diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs index 9b7826a5b2d..632ab3120d0 100644 --- a/compiler/rustc_hir_analysis/src/collect.rs +++ b/compiler/rustc_hir_analysis/src/collect.rs @@ -18,7 +18,9 @@ use rustc_ast::Recovered; use rustc_data_structures::captures::Captures; use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_data_structures::unord::UnordMap; -use rustc_errors::{struct_span_code_err, Applicability, Diag, ErrorGuaranteed, StashKey, E0228}; +use rustc_errors::{ + struct_span_code_err, Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, StashKey, E0228, +}; use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{self, walk_generics, Visitor}; @@ -161,7 +163,7 @@ pub struct CollectItemTypesVisitor<'tcx> { /// and suggest adding type parameters in the appropriate place, taking into consideration any and /// all already existing generic type parameters to avoid suggesting a name that is already in use. pub(crate) fn placeholder_type_error<'tcx>( - tcx: TyCtxt<'tcx>, + cx: &dyn HirTyLowerer<'tcx>, generics: Option<&hir::Generics<'_>>, placeholder_types: Vec, suggest: bool, @@ -172,21 +174,21 @@ pub(crate) fn placeholder_type_error<'tcx>( return; } - placeholder_type_error_diag(tcx, generics, placeholder_types, vec![], suggest, hir_ty, kind) + placeholder_type_error_diag(cx, generics, placeholder_types, vec![], suggest, hir_ty, kind) .emit(); } -pub(crate) fn placeholder_type_error_diag<'tcx>( - tcx: TyCtxt<'tcx>, +pub(crate) fn placeholder_type_error_diag<'cx, 'tcx>( + cx: &'cx dyn HirTyLowerer<'tcx>, generics: Option<&hir::Generics<'_>>, placeholder_types: Vec, additional_spans: Vec, suggest: bool, hir_ty: Option<&hir::Ty<'_>>, kind: &'static str, -) -> Diag<'tcx> { +) -> Diag<'cx> { if placeholder_types.is_empty() { - return bad_placeholder(tcx, additional_spans, kind); + return bad_placeholder(cx, additional_spans, kind); } let params = generics.map(|g| g.params).unwrap_or_default(); @@ -210,7 +212,7 @@ pub(crate) fn placeholder_type_error_diag<'tcx>( } let mut err = - bad_placeholder(tcx, placeholder_types.into_iter().chain(additional_spans).collect(), kind); + bad_placeholder(cx, placeholder_types.into_iter().chain(additional_spans).collect(), kind); // Suggest, but only if it is not a function in const or static if suggest { @@ -224,7 +226,7 @@ pub(crate) fn placeholder_type_error_diag<'tcx>( // Check if parent is const or static is_const_or_static = matches!( - tcx.parent_hir_node(hir_ty.hir_id), + cx.tcx().parent_hir_node(hir_ty.hir_id), Node::Item(&hir::Item { kind: hir::ItemKind::Const(..) | hir::ItemKind::Static(..), .. @@ -267,7 +269,16 @@ fn reject_placeholder_type_signatures_in_item<'tcx>( let mut visitor = HirPlaceholderCollector::default(); visitor.visit_item(item); - placeholder_type_error(tcx, Some(generics), visitor.0, suggest, None, item.kind.descr()); + let icx = ItemCtxt::new(tcx, item.owner_id.def_id); + + placeholder_type_error( + icx.lowerer(), + Some(generics), + visitor.0, + suggest, + None, + item.kind.descr(), + ); } impl<'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'tcx> { @@ -329,15 +340,15 @@ impl<'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'tcx> { /////////////////////////////////////////////////////////////////////////// // Utility types and common code for the above passes. -fn bad_placeholder<'tcx>( - tcx: TyCtxt<'tcx>, +fn bad_placeholder<'cx, 'tcx>( + cx: &'cx dyn HirTyLowerer<'tcx>, mut spans: Vec, kind: &'static str, -) -> Diag<'tcx> { +) -> Diag<'cx> { let kind = if kind.ends_with('s') { format!("{kind}es") } else { format!("{kind}s") }; spans.sort(); - tcx.dcx().create_err(errors::PlaceholderNotAllowedItemSignatures { spans, kind }) + cx.dcx().create_err(errors::PlaceholderNotAllowedItemSignatures { spans, kind }) } impl<'tcx> ItemCtxt<'tcx> { @@ -370,6 +381,10 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> { self.tcx } + fn dcx(&self) -> DiagCtxtHandle<'_> { + self.tcx.dcx().taintable_handle(&self.tainted_by_errors) + } + fn item_def_id(&self) -> LocalDefId { self.item_def_id } @@ -377,14 +392,13 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> { fn re_infer(&self, span: Span, reason: RegionInferReason<'_>) -> ty::Region<'tcx> { if let RegionInferReason::BorrowedObjectLifetimeDefault = reason { let e = struct_span_code_err!( - self.tcx().dcx(), + self.dcx(), span, E0228, "the lifetime bound for this object type cannot be deduced \ from context; please supply an explicit bound" ) .emit(); - self.set_tainted_by_errors(e); ty::Region::new_error(self.tcx(), e) } else { // This indicates an illegal lifetime in a non-assoc-trait position @@ -509,10 +523,6 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> { None } - fn set_tainted_by_errors(&self, err: ErrorGuaranteed) { - self.tainted_by_errors.set(Some(err)); - } - fn lower_fn_sig( &self, decl: &hir::FnDecl<'tcx>, @@ -570,7 +580,7 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> { // `ident_span` to not emit an error twice when we have `fn foo(_: fn() -> _)`. let mut diag = crate::collect::placeholder_type_error_diag( - tcx, + self, generics, visitor.0, infer_replacements.iter().map(|(s, _)| *s).collect(), @@ -590,7 +600,7 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> { ); } - self.set_tainted_by_errors(diag.emit()); + diag.emit(); } (input_tys, output_ty) @@ -639,6 +649,7 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) { let it = tcx.hir().item(item_id); debug!(item = %it.ident, id = %it.hir_id()); let def_id = item_id.owner_id.def_id; + let icx = ItemCtxt::new(tcx, def_id); match &it.kind { // These don't define types. @@ -663,7 +674,7 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) { let mut visitor = HirPlaceholderCollector::default(); visitor.visit_foreign_item(item); placeholder_type_error( - tcx, + icx.lowerer(), None, visitor.0, false, @@ -742,7 +753,14 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) { if !ty.is_suggestable_infer_ty() { let mut visitor = HirPlaceholderCollector::default(); visitor.visit_item(it); - placeholder_type_error(tcx, None, visitor.0, false, None, it.kind.descr()); + placeholder_type_error( + icx.lowerer(), + None, + visitor.0, + false, + None, + it.kind.descr(), + ); } } @@ -760,6 +778,7 @@ fn lower_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) { let trait_item = tcx.hir().trait_item(trait_item_id); let def_id = trait_item_id.owner_id; tcx.ensure().generics_of(def_id); + let icx = ItemCtxt::new(tcx, def_id.def_id); match trait_item.kind { hir::TraitItemKind::Fn(..) => { @@ -776,7 +795,14 @@ fn lower_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) { // Account for `const C: _;`. let mut visitor = HirPlaceholderCollector::default(); visitor.visit_trait_item(trait_item); - placeholder_type_error(tcx, None, visitor.0, false, None, "associated constant"); + placeholder_type_error( + icx.lowerer(), + None, + visitor.0, + false, + None, + "associated constant", + ); } } @@ -787,7 +813,7 @@ fn lower_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) { // Account for `type T = _;`. let mut visitor = HirPlaceholderCollector::default(); visitor.visit_trait_item(trait_item); - placeholder_type_error(tcx, None, visitor.0, false, None, "associated type"); + placeholder_type_error(icx.lowerer(), None, visitor.0, false, None, "associated type"); } hir::TraitItemKind::Type(_, None) => { @@ -798,7 +824,7 @@ fn lower_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) { let mut visitor = HirPlaceholderCollector::default(); visitor.visit_trait_item(trait_item); - placeholder_type_error(tcx, None, visitor.0, false, None, "associated type"); + placeholder_type_error(icx.lowerer(), None, visitor.0, false, None, "associated type"); } }; @@ -811,6 +837,7 @@ fn lower_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::ImplItemId) { tcx.ensure().type_of(def_id); tcx.ensure().predicates_of(def_id); let impl_item = tcx.hir().impl_item(impl_item_id); + let icx = ItemCtxt::new(tcx, def_id.def_id); match impl_item.kind { hir::ImplItemKind::Fn(..) => { tcx.ensure().codegen_fn_attrs(def_id); @@ -821,14 +848,21 @@ fn lower_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::ImplItemId) { let mut visitor = HirPlaceholderCollector::default(); visitor.visit_impl_item(impl_item); - placeholder_type_error(tcx, None, visitor.0, false, None, "associated type"); + placeholder_type_error(icx.lowerer(), None, visitor.0, false, None, "associated type"); } hir::ImplItemKind::Const(ty, _) => { // Account for `const T: _ = ..;` if !ty.is_suggestable_infer_ty() { let mut visitor = HirPlaceholderCollector::default(); visitor.visit_impl_item(impl_item); - placeholder_type_error(tcx, None, visitor.0, false, None, "associated constant"); + placeholder_type_error( + icx.lowerer(), + None, + visitor.0, + false, + None, + "associated constant", + ); } } } @@ -1385,7 +1419,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_, ty::PolyFn .. }) | Item(hir::Item { kind: ItemKind::Fn(sig, generics, _), .. }) => { - infer_return_ty_for_fn_sig(tcx, sig, generics, def_id, &icx) + infer_return_ty_for_fn_sig(sig, generics, def_id, &icx) } ImplItem(hir::ImplItem { kind: ImplItemKind::Fn(sig, _), generics, .. }) => { @@ -1402,7 +1436,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_, ty::PolyFn None, ) } else { - infer_return_ty_for_fn_sig(tcx, sig, generics, def_id, &icx) + infer_return_ty_for_fn_sig(sig, generics, def_id, &icx) } } @@ -1455,12 +1489,12 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_, ty::PolyFn } fn infer_return_ty_for_fn_sig<'tcx>( - tcx: TyCtxt<'tcx>, sig: &hir::FnSig<'tcx>, generics: &hir::Generics<'_>, def_id: