diff options
| -rw-r--r-- | compiler/rustc_resolve/src/late.rs | 201 |
1 files changed, 105 insertions, 96 deletions
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index f844930ad26..8ab2e99a205 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -2667,119 +2667,128 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> { let mut function_type_rib = Rib::new(kind); let mut function_value_rib = Rib::new(kind); let mut function_lifetime_rib = LifetimeRib::new(lifetime_kind); - let mut seen_bindings = FxHashMap::default(); - // Store all seen lifetimes names from outer scopes. - let mut seen_lifetimes = FxHashSet::default(); - - // We also can't shadow bindings from associated parent items. - for ns in [ValueNS, TypeNS] { - for parent_rib in self.ribs[ns].iter().rev() { - seen_bindings.extend(parent_rib.bindings.keys().map(|ident| (*ident, ident.span))); - - // Break at mod level, to account for nested items which are - // allowed to shadow generic param names. - if matches!(parent_rib.kind, RibKind::Module(..)) { - break; - } - } - } - // Forbid shadowing lifetime bindings - for rib in self.lifetime_ribs.iter().rev() { - seen_lifetimes.extend(rib.bindings.iter().map(|(ident, _)| *ident)); - if let LifetimeRibKind::Item = rib.kind { - break; + // Only check for shadowed bindings if we're declaring new params. + if !params.is_empty() { + let mut seen_bindings = FxHashMap::default(); + // Store all seen lifetimes names from outer scopes. + let mut seen_lifetimes = FxHashSet::default(); + + // We also can't shadow bindings from associated parent items. + for ns in [ValueNS, TypeNS] { + for parent_rib in self.ribs[ns].iter().rev() { + seen_bindings + .extend(parent_rib.bindings.keys().map(|ident| (*ident, ident.span))); + + // Break at mod level, to account for nested items which are + // allowed to shadow generic param names. + if matches!(parent_rib.kind, RibKind::Module(..)) { + break; + } + } } - } - - for param in params { - let ident = param.ident.normalize_to_macros_2_0(); - debug!("with_generic_param_rib: {}", param.id); - if let GenericParamKind::Lifetime = param.kind - && let Some(&original) = seen_lifetimes.get(&ident) - { - diagnostics::signal_lifetime_shadowing(self.r.tcx.sess, original, param.ident); - // Record lifetime res, so lowering knows there is something fishy. - self.record_lifetime_param(param.id, LifetimeRes::Error); - continue; + // Forbid shadowing lifetime bindings + for rib in self.lifetime_ribs.iter().rev() { + seen_lifetimes.extend(rib.bindings.iter().map(|(ident, _)| *ident)); + if let LifetimeRibKind::Item = rib.kind { + break; + } } - match seen_bindings.entry(ident) { - Entry::Occupied(entry) => { - let span = *entry.get(); - let err = ResolutionError::NameAlreadyUsedInParameterList(ident.name, span); - self.report_error(param.ident.span, err); - let rib = match param.kind { - GenericParamKind::Lifetime => { - // Record lifetime res, so lowering knows there is something fishy. - self.record_lifetime_param(param.id, LifetimeRes::Error); - continue; - } - GenericParamKind::Type { .. } => &mut function_type_rib, - GenericParamKind::Const { .. } => &mut function_value_rib, - }; + for param in params { + let ident = param.ident.normalize_to_macros_2_0(); + debug!("with_generic_param_rib: {}", param.id); - // Taint the resolution in case of errors to prevent follow up errors in typeck - self.r.record_partial_res(param.id, PartialRes::new(Res::Err)); - rib.bindings.insert(ident, Res::Err); + if let GenericParamKind::Lifetime = param.kind + && let Some(&original) = seen_lifetimes.get(&ident) + { + diagnostics::signal_lifetime_shadowing(self.r.tcx.sess, original, param.ident); + // Record lifetime res, so lowering knows there is something fishy. + self.record_lifetime_param(param.id, LifetimeRes::Error); continue; } - Entry::Vacant(entry) => { - entry.insert(param.ident.span); - } - } - if param.ident.name == kw::UnderscoreLifetime { - self.r - .dcx() - .emit_err(errors::UnderscoreLifetimeIsReserved { span: param.ident.span }); - // Record