diff options
34 files changed, 697 insertions, 154 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs index f1b1c33a105..e0140e281ee 100644 --- a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs +++ b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs @@ -362,6 +362,11 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> { self.region_bound_pairs .insert(ty::OutlivesPredicate(GenericKind::Projection(projection_b), r_a)); } + + OutlivesBound::RegionSubOpaque(r_a, def_id, substs) => { + self.region_bound_pairs + .insert(ty::OutlivesPredicate(GenericKind::Opaque(def_id, substs), r_a)); + } } } } diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 0208c364e43..99469d1e1e7 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -2481,6 +2481,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { let labeled_user_string = match bound_kind { GenericKind::Param(ref p) => format!("the parameter type `{}`", p), GenericKind::Projection(ref p) => format!("the associated type `{}`", p), + GenericKind::Opaque(def_id, substs) => { + format!("the opaque type `{}`", self.tcx.def_path_str_with_substs(def_id, substs)) + } }; if let Some(SubregionOrigin::CompareImplItemObligation { diff --git a/compiler/rustc_infer/src/infer/outlives/components.rs b/compiler/rustc_infer/src/infer/outlives/components.rs index b2d7f4a663a..14ee9f05190 100644 --- a/compiler/rustc_infer/src/infer/outlives/components.rs +++ b/compiler/rustc_infer/src/infer/outlives/components.rs @@ -3,8 +3,9 @@ // RFC for reference. use rustc_data_structures::sso::SsoHashSet; +use rustc_hir::def_id::DefId; use rustc_middle::ty::subst::{GenericArg, GenericArgKind}; -use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable}; +use rustc_middle::ty::{self, SubstsRef, Ty, TyCtxt, TypeVisitable}; use smallvec::{smallvec, SmallVec}; #[derive(Debug)] @@ -45,6 +46,8 @@ pub enum Component<'tcx> { // them. This gives us room to improve the regionck reasoning in // the future without breaking backwards compat. EscapingProjection(Vec<Component<'tcx>>), + + Opaque(DefId, SubstsRef<'tcx>), } /// Push onto `out` all the things that must outlive `'a` for the condition @@ -120,6 +123,17 @@ fn compute_components<'tcx>( out.push(Component::Param(p)); } + // Ignore lifetimes found in opaque types. Opaque types can + // have lifetimes in their substs which their hidden type doesn't + // actually use. If we inferred that an opaque type is outlived by + // its parameter lifetimes, then we could prove that any lifetime + // outlives any other lifetime, which is unsound. + // See https://github.com/rust-lang/rust/issues/84305 for + // more details. + ty::Opaque(def_id, substs) => { + out.push(Component::Opaque(def_id, substs)); + }, + // For projections, we prefer to generate an obligation like // `<P0 as Trait<P1...Pn>>::Foo: 'a`, because this gives the // regionck more ways to prove that it holds. However, @@ -168,7 +182,6 @@ fn compute_components<'tcx>( ty::Float(..) | // OutlivesScalar ty::Never | // ... ty::Adt(..) | // OutlivesNominalType - ty::Opaque(..) | // OutlivesNominalType (ish) ty::Foreign(..) | // OutlivesNominalType ty::Str | // OutlivesScalar (ish) ty::Slice(..) | // ... diff --git a/compiler/rustc_infer/src/infer/outlives/env.rs b/compiler/rustc_infer/src/infer/outlives/env.rs index 9922b156ebf..113d4f09066 100644 --- a/compiler/rustc_infer/src/infer/outlives/env.rs +++ b/compiler/rustc_infer/src/infer/outlives/env.rs @@ -142,6 +142,10 @@ impl<'a, 'tcx> OutlivesEnvironmentBuilder<'tcx> { self.region_bound_pairs .insert(ty::OutlivesPredicate(GenericKind::Projection(projection_b), r_a)); } + OutlivesBound::RegionSubOpaque(r_a, def_id, substs) => { + self.region_bound_pairs + .insert(ty::OutlivesPredicate(GenericKind::Opaque(def_id, substs), r_a)); + } OutlivesBound::RegionSubRegion(r_a, r_b) => { if let (ReEarlyBound(_) | ReFree(_), ReVar(vid_b)) = (r_a.kind(), r_b.kind()) { infcx diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index 5bd1774f6b1..229b69b92e6 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -68,10 +68,11 @@ use crate::infer::{ }; use crate::traits::{ObligationCause, ObligationCauseCode}; use rustc_data_structures::undo_log::UndoLogs; +use rustc_hir::def_id::DefId; use rustc_hir::def_id::LocalDefId; use rustc_middle::mir::ConstraintCategory; use rustc_middle::ty::subst::GenericArgKind; -use rustc_middle::ty::{self, Region, Ty, TyCtxt, TypeVisitable}; +use rustc_middle::ty::{self, Region, SubstsRef, Ty, TyCtxt, TypeVisitable}; use smallvec::smallvec; impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { @@ -283,6 +284,9 @@ where Component::Param(param_ty) => { self.param_ty_must_outlive(origin, region, *param_ty); } + Component::Opaque(def_id, substs) => { + self.opaque_must_outlive(*def_id, substs, origin, region) + } Component::Projection(projection_ty) => { self.projection_must_outlive(origin, region, *projection_ty); } @@ -314,17 +318,69 @@ where ); let generic = GenericKind::Param(param_ty); - let verify_bound = self.verify_bound.generic_bound(generic); + let verify_bound = self.verify_bound.param_bound(param_ty); self.delegate.push_verify(origin, generic, region, verify_bound); } #[instrument(level = "debug", skip(self))] + fn opaque_must_outlive( + &mut self, + def_id: DefId, + substs: SubstsRef<'tcx>, + origin: infer::SubregionOrigin<'tcx>, + region: ty::Region<'tcx>, + ) { + self.generic_must_outlive( + origin, + region, + GenericKind::Opaque(def_id, substs), + def_id, + substs, + true, + |ty| match *ty.kind() { + ty::Opaque(def_id, substs) => (def_id, substs), + _ => bug!("expected only projection types from env, not {:?