diff options
9 files changed, 87 insertions, 84 deletions
diff --git a/compiler/rustc_infer/src/infer/projection.rs b/compiler/rustc_infer/src/infer/projection.rs index 75455533181..38e74e53868 100644 --- a/compiler/rustc_infer/src/infer/projection.rs +++ b/compiler/rustc_infer/src/infer/projection.rs @@ -21,29 +21,18 @@ impl<'tcx> InferCtxt<'tcx> { recursion_depth: usize, obligations: &mut Vec<PredicateObligation<'tcx>>, ) -> Ty<'tcx> { - if self.next_trait_solver() { - // FIXME(-Ztrait-solver=next): Instead of branching here, - // completely change the normalization routine with the new solver. - // - // The new solver correctly handles projection equality so this hack - // is not necessary. if re-enabled it should emit `PredicateKind::AliasRelate` - // not `PredicateKind::Clause(ClauseKind::Projection(..))` as in the new solver - // `Projection` is used as `normalizes-to` which will fail for `<T as Trait>::Assoc eq ?0`. - return projection_ty.to_ty(self.tcx); - } else { - let def_id = projection_ty.def_id; - let ty_var = self.next_ty_var(TypeVariableOrigin { - kind: TypeVariableOriginKind::NormalizeProjectionType, - span: self.tcx.def_span(def_id), - }); - let projection = - ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::Projection( - ty::ProjectionPredicate { projection_ty, term: ty_var.into() }, - ))); - let obligation = - Obligation::with_depth(self.tcx, cause, recursion_depth, param_env, projection); - obligations.push(obligation); - ty_var - } + debug_assert!(!self.next_trait_solver()); + let def_id = projection_ty.def_id; + let ty_var = self.next_ty_var(TypeVariableOrigin { + kind: TypeVariableOriginKind::NormalizeProjectionType, + span: self.tcx.def_span(def_id), + }); + let projection = ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::Projection( + ty::ProjectionPredicate { projection_ty, term: ty_var.into() }, + ))); + let obligation = + Obligation::with_depth(self.tcx, cause, recursion_depth, param_env, projection); + obligations.push(obligation); + ty_var } } diff --git a/compiler/rustc_trait_selection/src/solve/normalize.rs b/compiler/rustc_trait_selection/src/solve/normalize.rs index 83da9db7bff..c0ee1a576e5 100644 --- a/compiler/rustc_trait_selection/src/solve/normalize.rs +++ b/compiler/rustc_trait_selection/src/solve/normalize.rs @@ -159,6 +159,7 @@ impl<'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for NormalizationFolder<'_, 'tcx> { fn try_fold_ty(&mut self, ty: Ty<'tcx>) -> Result<Ty<'tcx>, Self::Error> { let reveal = self.at.param_env.reveal(); let infcx = self.at.infcx; + debug_assert_eq!(ty, infcx.shallow_resolve(ty)); if !needs_normalization(&ty, reveal) { return Ok(ty); } @@ -192,6 +193,7 @@ impl<'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for NormalizationFolder<'_, 'tcx> { fn try_fold_const(&mut self, ct: ty::Const<'tcx>) -> Result<ty::Const<'tcx>, Self::Error> { let reveal = self.at.param_env.reveal(); let infcx = self.at.infcx; + debug_assert_eq!(ct, infcx.shallow_resolve(ct)); if !needs_normalization(&ct, reveal) { return Ok(ct); } diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 4cfe2bfcb12..1b1285e1b46 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -30,6 +30,7 @@ use std::fmt::Debug; use std::iter; use std::ops::ControlFlow; +use super::query::evaluate_obligation::InferCtxtExt; use super::NormalizeExt; /// Whether we do the orphan check relative to this crate or @@ -290,6 +291,20 @@ fn impl_intersection_has_impossible_obligation<'cx, 'tcx>( ) -> bool { let infcx = selcx.infcx; + let obligation_guaranteed_to_fail = move |obligation: &PredicateObligation<'tcx>| { + if infcx.next_trait_solver() { + infcx.evaluate_obligation(obligation).map_or(false, |result| !result.may_apply()) + } else { + // We use `evaluate_root_obligation` to correctly track + // intercrate ambiguity clauses. We do not need this