LocalDefId, icx: &ItemCtxt<'tcx>, ) -> ty::PolyFnSig<'tcx> { + let tcx = icx.tcx; let hir_id = tcx.local_def_id_to_hir_id(def_id); match sig.decl.output.get_infer_ret_ty() { @@ -1492,7 +1526,7 @@ fn infer_return_ty_for_fn_sig<'tcx>( let mut visitor = HirPlaceholderCollector::default(); visitor.visit_ty(ty); - let mut diag = bad_placeholder(tcx, visitor.0, "return type"); + let mut diag = bad_placeholder(icx.lowerer(), visitor.0, "return type"); let ret_ty = fn_sig.output(); // Don't leak types into signatures unless they're nameable! // For example, if a function returns itself, we don't want that diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs index 1e2b0c43233..974dd415f46 100644 --- a/compiler/rustc_hir_analysis/src/collect/type_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/type_of.rs @@ -12,6 +12,7 @@ use rustc_span::symbol::Ident; use rustc_span::{Span, DUMMY_SP}; use crate::errors::TypeofReservedKeywordUsed; +use crate::hir_ty_lowering::HirTyLowerer; use super::bad_placeholder; use super::ItemCtxt; @@ -357,7 +358,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_ .and_then(|body_id| { ty.is_suggestable_infer_ty().then(|| { infer_placeholder_type( - tcx, + icx.lowerer(), def_id, body_id, ty.span, @@ -381,7 +382,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_ ImplItemKind::Const(ty, body_id) => { if ty.is_suggestable_infer_ty() { infer_placeholder_type( - tcx, + icx.lowerer(), def_id, body_id, ty.span, @@ -405,7 +406,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_ ItemKind::Static(ty, .., body_id) => { if ty.is_suggestable_infer_ty() { infer_placeholder_type( - tcx, + icx.lowerer(), def_id, body_id, ty.span, @@ -418,7 +419,14 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_ } ItemKind::Const(ty, _, body_id) => { if ty.is_suggestable_infer_ty() { - infer_placeholder_type(tcx, def_id, body_id, ty.span, item.ident, "constant") + infer_placeholder_type( + icx.lowerer(), + def_id, + body_id, + ty.span, + item.ident, + "constant", + ) } else { icx.lower_ty(ty) } @@ -559,21 +567,22 @@ pub(super) fn type_of_opaque( } } -fn infer_placeholder_type<'a>( - tcx: TyCtxt<'a>, +fn infer_placeholder_type<'tcx>( + cx: &dyn HirTyLowerer<'tcx>, def_id: LocalDefId, body_id: hir::BodyId, span: Span, item_ident: Ident, kind: &'static str, -) -> Ty<'a> { +) -> Ty<'tcx> { + let tcx = cx.tcx(); let ty = tcx.diagnostic_only_typeck(def_id).node_type(body_id.hir_id); // If this came from a free `const` or `static mut?` item, // then the user may have written e.g. `const A = 42;`. // In this case, the parser has stashed a diagnostic for // us to improve in typeck so we do that now. - let guar = tcx + let guar = cx .dcx() .try_steal_modify_and_emit_err(span, StashKey::ItemNoType, |err| { if !ty.references_error() { @@ -602,7 +611,7 @@ fn infer_placeholder_type<'a>( } }) .unwrap_or_else(|| { - let mut diag = bad_placeholder(tcx, vec![span], kind); + let mut diag = bad_placeholder(cx, vec![span], kind); if !ty.references_error() { if let Some(ty) = ty.make_suggestable(tcx, false, None) { diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs index 802215b2843..a1feef9e15b 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs @@ -76,7 +76,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } if unbounds.len() > 1 { - tcx.dcx().emit_err(errors::MultipleRelaxedDefaultBounds { + self.dcx().emit_err(errors::MultipleRelaxedDefaultBounds { spans: unbounds.iter().map(|ptr| ptr.span).collect(), }); } @@ -90,7 +90,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { continue; } // There was a `?Trait` bound, but it was not `?Sized`; warn. - tcx.dcx().span_warn( + self.dcx().span_warn( unbound.span, "relaxing a default bound only does something for `?Sized`; \ all other traits are not bound by default", @@ -310,7 +310,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { duplicates .entry(assoc_item.def_id) .and_modify(|prev_span| { - tcx.dcx().emit_err(errors::ValueOfAssociatedStructAlreadySpecified { + self.dcx().emit_err(errors::ValueOfAssociatedStructAlreadySpecified { span: constraint.span, prev_span: *prev_span, item_name: constraint.ident, @@ -338,7 +338,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .into(), ty::GenericParamDefKind::Type { .. } => { let guar = *emitted_bad_param_err.get_or_insert_with(|| { - tcx.dcx().emit_err( + self.dcx().emit_err( crate::errors::ReturnTypeNotationIllegalParam::Type { span: path_span, param_span: tcx.def_span(param.def_id), @@ -349,7 +349,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } ty::GenericParamDefKind::Const { .. } => { let guar = *emitted_bad_param_err.get_or_insert_with(|| { - tcx.dcx().emit_err( + self.dcx().emit_err( crate::errors::ReturnTypeNotationIllegalParam::Const { span: path_span, param_span: tcx.def_span(param.def_id), @@ -371,7 +371,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { { alias_ty.into() } else { - return Err(tcx.dcx().emit_err(crate::errors::ReturnTypeNotationOnNonRpitit { + return Err(self.dcx().emit_err(crate::errors::ReturnTypeNotationOnNonRpitit { span: constraint.span, ty: tcx.liberate_late_bound_regions(assoc_item.def_id, output), fn_span: tcx.hir().span_if_local(assoc_item.def_id), @@ -417,7 +417,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let ty = alias_term .map_bound(|alias| tcx.type_of(alias.def_id).instantiate(tcx, alias.args)); let ty = - check_assoc_const_binding_type(tcx, constraint.ident, ty, constraint.hir_id); + check_assoc_const_binding_type(self, constraint.ident, ty, constraint.hir_id); tcx.feed_anon_const_type(anon_const.def_id, ty::EarlyBinder::bind(ty)); } @@ -426,7 +426,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { match constraint.kind { hir::AssocItemConstraintKind::Equality { .. } if let ty::AssocKind::Fn = assoc_kind => { - return Err(tcx.dcx().emit_err(crate::errors::ReturnTypeNotationEqualityBound { + return Err(self.dcx().emit_err(crate::errors::ReturnTypeNotationEqualityBound { span: constraint.span, })); } @@ -462,7 +462,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { late_bound_in_term, |br_name| { struct_span_code_err!( - tcx.dcx(), + self.dcx(), constraint.span, E0582, "binding for associated type `{}` references {}, \ @@ -519,7 +519,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { /// /// [^1]: . fn check_assoc_const_binding_type<'tcx>( - tcx: TyCtxt<'tcx>, + cx: &dyn HirTyLowerer<'tcx>, assoc_const: Ident, ty: ty::Binder<'tcx, Ty<'tcx>>, hir_id: hir::HirId, @@ -536,13 +536,14 @@ fn check_assoc_const_binding_type<'tcx>( } let mut collector = GenericParamAndBoundVarCollector { - tcx, + cx, params: Default::default(), vars: Default::default(), depth: ty::INNERMOST, }; let mut guar = ty.visit_with(&mut collector).break_value(); + let tcx = cx.tcx(); let ty_note = ty .make_suggestable(tcx, false, None) .map(|ty| crate::errors::TyOfAssocConstBindingNote { assoc_const, ty }); @@ -556,7 +557,7 @@ fn check_assoc_const_binding_type<'tcx>( for index in collector.params { let param = generics.param_at(index as _, tcx); let is_self_param = param.name == rustc_span::symbol::kw::SelfUpper; - guar.get_or_insert(tcx.dcx().emit_err(crate::errors::ParamInTyOfAssocConstBinding { + guar.get_or_insert(cx.dcx().emit_err(crate::errors::ParamInTyOfAssocConstBinding { span: assoc_const.span, assoc_const, param_name: param.name, @@ -574,7 +575,7 @@ fn check_assoc_const_binding_type<'tcx>( })); } for (var_def_id, var_name) in collector.vars { - guar.get_or_insert(tcx.dcx().emit_err( + guar.get_or_insert(cx.dcx().emit_err( crate::errors::EscapingBoundVarInTyOfAssocConstBinding { span: assoc_const.span, assoc_const, @@ -590,14 +591,14 @@ fn check_assoc_const_binding_type<'tcx>( Ty::new_error(tcx, guar) } -struct GenericParamAndBoundVarCollector<'tcx> { - tcx: TyCtxt<'tcx>, +struct GenericParamAndBoundVarCollector<'a, 'tcx> { + cx: &'a dyn HirTyLowerer<'tcx>, params: FxIndexSet, vars: FxIndexSet<(DefId, Symbol)>, depth: ty::DebruijnIndex, } -impl<'tcx> TypeVisitor> for GenericParamAndBoundVarCollector<'tcx> { +impl<'tcx> TypeVisitor> for GenericParamAndBoundVarCollector<'_, 'tcx> { type Result = ControlFlow; fn visit_binder>>( @@ -620,7 +621,7 @@ impl<'tcx> TypeVisitor> for GenericParamAndBoundVarCollector<'tcx> ty::BoundTyKind::Param(def_id, name) => (def_id, name), ty::BoundTyKind::Anon => { let reported = self - .tcx + .cx .dcx() .delayed_bug(format!("unexpected anon bound ty: {:?}", bt.var)); return ControlFlow::Break(reported); @@ -643,7 +644,7 @@ impl<'tcx> TypeVisitor> for GenericParamAndBoundVarCollector<'tcx> ty::BrNamed(def_id, name) => (def_id, name), ty::BrAnon | ty::BrEnv => { let guar = self - .tcx + .cx .dcx() .delayed_bug(format!("unexpected bound region kind: {:?