}", ty), + }, + ); + } + + #[instrument(level = "debug", skip(self))] fn projection_must_outlive( &mut self, origin: infer::SubregionOrigin<'tcx>, region: ty::Region<'tcx>, projection_ty: ty::ProjectionTy<'tcx>, ) { + self.generic_must_outlive( + origin, + region, + GenericKind::Projection(projection_ty), + projection_ty.item_def_id, + projection_ty.substs, + false, + |ty| match ty.kind() { + ty::Projection(projection_ty) => (projection_ty.item_def_id, projection_ty.substs), + _ => bug!("expected only projection types from env, not {:?}", ty), + }, + ); + } + + #[instrument(level = "debug", skip(self, filter))] + fn generic_must_outlive( + &mut self, + origin: infer::SubregionOrigin<'tcx>, + region: ty::Region<'tcx>, + generic: GenericKind<'tcx>, + def_id: DefId, + substs: SubstsRef<'tcx>, + is_opaque: bool, + filter: impl Fn(Ty<'tcx>) -> (DefId, SubstsRef<'tcx>), + ) { + // An optimization for a common case with opaque types. + if substs.is_empty() { + return; + } + // This case is thorny for inference. The fundamental problem is // that there are many cases where we have choice, and inference // doesn't like choice (the current region inference in @@ -343,16 +399,15 @@ where // These are guaranteed to apply, no matter the inference // results. let trait_bounds: Vec<_> = - self.verify_bound.projection_declared_bounds_from_trait(projection_ty).collect(); + self.verify_bound.declared_region_bounds(def_id, substs).collect(); debug!(?trait_bounds); // Compute the bounds we can derive from the environment. This // is an "approximate" match -- in some cases, these bounds // may not apply. - let mut approx_env_bounds = - self.verify_bound.projection_approx_declared_bounds_from_env(projection_ty); - debug!("projection_must_outlive: approx_env_bounds={:?}", approx_env_bounds); + let mut approx_env_bounds = self.verify_bound.approx_declared_bounds_from_env(generic); + debug!(?approx_env_bounds); // Remove outlives bounds that we get from the environment but // which are also deducible from the trait. This arises (cc @@ -366,14 +421,8 @@ where // If the declaration is `trait Trait<'b> { type Item: 'b; }`, then `projection_declared_bounds_from_trait` // will be invoked with `['b => ^1]` and so we will get `^1` returned. let bound = bound_outlives.skip_binder(); - match *bound.0.kind() { - ty::Projection(projection_ty) => self - .verify_bound - .projection_declared_bounds_from_trait(projection_ty) - .all(|r| r != bound.1), - - _ => panic!("expected only projection types from env, not {:?}", bound.0), - } + let (def_id, substs) = filter(bound.0); + self.verify_bound.declared_region_bounds(def_id, substs).all(|r| r != bound.1) }); // If declared bounds list is empty, the only applicable rule is @@ -390,29 +439,11 @@ where // the problem is to add `T: 'r`, which isn't true. So, if there are no // inference variables, we use a verify constraint instead of adding // edges, which winds up enforcing the same condition. - let needs_infer = projection_ty.needs_infer(); - if approx_env_bounds.is_empty() && trait_bounds.is_empty() && needs_infer { - debug!("projection_must_outlive: no declared bounds"); - - let constraint = origin.to_constraint_category(); - for k in projection_ty.substs { - match k.unpack() { - GenericArgKind::Lifetime(lt) => { - self.delegate.push_sub_region_constraint( - origin.clone(), - region, - lt, - constraint, - ); - } - GenericArgKind::Type(ty) => { - self.type_must_outlive(origin.clone(), ty, region, constraint); - } - GenericArgKind::Const(_) => { - // Const parameters don't impose constraints. - } - } - } + let needs_infer = substs.needs_infer(); + if approx_env_bounds.is_empty() && trait_bounds.is_empty() && (needs_infer || is_opaque) { + debug!("no declared bounds"); + + self.substs_must_outlive(substs, origin, region); return; } @@ -442,8 +473,8 @@ where .all(|b| b == Some(trait_bounds[0])) { let unique_bound = trait_bounds[0]; - debug!("projection_must_outlive: unique trait bound = {:?}", unique_bound); - debug!("projection_must_outlive: unique declared bound appears in trait ref"); + debug!(?unique_bound); + debug!("unique declared bound appears in trait ref"); let category = origin.to_constraint_category(); self.delegate.push_sub_region_constraint(origin, region, unique_bound, category); return; @@ -454,11 +485,42 @@ where // projection outlive; in some cases, this may add insufficient // edges into the inference graph, leading to inference failures // even though a satisfactory solution exists. - let generic = GenericKind::Projection(projection_ty); - let verify_bound = self.verify_bound.generic_bound(generic); + let verify_bound = self.verify_bound.projection_opaque_bounds( + generic, + def_id, + substs, + &mut Default::default(), + ); debug!("projection_must_outlive: pushing {:?}", verify_bound); self.delegate.push_verify(origin, generic, region, verify_bound); } + + fn substs_must_outlive( + &mut self, + substs: SubstsRef<'tcx>, + origin: infer::SubregionOrigin<'tcx>, + region: ty::Region<'tcx>, + ) { + let constraint = origin.to_constraint_category(); + for k in substs { + match k.unpack() { + GenericArgKind::Lifetime(lt) => { + self.delegate.push_sub_region_constraint( + origin.clone(), + region, + lt, + constraint, + ); + } + GenericArgKind::Type(ty) => { + self.type_must_outlive(origin.clone(), ty, region, constraint); + } + GenericArgKind::Const(_) => { + // Const parameters don't impose constraints. + } + } + } + } } impl<'cx, 'tcx> TypeOutlivesDelegate<'tcx> for &'cx InferCtxt<'cx, 'tcx> { diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs index e344e192a76..f470b2eb8c1 100644 --- a/compiler/rustc_infer/src/infer/outlives/verify.rs +++ b/compiler/rustc_infer/src/infer/outlives/verify.rs @@ -2,11 +2,10 @@ use crate::infer::outlives::components::{compute_components_recursive, Component use crate::infer::outlives::env::RegionBoundPairs; use crate::infer::region_constraints::VerifyIfEq; use crate::infer::{GenericKind, VerifyBound}; -use rustc_data_structures::captures::Captures; use rustc_data_structures::sso::SsoHashSet; use rustc_hir::def_id::DefId; use rustc_middle::ty::GenericArg; -use rustc_middle::ty::{self, EarlyBinder, OutlivesPredicate, Ty, TyCtxt}; +use rustc_middle::ty::{self, EarlyBinder, OutlivesPredicate, SubstsRef, Ty, TyCtxt}; use smallvec::smallvec; @@ -38,20 +37,8 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { Self { tcx, region_bound_pairs, implicit_region_bound, param_env } } - /// Returns a "verify bound" that encodes what we know about - /// `generic` and the regions it outlives. - pub fn generic_bound(&self, generic: GenericKind<'tcx>) -> VerifyBound<'tcx> { - let mut visited = SsoHashSet::new(); - match generic { - GenericKind::Param(param_ty) => self.param_bound(param_ty), - GenericKind::Projection(projection_ty) => { - self.projection_bound(projection_ty, &mut visited) - } - } - } - #[instrument(level = "debug", skip(self))] - fn param_bound(&self, param_ty: ty::ParamTy) -> VerifyBound<'tcx> { + pub fn param_bound(&self, param_ty: ty::ParamTy) -> VerifyBound<'tcx> { // Start with anything like `T: 'a` we can scrape from the // environment. If the environment contains something like // `for<'a> T: 'a`, then we know that `T` outlives everything. @@ -105,41 +92,31 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { /// the clause from the environment only applies if `'0 = 'a`, /// which we don't know yet. But we would still include `'b` in /// this list. - pub fn projection_approx_declared_bounds_from_env( + pub fn approx_declared_bounds_from_env( &self, - projection_ty: ty::ProjectionTy<'tcx>, + generic: GenericKind<'tcx>, ) -> Vec<ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>> { - let projection_ty = GenericKind::Projection(projection_ty).to_ty(self.tcx); + let projection_ty = generic.to_ty(self.tcx); let erased_projection_ty = self.tcx.erase_regions(projection_ty); self.declared_generic_bounds_from_env_for_erased_ty(erased_projection_ty) } - /// Searches the where-clauses in scope for regions that - /// `projection_ty` is known to outlive. Currently requires an - /// exact match. - pub fn projection_declared_bounds_from_trait( + #[instrument(level = "debug", skip(self, visited))] + pub fn projection_opaque_bounds( &self, - projection_ty: ty::ProjectionTy<'tcx>, - ) -> impl Iterator<Item = ty::Region<'tcx>> + 'cx + Captures<'tcx> { - self.declared_projection_bounds_from_trait(projection_ty) - } - - pub fn projection_bound( - &self, - projection_ty: ty::ProjectionTy<'tcx>, + generic: GenericKind<'tcx>, + def_id: DefId, + substs: SubstsRef<'tcx>, visited: &mut SsoHashSet<GenericArg<'tcx>>, ) -> VerifyBound<'tcx> { - debug!("projection_bound(projection_ty={:?})", projection_ty); - - let projection_ty_as_ty = - self.tcx.mk_projection(projection_ty.item_def_id, projection_ty.substs); + let generic_ty = generic.to_ty(self.tcx); // Search the env for where clauses like `P: 'a`. - let env_bounds = self - .projection_approx_declared_bounds_from_env(projection_ty) + let projection_opaque_bounds = self + .approx_declared_bounds_from_env(generic) .into_iter() .map(|binder| { - if let Some(ty::OutlivesPredicate(ty, r)) = binder.no_bound_vars() && ty == projection_ty_as_ty { + if let Some(ty::OutlivesPredicate(ty, r)) = binder.no_bound_vars() && ty == generic_ty { // Micro-optimize if this is an exact match (this // occurs often when there are no region variables // involved). @@ -149,21 +126,19 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { VerifyBound::IfEq(verify_if_eq_b) } }); - // Extend with bounds that we can find from the trait. - let trait_bounds = self - .projection_declared_bounds_from_trait(projection_ty) - .map(|r| VerifyBound::OutlivedBy(r)); + let trait_bounds = + self.declared_region_bounds(def_id, substs).map(|r| VerifyBound::OutlivedBy(r)); // see the extensive comment in projection_must_outlive let recursive_bound = { let mut components = smallvec![]; - let ty = self.tcx.mk_projection(projection_ty.item_def_id, projection_ty.substs); - compute_components_recursive(self.tcx, ty.into(), &mut components, visited); + compute_components_recursive(self.tcx, generic_ty.into(), &mut components, visited); self.bound_from_components(&components, visited) }; - VerifyBound::AnyBound(env_bounds.chain(trait_bounds).collect()).or(recursive_bound) + VerifyBound::AnyBound(projection_opaque_bounds.chain(trait_bounds).collect()) + .or(recursive_bound) } fn bound_from_components( @@ -195,7 +170,18 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { match *component { Component::Region(lt) => VerifyBound::OutlivedBy(lt), Component::Param(param_ty) => self.param_bound(param_ty), - Component::Projection(projection_ty) => self.projection_bound(projection_ty, visited), + Component::Opaque(did, substs) => self.projection_opaque_bounds( + GenericKind::Opaque(did, substs), + did, + substs, + visited, + ), + Component::Projection(projection_ty) => self.projection_opaque_bounds( + GenericKind::Projection(projection_ty), + projection_ty.item_def_id, + projection_ty.substs, + visited, + ), Component::EscapingProjection(ref components) => { self.bound_from_components(components, visited) } @@ -293,30 +279,6 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { /// } /// ``` /// - /// then this function would return `'x`. This is subject to the - /// limitations around higher-ranked bounds described in - /// `region_bounds_declared_on_associated_item`. - fn declared_projection_bounds_from_trait( - &self, - projection_ty: ty::ProjectionTy<'tcx>, - ) -> impl Iterator<Item = ty::Region<'tcx>> + 'cx + Captures<'tcx> { - debug!