diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs index 3d154a93fb2..08ee3761bac 100644 --- a/compiler/rustc_ast_lowering/src/item.rs +++ b/compiler/rustc_ast_lowering/src/item.rs @@ -305,7 +305,10 @@ fn lower_item_kind( ); this.arena.alloc(this.ty(span, hir::TyKind::Err(guar))) } - Some(ty) => this.lower_ty(ty, &ImplTraitContext::TypeAliasesOpaqueTy), + Some(ty) => this.lower_ty( + ty, + &ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: false }, + ), }, ); hir::ItemKind::TyAlias(ty, generics) @@ -852,7 +855,10 @@ fn lower_impl_item(&mut self, i: &AssocItem) -> &'hir hir::ImplItem<'hir> { hir::ImplItemKind::Type(ty) } Some(ty) => { - let ty = this.lower_ty(ty, &ImplTraitContext::TypeAliasesOpaqueTy); + let ty = this.lower_ty( + ty, + &ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: true }, + ); hir::ImplItemKind::Type(ty) } }, diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs index 1fd7cc66470..cd6614a54a4 100644 --- a/compiler/rustc_ast_lowering/src/lib.rs +++ b/compiler/rustc_ast_lowering/src/lib.rs @@ -247,7 +247,7 @@ enum ImplTraitContext { in_trait: bool, }, /// Impl trait in type aliases. - TypeAliasesOpaqueTy, + TypeAliasesOpaqueTy { in_assoc_ty: bool }, /// `impl Trait` is unstably accepted in this position. FeatureGated(ImplTraitPosition, Symbol), /// `impl Trait` is not accepted in this position. @@ -1407,14 +1407,15 @@ fn lower_ty_direct(&mut self, t: &Ty, itctx: &ImplTraitContext) -> hir::Ty<'hir> *in_trait, itctx, ), - ImplTraitContext::TypeAliasesOpaqueTy => self.lower_opaque_impl_trait( - span, - hir::OpaqueTyOrigin::TyAlias, - *def_node_id, - bounds, - false, - itctx, - ), + &ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty } => self + .lower_opaque_impl_trait( + span, + hir::OpaqueTyOrigin::TyAlias { in_assoc_ty }, + *def_node_id, + bounds, + false, + itctx, + ), ImplTraitContext::Universal => { let span = t.span; self.create_def( @@ -1534,13 +1535,16 @@ fn lower_opaque_impl_trait( // If this came from a TAIT (as opposed to a function that returns an RPIT), we only want // to capture the lifetimes that appear in the bounds. So visit the bounds to find out // exactly which ones those are. - let lifetimes_to_remap = if origin == hir::OpaqueTyOrigin::TyAlias { - // in a TAIT like `type Foo<'a> = impl Foo<'a>`, we don't keep all the lifetime parameters - Vec::new() - } else { - // in fn return position, like the `fn test<'a>() -> impl Debug + 'a` example, - // we only keep the lifetimes that appear in the `impl Debug` itself: - lifetime_collector::lifetimes_in_bounds(&self.resolver, bounds) + let lifetimes_to_remap = match origin { + hir::OpaqueTyOrigin::TyAlias { .. } => { + // in a TAIT like `type Foo<'a> = impl Foo<'a>`, we don't keep all the lifetime parameters + Vec::new() + } + hir::OpaqueTyOrigin::AsyncFn(..) | hir::OpaqueTyOrigin::FnReturn(..) => { + // in fn return position, like the `fn test<'a>() -> impl Debug + 'a` example, + // we only keep the lifetimes that appear in the `impl Debug` itself: + lifetime_collector::lifetimes_in_bounds(&self.resolver, bounds) + } }; debug!(?lifetimes_to_remap); diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs index 4970ece5e7d..309f23d9226 100644 --- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs +++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs @@ -265,7 +265,7 @@ fn infer_opaque_definition_from_instantiation( // Only check this for TAIT. RPIT already supports `tests/ui/impl-trait/nested-return-type2.rs` // on stable and we'd break that. - let OpaqueTyOrigin::TyAlias = origin else { + let OpaqueTyOrigin::TyAlias { .. } = origin else { return definition_ty; }; let def_id = opaque_type_key.def_id; @@ -360,7 +360,7 @@ fn check_opaque_type_parameter_valid( // which would error here on all of the `'static` args. OpaqueTyOrigin::FnReturn(..) | OpaqueTyOrigin::AsyncFn(..) => return Ok(()), // Check these - OpaqueTyOrigin::TyAlias => {} + OpaqueTyOrigin::TyAlias { .. } => {} } let opaque_generics = tcx.generics_of(opaque_type_key.def_id); let mut seen_params: FxIndexMap<_, Vec<_>> = FxIndexMap::default(); diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs index 38cd5865cc3..932f0396282 100644 --- a/compiler/rustc_hir/src/hir.rs +++ b/compiler/rustc_hir/src/hir.rs @@ -2662,7 +2662,10 @@ pub enum OpaqueTyOrigin { /// `async fn` AsyncFn(LocalDefId), /// type aliases: `type Foo = impl Trait;` - TyAlias, + TyAlias { + /// associated types in impl blocks for traits. + in_assoc_ty: bool, + }, } /// The various kinds of types recognized by the compiler. diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index 5187e63f8e3..78ffe59679a 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -397,7 +397,7 @@ fn check_opaque_meets_bounds<'tcx>( ) { let defining_use_anchor = match *origin { hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did, - hir::OpaqueTyOrigin::TyAlias => def_id, + hir::OpaqueTyOrigin::TyAlias { .. } => tcx.impl_trait_parent(def_id), }; let param_env = tcx.param_env(defining_use_anchor); @@ -455,10 +455,10 @@ fn check_opaque_meets_bounds<'tcx>( // They can only be referenced as ` as Trait<&'static T>>::AssocTy`. // We don't have to check them here because their well-formedness follows from the WF of // the projection input types in the defining- and use-sites. - hir::OpaqueTyOrigin::TyAlias + hir::OpaqueTyOrigin::TyAlias { .. } if tcx.def_kind(tcx.parent(def_id.to_def_id())) == DefKind::OpaqueTy => {} // Can have different predicates to their defining use - hir::OpaqueTyOrigin::TyAlias => { + hir::OpaqueTyOrigin::TyAlias { .. } => { let wf_tys = ocx.assumed_wf_types(param_env, span, def_id); let implied_bounds = infcx.implied_bounds_tys(param_env, def_id, wf_tys); let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds); diff --git a/compiler/rustc_hir_analysis/src/check/dropck.rs b/compiler/rustc_hir_analysis/src/check/dropck.rs index 5ba1ca1c807..e0ba255cc06 100644 --- a/compiler/rustc_hir_analysis/src/check/dropck.rs +++ b/compiler/rustc_hir_analysis/src/check/dropck.rs @@ -6,7 +6,7 @@ use rustc_infer::infer::outlives::env::OutlivesEnvironment; use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt}; use rustc_middle::ty::subst::SubstsRef; -use rustc_middle::ty::util::IgnoreRegions; +use rustc_middle::ty::util::CheckRegions; use rustc_middle::ty::{self, TyCtxt}; use rustc_trait_selection::traits::{self, ObligationCtxt}; @@ -81,7 +81,7 @@ fn ensure_drop_params_and_item_params_correspond<'tcx>( self_type_did: DefId, adt_to_impl_substs: SubstsRef<'tcx>, ) -> Result<(), ErrorGuaranteed> { - let Err(arg) = tcx.uses_unique_generic_params(adt_to_impl_substs, IgnoreRegions::No) else { + let Err(arg) = tcx.uses_unique_generic_params(adt_to_impl_substs, CheckRegions::OnlyEarlyBound) else { return Ok(()) }; diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs index 272177dfbd0..23beacd2a8c 100644 --- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs +++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs @@ -6,7 +6,7 @@ use rustc_errors::{Diagnostic, ErrorGuaranteed}; use rustc_hir as hir; use rustc_middle::ty::subst::InternalSubsts; -use rustc_middle::ty::util::IgnoreRegions; +use rustc_middle::ty::util::CheckRegions; use rustc_middle::ty::{ self, AliasKind, ImplPolarity, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, @@ -507,7 +507,7 @@ fn lint_auto_trait_impl<'tcx>( // Impls which completely cover a given root type are fine as they // disable auto impls entirely. So only lint if the substs // are not a permutation of the identity substs. - let Err(arg) = tcx.uses_unique_generic_params(substs, IgnoreRegions::Yes) else { + let Err(arg) = tcx.uses_unique_generic_params(substs, CheckRegions::No) else { // ok return; }; diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs index b65817ee95e..2f808d4ce73 100644 --- a/compiler/rustc_hir_analysis/src/collect.rs +++ b/compiler/rustc_hir_analysis/src/collect.rs @@ -1483,7 +1483,7 @@ fn generator_kind(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool { match tcx.hir().get_by_def_id(def_id) { Node::Item(hir::Item { kind: hir::ItemKind::OpaqueTy(opaque), .. }) => { - matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias) + matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias { .. }) } _ => bug!("tried getting opaque_ty_origin for non-opaque: {:?}", def_id), } diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs index ab2932bf969..ed60998ec8d 100644 --- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs @@ -159,7 +159,10 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics { } Some(fn_def_id.to_def_id()) } - ItemKind::OpaqueTy(hir::OpaqueTy { origin: hir::OpaqueTyOrigin::TyAlias, .. }) => { + ItemKind::OpaqueTy(hir::OpaqueTy { + origin: hir::OpaqueTyOrigin::TyAlias { .. }, + .. + }) => { let parent_id = tcx.hir().get_parent_item(hir_id); assert_ne!