}", br.kind)); return ControlFlow::Break(guar); @@ -661,7 +662,7 @@ impl<'tcx> TypeVisitor> for GenericParamAndBoundVarCollector<'tcx> self.params.insert(param.index); } ty::ConstKind::Bound(db, ty::BoundVar { .. }) if db >= self.depth => { - let guar = self.tcx.dcx().delayed_bug("unexpected escaping late-bound const var"); + let guar = self.cx.dcx().delayed_bug("unexpected escaping late-bound const var"); return ControlFlow::Break(guar); } _ if ct.has_param() || ct.has_bound_vars() => return ct.super_visit_with(self), diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs index e8bd7f2a5b2..ebd2a63d555 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs @@ -46,7 +46,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { return; } - self.tcx().dcx().emit_err(MissingTypeParams { + self.dcx().emit_err(MissingTypeParams { span, def_span: self.tcx().def_span(def_id), span_snippet: self.tcx().sess.source_map().span_to_snippet(span).ok(), @@ -109,7 +109,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { if is_impl { let trait_name = self.tcx().def_path_str(trait_def_id); - self.tcx().dcx().emit_err(ManualImplementation { span, trait_name }); + self.dcx().emit_err(ManualImplementation { span, trait_name }); } } @@ -156,7 +156,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { if is_dummy { err.label = Some(errors::AssocItemNotFoundLabel::NotFound { span }); - return tcx.dcx().emit_err(err); + return self.dcx().emit_err(err); } let all_candidate_names: Vec<_> = all_candidates() @@ -174,7 +174,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { assoc_kind: assoc_kind_str, suggested_name, }); - return tcx.dcx().emit_err(err); + return self.dcx().emit_err(err); } // If we didn't find a good item in the supertraits (or couldn't get @@ -239,10 +239,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { assoc_kind: assoc_kind_str, suggested_name, }); - return tcx.dcx().emit_err(err); + return self.dcx().emit_err(err); } - let mut err = tcx.dcx().create_err(err); + let mut err = self.dcx().create_err(err); if suggest_constraining_type_param( tcx, generics, @@ -264,7 +264,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } return err.emit(); } - return tcx.dcx().emit_err(err); + return self.dcx().emit_err(err); } } @@ -291,7 +291,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { err.label = Some(errors::AssocItemNotFoundLabel::NotFound { span: assoc_name.span }); } - tcx.dcx().emit_err(err) + self.dcx().emit_err(err) } fn complain_about_assoc_kind_mismatch( @@ -347,7 +347,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { (ident.span, None, assoc_kind, assoc_item.kind) }; - tcx.dcx().emit_err(errors::AssocKindMismatch { + self.dcx().emit_err(errors::AssocKindMismatch { span, expected: super::assoc_kind_str(expected), got: super::assoc_kind_str(got), @@ -366,8 +366,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { traits: &[String], name: Symbol, ) -> ErrorGuaranteed { - let mut err = - struct_span_code_err!(self.tcx().dcx(), span, E0223, "ambiguous associated type"); + let mut err = struct_span_code_err!(self.dcx(), span, E0223, "ambiguous associated type"); if self .tcx() .resolutions(()) @@ -463,9 +462,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } } } - let reported = err.emit(); - self.set_tainted_by_errors(reported); - reported + err.emit() } pub(crate) fn complain_about_ambiguous_inherent_assoc_ty( @@ -475,16 +472,14 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { span: Span, ) -> ErrorGuaranteed { let mut err = struct_span_code_err!( - self.tcx().dcx(), + self.dcx(), name.span, E0034, "multiple applicable items in scope" ); err.span_label(name.span, format!("multiple `{name}` found")); self.note_ambiguous_inherent_assoc_ty(&mut err, candidates, span); - let reported = err.emit(); - self.set_tainted_by_errors(reported); - reported + err.emit() } // FIXME(fmease): Heavily adapted from `rustc_hir_typeck::method::suggest`. Deduplicate. @@ -576,7 +571,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { }; let mut err = struct_span_code_err!( - tcx.dcx(), + self.dcx(), name.span, E0220, "associated type `{name}` not found for `{self_ty}` in the current scope" @@ -662,7 +657,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { bounds.sort(); bounds.dedup(); - let mut err = tcx.dcx().struct_span_err( + let mut err = self.dcx().struct_span_err( name.span, format!("the associated type `{name}` exists for `{self_ty}`, but its trait bounds were not satisfied") ); @@ -829,7 +824,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { trait_bound_spans.sort(); let mut err = struct_span_code_err!( - tcx.dcx(), + self.dcx(), trait_bound_spans, E0191, "the value of the associated type{} {} must be specified", @@ -974,7 +969,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } } - self.set_tainted_by_errors(err.emit()); + err.emit(); } /// On ambiguous associated type, look for an associated function whose name matches the @@ -1011,17 +1006,14 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .filter_by_name_unhygienic(Symbol::intern(&name)) .next() { - let reported = - struct_span_code_err!(tcx.dcx(), span, E0223, "ambiguous associated type") - .with_span_suggestion_verbose( - ident2.span.to(ident3.span), - format!("there is an associated function with a similar name: `{name}`"), - name, - Applicability::MaybeIncorrect, - ) - .emit(); - self.set_tainted_by_errors(reported); - Err(reported) + Err(struct_span_code_err!(self.dcx(), span, E0223, "ambiguous associated type") + .with_span_suggestion_verbose( + ident2.span.to(ident3.span), + format!("there is an associated function with a similar name: `{name}`"), + name, + Applicability::MaybeIncorrect, + ) + .emit()) } else { Ok(()) } @@ -1120,7 +1112,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let last_span = *arg_spans.last().unwrap(); let span: MultiSpan = arg_spans.into(); let mut err = struct_span_code_err!( - self.tcx().dcx(), + self.dcx(), span, E0109, "{kind} arguments are not allowed on {this_type}", @@ -1130,20 +1122,17 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { err.span_label(span, format!("not allowed on {what}")); } generics_args_err_extend(self.tcx(), segments, &mut err, err_extend); - let reported = err.emit(); - self.set_tainted_by_errors(reported); - reported + err.emit() } pub fn report_trait_object_addition_traits_error( &self, regular_traits: &Vec>, ) -> ErrorGuaranteed { - let tcx = self.tcx(); let first_trait = ®ular_traits[0]; let additional_trait = ®ular_traits[1]; let mut err = struct_span_code_err!( - tcx.dcx(), + self.dcx(), additional_trait.bottom().1, E0225, "only auto traits can be used as additional traits in a trait object" @@ -1169,9 +1158,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { for more information on them, visit \ ", ); - let reported = err.emit(); - self.set_tainted_by_errors(reported); - reported + err.emit() } pub fn report_trait_object_with_no_traits_error( @@ -1185,20 +1172,19 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .map(|&(trait_ref, _)| trait_ref.def_id()) .find(|&trait_ref| tcx.is_trait_alias(trait_ref)) .map(|trait_ref| tcx.def_span(trait_ref)); - let reported = - tcx.dcx().emit_err(TraitObjectDeclaredWithNoTraits { span, trait_alias_span }); - self.set_tainted_by_errors(reported); - reported + + self.dcx().emit_err(TraitObjectDeclaredWithNoTraits { span, trait_alias_span }) } } /// Emit an error for the given associated item constraint. pub fn prohibit_assoc_item_constraint( - tcx: TyCtxt<'_>, + cx: &dyn HirTyLowerer<'_>, constraint: &hir::AssocItemConstraint<'_>, segment: Option<(DefId, &hir::PathSegment<'_>, Span)>, ) -> ErrorGuaranteed { - let mut err = tcx.dcx().create_err(AssocItemConstraintsNotAllowedHere { + let tcx = cx.tcx(); + let mut err = cx.dcx().create_err(AssocItemConstraintsNotAllowedHere { span: constraint.span, fn_trait_expansion: if let Some((_, segment, span)) = segment && segment.args().parenthesized == hir::GenericArgsParentheses::ParenSugar diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs index 90836f0a54f..b1c77db9f37 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs @@ -1,4 +1,4 @@ -use super::IsMethodCall; +use super::{HirTyLowerer, IsMethodCall}; use crate::errors::wrong_number_of_generic_args::{GenericArgsInfo, WrongNumberOfGenericArgs}; use crate::hir_ty_lowering::{ errors::prohibit_assoc_item_constraint, ExplicitLateBound, GenericArgCountMismatch, @@ -13,7 +13,7 @@ use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::DefId; use rustc_hir::GenericArg; use rustc_middle::ty::{ - self, GenericArgsRef, GenericParamDef, GenericParamDefKind, IsSuggestable, Ty, TyCtxt, + self, GenericArgsRef, GenericParamDef, GenericParamDefKind, IsSuggestable, Ty, }; use rustc_session::lint::builtin::LATE_BOUND_LIFETIME_ARGUMENTS; use rustc_span::symbol::{kw, sym}; @@ -22,15 +22,16 @@ use smallvec::SmallVec; /// Report an error that a generic argument did not match the generic parameter that was /// expected. fn generic_arg_mismatch_err( - tcx: TyCtxt<'_>, + cx: &dyn HirTyLowerer<'_>, arg: &GenericArg<'_>, param: &GenericParamDef, possible_ordering_error: bool, help: Option, ) -> ErrorGuaranteed { + let tcx = cx.tcx(); let sess = tcx.sess; let mut err = struct_span_code_err!( - tcx.dcx(), + cx.dcx(), arg.span(), E0747, "{} provided when a {} was expected", @@ -171,7 +172,7 @@ fn generic_arg_mismatch_err( /// - `inferred_kind`: if no parameter was provided, and inference /// is enabled, then creates a suitable inference variable. pub fn lower_generic_args<'tcx: 'a, 'a>( - tcx: TyCtxt<'tcx>, + cx: &dyn HirTyLowerer<'tcx>, def_id: DefId, parent_args: &[ty::GenericArg<'tcx>], has_self: bool, @@ -179,6 +180,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>( arg_count: &GenericArgCountResult, ctx: &mut impl GenericArgsLowerer<'a, 'tcx>, ) -> GenericArgsRef<'tcx> { + let tcx = cx.tcx(); // Collect the segments of the path; we need to instantiate arguments // for parameters throughout the entire path (wherever there are // generic parameters). @@ -326,7 +328,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>( param_types_present.dedup(); generic_arg_mismatch_err( - tcx, + cx, arg, param, !args_iter.clone().is_sorted_by_key(|arg| arg.to_ord()), @@ -381,7 +383,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>( assert_eq!