diff options
| -rw-r--r-- | compiler/rustc_passes/src/check_const.rs | 122 |
1 files changed, 54 insertions, 68 deletions
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs index 15e24299075..e0922d41937 100644 --- a/compiler/rustc_passes/src/check_const.rs +++ b/compiler/rustc_passes/src/check_const.rs @@ -10,6 +10,7 @@ use rustc_attr as attr; use rustc_errors::struct_span_err; use rustc_hir as hir; +use rustc_hir::def::DefKind; use rustc_hir::def_id::LocalDefId; use rustc_hir::intravisit::{self, Visitor}; use rustc_middle::hir::nested_filter; @@ -58,88 +59,73 @@ impl NonConstExpr { fn check_mod_const_bodies(tcx: TyCtxt<'_>, module_def_id: LocalDefId) { let mut vis = CheckConstVisitor::new(tcx); tcx.hir().visit_item_likes_in_module(module_def_id, &mut vis.as_deep_visitor()); - tcx.hir().visit_item_likes_in_module(module_def_id, &mut CheckConstTraitVisitor::new(tcx)); + for id in tcx.hir_module_items(module_def_id).items() { + check_item(tcx, id); + } } pub(crate) fn provide(providers: &mut Providers) { *providers = Providers { check_mod_const_bodies, ..*providers }; } -struct CheckConstTraitVisitor<'tcx> { - tcx: TyCtxt<'tcx>, -} +fn check_item<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) { + let _: Option<_> = try { + if !matches!(tcx.hir().def_kind(id.def_id), DefKind::Impl) { + None? + } -impl<'tcx> CheckConstTraitVisitor<'tcx> { - fn new(tcx: TyCtxt<'tcx>) -> Self { - CheckConstTraitVisitor { tcx } - } -} + let item = tcx.hir().item(id); + if let hir::ItemKind::Impl(ref imp) = item.kind && let hir::Constness::Const = imp.constness { + let trait_def_id = imp.of_trait.as_ref()?.trait_def_id()?; + let ancestors = tcx + .trait_def(trait_def_id) + .ancestors(tcx, item.def_id.to_def_id()) + .ok()?; + let mut to_implement = Vec::new(); -impl<'tcx> hir::itemlikevisit::ItemLikeVisitor<'tcx> for CheckConstTraitVisitor<'tcx> { - /// check for const trait impls, and errors if the impl uses provided/default functions - /// of the trait being implemented; as those provided functions can be non-const. - fn visit_item<'hir>(&mut self, item: &'hir hir::Item<'hir>) { - let _: Option<_> = try { - if let hir::ItemKind::Impl(ref imp) = item.kind && let hir::Constness::Const = imp.constness { - let trait_def_id = imp.of_trait.as_ref()?.trait_def_id()?; - let ancestors = self - .tcx - .trait_def(trait_def_id) - .ancestors(self.tcx, item.def_id.to_def_id()) - .ok()?; - let mut to_implement = Vec::new(); - - for trait_item in self.tcx.associated_items(trait_def_id).in_definition_order() + for trait_item in tcx.associated_items(trait_def_id).in_definition_order() + { + if let ty::AssocItem { + kind: ty::AssocKind::Fn, + defaultness, + def_id: trait_item_id, + .. + } = *trait_item + { + // we can ignore functions that do not have default bodies: + // if those are unimplemented it will be caught by typeck. + if !defaultness.has_value() + || tcx + .has_attr(trait_item_id, sym::default_method_body_is_const) { - if let ty::AssocItem { - kind: ty::AssocKind::Fn, - defaultness, - def_id: trait_item_id, - .. - } = *trait_item - { - // we can ignore functions that do not have default bodies: - // if those are unimplemented it will be caught by typeck. - if !defaultness.has_value() - || self - .tcx - .has_attr(trait_item_id, sym::default_method_body_is_const) - { - continue; - } - - let is_implemented = ancestors - .leaf_def(self.tcx, trait_item_id) - .map(|node_item| !node_item.defining_node.is_from_trait()) - .unwrap_or(false); - - if !is_implemented { - to_implement.push(self.tcx.item_name(trait_item_id).to_string()); - } - } + continue; } - // all nonconst trait functions (not marked with #[default_method_body_is_const]) - // must be implemented - if !to_implement.is_empty() { - self.tcx - .sess - .struct_span_err( - item.span, - "const trait implementations may not use non-const default functions", - ) - .note(&format!("`{}` not implemented", to_implement.join("`, `"))) - .emit(); + let is_implemented = ancestors + .leaf_def(tcx, trait_item_id) + .map(|node_item| !node_item.defining_node.is_from_trait()) + .unwrap_or(false); + + if !is_implemented { + to_implement.push(tcx.item_name(trait_item_id).to_string()); } + } } - }; - } - fn visit_trait_item<'hir>(&mut self, _: &'hir hir::TraitItem<'hir>) {} - - fn visit_impl_item<'hir>(&mut self, _: &'hir hir::ImplItem<'hir>) {} - - fn visit_foreign_item<'hir>(&mut self, _: &'hir hir::ForeignItem<'hir>) {} + // all nonconst trait functions (not marked with #[default_method_body_is_const]) + // must be implemented + if !to_implement.is_empty() { + tcx + .sess + .struct_span_err( + item.span, + "const trait implementations may not use non-const default functions", + ) + .note(&format!("`{}` not implemented", to_implement.join("`, `"))) + .emit(); + } + } + }; } #[derive(Copy, Clone)] |