lifetime res, so lowering knows there is something fishy. - self.record_lifetime_param(param.id, LifetimeRes::Error); - continue; - } + match seen_bindings.entry(ident) { + Entry::Occupied(entry) => { + let span = *entry.get(); + let err = ResolutionError::NameAlreadyUsedInParameterList(ident.name, span); + self.report_error(param.ident.span, err); + let rib = match param.kind { + GenericParamKind::Lifetime => { + // Record lifetime res, so lowering knows there is something fishy. + self.record_lifetime_param(param.id, LifetimeRes::Error); + continue; + } + GenericParamKind::Type { .. } => &mut function_type_rib, + GenericParamKind::Const { .. } => &mut function_value_rib, + }; - if param.ident.name == kw::StaticLifetime { - self.r.dcx().emit_err(errors::StaticLifetimeIsReserved { - span: param.ident.span, - lifetime: param.ident, - }); - // Record lifetime res, so lowering knows there is something fishy. - self.record_lifetime_param(param.id, LifetimeRes::Error); - continue; - } + // Taint the resolution in case of errors to prevent follow up errors in typeck + self.r.record_partial_res(param.id, PartialRes::new(Res::Err)); + rib.bindings.insert(ident, Res::Err); + continue; + } + Entry::Vacant(entry) => { + entry.insert(param.ident.span); + } + } - let def_id = self.r.local_def_id(param.id); + if param.ident.name == kw::UnderscoreLifetime { + self.r + .dcx() + .emit_err(errors::UnderscoreLifetimeIsReserved { span: param.ident.span }); + // Record lifetime res, so lowering knows there is something fishy. + self.record_lifetime_param(param.id, LifetimeRes::Error); + continue; + } - // Plain insert (no renaming). - let (rib, def_kind) = match param.kind { - GenericParamKind::Type { .. } => (&mut function_type_rib, DefKind::TyParam), - GenericParamKind::Const { .. } => (&mut function_value_rib, DefKind::ConstParam), - GenericParamKind::Lifetime => { - let res = LifetimeRes::Param { param: def_id, binder }; - self.record_lifetime_param(param.id, res); - function_lifetime_rib.bindings.insert(ident, (param.id, res)); + if param.ident.name == kw::StaticLifetime { + self.r.dcx().emit_err(errors::StaticLifetimeIsReserved { + span: param.ident.span, + lifetime: param.ident, + }); + // Record lifetime res, so lowering knows there is something fishy. + self.record_lifetime_param(param.id, LifetimeRes::Error); continue; } - }; - let res = match kind { - RibKind::Item(..) | RibKind::AssocItem => Res::Def(def_kind, def_id.to_def_id()), - RibKind::Normal => { - // FIXME(non_lifetime_binders): Stop special-casing - // const params to error out here. - if self.r.tcx.features().non_lifetime_binders - && matches!(param.kind, GenericParamKind::Type { .. }) - { + let def_id = self.r.local_def_id(param.id); + + // Plain insert (no renaming). + let (rib, def_kind) = match param.kind { + GenericParamKind::Type { .. } => (&mut function_type_rib, DefKind::TyParam), + GenericParamKind::Const { .. } => { + (&mut function_value_rib, DefKind::ConstParam) + } + GenericParamKind::Lifetime => { + let res = LifetimeRes::Param { param: def_id, binder }; + self.record_lifetime_param(param.id, res); + function_lifetime_rib.bindings.insert(ident, (param.id, res)); + continue; + } + }; + + let res = match kind { + RibKind::Item(..) | RibKind::AssocItem => { Res::Def(def_kind, def_id.to_def_id()) - } else { - Res::Err } - } - _ => span_bug!(param.ident.span, "Unexpected rib kind {:?}", kind), - }; - self.r.record_partial_res(param.id, PartialRes::new(res)); - rib.bindings.insert(ident, res); + RibKind::Normal => { + // FIXME(non_lifetime_binders): Stop special-casing + // const params to error out here. + if self.r.tcx.features().non_lifetime_binders + && matches!(param.kind, GenericParamKind::Type { .. }) + { + Res::Def(def_kind, def_id.to_def_id()) + } else { + Res::Err + } + } + _ => span_bug!(param.ident.span, "Unexpected rib kind {:?}", kind), + }; + self.r.record_partial_res(param.id, PartialRes::new(res)); + rib.bindings.insert(ident, res); + } } self.lifetime_ribs.push(function_lifetime_rib); |