusted(base) - && let ty::FnDef(def_id, _substs) = ty.kind() - && let Some(hir::Node::Item(hir::Item { ident, span, vis_span, .. })) = - hir.get_if_local(*def_id) - { - let msg = format!( - "alternatively, consider making `fn {}` asynchronous", - ident + let msg = format!( + "alternatively, consider making `fn {}` asynchronous", + ident + ); + if vis_span.is_empty() { + err.span_suggestion_verbose( + span.shrink_to_lo(), + &msg, + "async ", + Applicability::MaybeIncorrect, + ); + } else { + err.span_suggestion_verbose( + vis_span.shrink_to_hi(), + &msg, + " async", + Applicability::MaybeIncorrect, ); - if vis_span.is_empty() { - err.span_suggestion_verbose( - span.shrink_to_lo(), - &msg, - "async ", - Applicability::MaybeIncorrect, - ); - } else { - err.span_suggestion_verbose( - vis_span.shrink_to_hi(), - &msg, - " async", - Applicability::MaybeIncorrect, - ); - } } - } + } } } } |