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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:06:31 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:06:31 +0000 |
commit | 2ff14448863ac1a1dd9533461708e29aae170c2d (patch) | |
tree | 85b9fea2bbfe3f06473cfa381eed11f273b57c5c /compiler/rustc_traits | |
parent | Adding debian version 1.64.0+dfsg1-1. (diff) | |
download | rustc-2ff14448863ac1a1dd9533461708e29aae170c2d.tar.xz rustc-2ff14448863ac1a1dd9533461708e29aae170c2d.zip |
Adding debian version 1.65.0+dfsg1-2.debian/1.65.0+dfsg1-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_traits')
-rw-r--r-- | compiler/rustc_traits/src/chalk/lowering.rs | 13 | ||||
-rw-r--r-- | compiler/rustc_traits/src/implied_outlives_bounds.rs | 69 | ||||
-rw-r--r-- | compiler/rustc_traits/src/lib.rs | 4 | ||||
-rw-r--r-- | compiler/rustc_traits/src/type_op.rs | 58 |
4 files changed, 79 insertions, 65 deletions
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs index c7c604e14..45d5ea93d 100644 --- a/compiler/rustc_traits/src/chalk/lowering.rs +++ b/compiler/rustc_traits/src/chalk/lowering.rs @@ -191,7 +191,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi GenericArgKind::Const(..) => { chalk_ir::GoalData::All(chalk_ir::Goals::empty(interner)) } - GenericArgKind::Lifetime(lt) => bug!("unexpect well formed predicate: {:?}", lt), + GenericArgKind::Lifetime(lt) => bug!("unexpected well formed predicate: {:?}", lt), }, ty::PredicateKind::ObjectSafe(t) => chalk_ir::GoalData::DomainGoal( @@ -326,7 +326,8 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Ty<RustInterner<'tcx>>> for Ty<'tcx> { )), }) } - ty::Dynamic(predicates, region) => chalk_ir::TyKind::Dyn(chalk_ir::DynTy { + // FIXME(dyn-star): handle the dynamic kind (dyn or dyn*) + ty::Dynamic(predicates, region, _kind) => chalk_ir::TyKind::Dyn(chalk_ir::DynTy { bounds: predicates.lower_into(interner), lifetime: region.lower_into(interner), }), @@ -485,10 +486,6 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::Lifetime<RustInterner<'tcx>>> for Region<'t }) .intern(interner) } - ty::ReEmpty(ui) => { - chalk_ir::LifetimeData::Empty(chalk_ir::UniverseIndex { counter: ui.index() }) - .intern(interner) - } ty::ReErased => chalk_ir::LifetimeData::Erased.intern(interner), } } @@ -510,8 +507,8 @@ impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'t name: ty::BoundRegionKind::BrAnon(p.idx as u32), }), chalk_ir::LifetimeData::Static => return interner.tcx.lifetimes.re_static, - chalk_ir::LifetimeData::Empty(ui) => { - ty::ReEmpty(ty::UniverseIndex::from_usize(ui.counter)) + chalk_ir::LifetimeData::Empty(_) => { + bug!("Chalk should not have been passed an empty lifetime.") } chalk_ir::LifetimeData::Erased => return interner.tcx.lifetimes.re_erased, chalk_ir::LifetimeData::Phantom(void, _) => match *void {}, diff --git a/compiler/rustc_traits/src/implied_outlives_bounds.rs b/compiler/rustc_traits/src/implied_outlives_bounds.rs index e3e78f70b..691b79f10 100644 --- a/compiler/rustc_traits/src/implied_outlives_bounds.rs +++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs @@ -49,7 +49,8 @@ fn compute_implied_outlives_bounds<'tcx>( let mut checked_wf_args = rustc_data_structures::fx::FxHashSet::default(); let mut wf_args = vec![ty.into()]; - let mut implied_bounds = vec![]; + let mut outlives_bounds: Vec<ty::OutlivesPredicate<ty::GenericArg<'tcx>, ty::Region<'tcx>>> = + vec![]; let mut fulfill_cx = <dyn TraitEngine<'tcx>>::new(tcx); @@ -65,30 +66,17 @@ fn compute_implied_outlives_bounds<'tcx>( // than the ultimate set. (Note: normally there won't be // unresolved inference variables here anyway, but there might be // during typeck under some circumstances.) + // + // FIXME(@lcnr): It's not really "always fine", having fewer implied + // bounds can be backward incompatible, e.g. #101951 was caused by + // us not dealing with inference vars in `TypeOutlives` predicates. let obligations = wf::obligations(infcx, param_env, hir::CRATE_HIR_ID, 0, arg, DUMMY_SP) .unwrap_or_default(); - // N.B., all of these predicates *ought* to be easily proven - // true. In fact, their correctness is (mostly) implied by - // other parts of the program. However, in #42552, we had - // an annoying scenario where: - // - // - Some `T::Foo` gets normalized, resulting in a - // variable `_1` and a `T: Trait<Foo=_1>` constraint - // (not sure why it couldn't immediately get - // solved). This result of `_1` got cached. - // - These obligations were