("projection_bounds(projection_ty={:?})", projection_ty); - let tcx = self.tcx; - self.region_bounds_declared_on_associated_item(projection_ty.item_def_id) - .map(move |r| EarlyBinder(r).subst(tcx, projection_ty.substs)) - } - - /// Given the `DefId` of an associated item, returns any region - /// bounds attached to that associated item from the trait definition. - /// - /// For example: - /// - /// ```rust - /// trait Foo<'a> { - /// type Bar: 'a; - /// } - /// ``` - /// /// If we were given the `DefId` of `Foo::Bar`, we would return /// `'a`. You could then apply the substitutions from the /// projection to convert this into your namespace. This also @@ -336,17 +298,20 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { /// /// This is for simplicity, and because we are not really smart /// enough to cope with such bounds anywhere. - fn region_bounds_declared_on_associated_item( + pub fn declared_region_bounds( &self, - assoc_item_def_id: DefId, + def_id: DefId, + substs: SubstsRef<'tcx>, ) -> impl Iterator<Item = ty::Region<'tcx>> { let tcx = self.tcx; - let bounds = tcx.item_bounds(assoc_item_def_id); + let bounds = tcx.item_bounds(def_id); + trace!("{:#?}", bounds); bounds .into_iter() .filter_map(|p| p.to_opt_type_outlives()) .filter_map(|p| p.no_bound_vars()) .map(|b| b.1) + .map(move |r| EarlyBinder(r).subst(tcx, substs)) } /// Searches through a predicate list for a predicate `T: 'a`. diff --git a/compiler/rustc_infer/src/infer/region_constraints/mod.rs b/compiler/rustc_infer/src/infer/region_constraints/mod.rs index e43d28ee56e..67b3da68720 100644 --- a/compiler/rustc_infer/src/infer/region_constraints/mod.rs +++ b/compiler/rustc_infer/src/infer/region_constraints/mod.rs @@ -12,8 +12,10 @@ use rustc_data_structures::intern::Interned; use rustc_data_structures::sync::Lrc; use rustc_data_structures::undo_log::UndoLogs; use rustc_data_structures::unify as ut; +use rustc_hir::def_id::DefId; use rustc_index::vec::IndexVec; use rustc_middle::infer::unify_key::{RegionVidKey, UnifiedRegion}; +use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::ReStatic; use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_middle::ty::{ReLateBound, ReVar}; @@ -168,6 +170,7 @@ pub struct Verify<'tcx> { pub enum GenericKind<'tcx> { Param(ty::ParamTy), Projection(ty::ProjectionTy<'tcx>), + Opaque(DefId, SubstsRef<'tcx>), } /// Describes the things that some `GenericKind` value `G` is known to @@ -747,6 +750,9 @@ impl<'tcx> fmt::Debug for GenericKind<'tcx> { match *self { GenericKind::Param(ref p) => write!(f, "{:?}", p), GenericKind::Projection(ref p) => write!(f, "{:?}", p), + GenericKind::Opaque(def_id, substs) => ty::tls::with(|tcx| { + write!(f, "{}", tcx.def_path_str_with_substs(def_id, tcx.lift(substs).unwrap())) + }), } } } @@ -756,6 +762,9 @@ impl<'tcx> fmt::Display for GenericKind<'tcx> { match *self { GenericKind::Param(ref p) => write!(f, "{}", p), GenericKind::Projection(ref p) => write!(f, "{}", p), + GenericKind::Opaque(def_id, substs) => ty::tls::with(|tcx| { + write!(f, "{}", tcx.def_path_str_with_substs(def_id, tcx.lift(substs).unwrap())) + }), } } } @@ -765,6 +774,7 @@ impl<'tcx> GenericKind<'tcx> { match *self { GenericKind::Param(ref p) => p.to_ty(tcx), GenericKind::Projection(ref p) => tcx.mk_projection(p.item_def_id, p.substs), + GenericKind::Opaque(def_id, substs) => tcx.mk_opaque(def_id, substs), } } } diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index f5a1edf6d81..e12c069dcc1 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -246,6 +246,13 @@ impl<'tcx> Elaborator<'tcx> { Component::UnresolvedInferenceVariable(_) => None, + Component::Opaque(def_id, substs) => { + let ty = tcx.mk_opaque(def_id, substs); + Some(ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate( + ty, r_min, + ))) + } + Component::Projection(projection) => { // We might end up here if we have `Foo<<Bar as Baz>::Assoc>: 'a`. // With this, we can deduce that `<Bar as Baz>::Assoc: 'a`. @@ -262,8 +269,9 @@ impl<'tcx> Elaborator<'tcx> { None } }) - .map(ty::Binder::dummy) - .map(|predicate_kind| predicate_kind.to_predicate(tcx)) + .map(|predicate_kind| { + bound_predicate.rebind(predicate_kind).to_predicate(tcx) + }) .filter(|&predicate| visited.insert(predicate)) .map(|predicate| { predicate_obligation( diff --git a/compiler/rustc_middle/src/traits/query.rs b/compiler/rustc_middle/src/traits/query.rs index 0e6cacb9fd0..fb152b63f63 100644 --- a/compiler/rustc_middle/src/traits/query.rs +++ b/compiler/rustc_middle/src/traits/query.rs @@ -8,8 +8,9 @@ use crate::error::DropCheckOverflow; use crate::infer::canonical::{Canonical, QueryResponse}; use crate::ty::error::TypeError; -use crate::ty::subst::GenericArg; +use crate::ty::subst::{GenericArg, SubstsRef}; use crate::ty::{self, Ty, TyCtxt}; +use rustc_hir::def_id::DefId; use rustc_span::source_map::Span; use std::iter::FromIterator; @@ -219,4 +220,5 @@ pub enum OutlivesBound<'tcx> { RegionSubRegion(ty::Region<'tcx>, ty::Region<'tcx>), RegionSubParam(ty::Region<'tcx>, ty::ParamTy), RegionSubProjection(ty::Region<'tcx>, ty::ProjectionTy<'tcx>), + RegionSubOpaque(ty::Region<'tcx>, DefId, SubstsRef<'tcx>), } diff --git a/compiler/rustc_traits/src/implied_outlives_bounds.rs b/compiler/rustc_traits/src/implied_outlives_bounds.rs index 691b79f1053..32aca4a8a3f 100644 --- a/compiler/rustc_traits/src/implied_outlives_bounds.rs +++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs @@ -156,6 +156,9 @@ fn implied_bounds_from_components<'tcx>( Component::Region(r) => Some(OutlivesBound::RegionSubRegion(sub_region, r)), Component::Param(p) => Some(OutlivesBound::RegionSubParam(sub_region, p)), Component::Projection(p) => Some(OutlivesBound::RegionSubProjection(sub_region, p)), + Component::Opaque(def_id, substs) => { + Some(OutlivesBound::RegionSubOpaque(sub_region, def_id, substs)) + } Component::EscapingProjection(_) => // If the projection has escaping regions, don't // try to infer any implied bounds even for its diff --git a/compiler/rustc_typeck/src/mem_categorization.rs b/compiler/rustc_typeck/src/mem_categorization.rs index ced919f66db..39610e3ae38 100644 --- a/compiler/rustc_typeck/src/mem_categorization.rs +++ b/compiler/rustc_typeck/src/mem_categorization.rs @@ -265,6 +265,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { self.cat_expr_adjusted_with(expr, || Ok(previous), adjustment) } + #[instrument(level = "debug", skip(self, previous))] fn cat_expr_adjusted_with<F>( &self, expr: &hir::Expr<'_>, @@ -274,7 +275,6 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { where F: FnOnce() -> McResult<PlaceWithHirId<'tcx>>, { - debug!("cat_expr_adjusted_with({:?}): {:?}", adjustment, expr); let target = self.resolve_vars_if_possible(adjustment.target); match adjustment.kind { adjustment::Adjust::Deref(overloaded) => { @@ -299,6 +299,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { } } + #[instrument(level = "debug", skip(self))] pub(crate) fn cat_expr_unadjusted( &self, expr: &hir::Expr<'_>, @@ -387,6 +388,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { } } + #[instrument(level = "debug", skip(self, span))] pub(crate) fn cat_res( &self, hir_id: hir::HirId, @@ -394,8 +396,6 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { expr_ty: Ty<'tcx>, res: Res, ) -> McResult<PlaceWithHirId<'tcx>> { - debug!("cat_res: id={:?} expr={:?} def={:?}", hir_id, expr_ty, res); - match res { Res::Def( DefKind::Ctor(..) @@ -475,13 +475,12 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { ret } + #[instrument(level = "debug", skip(self))] fn cat_overloaded_place( &self, expr: &hir::Expr<'_>, base: &hir::Expr<'_>, ) -> McResult<PlaceWithHirId<'tcx>> { - debug!("cat_overloaded_place(expr={:?}, base={:?})", expr, base); - // Reconstruct the output assuming it's a reference with the // same region and mutability as the receiver. This holds for // `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`. @@ -497,13 +496,12 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { self.cat_deref(expr, base) } + #[instrument(level = "debug", skip(self, node))] fn cat_deref( &self, node: &impl HirNode, base_place: PlaceWithHirId<'tcx>, ) -> McResult<PlaceWithHirId<'tcx>> { - debug!("cat_deref: base_place={:?}", base_place); - let base_curr_ty = base_place.place.ty(); let deref_ty = match base_curr_ty.builtin_deref(true) { Some(mt) => mt.ty, diff --git a/compiler/rustc_typeck/src/outlives/utils.rs b/compiler/rustc_typeck/src/outlives/utils.rs index 3e8d023fb55..0409c7081dc 100644 --- a/compiler/rustc_typeck/src/outlives/utils.rs +++ b/compiler/rustc_typeck/src/outlives/utils.rs @@ -96,6 +96,23 @@ pub(crate) fn insert_outlives_predicate<'tcx>( .or_insert(span); } + Component::Opaque(def_id, substs) => { + // This would arise from something like: + // + // ```rust + // type Opaque<T> = impl Sized; + // fn defining<T>() -> Opaque<T> {} + // struct Ss<'a, T>(&'a Opaque<T>); + // ``` + // + // Here we want to have an implied bound `Opaque<T>: 'a` + + let ty = tcx.mk_opaque(def_id, substs); + required_predicates + .entry(ty::OutlivesPredicate(ty.into(), outlived_region)) + .or_insert(span); + } + Component::EscapingProjection(_) => { // As above, but the projection involves // late-bound regions. Therefore, the WF diff --git a/src/test/ui/generic-associated-types/bugs/issue-86218.stderr b/src/test/ui/generic-associated-types/bugs/issue-86218.stderr deleted file mode 100644 index de1b464a41d..00000000000 --- a/src/test/ui/generic-associated-types/bugs/issue-86218.stderr +++ /dev/null @@ -1,23 +0,0 @@ -error[E0477]: the type `<() as Yay<&'a ()>>::InnerStream<'s>` does not fulfill the required lifetime - --> $DIR/issue-86218.rs:22:28 - | -LL | type InnerStream<'s> = impl Stream<Item = i32> + 's; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | -note: type must outlive the lifetime `'s` as defined here as required by this binding - --> $DIR/issue-86218.rs:22:22 - | -LL | type InnerStream<'s> = impl Stream<Item = i32> + 's; - | ^^ - -error: unconstrained opaque type - --> $DIR/issue-86218.rs:22:28 - | -LL | type InnerStream<'s> = impl Stream<Item = i32> + 's; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | - = note: `InnerStream` must be used in combination with a concrete type within the same module - -error: aborting due to 2 previous errors - -For more information about this error, try `rustc --explain E0477`. diff --git a/src/test/ui/generic-associated-types/issue-86218-2.rs b/src/test/ui/generic-associated-types/issue-86218-2.rs new file mode 100644 index 00000000000..63c839ea871 --- /dev/null +++ b/src/test/ui/generic-associated-types/issue-86218-2.rs @@ -0,0 +1,23 @@ +// check-pass + +#![feature(type_alias_impl_trait)] + +pub trait Stream { + type Item; +} + +impl Stream for () { + type Item = i32; +} + +trait Yay<AdditionalValue> { + type InnerStream<'s>: Stream<Item = i32> + 's; + fn foo<'s>() -> Self::InnerStream<'s>; +} + +impl<T> Yay<T> for () { + type InnerStream<'s> = impl Stream<Item = i32> + 's; + fn foo<'s>() -> Self::InnerStream<'s> { () } +} + +fn main() {} diff --git a/src/test/ui/generic-associated-types/bugs/issue-86218.rs b/src/test/ui/generic-associated-types/issue-86218.rs index 3a2d758e7d6..b2c3071f06b 100644 --- a/src/test/ui/generic-associated-types/bugs/issue-86218.rs +++ b/src/test/ui/generic-associated-types/issue-86218.rs @@ -1,7 +1,4 @@ -// check-fail -// known-bug: #86218 - -// This should pass, but seems to run into a TAIT issue. +// check-pass #![feature(type_alias_impl_trait)] @@ -20,7 +17,8 @@ trait Yay<AdditionalValue> { impl<'a> Yay<&'a ()> for () { type InnerStream<'s> = impl Stream<Item = i32> + 's; - fn foo<'s>() -> Self::InnerStream<'s> { todo!