diff options
| -rw-r--r-- | src/librustc/traits/error_reporting.rs | 78 |
1 files changed, 45 insertions, 33 deletions
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs index b1652f58772..18f083e154a 100644 --- a/src/librustc/traits/error_reporting.rs +++ b/src/librustc/traits/error_reporting.rs @@ -1244,6 +1244,42 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { Obligation::new(cause, param_env, new_trait_ref.to_predicate()) } + /// Given a closure's `DefId`, return the given name of the closure. + /// + /// This doesn't account for reassignments, but it's only used for suggestions. + fn get_closure_name( + &self, + def_id: DefId, + err: &mut DiagnosticBuilder<'_>, + msg: &str, + ) -> Option<String> { + let get_name = |err: &mut DiagnosticBuilder<'_>, kind: &hir::PatKind| -> Option<String> { + // Get the local name of this closure. This can be inaccurate because + // of the possibility of reassignment, but this should be good enough. + match &kind { + hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, name, None) => { + Some(format!("{}", name)) + } + _ => { + err.note(&msg); + None + } + } + }; + + let hir = self.tcx.hir(); + let hir_id = hir.as_local_hir_id(def_id)?; + let parent_node = hir.get_parent_node(hir_id); + match hir.find(parent_node) { + Some(hir::Node::Stmt(hir::Stmt { + kind: hir::StmtKind::Local(local), .. + })) => get_name(err, &local.pat.kind), + // Different to previous arm because one is `&hir::Local` and the other + // is `P<hir::Local>`. + Some(hir::Node::Local(local)) => get_name(err, &local.pat.kind), + _ => return None, + } + } /// We tried to apply the bound to an `fn` or closure. Check whether calling it would /// evaluate to a type that *would* satisfy the trait binding. If it would, suggest calling @@ -1274,19 +1310,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { obligation.param_env, ); - let get_name = |err: &mut DiagnosticBuilder<'_>, kind: &hir::PatKind| -> Option<String> { - // Get the local name of this closure. This can be inaccurate because - // of the possibility of reassignment, but this should be good enough. - match &kind { - hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, name, None) => { - Some(format!("{}", name)) - } - _ => { - err.note(&msg); - None - } - } - }; match self.evaluate_obligation(&obligation) { Ok(EvaluationResult::EvaluatedToOk) | Ok(EvaluationResult::EvaluatedToOkModuloRegions) | @@ -1301,29 +1324,14 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { .. })) => { err.span_label(*span, "consider calling this closure"); - let hir_id = match hir.as_local_hir_id(def_id) { - Some(hir_id) => hir_id, + let name = match self.get_closure_name(def_id, err, &msg) { + Some(name) => name, None => return, }; - let parent_node = hir.get_parent_node(hir_id); - let name = match hir.find(parent_node) { - Some(hir::Node::Stmt(hir::Stmt { - kind: hir::StmtKind::Local(local), .. - })) => match get_name(err, &local.pat.kind) { - Some(name) => name, - None => return, - }, - // Different to previous arm because one is `&hir::Local` and the other - // is `P<hir::Local>`. - Some(hir::Node::Local(local)) => match get_name(err, &local.pat.kind) { - Some(name) => name, - None => return, - }, - _ => return, - }; let args = decl.inputs.iter() .map(|_| "_") - .collect::<Vec<_>>().join(", "); + .collect::<Vec<_>>() + .join(", "); format!("{}({})", name, args) } Some(hir::Node::Item(hir::Item { @@ -1336,9 +1344,13 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { let args = body.params.iter() .map(|arg| match &arg.pat.kind { hir::PatKind::Binding(_, _, ident, None) + // FIXME: provide a better suggestion when encountering `SelfLower`, it + // should suggest a method call. if ident.name != kw::SelfLower => ident.to_string(), _ => "_".to_string(), - }).collect::<Vec<_>>().join(", "); + }) + .collect::<Vec<_>>() + .join(", "); format!("{}({})", ident, args) } _ => return, |