(kind, "lifetime"); let (provided_arg, param) = force_infer_lt.expect("lifetimes ought to have been inferred"); - generic_arg_mismatch_err(tcx, provided_arg, param, false, None); + generic_arg_mismatch_err(cx, provided_arg, param, false, None); } break; @@ -405,7 +407,7 @@ pub fn lower_generic_args<'tcx: 'a, 'a>( /// Checks that the correct number of generic arguments have been provided. /// Used specifically for function calls. pub fn check_generic_arg_count_for_call( - tcx: TyCtxt<'_>, + cx: &dyn HirTyLowerer<'_>, def_id: DefId, generics: &ty::Generics, seg: &hir::PathSegment<'_>, @@ -416,14 +418,14 @@ pub fn check_generic_arg_count_for_call( IsMethodCall::No => GenericArgPosition::Value, }; let has_self = generics.parent.is_none() && generics.has_self; - check_generic_arg_count(tcx, def_id, seg, generics, gen_pos, has_self) + check_generic_arg_count(cx, def_id, seg, generics, gen_pos, has_self) } /// Checks that the correct number of generic arguments have been provided. /// This is used both for datatypes and function calls. -#[instrument(skip(tcx, gen_pos), level = "debug")] +#[instrument(skip(cx, gen_pos), level = "debug")] pub(crate) fn check_generic_arg_count( - tcx: TyCtxt<'_>, + cx: &dyn HirTyLowerer<'_>, def_id: DefId, seg: &hir::PathSegment<'_>, gen_params: &ty::Generics, @@ -456,11 +458,11 @@ pub(crate) fn check_generic_arg_count( if gen_pos != GenericArgPosition::Type && let Some(c) = gen_args.constraints.first() { - prohibit_assoc_item_constraint(tcx, c, None); + prohibit_assoc_item_constraint(cx, c, None); } let explicit_late_bound = - prohibit_explicit_late_bound_lifetimes(tcx, gen_params, gen_args, gen_pos); + prohibit_explicit_late_bound_lifetimes(cx, gen_params, gen_args, gen_pos); let mut invalid_args = vec![]; @@ -486,8 +488,8 @@ pub(crate) fn check_generic_arg_count( GenericArgsInfo::MissingLifetimes { num_missing_args } }; - let reported = tcx.dcx().emit_err(WrongNumberOfGenericArgs::new( - tcx, + let reported = cx.dcx().emit_err(WrongNumberOfGenericArgs::new( + cx.tcx(), gen_args_info, seg, gen_params, @@ -571,9 +573,9 @@ pub(crate) fn check_generic_arg_count( debug!(?gen_args_info); let reported = gen_args.has_err().unwrap_or_else(|| { - tcx.dcx() + cx.dcx() .create_err(WrongNumberOfGenericArgs::new( - tcx, + cx.tcx(), gen_args_info, seg, gen_params, @@ -621,7 +623,7 @@ pub(crate) fn check_generic_arg_count( /// Prohibits explicit lifetime arguments if late-bound lifetime parameters /// are present. This is used both for datatypes and function calls. pub(crate) fn prohibit_explicit_late_bound_lifetimes( - tcx: TyCtxt<'_>, + cx: &dyn HirTyLowerer<'_>, def: &ty::Generics, args: &hir::GenericArgs<'_>, position: GenericArgPosition, @@ -642,13 +644,13 @@ pub(crate) fn prohibit_explicit_late_bound_lifetimes( if position == GenericArgPosition::Value && args.num_lifetime_params() != param_counts.lifetimes { - struct_span_code_err!(tcx.dcx(), span, E0794, "{}", msg) + struct_span_code_err!(cx.dcx(), span, E0794, "{}", msg) .with_span_note(span_late, note) .emit(); } else { let mut multispan = MultiSpan::from_span(span); multispan.push_span_label(span_late, note); - tcx.node_span_lint( + cx.tcx().node_span_lint( LATE_BOUND_LIFETIME_ARGUMENTS, args.args[0].hir_id(), multispan, diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs index b7fa736ffcc..29c71c3fa50 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs @@ -60,7 +60,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let msg = "trait objects must include the `dyn` keyword"; let label = "add `dyn` keyword before this trait"; let mut diag = - rustc_errors::struct_span_code_err!(tcx.dcx(), self_ty.span, E0782, "{}", msg); + rustc_errors::struct_span_code_err!(self.dcx(), self_ty.span, E0782, "{}", msg); if self_ty.span.can_be_used_for_suggestions() && !self.maybe_suggest_impl_trait(self_ty, &mut diag) { diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index 0747686b38b..a665306f2c6 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -28,7 +28,8 @@ use crate::require_c_abi_if_c_variadic; use rustc_ast::TraitObjectSyntax; use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_errors::{ - codes::*, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, FatalError, + codes::*, struct_span_code_err, Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, + FatalError, }; use rustc_hir as hir; use rustc_hir::def::{CtorOf, DefKind, Namespace, Res}; @@ -102,6 +103,8 @@ pub enum RegionInferReason<'a> { pub trait HirTyLowerer<'tcx> { fn tcx(&self) -> TyCtxt<'tcx>; + fn dcx(&self) -> DiagCtxtHandle<'_>; + /// Returns the [`LocalDefId`] of the overarching item whose constituents get lowered. fn item_def_id(&self) -> LocalDefId; @@ -177,12 +180,6 @@ pub trait HirTyLowerer<'tcx> { /// The inference context of the lowering context if applicable. fn infcx(&self) -> Option<&InferCtxt<'tcx>>; - /// Taint the context with errors. - /// - /// Invoke this when you encounter an error from some prior pass like name resolution. - /// This is used to help suppress derived errors typeck might otherwise report. - fn set_tainted_by_errors(&self, e: ErrorGuaranteed); - /// Convenience method for coercing the lowering context into a trait object type. /// /// Most lowering routines are defined on the trait object type directly @@ -323,7 +320,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { ty::BoundConstness::NotConst, ); if let Some(c) = item_segment.args().constraints.first() { - prohibit_assoc_item_constraint(self.tcx(), c, Some((def_id, item_segment, span))); + prohibit_assoc_item_constraint(self, c, Some((def_id, item_segment, span))); } args } @@ -394,7 +391,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } let mut arg_count = check_generic_arg_count( - tcx, + self, def_id, segment, generics, @@ -402,10 +399,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { self_ty.is_some(), ); - if let Err(err) = &arg_count.correct { - self.set_tainted_by_errors(err.reported); - } - // Skip processing if type has no generic parameters. // Traits always have `Self` as a generic parameter, which means they will not return early // here and so associated item constraints will be handled regardless of whether there are @@ -562,11 +555,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { && generics.has_self && !tcx.is_const_trait(def_id) { - let reported = tcx.dcx().emit_err(crate::errors::ConstBoundForNonConstTrait { + let reported = self.dcx().emit_err(crate::errors::ConstBoundForNonConstTrait { span, modifier: constness.as_str(), }); - self.set_tainted_by_errors(reported); arg_count.correct = Err(GenericArgCountMismatch { reported, invalid_args: vec![] }); } @@ -579,7 +571,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { incorrect_args: &arg_count.correct, }; let args = lower_generic_args( - tcx, + self, def_id, parent_args, self_ty.is_some(), @@ -609,7 +601,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { ty::BoundConstness::NotConst, ); if let Some(c) = item_segment.args().constraints.first() { - prohibit_assoc_item_constraint(self.tcx(), c, Some((item_def_id, item_segment, span))); + prohibit_assoc_item_constraint(self, c, Some((item_def_id, item_segment, span))); } args } @@ -715,7 +707,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // would not be well-formed! if polarity != ty::PredicatePolarity::Positive { assert!( - self.tcx().dcx().has_errors().is_some(), + self.dcx().has_errors().is_some(), "negative trait bounds should not have assoc item constraints", ); continue; @@ -761,11 +753,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { constness, ); if let Some(c) = trait_segment.args().constraints.first() { - prohibit_assoc_item_constraint( - self.tcx(), - c, - Some((trait_def_id, trait_segment, span)), - ); + prohibit_assoc_item_constraint(self, c, Some((trait_def_id, trait_segment, span))); } ty::TraitRef::new_from_args(self.tcx(), trait_def_id, generic_args) } @@ -877,7 +865,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { span, constraint, ); - self.set_tainted_by_errors(reported); return Err(reported); }; debug!(?bound); @@ -887,7 +874,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let assoc_kind_str = assoc_kind_str(assoc_kind); let ty_param_name = &ty_param_name.to_string(); - let mut err = tcx.dcx().create_err(crate::errors::AmbiguousAssocItem { + let mut err = self.dcx().create_err(crate::errors::AmbiguousAssocItem { span, assoc_kind: assoc_kind_str, assoc_name, @@ -960,7 +947,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { )); } let reported = err.emit(); - self.set_tainted_by_errors(reported); if !where_bounds.is_empty() { return Err(reported); } @@ -1059,7 +1045,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // trait reference. let Some(trait_ref) = tcx.impl_trait_ref(impl_def_id) else { // A cycle error occurred, most likely. - tcx.dcx().span_bug(span, "expected cycle error"); + self.dcx().span_bug(span, "expected cycle error"); }; self.probe_single_bound_for_assoc_item( @@ -1089,10 +1075,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let reported = if variant_resolution.is_some() { // Variant in type position let msg = format!("expected type, found variant `{assoc_ident}`"); - tcx.dcx().span_err(span, msg) + self.dcx().span_err(span, msg) } else if qself_ty.is_enum() { let mut err = struct_span_code_err!( - tcx.dcx(), + self.dcx(), assoc_ident.span, E0599, "no variant named `{}` found for enum `{}`", @@ -1133,7 +1119,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } else if let ty::Alias(ty::Opaque, alias_ty) = qself_ty.kind() { // `::Assoc` makes no sense. struct_span_code_err!