(parent_id, hir::CRATE_OWNER_ID); debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent_id); diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs index e04658c8e77..a33990813b8 100644 --- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs @@ -721,7 +721,7 @@ pub(super) fn type_param_predicates( | ItemKind::TyAlias(_, generics) | ItemKind::OpaqueTy(OpaqueTy { generics, - origin: hir::OpaqueTyOrigin::TyAlias, + origin: hir::OpaqueTyOrigin::TyAlias { .. }, .. }) | ItemKind::Enum(_, generics) diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs index 5c7f7f10b17..92ae93cf4cc 100644 --- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs +++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs @@ -526,7 +526,8 @@ fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) { }); } hir::ItemKind::OpaqueTy(hir::OpaqueTy { - origin: hir::OpaqueTyOrigin::TyAlias, .. + origin: hir::OpaqueTyOrigin::TyAlias { .. }, + .. }) => { // Opaque types are visited when we visit the // `TyKind::OpaqueDef`, so that they have the lifetimes from @@ -707,7 +708,7 @@ fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) { let opaque_ty = self.tcx.hir().item(item_id); match &opaque_ty.kind { hir::ItemKind::OpaqueTy(hir::OpaqueTy { - origin: hir::OpaqueTyOrigin::TyAlias, + origin: hir::OpaqueTyOrigin::TyAlias { .. }, .. }) => { intravisit::walk_ty(self, ty); diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs index 8df0166f76b..6c7c2b9eea2 100644 --- a/compiler/rustc_hir_analysis/src/collect/type_of.rs +++ b/compiler/rustc_hir_analysis/src/collect/type_of.rs @@ -426,9 +426,10 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder { - find_opaque_ty_constraints_for_tait(tcx, def_id) - } + ItemKind::OpaqueTy(OpaqueTy { + origin: hir::OpaqueTyOrigin::TyAlias { .. }, + .. + }) => find_opaque_ty_constraints_for_tait(tcx, def_id), // Opaque types desugared from `impl Trait`. ItemKind::OpaqueTy(OpaqueTy { origin: diff --git a/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs index 064811bd29d..421eb807a14 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs @@ -2,6 +2,7 @@ use rustc_errors::Applicability::{MachineApplicable, MaybeIncorrect}; use rustc_errors::{pluralize, Diagnostic, MultiSpan}; use rustc_hir as hir; +use rustc_hir::def::DefKind; use rustc_middle::traits::ObligationCauseCode; use rustc_middle::ty::error::ExpectedFound; use rustc_middle::ty::print::Printer; @@ -256,6 +257,15 @@ fn foo(&self, x: T) -> T { x } ); } } + (ty::Alias(ty::Opaque, alias), _) | (_, ty::Alias(ty::Opaque, alias)) if alias.def_id.is_local() && matches!(tcx.def_kind(body_owner_def_id), DefKind::AssocFn | DefKind::AssocConst) => { + if tcx.is_type_alias_impl_trait(alias.def_id) { + if !tcx.opaque_types_defined_by(body_owner_def_id.expect_local()).contains(&alias.def_id.expect_local()) { + diag.span_note(tcx.def_span(body_owner_def_id), "\ + this item must have the opaque type in its signature \ + in order to be able to register hidden types"); + } + } + } (ty::FnPtr(_), ty::FnDef(def, _)) if let hir::def::DefKind::Fn = tcx.def_kind(def) => { diag.note( diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs index 362b22b23a8..545310ad351 100644 --- a/compiler/rustc_infer/src/infer/opaque_types.rs +++ b/compiler/rustc_infer/src/infer/opaque_types.rs @@ -149,7 +149,7 @@ pub fn handle_opaque_type( // no one encounters it in practice. // It does occur however in `fn fut() -> impl Future { async { 42 } }`, // where it is of no concern, so we only check for TAITs. - if let Some(OpaqueTyOrigin::TyAlias) = + if let Some(OpaqueTyOrigin::TyAlias { .. }) = b_def_id.as_local().and_then(|b_def_id| self.opaque_type_origin(b_def_id)) { self.tcx.sess.emit_err(OpaqueHiddenTypeDiag { @@ -381,8 +381,12 @@ pub fn opaque_type_origin(&self, def_id: LocalDefId) -> Option { // Anonymous `impl Trait` hir::OpaqueTyOrigin::FnReturn(parent) => parent == parent_def_id, // Named `type Foo = impl Bar;` - hir::OpaqueTyOrigin::TyAlias => { - may_define_opaque_type(self.tcx, parent_def_id, opaque_hir_id) + hir::OpaqueTyOrigin::TyAlias { in_assoc_ty } => { + if in_assoc_ty { + self.tcx.opaque_types_defined_by(parent_def_id).contains(&def_id) + } else { + may_define_opaque_type(self.tcx, parent_def_id, opaque_hir_id) + } } }; in_definition_scope.then_some(origin) diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs index 29cf432b8f9..043410c47e0 100644 --- a/compiler/rustc_metadata/src/rmeta/encoder.rs +++ b/compiler/rustc_metadata/src/rmeta/encoder.rs @@ -1641,9 +1641,10 @@ fn encode_info_for_item(&mut self, item: &'tcx hir::Item<'tcx>) { } hir::ItemKind::OpaqueTy(ref opaque) => { self.encode_explicit_item_bounds(def_id); - self.tables - .is_type_alias_impl_trait - .set(def_id.index, matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias)); + self.tables.is_type_alias_impl_trait.set( + def_id.index, + matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias { .. }), + ); } hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => { self.tables.impl_defaultness.set_some(def_id.index, *defaultness); diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs index 28a9c1eef1a..b45f7caaabe 100644 --- a/compiler/rustc_middle/src/query/erase.rs +++ b/compiler/rustc_middle/src/query/erase.rs @@ -172,6 +172,10 @@ impl EraseType for ty::Binder<'_, ty::FnSig<'_>> { type Result = [u8; size_of::>>()]; } +impl EraseType for ty::Binder<'_, &'_ ty::List>> { + type Result = [u8; size_of::>>>()]; +} + impl EraseType for (&'_ T0, &'_ T1) { type Result = [u8; size_of::<(&'static (), &'static ())>()]; } diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs index 9fad2816b0d..5acdd68e60e 100644 --- a/compiler/rustc_middle/src/query/mod.rs +++ b/compiler/rustc_middle/src/query/mod.rs @@ -236,6 +236,15 @@ cache_on_disk_if { key.is_local() } } + query opaque_types_defined_by( + key: LocalDefId + ) -> &'tcx [LocalDefId] { + desc { + |tcx| "computing the opaque types defined by `{}`", + tcx.def_path_str(key.to_def_id()) + } + } + /// Returns the list of bounds that can be used for /// `SelectionCandidate::ProjectionCandidate(_)` and /// `ProjectionTyCandidate::TraitDef`. diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index f882f54d628..b414e1200cd 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -2476,6 +2476,18 @@ pub fn impl_trait_in_trait_parent_fn(self, mut def_id: DefId) -> DefId { } } + /// Returns the `DefId` of the item within which the `impl Trait` is declared. + /// For type-alias-impl-trait this is the `type` alias. + /// For impl-trait-in-assoc-type this is the assoc type. + /// For return-position-impl-trait this is the function. + pub fn impl_trait_parent(self, mut def_id: LocalDefId) -> LocalDefId { + // Find the surrounding item (type alias or assoc type) + while let DefKind::OpaqueTy = self.def_kind(def_id) { + def_id = self.local_parent(def_id); + } + def_id + } + pub fn impl_method_has_trait_impl_trait_tys(self, def_id: DefId) -> bool { if self.def_kind(def_id) != DefKind::AssocFn { return false; @@ -2520,7 +2532,7 @@ pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option hir::OpaqueTyOrigin::FnReturn(parent) | hir::OpaqueTyOrigin::AsyncFn(parent) => { Some(parent) } - hir::OpaqueTyOrigin::TyAlias => None, + hir::OpaqueTyOrigin::TyAlias { .. } => None, }; } } diff --git a/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs b/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs index 9332b0430ff..a0c8d299f48 100644 --- a/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs +++ b/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs @@ -32,7 +32,7 @@ impl<'tcx> TyCtxt<'tcx> { /// /// This should only be used outside of type inference. For example, /// it assumes that normalization will succeed. - #[tracing::instrument(level = "debug", skip(self, param_env))] + #[tracing::instrument(level = "debug", skip(self, param_env), ret)] pub fn normalize_erasing_regions(self, param_env: ty::ParamEnv<'tcx>, value: T) -> T where T: TypeFoldable>, diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index 488d83b5f67..d175cf72d67 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -1265,7 +1265,7 @@ pub fn trait_def_id(self, tcx: TyCtxt<'tcx>) -> DefId { /// Extracts the underlying trait reference and own substs from this projection. /// For example, if this is a projection of `::Item<'a>`, - /// then this function would return a `T: Iterator` trait reference and `['a]` as the own substs + /// then this function would return a `T: StreamingIterator` trait reference and `['a]` as the own substs pub fn trait_ref_and_own_substs( self, tcx: TyCtxt<'tcx>, diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs index bcb51db9bcf..9bab693156b 100644 --- a/compiler/rustc_middle/src/ty/util.rs +++ b/compiler/rustc_middle/src/ty/util.rs @@ -34,9 +34,14 @@ pub struct Discr<'tcx> { /// Used as an input to [`TyCtxt::uses_unique_generic_params`]. #[derive(Copy, Clone, Debug, PartialEq, Eq)] -pub enum IgnoreRegions { - Yes, +pub enum CheckRegions { No, + /// Only permit early bound regions. This is useful for Adts which + /// can never have late bound regions. + OnlyEarlyBound, + /// Permit both late bound and early bound regions. Use this for functions, + /// which frequently have late bound regions. + Bound, } #[derive(Copy, Clone, Debug)] @@ -468,21 +473,28 @@ pub fn destructor_constraints(self, def: ty::AdtDef<'tcx>) -> Vec, - ignore_regions: IgnoreRegions, + ignore_regions: CheckRegions, ) -> Result<(), NotUniqueParam<'tcx>> { let mut seen = GrowableBitSet::default(); + let mut seen_late = FxHashSet::default(); for arg in substs { match arg.unpack() { - GenericArgKind::Lifetime(lt) => { - if ignore_regions == IgnoreRegions::No { - let ty::ReEarlyBound(p) = lt.kind() else { - return Err(NotUniqueParam::NotParam(lt.into())) - }; + GenericArgKind::Lifetime(lt) => match (ignore_regions, lt.kind()) { + (CheckRegions::Bound, ty::ReLateBound(di, reg)) => { + if !seen_late.insert((di, reg)) { + return Err(NotUniqueParam::DuplicateParam(lt.into())); + } + } + (CheckRegions::OnlyEarlyBound | CheckRegions::Bound, ty::ReEarlyBound(p)) => { if !seen.insert(p.index) { return Err(NotUniqueParam::DuplicateParam(lt.into())); } } - } + (CheckRegions::OnlyEarlyBound | CheckRegions::Bound, _) => { + return Err(NotUniqueParam::NotParam(lt.into())); + } + (CheckRegions::No, _) => {} + }, GenericArgKind::Type(t) => match t.kind() { ty::Param(p) => { if !seen.insert(p.index) { diff --git a/compiler/rustc_ty_utils/messages.ftl b/compiler/rustc_ty_utils/messages.ftl index 15a14112f4a..5bc3e3c00c9 100644 --- a/compiler/rustc_ty_utils/messages.ftl +++ b/compiler/rustc_ty_utils/messages.ftl @@ -55,3 +55,11 @@ ty_utils_multiple_array_fields_simd_type = monomorphising SIMD type `{$ty}` with ty_utils_oversized_simd_type = monomorphising SIMD type `{$ty}` of length greater than {$max_lanes} ty_utils_non_primitive_simd_type = monomorphising SIMD type `{$ty}` with a non-primitive-scalar (integer/float/pointer) element type `{$e_ty}` + +ty_utils_impl_trait_duplicate_arg = non-defining opaque type use in defining scope + .label = generic argument `{$arg}` used twice + .note = for this opaque type + +ty_utils_impl_trait_not_param = non-defining opaque type use in defining scope + .label = argument `{$arg}` is not a generic parameter + .note = for this opaque type diff --git a/compiler/rustc_ty_utils/src/errors.rs b/compiler/rustc_ty_utils/src/errors.rs index 3d3fc50e6e5..553bf40ef3a 100644 --- a/compiler/rustc_ty_utils/src/errors.rs +++ b/compiler/rustc_ty_utils/src/errors.rs @@ -1,7 +1,7 @@ //! Errors emitted by ty_utils use rustc_macros::{Diagnostic, Subdiagnostic}; -use rustc_middle::ty::Ty; +use rustc_middle::ty::{GenericArg, Ty}; use rustc_span::Span; #[derive(Diagnostic)] @@ -100,3 +100,25 @@ pub struct NonPrimitiveSimdType<'tcx> { pub ty: Ty<'tcx>, pub e_ty: Ty<'tcx>, } + +#[derive(Diagnostic)] +#[diag(ty_utils_impl_trait_duplicate_arg)] +pub struct DuplicateArg<'tcx> { + pub arg: GenericArg<'tcx>, + #[primary_span] + #[label] + pub span: Span, + #[note] + pub opaque_span: Span, +} + +#[derive(Diagnostic)] +#[diag(ty_utils_impl_trait_not_param)] +pub struct NotParam<'tcx> { + pub arg: GenericArg<'tcx>, + #[primary_span] + #[label] + pub span: Span, + #[note] + pub opaque_span: Span, +} diff --git a/compiler/rustc_ty_utils/src/lib.rs b/compiler/rustc_ty_utils/src/lib.rs index 73a2f6af579..8306c5ae493 100644 --- a/compiler/rustc_ty_utils/src/lib.rs +++ b/compiler/rustc_ty_utils/src/lib.rs @@ -33,6 +33,7 @@ mod layout; mod layout_sanity_check; mod needs_drop; +mod opaque_types; pub mod representability; mod structural_match; mod ty; @@ -47,6 +48,7 @@ pub fn provide(providers: &mut Providers) { implied_bounds::provide(providers); layout::provide(providers); needs_drop::provide(providers); + opaque_types::provide(providers); representability::provide(providers); ty::provide(providers); instance::provide(providers); diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs new file mode 100644 index 00000000000..25ebb333bf7 --- /dev/null +++ b/compiler/rustc_ty_utils/src/opaque_types.rs @@ -0,0 +1,197 @@ +use rustc_data_structures::fx::FxHashSet; +use rustc_errors::ErrorGuaranteed; +use rustc_hir::{def::DefKind, def_id::LocalDefId}; +use rustc_middle::ty::util::{CheckRegions, NotUniqueParam}; +use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::ty::{TypeSuperVisitable, TypeVisitable, TypeVisitor}; +use rustc_span::Span; +use rustc_type_ir::AliasKind; +use std::ops::ControlFlow; + +use crate::errors::{DuplicateArg, NotParam}; + +struct OpaqueTypeCollector<'tcx> { + tcx: TyCtxt<'tcx>, + opaques: Vec, + /// The `DefId` of the item which we are collecting opaque types for. + item: LocalDefId, + + /// Avoid infinite recursion due to recursive declarations. + seen: FxHashSet, +} + +impl<'tcx> OpaqueTypeCollector<'tcx> { + fn collect( + tcx: TyCtxt<'tcx>, + item: LocalDefId, + val: ty::Binder<'tcx, impl TypeVisitable>>, + ) -> Vec { + let mut collector = Self { tcx, opaques: Vec::new(), item, seen: Default::default() }; + val.skip_binder().visit_with(&mut collector); + collector.opaques + } + + fn span(&self) -> Span { + self.tcx.def_span(self.item) + } + + fn parent(&self) -> Option { + match self.tcx.def_kind(self.item) { + DefKind::Fn => None, + DefKind::AssocFn | DefKind::AssocTy | DefKind::AssocConst => { + Some(self.tcx.local_parent(self.item)) + } + other => span_bug!( + self.tcx.def_span(self.item), + "unhandled item with opaque types: {other:?