() } + //^ ERROR does not fulfill the required lifetime + fn foo<'s>() -> Self::InnerStream<'s> { () } } fn main() {} diff --git a/src/test/ui/impl-trait/unactionable_diagnostic.fixed b/src/test/ui/impl-trait/unactionable_diagnostic.fixed new file mode 100644 index 00000000000..6c2505177fe --- /dev/null +++ b/src/test/ui/impl-trait/unactionable_diagnostic.fixed @@ -0,0 +1,25 @@ +// run-rustfix + +pub trait Trait {} + +pub struct Foo; + +impl Trait for Foo {} + +fn foo<'x, P>( + _post: P, + x: &'x Foo, +) -> &'x impl Trait { + x +} + +pub fn bar<'t, T: 't>( + //~^ HELP: consider adding an explicit lifetime bound... + post: T, + x: &'t Foo, +) -> &'t impl Trait { + foo(post, x) + //~^ ERROR: the parameter type `T` may not live long enough +} + +fn main() {} diff --git a/src/test/ui/impl-trait/unactionable_diagnostic.rs b/src/test/ui/impl-trait/unactionable_diagnostic.rs new file mode 100644 index 00000000000..bce35cbdd0d --- /dev/null +++ b/src/test/ui/impl-trait/unactionable_diagnostic.rs @@ -0,0 +1,25 @@ +// run-rustfix + +pub trait Trait {} + +pub struct Foo; + +impl Trait for Foo {} + +fn foo<'x, P>( + _post: P, + x: &'x Foo, +) -> &'x impl Trait { + x +} + +pub fn bar<'t, T>( + //~^ HELP: consider adding an explicit lifetime bound... + post: T, + x: &'t Foo, +) -> &'t impl Trait { + foo(post, x) + //~^ ERROR: the parameter type `T` may not live long enough +} + +fn main() {} diff --git a/src/test/ui/impl-trait/unactionable_diagnostic.stderr b/src/test/ui/impl-trait/unactionable_diagnostic.stderr new file mode 100644 index 00000000000..a32004cda1a --- /dev/null +++ b/src/test/ui/impl-trait/unactionable_diagnostic.stderr @@ -0,0 +1,14 @@ +error[E0309]: the parameter type `T` may not live long enough + --> $DIR/unactionable_diagnostic.rs:21:5 + | +LL | foo(post, x) + | ^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound... + | +LL | pub fn bar<'t, T: 't>( + | ++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0309`. diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds.rs b/src/test/ui/type-alias-impl-trait/implied_bounds.rs new file mode 100644 index 00000000000..53cbf8d2290 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds.rs @@ -0,0 +1,51 @@ +#![feature(type_alias_impl_trait)] + +type WithLifetime<'a> = impl Equals<SelfType = ()>; +fn _defining_use<'a>() -> WithLifetime<'a> {} + +trait Convert<'a> { + type Witness; + fn convert<'b, T: ?Sized>(_proof: &'b Self::Witness, x: &'a T) -> &'b T; +} + +impl<'a> Convert<'a> for () { + type Witness = WithLifetime<'a>; + + fn convert<'b, T: ?Sized>(_proof: &'b WithLifetime<'a>, x: &'a T) -> &'b T { + // compiler used to think it gets to assume 'a: 'b here because + // of the `&'b WithLifetime<'a>` argument + x + //~^ ERROR lifetime may not live long enough + } +} + +fn extend_lifetime<'a, 'b, T: ?Sized>(x: &'a T) -> &'b T { + WithLifetime::<'a>::convert_helper::<(), T>(&(), x) +} + +trait Equals { + type SelfType; + fn convert_helper<'a, 'b, W: Convert<'a, Witness = Self>, T: ?Sized>( + proof: &'b Self::SelfType, + x: &'a T, + ) -> &'b T; +} + +impl<S> Equals for S { + type SelfType = Self; + fn convert_helper<'a, 'b, W: Convert<'a, Witness = Self>, T: ?Sized>( + proof: &'b Self, + x: &'a T, + ) -> &'b T { + W::convert(proof, x) + } +} + +fn main() { + let r; + { + let x = String::from("Hello World?"); + r = extend_lifetime(&x); + } + println!("{}", r); +} diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds.stderr b/src/test/ui/type-alias-impl-trait/implied_bounds.stderr new file mode 100644 index 00000000000..6f11b66634b --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds.stderr @@ -0,0 +1,16 @@ +error: lifetime may not live long enough + --> $DIR/implied_bounds.rs:17:9 + | +LL | impl<'a> Convert<'a> for () { + | -- lifetime `'a` defined here +... +LL | fn convert<'b, T: ?Sized>(_proof: &'b WithLifetime<'a>, x: &'a T) -> &'b T { + | -- lifetime `'b` defined here +... +LL | x + | ^ associated function was supposed to return data with lifetime `'b` but it is returning data with lifetime `'a` + | + = help: consider adding the following bound: `'a: 'b` + +error: aborting due to previous error + diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds2.rs b/src/test/ui/type-alias-impl-trait/implied_bounds2.rs new file mode 100644 index 00000000000..b4c4c013cd2 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds2.rs @@ -0,0 +1,10 @@ +// check-pass + +#![feature(type_alias_impl_trait)] + +type Ty<'a, A> = impl Sized + 'a; +fn defining<'a, A>() -> Ty<'a, A> {} +fn assert_static<T: 'static>() {} +fn test<'a, A>() where Ty<'a, A>: 'static, { assert_static::<Ty<'a, A>>() } + +fn main() {} diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds3.rs b/src/test/ui/type-alias-impl-trait/implied_bounds3.rs new file mode 100644 index 00000000000..e39c613281d --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds3.rs @@ -0,0 +1,18 @@ +// check-pass + +fn foo<F>(_: F) +where + F: 'static, +{ +} + +fn from<F: Send>(f: F) -> impl Send { + f +} + +fn