( - tcx.dcx(), + self.dcx(), tcx.def_span(alias_ty.def_id), E0667, "`impl Trait` is not allowed in path parameters" @@ -1153,7 +1139,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { assoc_ident.name, ) }; - self.set_tainted_by_errors(reported); return Err(reported); } }; @@ -1404,13 +1389,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let tcx = self.tcx(); if !tcx.visibility(item_def_id).is_accessible_from(scope, tcx) { - let reported = tcx.dcx().emit_err(crate::errors::AssocItemIsPrivate { + self.dcx().emit_err(crate::errors::AssocItemIsPrivate { span, kind: tcx.def_descr(item_def_id), name: ident, defined_here_label: tcx.def_span(item_def_id), }); - self.set_tainted_by_errors(reported); } tcx.check_stability(item_def_id, Some(block), span, None); @@ -1564,7 +1548,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { for segment in segments { // Only emit the first error to avoid overloading the user with error messages. if let Some(c) = segment.args().constraints.first() { - return Err(prohibit_assoc_item_constraint(self.tcx(), c, None)); + return Err(prohibit_assoc_item_constraint(self, c, None)); } } @@ -1824,7 +1808,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // `AlwaysApplicable` impl needs a `T: ?Sized` bound for // this to compile if we were to normalize here. if forbid_generic && ty.has_param() { - let mut err = tcx.dcx().struct_span_err( + let mut err = self.dcx().struct_span_err( path.span, "generic `Self` types are currently not permitted in anonymous constants", ); @@ -1836,7 +1820,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { err.span_note(impl_.self_ty.span, "not a concrete type"); } let reported = err.emit(); - self.set_tainted_by_errors(reported); Ty::new_error(tcx, reported) } else { ty @@ -1877,7 +1860,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .tcx() .dcx() .span_delayed_bug(path.span, "path with `Res::Err` but no error emitted"); - self.set_tainted_by_errors(e); Ty::new_error(self.tcx(), e) } Res::Def(..) => { @@ -1888,7 +1870,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { ); Ty::new_error( self.tcx(), - self.tcx().dcx().span_delayed_bug(span, "incorrect resolution for `Self`"), + self.dcx().span_delayed_bug(span, "incorrect resolution for `Self`"), ) } _ => span_bug!(span, "unexpected resolution: {:?}", path.res), @@ -1961,7 +1943,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let sig_span = self.tcx().def_span(sig_id); let mut try_emit = |descr| { if emit { - self.tcx().dcx().emit_err(crate::errors::NotSupportedDelegation { + self.dcx().emit_err(crate::errors::NotSupportedDelegation { span, descr, callee_span: sig_span, @@ -2011,8 +1993,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { ) -> Ty<'tcx> { if self.check_delegation_constraints(sig_id, span, idx == hir::InferDelegationKind::Output) { - let e = self.tcx().dcx().span_delayed_bug(span, "not supported delegation case"); - self.set_tainted_by_errors(e); + let e = self.dcx().span_delayed_bug(span, "not supported delegation case"); return Ty::new_error(self.tcx(), e); }; let sig = self.tcx().fn_sig(sig_id); @@ -2177,7 +2158,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let ty = self.lower_ty(ty); let pat_ty = match pat.kind { hir::PatKind::Wild => { - let err = tcx.dcx().emit_err(WildPatTy { span: pat.span }); + let err = self.dcx().emit_err(WildPatTy { span: pat.span }); Ty::new_error(tcx, err) } hir::PatKind::Range(start, end, include_end) => { @@ -2357,7 +2338,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { self.validate_late_bound_regions(late_bound_in_args, late_bound_in_ret, |br_name| { struct_span_code_err!( - tcx.dcx(), + self.dcx(), decl.output.span(), E0581, "return type references {}, which is not constrained by the fn input types", @@ -2408,11 +2389,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } #[instrument(level = "trace", skip(self, generate_err))] - fn validate_late_bound_regions( - &self, + fn validate_late_bound_regions<'cx>( + &'cx self, constrained_regions: FxHashSet, referenced_regions: FxHashSet, - generate_err: impl Fn(&str) -> Diag<'tcx>, + generate_err: impl Fn(&str) -> Diag<'cx>, ) { for br in referenced_regions.difference(&constrained_regions) { let br_name = match *br { @@ -2437,7 +2418,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { err.note("consider introducing a named lifetime parameter"); } - self.set_tainted_by_errors(err.emit()); + err.emit(); } } @@ -2478,7 +2459,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // error. let r = derived_region_bounds[0]; if derived_region_bounds[1..].iter().any(|r1| r != *r1) { - self.set_tainted_by_errors(tcx.dcx().emit_err(AmbiguousLifetimeBound { span })); + self.dcx().emit_err(AmbiguousLifetimeBound { span }); } Some(r) } diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs index 8ef4740431c..aafadc7f9cb 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs @@ -236,7 +236,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { Ty::new_misc_error(tcx).into() } else if arg.walk().any(|arg| arg == dummy_self.into()) { references_self = true; - let guar = tcx.dcx().span_delayed_bug( + let guar = self.dcx().span_delayed_bug( span, "trait object trait bounds reference `Self`", ); @@ -262,8 +262,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { if references_self { let def_id = i.bottom().0.def_id(); - let reported = struct_span_code_err!( - tcx.dcx(), + struct_span_code_err!( + self.dcx(), i.bottom().1, E0038, "the {} `{}` cannot be made into an object", @@ -275,7 +275,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .error_msg(), ) .emit(); - self.set_tainted_by_errors(reported); } ty::ExistentialTraitRef { def_id: trait_ref.def_id, args } diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs index e35130c66a2..ea9567f4e3d 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -1139,7 +1139,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // parameter's value explicitly, so we have to do some error- // checking here. let arg_count = - check_generic_arg_count_for_call(tcx, def_id, generics, seg, IsMethodCall::No); + check_generic_arg_count_for_call(self, def_id, generics, seg, IsMethodCall::No); if let ExplicitLateBound::Yes = arg_count.explicit_late_bound { explicit_late_bound = ExplicitLateBound::Yes; @@ -1375,7 +1375,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let args_raw = self_ctor_args.unwrap_or_else(|| { lower_generic_args( - tcx, + self, def_id, &[], has_self, diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs index da68da029b4..b5796fbd48a 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs @@ -5,7 +5,7 @@ mod checks; mod inspect_obligations; mod suggestions; -use rustc_errors::{DiagCtxtHandle, ErrorGuaranteed}; +use rustc_errors::DiagCtxtHandle; use crate::coercion::DynamicCoerceMany; use crate::fallback::DivergingFallbackBehavior; @@ -217,6 +217,10 @@ impl<'tcx> HirTyLowerer<'tcx> for FnCtxt<'_, 'tcx> { self.tcx } + fn dcx(&self) -> DiagCtxtHandle<'_> { + self.root_ctxt.dcx() + } + fn item_def_id(&self) -> LocalDefId { self.body_id } @@ -338,10 +342,6 @@ impl<'tcx> HirTyLowerer<'tcx> for FnCtxt<'_, 'tcx> { Some(&self.infcx) } - fn set_tainted_by_errors(&self, e: ErrorGuaranteed) { - self.infcx.set_tainted_by_errors(e) - } - fn lower_fn_sig( &self, decl: &rustc_hir::FnDecl<'tcx>, diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs index 02844bcadac..e574fde14fb 100644 --- a/compiler/rustc_hir_typeck/src/method/confirm.rs +++ b/compiler/rustc_hir_typeck/src/method/confirm.rs @@ -354,7 +354,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { let generics = self.tcx.generics_of(pick.item.def_id); let arg_count_correct = check_generic_arg_count_for_call( - self.tcx, + self.fcx, pick.item.def_id, generics, seg, @@ -425,7 +425,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { } let args = lower_generic_args( - self.tcx, + self.fcx, pick.item.def_id, parent_args, false, diff --git a/tests/ui/associated-types/associated-types-eq-expr-path.rs b/tests/ui/associated-types/associated-types-eq-expr-path.rs index 67831f91303..3179811274e 100644 --- a/tests/ui/associated-types/associated-types-eq-expr-path.rs +++ b/tests/ui/associated-types/associated-types-eq-expr-path.rs @@ -7,11 +7,12 @@ trait Foo { impl Foo for isize { type A = usize; - fn bar() -> isize { 42 } + fn bar() -> isize { + 42 + } } pub fn main() { let x: isize = Foo::::bar(); //~^ ERROR associated item constraints are not allowed here - //~| ERROR cannot call } diff --git a/tests/ui/associated-types/associated-types-eq-expr-path.stderr b/tests/ui/associated-types/associated-types-eq-expr-path.stderr index 4f28b3cb2de..bbe021fbc55 100644 --- a/tests/ui/associated-types/associated-types-eq-expr-path.stderr +++ b/tests/ui/associated-types/associated-types-eq-expr-path.stderr @@ -1,25 +1,9 @@ error[E0229]: associated item constraints are not allowed here - --> $DIR/associated-types-eq-expr-path.rs:14:26 + --> $DIR/associated-types-eq-expr-path.rs:16:26 | LL | let x: isize = Foo::::bar(); | ^^^^^^^^^ associated item constraint not allowed here -error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type - --> $DIR/associated-types-eq-expr-path.rs:14:20 - | -LL | fn bar() -> isize; - | ------------------ `Foo::bar` defined here -... -LL | let x: isize = Foo::::bar(); - | ^^^^^^^^^^^^^^^^^^^^^^^ cannot call associated function of trait - | -help: use the fully-qualified path to the only available implementation - | -LL - let x: isize = Foo::::bar(); -LL + let x: isize = >::bar(); - | +error: aborting due to 1 previous error -error: aborting due to 2 previous errors - -Some errors have detailed explanations: E0229, E0790. -For more information about an error, try `rustc --explain E0229`. +For more information about this error, try `rustc --explain E0229`. diff --git a/tests/ui/const-generics/assoc_const_as_type_argument.rs b/tests/ui/const-generics/assoc_const_as_type_argument.rs index bec6102417c..ffc7f116a94 100644 --- a/tests/ui/const-generics/assoc_const_as_type_argument.rs +++ b/tests/ui/const-generics/assoc_const_as_type_argument.rs @@ -8,7 +8,6 @@ fn foo() { bar::<::ASSOC>(); //~^ ERROR: expected associated type, found associated constant `Trait::ASSOC` //~| ERROR: unresolved item provided when a constant was expected - //~| ERROR type annotations needed } fn main() {} diff --git a/tests/ui/const-generics/assoc_const_as_type_argument.stderr b/tests/ui/const-generics/assoc_const_as_type_argument.stderr index 53edc19b28c..ac009546135 100644 --- a/tests/ui/const-generics/assoc_const_as_type_argument.stderr +++ b/tests/ui/const-generics/assoc_const_as_type_argument.stderr @@ -15,19 +15,7 @@ help: if this generic argument was intended as a const parameter, surround it wi LL | bar::<{ ::ASSOC }>(); | + + -error[E0284]: type annotations needed - --> $DIR/assoc_const_as_type_argument.rs:8:5 - | -LL | bar::<::ASSOC>(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `bar` - | -note: required by a const generic parameter in `bar` - --> $DIR/assoc_const_as_type_argument.rs:5:8 - | -LL | fn bar() {} - | ^^^^^^^^^^^^^^ required by this const generic parameter in `bar` +error: aborting due to 2 previous errors -error: aborting due to 3 previous errors - -Some errors have detailed explanations: E0284, E0575, E0747. -For more information about an error, try `rustc --explain E0284`. +Some errors have detailed explanations: E0575, E0747. +For more information about an error, try `rustc --explain E0575`. diff --git a/tests/ui/const-generics/const-arg-in-const-arg.min.stderr b/tests/ui/const-generics/const-arg-in-const-arg.min.stderr index 2ea9d6b35b4..ce7fce25993 100644 --- a/tests/ui/const-generics/const-arg-in-const-arg.min.stderr +++ b/tests/ui/const-generics/const-arg-in-const-arg.min.stderr @@ -17,7 +17,7 @@ LL | let _: [u8; bar::()]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:19:23 + --> $DIR/const-arg-in-const-arg.rs:18:23 | LL | let _: [u8; faz::<'a>(&())]; | ^^ cannot perform const operation using `'a` @@ -26,7 +26,7 @@ LL | let _: [u8; faz::<'a>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:21:23 + --> $DIR/const-arg-in-const-arg.rs:20:23 | LL | let _: [u8; baz::<'a>(&())]; | ^^ cannot perform const operation using `'a` @@ -35,7 +35,7 @@ LL | let _: [u8; baz::<'a>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:22:23 + --> $DIR/const-arg-in-const-arg.rs:21:23 | LL | let _: [u8; faz::<'b>(&())]; | ^^ cannot perform const operation using `'b` @@ -44,7 +44,7 @@ LL | let _: [u8; faz::<'b>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:24:23 + --> $DIR/const-arg-in-const-arg.rs:23:23 | LL | let _: [u8; baz::<'b>(&())]; | ^^ cannot perform const operation using `'b` @@ -53,7 +53,7 @@ LL | let _: [u8; baz::<'b>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:27:23 + --> $DIR/const-arg-in-const-arg.rs:26:23 | LL | let _ = [0; bar::()]; | ^ cannot perform const operation using `N` @@ -62,7 +62,7 @@ LL | let _ = [0; bar::()]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:30:23 + --> $DIR/const-arg-in-const-arg.rs:28:23 | LL | let _ = [0; faz::<'a>(&())]; | ^^ cannot perform const operation using `'a` @@ -71,7 +71,7 @@ LL | let _ = [0; faz::<'a>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:32:23 + --> $DIR/const-arg-in-const-arg.rs:30:23 | LL | let _ = [0; baz::<'a>(&())]; | ^^ cannot perform const operation using `'a` @@ -80,7 +80,7 @@ LL | let _ = [0; baz::<'a>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:33:23 + --> $DIR/const-arg-in-const-arg.rs:31:23 | LL | let _ = [0; faz::<'b>(&())]; | ^^ cannot perform const operation using `'b` @@ -89,7 +89,7 @@ LL | let _ = [0; faz::<'b>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:35:23 + --> $DIR/const-arg-in-const-arg.rs:33:23 | LL | let _ = [0; baz::<'b>(&())]; | ^^ cannot perform const operation using `'b` @@ -98,7 +98,7 @@ LL | let _ = [0; baz::<'b>(&())]; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:36:24 + --> $DIR/const-arg-in-const-arg.rs:34:24 | LL | let _: Foo<{ foo::() }>; | ^ cannot perform const operation using `T` @@ -107,7 +107,7 @@ LL | let _: Foo<{ foo::() }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:37:24 + --> $DIR/const-arg-in-const-arg.rs:35:24 | LL | let _: Foo<{ bar::() }>; | ^ cannot perform const operation using `N` @@ -116,7 +116,7 @@ LL | let _: Foo<{ bar::() }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:40:24 + --> $DIR/const-arg-in-const-arg.rs:37:24 | LL | let _: Foo<{ faz::<'a>(&()) }>; | ^^ cannot perform const operation using `'a` @@ -125,7 +125,7 @@ LL | let _: Foo<{ faz::<'a>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:42:24 + --> $DIR/const-arg-in-const-arg.rs:39:24 | LL | let _: Foo<{ baz::<'a>(&()) }>; | ^^ cannot perform const operation using `'a` @@ -134,7 +134,7 @@ LL | let _: Foo<{ baz::<'a>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:43:24 + --> $DIR/const-arg-in-const-arg.rs:40:24 | LL | let _: Foo<{ faz::<'b>(&()) }>; | ^^ cannot perform const operation using `'b` @@ -143,7 +143,7 @@ LL | let _: Foo<{ faz::<'b>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:45:24 + --> $DIR/const-arg-in-const-arg.rs:42:24 | LL | let _: Foo<{ baz::<'b>(&()) }>; | ^^ cannot perform const operation using `'b` @@ -152,7 +152,7 @@ LL | let _: Foo<{ baz::<'b>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:46:27 + --> $DIR/const-arg-in-const-arg.rs:43:27 | LL | let _ = Foo::<{ foo::() }>; | ^ cannot perform const operation using `T` @@ -161,7 +161,7 @@ LL | let _ = Foo::<{ foo::() }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:47:27 + --> $DIR/const-arg-in-const-arg.rs:44:27 | LL | let _ = Foo::<{ bar::() }>; | ^ cannot perform const operation using `N` @@ -170,7 +170,7 @@ LL | let _ = Foo::<{ bar::() }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:50:27 + --> $DIR/const-arg-in-const-arg.rs:46:27 | LL | let _ = Foo::<{ faz::<'a>(&()) }>; | ^^ cannot perform const operation using `'a` @@ -179,7 +179,7 @@ LL | let _ = Foo::<{ faz::<'a>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:52:27 + --> $DIR/const-arg-in-const-arg.rs:48:27 | LL | let _ = Foo::<{ baz::<'a>(&()) }>; | ^^ cannot perform const operation using `'a` @@ -188,7 +188,7 @@ LL | let _ = Foo::<{ baz::<'a>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:53:27 + --> $DIR/const-arg-in-const-arg.rs:49:27 | LL | let _ = Foo::<{ faz::<'b>(&()) }>; | ^^ cannot perform const operation using `'b` @@ -197,7 +197,7 @@ LL | let _ = Foo::<{ faz::<'b>(&()) }>; = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/const-arg-in-const-arg.rs:55:27 + --> $DIR/const-arg-in-const-arg.rs:51:27 | LL | let _ = Foo::<{ baz::<'b>(&()) }>; | ^^ cannot perform const operation using `'b` @@ -216,20 +216,8 @@ help: if this generic argument was intended as a const parameter, surround it wi LL | let _: [u8; bar::<{ N }>()]; | + + -error[E0284]: type annotations needed - --> $DIR/const-arg-in-const-arg.rs:16:17 - | -LL | let _: [u8; bar::()]; - | ^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `bar` - | -note: required by a const generic parameter in `bar` - --> $DIR/const-arg-in-const-arg.rs:9:14 - | -LL | const fn bar() -> usize { N } - | ^^^^^^^^^^^^^^ required by this const generic parameter in `bar` - error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:19:23 + --> $DIR/const-arg-in-const-arg.rs:18:23 | LL | let _: [u8; faz::<'a>(&())]; | ^^ @@ -241,7 +229,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:22:23 + --> $DIR/const-arg-in-const-arg.rs:21:23 | LL | let _: [u8; faz::<'b>(&())]; | ^^ @@ -253,7 +241,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0747]: unresolved item provided when a constant was expected - --> $DIR/const-arg-in-const-arg.rs:37:24 + --> $DIR/const-arg-in-const-arg.rs:35:24 | LL | let _: Foo<{ bar::() }>; | ^ @@ -263,20 +251,8 @@ help: if this generic argument was intended as a const parameter, surround it wi LL | let _: Foo<{ bar::<{ N }>() }>; | + + -error[E0284]: type annotations needed - --> $DIR/const-arg-in-const-arg.rs:37:18 - | -LL | let _: Foo<{ bar::() }>; - | ^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `bar` - | -note: required by a const generic parameter in `bar` - --> $DIR/const-arg-in-const-arg.rs:9:14 - | -LL | const fn bar() -> usize { N } - | ^^^^^^^^^^^^^^ required by this const generic parameter in `bar` - error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:40:24 + --> $DIR/const-arg-in-const-arg.rs:37:24 | LL | let _: Foo<{ faz::<'a>(&()) }>; | ^^ @@ -288,7 +264,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:43:24 + --> $DIR/const-arg-in-const-arg.rs:40:24 | LL | let _: Foo<{ faz::<'b>(&()) }>; | ^^ @@ -300,7 +276,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error: constant expression depends on a generic parameter - --> $DIR/const-arg-in-const-arg.rs:26:17 + --> $DIR/const-arg-in-const-arg.rs:25:17 | LL | let _ = [0; foo::()]; | ^^^^^^^^^^ @@ -308,7 +284,7 @@ LL | let _ = [0; foo::()]; = note: this may fail depending on what value the parameter takes error[E0747]: unresolved item provided when a constant was expected - --> $DIR/const-arg-in-const-arg.rs:27:23 + --> $DIR/const-arg-in-const-arg.rs:26:23 | LL | let _ = [0; bar::()]; | ^ @@ -318,20 +294,8 @@ help: if this generic argument was intended as a const parameter, surround it wi LL | let _ = [0; bar::<{ N }>()]; | + + -error[E0284]: type annotations needed - --> $DIR/const-arg-in-const-arg.rs:27:17 - | -LL | let _ = [0; bar::()]; - | ^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `bar` - | -note: required by a const generic parameter in `bar` - --> $DIR/const-arg-in-const-arg.rs:9:14 - | -LL | const fn bar() -> usize { N } - | ^^^^^^^^^^^^^^ required by this const generic parameter in `bar` - error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:30:23 + --> $DIR/const-arg-in-const-arg.rs:28:23 | LL | let _ = [0; faz::<'a>(&())]; | ^^ @@ -343,7 +307,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:33:23 + --> $DIR/const-arg-in-const-arg.rs:31:23 | LL | let _ = [0; faz::<'b>(&())]; | ^^ @@ -355,7 +319,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0747]: unresolved item provided when a constant was expected - --> $DIR/const-arg-in-const-arg.rs:47:27 + --> $DIR/const-arg-in-const-arg.rs:44:27 | LL | let _ = Foo::<{ bar::() }>; | ^ @@ -365,20 +329,8 @@ help: if this generic argument was intended as a const parameter, surround it wi LL | let _ = Foo::<{ bar::<{ N }>() }>; | + + -error[E0284]: type annotations needed - --> $DIR/const-arg-in-const-arg.rs:47:21 - | -LL | let _ = Foo::<{ bar::() }>; - | ^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `bar` - | -note: required by a const generic parameter in `bar` - --> $DIR/const-arg-in-const-arg.rs:9:14 - | -LL | const fn bar() -> usize { N } - | ^^^^^^^^^^^^^^ required by this const generic parameter in `bar` - error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:50:27 + --> $DIR/const-arg-in-const-arg.rs:46:27 | LL | let _ = Foo::<{ faz::<'a>(&()) }>; | ^^ @@ -390,7 +342,7 @@ LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ error[E0794]: cannot specify lifetime arguments explicitly if late bound lifetime parameters are present - --> $DIR/const-arg-in-const-arg.rs:53:27 + --> $DIR/const-arg-in-const-arg.rs:49:27 | LL | let _ = Foo::<{ faz::<'b>(&()) }>; | ^^ @@ -401,7 +353,7 @@ note: the late bound lifetime parameter is introduced here LL | const fn faz<'a>(_: &'a ()) -> usize { 13 } | ^^ -error: aborting due to 40 previous errors +error: aborting due to 36 previous errors -Some errors have detailed explanations: E0284, E0747, E0794. -For more information about an error, try `rustc --explain E0284`. +Some errors have detailed explanations: E0747, E0794. +For more information about an error, try `rustc --explain E0747`. diff --git a/tests/ui/const-generics/const-arg-in-const-arg.rs b/tests/ui/const-generics/const-arg-in-const-arg.rs index b95c63309f7..27b74489fe8 100644 --- a/tests/ui/const-generics/const-arg-in-const-arg.rs +++ b/tests/ui/const-generics/const-arg-in-const-arg.rs @@ -15,7 +15,6 @@ fn test<'a, 'b, T, const N: usize>() where &'b (): Sized { let _: [u8; foo::()]; //[min]~ ERROR generic parameters may not let _: [u8; bar::()]; //[min]~ ERROR generic parameters may not //[min]~^ ERROR unresolved item provided when a constant was expected - //[min]~| ERROR type annotations needed let _: [u8; faz::<'a>(&())]; //[min]~ ERROR generic parameters may not //[min]~^ ERROR cannot specify lifetime arguments let _: [u8; baz::<'a>(&())]; //[min]~ ERROR generic parameters may not @@ -26,7 +25,6 @@ fn test<'a, 'b, T, const N: usize>() where &'b (): Sized { let _ = [0; foo::()]; //[min]~ ERROR constant expression depends on a generic parameter let _ = [0; bar::()]; //[min]~ ERROR generic parameters may not //[min]~^ ERROR unresolved item provided when a constant was expected - //[min]~| ERROR type annotations needed let _ = [0; faz::<'a>(&())]; //[min]~ ERROR generic parameters may not //[min]~^ ERROR cannot specify lifetime arguments let _ = [0; baz::<'a>(&())]; //[min]~ ERROR generic parameters may not @@ -36,7 +34,6 @@ fn test<'a, 'b, T, const N: usize>() where &'b (): Sized { let _: Foo<{ foo::() }>; //[min]~ ERROR generic parameters may not let _: Foo<{ bar::() }>; //[min]~ ERROR generic parameters may not //[min]~^ ERROR unresolved item provided when a constant was expected - //[min]~| ERROR type annotations needed let _: Foo<{ faz::<'a>(&()) }>; //[min]~ ERROR generic parameters may not //[min]~^ ERROR cannot specify lifetime arguments let _: Foo<{ baz::<'a>(&()) }>; //[min]~ ERROR generic parameters may not @@ -46,7 +43,6 @@ fn test<'a, 'b, T, const N: usize>() where &'b (): Sized { let _ = Foo::<{ foo::() }>; //[min]~ ERROR generic parameters may not let _ = Foo::<{ bar::() }>; //[min]~ ERROR generic parameters may not //[min]~^ ERROR unresolved item provided when a constant was expected - //[min]~| ERROR type annotations needed let _ = Foo::<{ faz::<'a>(&()) }>; //[min]~ ERROR generic parameters may not //[min]~^ ERROR cannot specify lifetime arguments let _ = Foo::<{ baz::<'a>(&()) }>; //[min]~ ERROR generic parameters may not diff --git a/tests/ui/const-generics/issues/issue-62878.min.stderr b/tests/ui/const-generics/issues/issue-62878.min.stderr index 3fd50bbe298..5205726d738 100644 --- a/tests/ui/const-generics/issues/issue-62878.min.stderr +++ b/tests/ui/const-generics/issues/issue-62878.min.stderr @@ -30,31 +30,7 @@ help: add `#![feature(generic_arg_infer)]` to the crate attributes to enable LL + #![feature(generic_arg_infer)] | -error[E0284]: type annotations needed - --> $DIR/issue-62878.rs:10:5 - | -LL | foo::<_, { [1] }>(); - | ^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `foo` - | -note: required by a const generic parameter in `foo` - --> $DIR/issue-62878.rs:5:8 - | -LL | fn foo() {} - | ^^^^^^^^^^^^^^ required by this const generic parameter in `foo` +error: aborting due to 3 previous errors -error[E0284]: type annotations needed - --> $DIR/issue-62878.rs:10:5 - | -LL | foo::<_, { [1] }>(); - | ^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `A` declared on the function `foo` - | -note: required by a const generic parameter in `foo` - --> $DIR/issue-62878.rs:5:24 - | -LL | fn foo() {} - | ^^^^^^^^^^^^^^^^ required by this const generic parameter in `foo` - -error: aborting due to 5 previous errors - -Some errors have detailed explanations: E0284, E0747, E0770. -For more information about an error, try `rustc --explain E0284`. +Some errors have detailed explanations: E0747, E0770. +For more information about an error, try `rustc --explain E0747`. diff --git a/tests/ui/const-generics/issues/issue-62878.rs b/tests/ui/const-generics/issues/issue-62878.rs index c784e95edd8..0b5269df85e 100644 --- a/tests/ui/const-generics/issues/issue-62878.rs +++ b/tests/ui/const-generics/issues/issue-62878.rs @@ -9,6 +9,4 @@ fn foo() {} fn main() { foo::<_, { [1] }>(); //[min]~^ ERROR: type provided when a constant was expected - //[min]~| ERROR type annotations needed - //[min]~| ERROR type annotations needed } diff --git a/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.rs b/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.rs index 497c020bde4..e12e07a28e7 100644 --- a/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.rs +++ b/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.rs @@ -12,7 +12,6 @@ fn b() { //~^ ERROR expected trait, found constant `BAR` //~| ERROR expected trait, found constant `BAR` //~| ERROR type provided when a constant was expected - //~| ERROR type annotations needed } fn c() { foo::<3 + 3>(); //~ ERROR expressions must be enclosed in braces diff --git a/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.stderr b/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.stderr index c2ba517f609..d9bcc523b1f 100644 --- a/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.stderr +++ b/tests/ui/const-generics/min_const_generics/const-expression-suggest-missing-braces.stderr @@ -10,7 +10,7 @@ LL | foo::<{ BAR + 3 }>(); | + + error: expressions must be enclosed in braces to be used as const generic arguments - --> $DIR/const-expression-suggest-missing-braces.rs:18:11 + --> $DIR/const-expression-suggest-missing-braces.rs:17:11 | LL | foo::<3 + 3>(); | ^^^^^ @@ -21,7 +21,7 @@ LL | foo::<{ 3 + 3 }>(); | + + error: expected one of `,` or `>`, found `-` - --> $DIR/const-expression-suggest-missing-braces.rs:21:15 + --> $DIR/const-expression-suggest-missing-braces.rs:20:15 | LL | foo::(); | ^ expected one of `,` or `>` @@ -32,7 +32,7 @@ LL | foo::<{ BAR - 3 }>(); | + + error: expected one of `,` or `>`, found `-` - --> $DIR/const-expression-suggest-missing-braces.rs:24:15 + --> $DIR/const-expression-suggest-missing-braces.rs:23:15 | LL | foo::(); | ^ expected one of `,` or `>` @@ -43,7 +43,7 @@ LL | foo::<{ BAR - BAR }>(); | + + error: expressions must be enclosed in braces to be used as const generic arguments - --> $DIR/const-expression-suggest-missing-braces.rs:27:11 + --> $DIR/const-expression-suggest-missing-braces.rs:26:11 | LL | foo::<100 - BAR>(); | ^^^^^^^^^ @@ -54,7 +54,7 @@ LL | foo::<{ 100 - BAR }>(); | + + error: expected one of `,` or `>`, found `(` - --> $DIR/const-expression-suggest-missing-braces.rs:30:19 + --> $DIR/const-expression-suggest-missing-braces.rs:29:19 | LL | foo::()>(); | ^ expected one of `,` or `>` @@ -65,7 +65,7 @@ LL | foo::<{ bar() }>(); | + + error: expected one of `,` or `>`, found `(` - --> $DIR/const-expression-suggest-missing-braces.rs:33:21 + --> $DIR/const-expression-suggest-missing-braces.rs:32:21 | LL | foo::()>(); | ^ expected one of `,` or `>` @@ -76,7 +76,7 @@ LL | foo::<{ bar::() }>(); | + + error: expected one of `,` or `>`, found `(` - --> $DIR/const-expression-suggest-missing-braces.rs:36:21 + --> $DIR/const-expression-suggest-missing-braces.rs:35:21 | LL | foo::() + BAR>(); | ^ expected one of `,` or `>` @@ -87,7 +87,7 @@ LL | foo::<{ bar::() + BAR }>(); | + + error: expected one of `,` or `>`, found `(` - --> $DIR/const-expression-suggest-missing-braces.rs:39:21 + --> $DIR/const-expression-suggest-missing-braces.rs:38:21 | LL | foo::() - BAR>(); | ^ expected one of `,` or `>` @@ -98,7 +98,7 @@ LL | foo::<{ bar::() - BAR }>(); | + + error: expected one of `,` or `>`, found `-` - --> $DIR/const-expression-suggest-missing-braces.rs:42:15 + --> $DIR/const-expression-suggest-missing-braces.rs:41:15 | LL | foo::()>(); | ^ expected one of `,` or `>` @@ -109,7 +109,7 @@ LL | foo::<{ BAR - bar::() }>(); | + + error: expected one of `,` or `>`, found `-` - --> $DIR/const-expression-suggest-missing-braces.rs:45:15 + --> $DIR/const-expression-suggest-missing-braces.rs:44:15 | LL | foo::()>(); | ^ expected one of `,` or `>` @@ -137,19 +137,7 @@ error[E0747]: type provided when a constant was expected LL | foo::(); | ^^^^^^^^^ -error[E0284]: type annotations needed - --> $DIR/const-expression-suggest-missing-braces.rs:11:5 - | -LL | foo::(); - | ^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `C` declared on the function `foo` - | -note: required by a const generic parameter in `foo` - --> $DIR/const-expression-suggest-missing-braces.rs:1:8 - | -LL | fn foo() {} - | ^^^^^^^^^^^^^^ required by this const generic parameter in `foo` +error: aborting due to 14 previous errors -error: aborting due to 15 previous errors - -Some errors have detailed explanations: E0284, E0404, E0747. -For more information about an error, try `rustc --explain E0284`. +Some errors have detailed explanations: E0404, E0747. +For more information about an error, try `rustc --explain E0404`. diff --git a/tests/ui/const-generics/min_const_generics/macro-fail.rs b/tests/ui/const-generics/min_const_generics/macro-fail.rs index 25726490c2c..8cfa5293cc2 100644 --- a/tests/ui/const-generics/min_const_generics/macro-fail.rs +++ b/tests/ui/const-generics/min_const_generics/macro-fail.rs @@ -16,7 +16,6 @@ fn make_marker() -> impl Marker { //~| ERROR: type provided when a constant was expected Example:: //~^ ERROR: type provided when a constant was expected - //~| ERROR type annotations needed } fn from_marker(_: impl Marker<{ @@ -37,10 +36,8 @@ fn main() { let _fail = Example::; //~^ ERROR: type provided when a constant - //~| ERROR type annotations needed let _fail = Example::; //~^ ERROR unexpected end of macro invocation //~| ERROR: type provided when a constant was expected - //~| ERROR type annotations needed } diff --git a/tests/ui/const-generics/min_const_generics/macro-fail.stderr b/tests/ui/const-generics/min_const_generics/macro-fail.stderr index 4e183fe5b1c..34764982bb0 100644 --- a/tests/ui/const-generics/min_const_generics/macro-fail.stderr +++ b/tests/ui/const-generics/min_const_generics/macro-fail.stderr @@ -1,5 +1,5 @@ error: expected type, found `{` - --> $DIR/macro-fail.rs:31:27 + --> $DIR/macro-fail.rs:30:27 | LL | fn make_marker() -> impl Marker { | ---------------------- @@ -13,7 +13,7 @@ LL | ($rusty: ident) => {{ let $rusty = 3; *&$rusty }} = note: this error originates in the macro `gimme_a_const` (in Nightly builds, run with -Z macro-backtrace for more info) error: expected type, found `{` - --> $DIR/macro-fail.rs:31:27 + --> $DIR/macro-fail.rs:30:27 | LL | Example:: | ---------------------- @@ -41,7 +41,7 @@ LL | let _fail = Example::; = note: this error originates in the macro `external_macro` (in Nightly builds, run with -Z macro-backtrace for more info) error: unexpected end of macro invocation - --> $DIR/macro-fail.rs:42:25 + --> $DIR/macro-fail.rs:40:25 | LL | macro_rules! gimme_a_const { | -------------------------- when calling this macro @@ -50,7 +50,7 @@ LL | let _fail = Example::; | ^^^^^^^^^^^^^^^^ missing tokens in macro arguments | note: while trying to match meta-variable `$rusty:ident` - --> $DIR/macro-fail.rs:31:8 + --> $DIR/macro-fail.rs:30:8 | LL | ($rusty: ident) => {{ let $rusty = 3; *&$rusty }} | ^^^^^^^^^^^^^ @@ -75,63 +75,18 @@ error[E0747]: type provided when a constant was expected LL | Example:: | ^^^^^^^^^^^^^^^^^^^^^^ -error[E0284]: type annotations needed - --> $DIR/macro-fail.rs:17:3 - | -LL | Example:: - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the struct `Example` - | -note: required by a const generic parameter in `Example` - --> $DIR/macro-fail.rs:1:16 - | -LL | struct Example; - | ^^^^^^^^^^^^^^ required by this const generic parameter in `Example` - error[E0747]: type provided when a constant was expected - --> $DIR/macro-fail.rs:38:25 + --> $DIR/macro-fail.rs:37:25 | LL | let _fail = Example::; | ^^^^^^^^^^^^^^^^^ error[E0747]: type provided when a constant was expected - --> $DIR/macro-fail.rs:42:25 + --> $DIR/macro-fail.rs:40:25 | LL | let _fail = Example::; | ^^^^^^^^^^^^^^^^ -error[E0284]: type annotations needed for `Example<_>` - --> $DIR/macro-fail.rs:38:7 - | -LL | let _fail = Example::; - | ^^^^^ ---------------------------- type must be known at this point - | -note: required by a const generic parameter in `Example` - --> $DIR/macro-fail.rs:1:16 - | -LL | struct Example; - | ^^^^^^^^^^^^^^ required by this const generic parameter in `Example` -help: consider giving `_fail` an explicit type, where the value of const parameter `N` is specified - | -LL | let _fail: Example = Example::; - | ++++++++++++ +error: aborting due to 9 previous errors -error[E0284]: type annotations needed for `Example<_>` - --> $DIR/macro-fail.rs:42:7 - | -LL | let _fail = Example::; - | ^^^^^ --------------------------- type must be known at this point - | -note: required by a const generic parameter in `Example` - --> $DIR/macro-fail.rs:1:16 - | -LL | struct Example; - | ^^^^^^^^^^^^^^ required by this const generic parameter in `Example` -help: consider giving `_fail` an explicit type, where the value of const parameter `N` is specified - | -LL | let _fail: Example = Example::; - | ++++++++++++ - -error: aborting due to 12 previous errors - -Some errors have detailed explanations: E0284, E0747. -For more information about an error, try `rustc --explain E0284`. +For more information about this error, try `rustc --explain E0747`. diff --git a/tests/ui/const-generics/suggest_const_for_array.rs b/tests/ui/const-generics/suggest_const_for_array.rs index 4d29d069375..b52fd152f97 100644 --- a/tests/ui/const-generics/suggest_const_for_array.rs +++ b/tests/ui/const-generics/suggest_const_for_array.rs @@ -5,8 +5,6 @@ fn example() {} fn other() { example::<[usize; 3]>(); //~^ ERROR type provided when a const - //~| ERROR type annotations needed example::<[usize; 4 + 5]>(); //~^ ERROR type provided when a const - //~| ERROR type annotations needed } diff --git a/tests/ui/const-generics/suggest_const_for_array.stderr b/tests/ui/const-generics/suggest_const_for_array.stderr index c867914070b..f0ad8368e5d 100644 --- a/tests/ui/const-generics/suggest_const_for_array.stderr +++ b/tests/ui/const-generics/suggest_const_for_array.stderr @@ -5,36 +5,11 @@ LL | example::<[usize; 3]>(); | ^^^^^^^^^^ help: array type provided where a `usize` was expected, try: `{ 3 }` error[E0747]: type provided when a constant was expected - --> $DIR/suggest_const_for_array.rs:9:15 + --> $DIR/suggest_const_for_array.rs:8:15 | LL | example::<[usize; 4 + 5]>(); | ^^^^^^^^^^^^^^ help: array type provided where a `usize` was expected, try: `{ 4 + 5 }` -error[E0284]: type annotations needed - --> $DIR/suggest_const_for_array.rs:6:5 - | -LL | example::<[usize; 3]>(); - | ^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `example` - | -note: required by a const generic parameter in `example` - --> $DIR/suggest_const_for_array.rs:3:12 - | -LL | fn example() {} - | ^^^^^^^^^^^^^^ required by this const generic parameter in `example` +error: aborting due to 2 previous errors -error[E0284]: type annotations needed - --> $DIR/suggest_const_for_array.rs:9:5 - | -LL | example::<[usize; 4 + 5]>(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `example` - | -note: required by a const generic parameter in `example` - --> $DIR/suggest_const_for_array.rs:3:12 - | -LL | fn example() {} - | ^^^^^^^^^^^^^^ required by this const generic parameter in `example` - -error: aborting due to 4 previous errors - -Some errors have detailed explanations: E0284, E0747. -For more information about an error, try `rustc --explain E0284`. +For more information about this error, try `rustc --explain E0747`. diff --git a/tests/ui/generics/generic-function-item-where-type.rs b/tests/ui/generics/generic-function-item-where-type.rs index 0e36018389e..e1b0578cadb 100644 --- a/tests/ui/generics/generic-function-item-where-type.rs +++ b/tests/ui/generics/generic-function-item-where-type.rs @@ -3,5 +3,4 @@ fn foo() {} fn main() { foo::
() //~^ ERROR constant provided when a type was expected - //~| ERROR type annotations needed } diff --git a/tests/ui/generics/generic-function-item-where-type.stderr b/tests/ui/generics/generic-function-item-where-type.stderr index 5b0c9a8ee6d..00e62843cb4 100644 --- a/tests/ui/generics/generic-function-item-where-type.stderr +++ b/tests/ui/generics/generic-function-item-where-type.stderr @@ -7,13 +7,6 @@ LL | foo::
() = help: `main` is a function item, not a type = help: function item types cannot be named directly -error[E0282]: type annotations needed - --> $DIR/generic-function-item-where-type.rs:4:5 - | -LL | foo::
() - | ^^^^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `foo` +error: aborting due to 1 previous error -error: aborting due to 2 previous errors - -Some errors have detailed explanations: E0282, E0747. -For more information about an error, try `rustc --explain E0282`. +For more information about this error, try `rustc --explain E0747`.