dropped on the floor here, - // rather than being registered. - // - Then later we would get a request to normalize - // `T::Foo` which would result in `_1` being used from - // the cache, but hence without the `T: Trait<Foo=_1>` - // constraint. As a result, `_1` never gets resolved, - // and we get an ICE (in dropck). - // - // Therefore, we register any predicates involving - // inference variables. We restrict ourselves to those - // involving inference variables both for efficiency and - // to avoids duplicate errors that otherwise show up. + // While these predicates should all be implied by other parts of + // the program, they are still relevant as they may constrain + // inference variables, which is necessary to add the correct + // implied bounds in some cases, mostly when dealing with projections. fulfill_cx.register_predicate_obligations( infcx, obligations.iter().filter(|o| o.predicate.has_infer_types_or_consts()).cloned(), @@ -96,10 +84,10 @@ fn compute_implied_outlives_bounds<'tcx>( // From the full set of obligations, just filter down to the // region relationships. - implied_bounds.extend(obligations.into_iter().flat_map(|obligation| { + outlives_bounds.extend(obligations.into_iter().filter_map(|obligation| { assert!(!obligation.has_escaping_bound_vars()); match obligation.predicate.kind().no_bound_vars() { - None => vec![], + None => None, Some(pred) => match pred { ty::PredicateKind::Trait(..) | ty::PredicateKind::Subtype(..) @@ -109,21 +97,18 @@ fn compute_implied_outlives_bounds<'tcx>( | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::TypeWellFormedFromEnv(..) => vec![], + | ty::PredicateKind::TypeWellFormedFromEnv(..) => None, ty::PredicateKind::WellFormed(arg) => { wf_args.push(arg); - vec![] + None } ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(r_a, r_b)) => { - vec![OutlivesBound::RegionSubRegion(r_b, r_a)] + Some(ty::OutlivesPredicate(r_a.into(), r_b)) } ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty_a, r_b)) => { - let ty_a = infcx.resolve_vars_if_possible(ty_a); - let mut components = smallvec![]; - push_outlives_components(tcx, ty_a, &mut components); - implied_bounds_from_components(r_b, components) + Some(ty::OutlivesPredicate(ty_a.into(), r_b)) } }, } @@ -133,9 +118,27 @@ fn compute_implied_outlives_bounds<'tcx>( // Ensure that those obligations that we had to solve // get solved *here*. match fulfill_cx.select_all_or_error(infcx).as_slice() { - [] => Ok(implied_bounds), - _ => Err(NoSolution), + [] => (), + _ => return Err(NoSolution), } + + // We lazily compute the outlives components as + // `select_all_or_error` constrains inference variables. + let implied_bounds = outlives_bounds + .into_iter() + .flat_map(|ty::OutlivesPredicate(a, r_b)| match a.unpack() { + ty::GenericArgKind::Lifetime(r_a) => vec![OutlivesBound::RegionSubRegion(r_b, r_a)], + ty::GenericArgKind::Type(ty_a) => { + let ty_a = infcx.resolve_vars_if_possible(ty_a); + let mut components = smallvec![]; + push_outlives_components(tcx, ty_a, &mut components); + implied_bounds_from_components(r_b, components) + } + ty::GenericArgKind::Const(_) => unreachable!(), + }) + .collect(); + + Ok(implied_bounds) } /// When we have an implied bound that `T: 'a`, we can further break diff --git a/compiler/rustc_traits/src/lib.rs b/compiler/rustc_traits/src/lib.rs index 2bea164c0..2d39e973e 100644 --- a/compiler/rustc_traits/src/lib.rs +++ b/compiler/rustc_traits/src/lib.rs @@ -1,7 +1,9 @@ //! New recursive solver modeled on Chalk's recursive solver. Most of //! the guts are broken up into modules; see the comments in those modules. -#![feature(let_else)] +#![deny(rustc::untranslatable_diagnostic)] +#![deny(rustc::diagnostic_outside_of_impl)] +#![cfg_attr(bootstrap, feature(let_else))] #![recursion_limit = "256"] #[macro_use] diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs index d895b647d..1bb6506b3 100644 --- a/compiler/rustc_traits/src/type_op.rs +++ b/compiler/rustc_traits/src/type_op.rs @@ -3,7 +3,7 @@ use rustc_hir::def_id::DefId; use rustc_infer::infer::at::ToTrace; use rustc_infer::infer::canonical::{Canonical, QueryResponse}; use rustc_infer::infer::{DefiningAnchor, InferCtxt, TyCtxtInferExt}; -use rustc_infer::traits::TraitEngineExt as _; +use rustc_infer::traits::{ObligationCauseCode, TraitEngineExt as _}; use rustc_middle::ty::query::Providers; use rustc_middle::ty::subst::{GenericArg, Subst, UserSelfTy, UserSubsts}; use rustc_middle::ty::{ @@ -22,6 +22,7 @@ use rustc_trait_selection::traits::query::type_op::subtype::Subtype; use rustc_trait_selection::traits::query::{Fallible, NoSolution}; use rustc_trait_selection::traits::{Normalized, Obligation, ObligationCause, TraitEngine}; use std::fmt; +use std::iter::zip; pub(crate) fn provide(p: &mut Providers) { *p = Providers { @@ -61,14 +62,15 @@ pub fn type_op_ascribe_user_type_with_span<'a, 'tcx: 'a>( mir_ty, def_id, user_substs ); - let mut cx = AscribeUserTypeCx { infcx, param_env, fulfill_cx }; - cx.relate_mir_and_user_ty(mir_ty, def_id, user_substs, span)?; + let mut cx = AscribeUserTypeCx { infcx, param_env, span: span.unwrap_or(DUMMY_SP), fulfill_cx }; + cx.relate_mir_and_user_ty(mir_ty, def_id, user_substs)?; Ok(()) } struct AscribeUserTypeCx<'me, 'tcx> { infcx: &'me InferCtxt<'me, 'tcx>, param_env: ParamEnv<'tcx>, + span: Span, fulfill_cx: &'me mut dyn TraitEngine<'tcx>, } @@ -77,12 +79,15 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { where T: TypeFoldable<'tcx>, { + self.normalize_with_cause(value, ObligationCause::misc(self.span, hir::CRATE_HIR_ID)) + } + + fn normalize_with_cause<T>(&mut self, value: T, cause: ObligationCause<'tcx>) -> T + where + T: TypeFoldable<'tcx>, + { self.infcx - .partially_normalize_associated_types_in( - ObligationCause::misc(DUMMY_SP, hir::CRATE_HIR_ID), - self.param_env, - value, - ) + .partially_normalize_associated_types_in(cause, self.param_env, value) .into_value_registering_obligations(self.infcx, self.fulfill_cx) } @@ -91,18 +96,13 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { T: ToTrace<'tcx>, { self.infcx - .at(&ObligationCause::dummy(), self.param_env) + .at(&ObligationCause::dummy_with_span(self.span), self.param_env) .relate(a, variance, b)? .into_value_registering_obligations(self.infcx, self.fulfill_cx); Ok(()) } - fn prove_predicate(&mut self, predicate: Predicate<'tcx>, span: Option<Span>) { - let cause = if let Some(span) = span { - ObligationCause::dummy_with_span(span) - } else { - ObligationCause::dummy() - }; + fn prove_predicate(&mut self, predicate: Predicate<'tcx>, cause: ObligationCause<'tcx>) { self.fulfill_cx.register_predicate_obligation( self.infcx, Obligation::new(cause, self.param_env, predicate), @@ -120,20 +120,20 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { EarlyBinder(value).subst(self.tcx(), substs) } + #[instrument(level = "debug", skip(self))] fn relate_mir_and_user_ty( &mut self, mir_ty: Ty<'tcx>, def_id: DefId, user_substs: UserSubsts<'tcx>, - span: Option<Span>, ) -> Result<(), NoSolution> { let UserSubsts { user_self_ty, substs } = user_substs; let tcx = self.tcx(); let ty = tcx.type_of(def_id); let ty = self.subst(ty, substs); - debug!("relate_type_and_user_type: ty of def-id is {:?}", ty); let ty = self.normalize(ty); + debug!("relate_type_and_user_type: ty of def-id is {:?}", ty); self.relate(mir_ty, Variance::Invariant, ty)?; @@ -144,10 +144,22 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { // outlives" error messages. let instantiated_predicates = self.tcx().predicates_of(def_id).instantiate(self.tcx(), substs); - debug!(?instantiated_predicates.predicates); - for instantiated_predicate in instantiated_predicates.predicates { - let instantiated_predicate = self.normalize(instantiated_predicate); - self.prove_predicate(instantiated_predicate, span); + + let cause = ObligationCause::dummy_with_span(self.span); + + debug!(?instantiated_predicates); + for (instantiated_predicate, predicate_span) in + zip(instantiated_predicates.predicates, instantiated_predicates.spans) + { + let span = if self.span == DUMMY_SP { predicate_span } else { self.span }; + let cause = ObligationCause::new( + span, + hir::CRATE_HIR_ID, + ObligationCauseCode::AscribeUserTypeProvePredicate(predicate_span), + ); + let instantiated_predicate = + self.normalize_with_cause(instantiated_predicate, cause.clone()); + self.prove_predicate(instantiated_predicate, cause); } if let Some(UserSelfTy { impl_def_id, self_ty }) = user_self_ty { @@ -160,7 +172,7 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { self.prove_predicate( ty::Binder::dummy(ty::PredicateKind::WellFormed(impl_self_ty.into())) .to_predicate(self.tcx()), - span, + cause.clone(), ); } @@ -177,7 +189,7 @@ impl<'me, 'tcx> AscribeUserTypeCx<'me, 'tcx> { // which...could happen with normalization... self.prove_predicate( ty::Binder::dummy(ty::PredicateKind::WellFormed(ty.into())).to_predicate(self.tcx()), - span, + cause, ); Ok(()) } |