}" + ), + } + } +} + +impl<'tcx> TypeVisitor> for OpaqueTypeCollector<'tcx> { + type BreakTy = ErrorGuaranteed; + + #[instrument(skip(self), ret, level = "trace")] + fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow { + match t.kind() { + ty::Alias(AliasKind::Opaque, alias_ty) if alias_ty.def_id.is_local() => { + if !self.seen.insert(alias_ty.def_id.expect_local()) { + return ControlFlow::Continue(()); + } + match self.tcx.uses_unique_generic_params(alias_ty.substs, CheckRegions::Bound) { + Ok(()) => { + // FIXME: implement higher kinded lifetime bounds on nested opaque types. They are not + // supported at all, so this is sound to do, but once we want to support them, you'll + // start seeing the error below. + + self.opaques.push(alias_ty.def_id.expect_local()); + + // Collect opaque types nested within the associated type bounds of this opaque type. + for (pred, _span) in self + .tcx + .explicit_item_bounds(alias_ty.def_id) + .subst_iter_copied(self.tcx, alias_ty.substs) + { + trace!(?pred); + pred.visit_with(self)?; + } + + ControlFlow::Continue(()) + } + Err(NotUniqueParam::NotParam(arg)) => { + let err = self.tcx.sess.emit_err(NotParam { + arg, + span: self.span(), + opaque_span: self.tcx.def_span(alias_ty.def_id), + }); + ControlFlow::Break(err) + } + Err(NotUniqueParam::DuplicateParam(arg)) => { + let err = self.tcx.sess.emit_err(DuplicateArg { + arg, + span: self.span(), + opaque_span: self.tcx.def_span(alias_ty.def_id), + }); + ControlFlow::Break(err) + } + } + } + ty::Alias(AliasKind::Projection, alias_ty) => { + if let Some(parent) = self.parent() { + trace!(?alias_ty); + let (trait_ref, own_substs) = alias_ty.trait_ref_and_own_substs(self.tcx); + + trace!(?trait_ref, ?own_substs); + // This avoids having to do normalization of `Self::AssocTy` by only + // supporting the case of a method defining opaque types from assoc types + // in the same impl block. + if trait_ref.self_ty() == self.tcx.type_of(parent).subst_identity() { + for assoc in self.tcx.associated_items(parent).in_definition_order() { + trace!(?assoc); + if assoc.trait_item_def_id == Some(alias_ty.def_id) { + // We reconstruct the generic args of the associated type within the impl + // from the impl's generics and the generic args passed to the type via the + // projection. + let substs = ty::InternalSubsts::identity_for_item( + self.tcx, + parent.to_def_id(), + ); + trace!(?substs); + let substs: Vec<_> = + substs.iter().chain(own_substs.iter().copied()).collect(); + trace!(?substs); + // Find opaque types in this associated type. + return self + .tcx + .type_of(assoc.def_id) + .subst(self.tcx, &substs) + .visit_with(self); + } + } + } + } + t.super_visit_with(self) + } + _ => t.super_visit_with(self), + } + } +} + +fn opaque_types_defined_by<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx [LocalDefId] { + let kind = tcx.def_kind(item); + trace!(?kind); + // FIXME(type_alias_impl_trait): This is definitely still wrong except for RPIT and impl trait in assoc types. + match kind { + // We're also doing this for `AssocTy` for the wf checks in `check_opaque_meets_bounds` + DefKind::Fn | DefKind::AssocFn | DefKind::AssocTy | DefKind::AssocConst => { + let defined_opaques = match kind { + DefKind::Fn => { + OpaqueTypeCollector::collect(tcx, item, tcx.fn_sig(item).subst_identity()) + } + DefKind::AssocFn => { + OpaqueTypeCollector::collect(tcx, item, tcx.fn_sig(item).subst_identity()) + } + DefKind::AssocTy | DefKind::AssocConst => OpaqueTypeCollector::collect( + tcx, + item, + ty::Binder::dummy(tcx.type_of(item).subst_identity()), + ), + _ => unreachable!(), + }; + tcx.arena.alloc_from_iter(defined_opaques) + } + DefKind::Mod + | DefKind::Struct + | DefKind::Union + | DefKind::Enum + | DefKind::Variant + | DefKind::Trait + | DefKind::TyAlias + | DefKind::ForeignTy + | DefKind::TraitAlias + | DefKind::TyParam + | DefKind::Const + | DefKind::ConstParam + | DefKind::Static(_) + | DefKind::Ctor(_, _) + | DefKind::Macro(_) + | DefKind::ExternCrate + | DefKind::Use + | DefKind::ForeignMod + | DefKind::AnonConst + | DefKind::InlineConst + | DefKind::OpaqueTy + | DefKind::ImplTraitPlaceholder + | DefKind::Field + | DefKind::LifetimeParam + | DefKind::GlobalAsm + | DefKind::Impl { .. } + | DefKind::Closure + | DefKind::Generator => &[], + } +} + +pub(super) fn provide(providers: &mut ty::query::Providers) { + *providers = ty::query::Providers { opaque_types_defined_by, ..