in the + // new solver. + selcx.evaluate_root_obligation(obligation).map_or( + false, // Overflow has occurred, and treat the obligation as possibly holding. + |result| !result.may_apply(), + ) + } + }; + let opt_failing_obligation = [&impl1_header.predicates, &impl2_header.predicates] .into_iter() .flatten() @@ -297,12 +312,7 @@ fn impl_intersection_has_impossible_obligation<'cx, 'tcx>( Obligation::new(infcx.tcx, ObligationCause::dummy(), param_env, predicate) }) .chain(obligations) - .find(|o| { - selcx.evaluate_root_obligation(o).map_or( - false, // Overflow has occurred, and treat the obligation as possibly holding. - |result| !result.may_apply(), - ) - }); + .find(obligation_guaranteed_to_fail); if let Some(failing_obligation) = opt_failing_obligation { debug!("overlap: obligation unsatisfiable {:?}", failing_obligation); diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 22d29efa071..9a8e9d97dda 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -447,6 +447,7 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> { depth: usize, obligations: &'a mut Vec<PredicateObligation<'tcx>>, ) -> AssocTypeNormalizer<'a, 'b, 'tcx> { + debug_assert!(!selcx.infcx.next_trait_solver()); AssocTypeNormalizer { selcx, param_env, @@ -1122,6 +1123,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>( obligations: &mut Vec<PredicateObligation<'tcx>>, ) -> Result<Option<Term<'tcx>>, InProgress> { let infcx = selcx.infcx; + debug_assert!(!selcx.infcx.next_trait_solver()); // Don't use the projection cache in intercrate mode - // the `infcx` may be re-used between intercrate in non-intercrate // mode, which could lead to using incorrect cache results. diff --git a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs index e29e1b25919..a50644bb709 100644 --- a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs +++ b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs @@ -97,6 +97,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { } }) } else { + assert!(!self.intercrate); let c_pred = self.canonicalize_query_keep_static( param_env.and(obligation.predicate), &mut _orig_values, diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs index 42c2c37eca2..979498fb6e6 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs @@ -1,3 +1,4 @@ +use crate::solve; use crate::traits::query::NoSolution; use crate::traits::wf; use crate::traits::ObligationCtxt; @@ -6,6 +7,7 @@ use rustc_infer::infer::canonical::Canonical; use rustc_infer::infer::outlives::components::{push_outlives_components, Component}; use rustc_infer::traits::query::OutlivesBound; use rustc_middle::infer::canonical::CanonicalQueryResponse; +use rustc_middle::traits::ObligationCause; use rustc_middle::ty::{self, ParamEnvAnd, Ty, TyCtxt, TypeVisitableExt}; use rustc_span::def_id::CRATE_DEF_ID; use rustc_span::source_map::DUMMY_SP; @@ -164,19 +166,29 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>( // 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)], + let mut implied_bounds = Vec::new(); + for ty::OutlivesPredicate(a, r_b) in outlives_bounds { + match a.unpack() { + ty::GenericArgKind::Lifetime(r_a) => { + implied_bounds.push(OutlivesBound::RegionSubRegion(r_b, r_a)) + } ty::GenericArgKind::Type(ty_a) => { - let ty_a = ocx.infcx.resolve_vars_if_possible(ty_a); + let mut ty_a = ocx.infcx.resolve_vars_if_possible(ty_a); + // Need to manually normalize in the new solver as `wf::obligations` does not. + if ocx.infcx.next_trait_solver() { + ty_a = solve::deeply_normalize( + ocx.infcx.at(&ObligationCause::dummy(), param_env), + ty_a, + ) + .map_err(|_errs| NoSolution)?; + } let mut components = smallvec![]; push_outlives_components(tcx, ty_a, &mut components); - implied_bounds_from_components(r_b, components) + implied_bounds.extend(implied_bounds_from_components(r_b, components)) } ty::GenericArgKind::Const(_) => unreachable!