bar<T>() { + foo(from(|| ())) +} + +fn main() { +} diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds_closure.rs b/src/test/ui/type-alias-impl-trait/implied_bounds_closure.rs new file mode 100644 index 00000000000..4cf35f95190 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds_closure.rs @@ -0,0 +1,31 @@ +trait StaticDefaultRef: 'static { + fn default_ref() -> &'static Self; +} + +impl StaticDefaultRef for str { + fn default_ref() -> &'static str { + "" + } +} + +fn into_impl(x: &str) -> &(impl ?Sized + AsRef<str> + StaticDefaultRef + '_) { + x +} + +fn extend_lifetime<'a>(x: &'a str) -> &'static str { + let t = into_impl(x); + helper(|_| t) //~ ERROR lifetime may not live long enough +} + +fn helper<T: ?Sized + AsRef<str> + StaticDefaultRef>(f: impl FnOnce(&T) -> &T) -> &'static str { + f(T::default_ref()).as_ref() +} + +fn main() { + let r; + { + let x = String::from("Hello World?"); + r = extend_lifetime(&x); + } + println!("{}", r); +} diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds_closure.stderr b/src/test/ui/type-alias-impl-trait/implied_bounds_closure.stderr new file mode 100644 index 00000000000..151564c3b45 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds_closure.stderr @@ -0,0 +1,11 @@ +error: lifetime may not live long enough + --> $DIR/implied_bounds_closure.rs:17:16 + | +LL | fn extend_lifetime<'a>(x: &'a str) -> &'static str { + | -- lifetime `'a` defined here +LL | let t = into_impl(x); +LL | helper(|_| t) + | ^ returning this value requires that `'a` must outlive `'static` + +error: aborting due to previous error + diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.rs b/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.rs new file mode 100644 index 00000000000..8023cd24f0b --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.rs @@ -0,0 +1,51 @@ +#![feature(type_alias_impl_trait)] + +type WithLifetime<T> = impl Equals<SelfType = ()>; +fn _defining_use<T>() -> WithLifetime<T> {} + +trait Convert<'a> { + type Witness; + fn convert<'b, T: ?Sized>(_proof: &'b Self::Witness, x: &'a T) -> &'b T; +} + +impl<'a> Convert<'a> for () { + type Witness = WithLifetime<&'a ()>; + + fn convert<'b, T: ?Sized>(_proof: &'b WithLifetime<&'a ()>, x: &'a T) -> &'b T { + // compiler used to think it gets to assume 'a: 'b here because + // of the `&'b WithLifetime<&'a ()>` argument + x + //~^ ERROR lifetime may not live long enough + } +} + +fn extend_lifetime<'a, 'b, T: ?Sized>(x: &'a T) -> &'b T { + WithLifetime::<&'a ()>::convert_helper::<(), T>(&(), x) +} + +trait Equals { + type SelfType; + fn convert_helper<'a, 'b, W: Convert<'a, Witness = Self>, T: ?Sized>( + proof: &'b Self::SelfType, + x: &'a T, + ) -> &'b T; +} + +impl<S> Equals for S { + type SelfType = Self; + fn convert_helper<'a, 'b, W: Convert<'a, Witness = Self>, T: ?Sized>( + proof: &'b Self, + x: &'a T, + ) -> &'b T { + W::convert(proof, x) + } +} + +fn main() { + let r; + { + let x = String::from("Hello World?"); + r = extend_lifetime(&x); + } + println!("{}", r); +} diff --git a/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.stderr b/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.stderr new file mode 100644 index 00000000000..cbc5e607318 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_bounds_from_types.stderr @@ -0,0 +1,16 @@ +error: lifetime may not live long enough + --> $DIR/implied_bounds_from_types.rs:17:9 + | +LL | impl<'a> Convert<'a> for () { + | -- lifetime `'a` defined here +... +LL | fn convert<'b, T: ?Sized>(_proof: &'b WithLifetime<&'a ()>, x: &'a T) -> &'b T { + | -- lifetime `'b` defined here +... +LL | x + | ^ associated function was supposed to return data with lifetime `'b` but it is returning data with lifetime `'a` + | + = help: consider adding the following bound: `'a: 'b` + +error: aborting due to previous error + diff --git a/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check.rs b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check.rs new file mode 100644 index 00000000000..b6a7264a529 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check.rs @@ -0,0 +1,27 @@ +#![feature(type_alias_impl_trait)] + +// known-bug: #99840 +// this should not compile +// check-pass + +type Alias = impl Sized; + +fn constrain() -> Alias { + 1i32 +} + +trait HideIt { + type Assoc; +} + +impl HideIt for () { + type Assoc = Alias; +} + +pub trait Yay {} + +impl Yay for <() as HideIt>::Assoc {} +// impl Yay for i32 {} // this already errors +// impl Yay for u32 {} // this also already errors + +fn main() {} diff --git a/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs new file mode 100644 index 00000000000..6e5b8f491ea --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs @@ -0,0 +1,43 @@ +#![feature(type_alias_impl_trait)] + +mod test_lifetime_param { + type Ty<'a> = impl Sized; + fn defining(a: &str) -> Ty<'_> { a } + fn assert_static<'a: 'static>() {} + //~^ WARN: unnecessary lifetime parameter `'a` + fn test<'a>() where Ty<'a>: 'static { assert_static::<'a>() } + //~^ ERROR: lifetime may not live long enough +} + +mod test_higher_kinded_lifetime_param { + type Ty<'a> = impl Sized; + fn defining(a: &str) -> Ty<'_> { a } + fn assert_static<'a: 'static>() {} + //~^ WARN: unnecessary lifetime parameter `'a` + fn test<'a>() where for<'b> Ty<'b>: 'a { assert_static::<'a>() } + //~^ ERROR: lifetime may not live long enough +} + +mod test_higher_kinded_lifetime_param2 { + fn assert_static<'a: 'static>() {} + //~^ WARN: unnecessary lifetime parameter `'a` + fn test<'a>() { assert_static::<'a>() } + //~^ ERROR: lifetime may not live long enough +} + +mod test_type_param { + type Ty<A> = impl Sized; + fn defining<A>(s: A) -> Ty<A> { s } + fn assert_static<A: 'static>() {} + fn test<A>() where Ty<A>: 'static { assert_static::<A>() } + //~^ ERROR: parameter type `A` may not live long enough +} + +mod test_implied_from_fn_sig { + type Opaque<T: 'static> = impl Sized; + fn defining<T: 'static>() -> Opaque<T> {} + fn assert_static<T: 'static>() {} + fn test<T>(_: Opaque<T>) { assert_static::<T>(); } +} + +fn main() {} diff --git a/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.stderr b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.stderr new file mode 100644 index 00000000000..887620a4d50 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check3.stderr @@ -0,0 +1,58 @@ +warning: unnecessary lifetime parameter `'a` + --> $DIR/implied_lifetime_wf_check3.rs:6:22 + | +LL | fn assert_static<'a: 'static>() {} + | ^^ + | + = help: you can use the `'static` lifetime directly, in place of `'a` + +warning: unnecessary lifetime parameter `'a` + --> $DIR/implied_lifetime_wf_check3.rs:15:22 + | +LL | fn assert_static<'a: 'static>() {} + | ^^ + | + = help: you can use the `'static` lifetime directly, in place of `'a` + +warning: unnecessary lifetime parameter `'a` + --> $DIR/implied_lifetime_wf_check3.rs:22:22 + | +LL | fn assert_static<'a: 'static>() {} + | ^^ + | + = help: you can use the `'static` lifetime directly, in place of `'a` + +error: lifetime may not live long enough + --> $DIR/implied_lifetime_wf_check3.rs:8:43 + | +LL | fn test<'a>() where Ty<'a>: 'static { assert_static::<'a>() } + | -- lifetime `'a` defined here ^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static` + +error: lifetime may not live long enough + --> $DIR/implied_lifetime_wf_check3.rs:17:46 + | +LL | fn test<'a>() where for<'b> Ty<'b>: 'a { assert_static::<'a>() } + | -- lifetime `'a` defined here ^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static` + +error: lifetime may not live long enough + --> $DIR/implied_lifetime_wf_check3.rs:24:21 + | +LL | fn test<'a>() { assert_static::<'a>() } + | -- ^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static` + | | + | lifetime `'a` defined here + +error[E0310]: the parameter type `A` may not live long enough + --> $DIR/implied_lifetime_wf_check3.rs:32:41 + | +LL | fn test<A>() where Ty<A>: 'static { assert_static::<A>() } + | ^^^^^^^^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound... + | +LL | fn test<A: 'static>() where Ty<A>: 'static { assert_static::<A>() } + | +++++++++ + +error: aborting due to 4 previous errors; 3 warnings emitted + +For more information about this error, try `rustc --explain E0310`. diff --git a/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs new file mode 100644 index 00000000000..ac32dbde04b --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs @@ -0,0 +1,11 @@ +#![feature(type_alias_impl_trait)] + +mod test_type_param_static { + type Ty<A> = impl Sized + 'static; + //~^ ERROR: the parameter type `A` may not live long enough + fn defining<A: 'static>(s: A) -> Ty<A> { s } + fn assert_static<A: 'static>() {} + fn test<A>() where Ty<A>: 'static { assert_static::<A>() } +} + +fn main() {} diff --git a/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr new file mode 100644 index 00000000000..47bc31e78c3 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr @@ -0,0 +1,14 @@ +error[E0310]: the parameter type `A` may not live long enough + --> $DIR/implied_lifetime_wf_check4_static.rs:4:18 + | +LL | type Ty<A> = impl Sized + 'static; + | ^^^^^^^^^^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound... + | +LL | type Ty<A: 'static> = impl Sized + 'static; + | +++++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0310`. diff --git a/src/test/ui/type-alias-impl-trait/issue-58662-generator-with-lifetime.rs b/src/test/ui/type-alias-impl-trait/issue-58662-generator-with-lifetime.rs index f20ddf02071..477b61390ed 100644 --- a/src/test/ui/type-alias-impl-trait/issue-58662-generator-with-lifetime.rs +++ b/src/test/ui/type-alias-impl-trait/issue-58662-generator-with-lifetime.rs @@ -16,7 +16,7 @@ fn rand_generator<'a>(rng: &'a ()) -> RandGenerator<'a> { } } -pub type RandGeneratorWithIndirection<'a> = impl Generator<Return = (), Yield = u64> + 'a; +pub type RandGeneratorWithIndirection<'c> = impl Generator<Return = (), Yield = u64> + 'c; pub fn rand_generator_with_indirection<'a>(rng: &'a ()) -> RandGeneratorWithIndirection<'a> { fn helper<'b>(rng: &'b ()) -> impl 'b + Generator<Return = (), Yield = u64> { move || { diff --git a/src/test/ui/type-alias-impl-trait/issue-58662-simplified.rs b/src/test/ui/type-alias-impl-trait/issue-58662-simplified.rs new file mode 100644 index 00000000000..27ca7d0fdc9 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/issue-58662-simplified.rs @@ -0,0 +1,20 @@ +// check-pass + +#![feature(generators, generator_trait)] +#![feature(type_alias_impl_trait)] + +trait Trait {} + +impl<T> Trait for T {} + +type Foo<'c> = impl Trait + 'c; +fn foo<'a>(rng: &'a ()) -> Foo<'a> { + fn helper<'b>(rng: &'b ()) -> impl 'b + Trait { + rng + } + + helper(rng) +} + +fn main() { +} diff --git a/src/test/ui/type-alias-impl-trait/unbounded_opaque_type.rs b/src/test/ui/type-alias-impl-trait/unbounded_opaque_type.rs new file mode 100644 index 00000000000..f43ad7dce1d --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/unbounded_opaque_type.rs @@ -0,0 +1,14 @@ +// check-pass + +#![feature(type_alias_impl_trait)] +type Opaque<T> = impl Sized; +fn defining<T>() -> Opaque<T> {} +struct Ss<'a, T>(&'a Opaque<T>); + + +fn test<'a, T>(_: Ss<'a, T>) { + // test that we have an implied bound `Opaque<T>: 'a` from fn signature + None::<&'a Opaque<T>>; +} + +fn main() {} |