*providers }; +} diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs index deb29b1e7a9..ff13daa6db4 100644 --- a/src/librustdoc/visit_ast.rs +++ b/src/librustdoc/visit_ast.rs @@ -455,7 +455,8 @@ fn visit_item_inner( | hir::ItemKind::Union(..) | hir::ItemKind::TyAlias(..) | hir::ItemKind::OpaqueTy(hir::OpaqueTy { - origin: hir::OpaqueTyOrigin::TyAlias, .. + origin: hir::OpaqueTyOrigin::TyAlias { .. }, + .. }) | hir::ItemKind::Static(..) | hir::ItemKind::Trait(..) diff --git a/tests/ui/generic-associated-types/issue-88595.rs b/tests/ui/generic-associated-types/issue-88595.rs index 5a40a612972..7de906e7ef3 100644 --- a/tests/ui/generic-associated-types/issue-88595.rs +++ b/tests/ui/generic-associated-types/issue-88595.rs @@ -19,4 +19,5 @@ impl<'a> A<'a> for C { type B<'b> = impl Clone; fn a(&'a self) -> Self::B<'a> {} //~ ERROR: non-defining opaque type use in defining scope + //~^ ERROR: mismatched types } diff --git a/tests/ui/generic-associated-types/issue-88595.stderr b/tests/ui/generic-associated-types/issue-88595.stderr index 79d3479af8c..d6caed85459 100644 --- a/tests/ui/generic-associated-types/issue-88595.stderr +++ b/tests/ui/generic-associated-types/issue-88595.stderr @@ -1,16 +1,34 @@ error: non-defining opaque type use in defining scope - --> $DIR/issue-88595.rs:21:35 + --> $DIR/issue-88595.rs:21:5 | LL | fn a(&'a self) -> Self::B<'a> {} - | ^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ generic argument `'a` used twice | -note: lifetime used multiple times - --> $DIR/issue-88595.rs:18:6 +note: for this opaque type + --> $DIR/issue-88595.rs:19:18 | -LL | impl<'a> A<'a> for C { - | ^^ LL | type B<'b> = impl Clone; - | ^^ + | ^^^^^^^^^^ -error: aborting due to previous error +error[E0308]: mismatched types + --> $DIR/issue-88595.rs:21:23 + | +LL | type B<'b> = impl Clone; + | ---------- the expected opaque type +LL | +LL | fn a(&'a self) -> Self::B<'a> {} + | - ^^^^^^^^^^^ expected opaque type, found `()` + | | + | implicitly returns `()` as its body has no tail or `return` expression + | + = note: expected opaque type `>::B<'a>` + found unit type `()` +note: this item must have the opaque type in its signature in order to be able to register hidden types + --> $DIR/issue-88595.rs:21:5 + | +LL | fn a(&'a self) -> Self::B<'a> {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/impl-trait/in-assoc-type-unconstrained.rs b/tests/ui/impl-trait/in-assoc-type-unconstrained.rs new file mode 100644 index 00000000000..c395b4195a0 --- /dev/null +++ b/tests/ui/impl-trait/in-assoc-type-unconstrained.rs @@ -0,0 +1,27 @@ +#![feature(impl_trait_in_assoc_type)] + +mod compare_ty { + trait Trait { + type Ty: IntoIterator; + } + impl Trait for () { + type Ty = Option; + //~^ ERROR: unconstrained opaque type + //~| ERROR: type mismatch resolving `::Ty::{opaque#0}> as IntoIterator>::Item == ()` + } +} + +mod compare_method { + trait Trait { + type Ty; + fn method() -> Self::Ty; + } + impl Trait for () { + type Ty = impl Sized; + //~^ ERROR: unconstrained opaque type + fn method() -> () {} + //~^ ERROR: method `method` has an incompatible type for trait + } +} + +fn main() {} diff --git a/tests/ui/impl-trait/in-assoc-type-unconstrained.stderr b/tests/ui/impl-trait/in-assoc-type-unconstrained.stderr new file mode 100644 index 00000000000..1097cd0f452 --- /dev/null +++ b/tests/ui/impl-trait/in-assoc-type-unconstrained.stderr @@ -0,0 +1,59 @@ +error[E0271]: type mismatch resolving `::Ty::{opaque#0}> as IntoIterator>::Item == ()` + --> $DIR/in-assoc-type-unconstrained.rs:8:19 + | +LL | type Ty = Option; + | ^^^^^^^^^^^^^^^^^^ expected `()`, found opaque type + | + = note: expected unit type `()` + found opaque type `<() as compare_ty::Trait>::Ty::{opaque#0}` +note: required by a bound in `compare_ty::Trait::Ty` + --> $DIR/in-assoc-type-unconstrained.rs:5:31 + | +LL | type Ty: IntoIterator; + | ^^^^^^^^^ required by this bound in `Trait::Ty` + +error: unconstrained opaque type + --> $DIR/in-assoc-type-unconstrained.rs:8:26 + | +LL | type Ty = Option; + | ^^^^^^^^^^ + | + = note: `Ty` must be used in combination with a concrete type within the same impl + +error[E0053]: method `method` has an incompatible type for trait + --> $DIR/in-assoc-type-unconstrained.rs:22:24 + | +LL | type Ty = impl Sized; + | ---------- the expected opaque type +LL | +LL | fn method() -> () {} + | ^^ + | | + | expected opaque type, found `()` + | help: change the output type to match the trait: `<() as compare_method::Trait>::Ty` + | +note: type in trait + --> $DIR/in-assoc-type-unconstrained.rs:17:24 + | +LL | fn method() -> Self::Ty; + | ^^^^^^^^ + = note: expected signature `fn() -> <() as compare_method::Trait>::Ty` + found signature `fn()` +note: this item must have the opaque type in its signature in order to be able to register hidden types + --> $DIR/in-assoc-type-unconstrained.rs:22:9 + | +LL | fn method() -> () {} + | ^^^^^^^^^^^^^^^^^ + +error: unconstrained opaque type + --> $DIR/in-assoc-type-unconstrained.rs:20:19 + | +LL | type Ty = impl Sized; + | ^^^^^^^^^^ + | + = note: `Ty` must be used in combination with a concrete type within the same impl + +error: aborting due to 4 previous errors + +Some errors have detailed explanations: E0053, E0271. +For more information about an error, try `rustc --explain E0053`. diff --git a/tests/ui/impl-trait/in-assoc-type.rs b/tests/ui/impl-trait/in-assoc-type.rs new file mode 100644 index 00000000000..36c54bdd6de --- /dev/null +++ b/tests/ui/impl-trait/in-assoc-type.rs @@ -0,0 +1,21 @@ +#![feature(impl_trait_in_assoc_type)] + +trait Foo { + type Bar; + fn foo(&self) -> >::Bar + where + Self: Foo<()>; +} + +impl Foo<()> for () { + type Bar = impl std::fmt::Debug; + fn foo(&self) -> Self::Bar {} +} + +impl Foo for () { + type Bar = u32; + fn foo(&self) -> >::Bar {} + //~^ ERROR: mismatched types +} + +fn main() {} diff --git a/tests/ui/impl-trait/in-assoc-type.stderr b/tests/ui/impl-trait/in-assoc-type.stderr new file mode 100644 index 00000000000..f0a272dc2d5 --- /dev/null +++ b/tests/ui/impl-trait/in-assoc-type.stderr @@ -0,0 +1,22 @@ +error[E0308]: mismatched types + --> $DIR/in-assoc-type.rs:17:22 + | +LL | type Bar = impl std::fmt::Debug; + | -------------------- the expected opaque type +... +LL | fn foo(&self) -> >::Bar {} + | --- ^^^^^^^^^^^^^^^^^^^^^^ expected opaque type, found `()` + | | + | implicitly returns `()` as its body has no tail or `return` expression + | + = note: expected opaque type `<() as Foo<()>>::Bar` + found unit type `()` +note: this item must have the opaque type in its signature in order to be able to register hidden types + --> $DIR/in-assoc-type.rs:17:5 + | +LL | fn foo(&self) -> >::Bar {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.stderr b/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.stderr index f7aff419544..fe62a8f3288 100644 --- a/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.stderr +++ b/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.stderr @@ -43,6 +43,11 @@ LL | fn eq(&self, _other: &(Bar, i32)) -> bool { | = note: expected signature `fn(&b::Bar, &(b::Foo, i32)) -> _` found signature `fn(&b::Bar, &(b::Bar, i32)) -> _` +note: this item must have the opaque type in its signature in order to be able to register hidden types + --> $DIR/recursive-type-alias-impl-trait-declaration-too-subtle.rs:24:9 + | +LL | fn eq(&self, _other: &(Bar, i32)) -> bool { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 4 previous errors diff --git a/tests/ui/type-alias-impl-trait/associated-type-impl-trait-lifetime.rs b/tests/ui/type-alias-impl-trait/associated-type-impl-trait-lifetime.rs index 551815d021a..58eaa9c2c42 100644 --- a/tests/ui/type-alias-impl-trait/associated-type-impl-trait-lifetime.rs +++ b/tests/ui/type-alias-impl-trait/associated-type-impl-trait-lifetime.rs @@ -5,15 +5,16 @@ trait Trait { type Opaque1; type Opaque2; - fn constrain(self); + fn constrain(self) -> (Self::Opaque1, Self::Opaque2); } impl<'a> Trait for &'a () { type Opaque1 = impl Sized; type Opaque2 = impl Sized + 'a; - fn constrain(self) { - let _: Self::Opaque1 = (); - let _: Self::Opaque2 = self; + fn constrain(self) -> (Self::Opaque1, Self::Opaque2) { + let a: Self::Opaque1 = (); + let b: Self::Opaque2 = self; + (a, b) } } diff --git a/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.rs b/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.rs new file mode 100644 index 00000000000..93c52126d69 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.rs @@ -0,0 +1,16 @@ +#![feature(impl_trait_in_assoc_type)] + +trait Foo { + type Foo; + fn bar(); +} + +impl Foo for () { + type Foo = impl std::fmt::Debug; + fn bar() { + let x: Self::Foo = (); + //~^ ERROR: mismatched types + } +} + +fn main() {} diff --git a/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.stderr b/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.stderr new file mode 100644 index 00000000000..2beed73cb85 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/invalid_impl_trait_in_assoc_ty.stderr @@ -0,0 +1,22 @@ +error[E0308]: mismatched types + --> $DIR/invalid_impl_trait_in_assoc_ty.rs:11:28 + | +LL | type Foo = impl std::fmt::Debug; + | -------------------- the expected opaque type +LL | fn bar() { +LL | let x: Self::Foo = (); + | --------- ^^ expected opaque type, found `()` + | | + | expected due to this + | + = note: expected opaque type `<() as Foo>::Foo` + found unit type `()` +note: this item must have the opaque type in its signature in order to be able to register hidden types + --> $DIR/invalid_impl_trait_in_assoc_ty.rs:10:5 + | +LL | fn bar() { + | ^^^^^^^^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`.