(), - }) - .collect(); + } + } Ok(implied_bounds) } diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 412b601c966..a0329259705 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -388,7 +388,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// `FnPtr`, when we wanted to report that it doesn't implement `Trait`. #[instrument(level = "trace", skip(self), ret)] fn reject_fn_ptr_impls( - &self, + &mut self, impl_def_id: DefId, obligation: &TraitObligation<'tcx>, impl_self_ty: Ty<'tcx>, @@ -464,7 +464,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ty::PredicateKind::Clause(ty::ClauseKind::Trait(pred)) })), ); - if let Ok(r) = self.infcx.evaluate_obligation(&obligation) { + if let Ok(r) = self.evaluate_root_obligation(&obligation) { if !r.may_apply() { return true; } diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index eb11163de42..20cfbd5fed5 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -34,8 +34,6 @@ use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_infer::infer::DefineOpaqueTypes; use rustc_infer::infer::LateBoundRegionConversionTime; -use rustc_infer::traits::TraitEngine; -use rustc_infer::traits::TraitEngineExt; use rustc_middle::dep_graph::{DepKind, DepNodeIndex}; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::ty::abstract_const::NotConstEvaluatable; @@ -312,6 +310,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { &mut self, stack: &TraitObligationStack<'o, 'tcx>, ) -> SelectionResult<'tcx, SelectionCandidate<'tcx>> { + debug_assert!(!self.infcx.next_trait_solver()); // Watch out for overflow. This intentionally bypasses (and does // not update) the cache. self.check_recursion_limit(&stack.obligation, &stack.obligation)?; @@ -526,21 +525,20 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// Evaluates whether the obligation `obligation` can be satisfied /// and returns an `EvaluationResult`. This is meant for the /// *initial* call. + /// + /// Do not use this directly, use `infcx.evaluate_obligation` instead. pub fn evaluate_root_obligation( &mut self, obligation: &PredicateObligation<'tcx>, ) -> Result<EvaluationResult, OverflowError> { + debug_assert!(!self.infcx.next_trait_solver()); self.evaluation_probe(|this| { let goal = this.infcx.resolve_vars_if_possible((obligation.predicate, obligation.param_env)); - let mut result = if this.infcx.next_trait_solver() { - this.evaluate_predicates_recursively_in_new_solver([obligation.clone()])? - } else { - this.evaluate_predicate_recursively( - TraitObligationStackList::empty(&ProvisionalEvaluationCache::default()), - obligation.clone(), - )? - }; + let mut result = this.evaluate_predicate_recursively( + TraitObligationStackList::empty(&ProvisionalEvaluationCache::default()), + obligation.clone(), + )?; // If the predicate has done any inference, then downgrade the // result to ambiguous. if this.infcx.shallow_resolve(goal) != goal { @@ -587,42 +585,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { where I: IntoIterator<Item = PredicateObligation<'tcx>> + std::fmt::Debug, { - if self.infcx.next_trait_solver() { - self.evaluate_predicates_recursively_in_new_solver(predicates) - } else { - let mut result = EvaluatedToOk; - for mut obligation in predicates { - obligation.set_depth_from_parent(stack.depth()); - let eval = self.evaluate_predicate_recursively(stack, obligation.clone())?; - if let EvaluatedToErr = eval { - // fast-path - EvaluatedToErr is the top of the lattice, - // so we don't need to look on the other predicates. - return Ok(EvaluatedToErr); - } else { - result = cmp::max(result, eval); - } + let mut result = EvaluatedToOk; + for mut obligation in predicates { + obligation.set_depth_from_parent(stack.depth()); + let eval = self.evaluate_predicate_recursively(stack, obligation.clone())?; + if let EvaluatedToErr = eval { + // fast-path - EvaluatedToErr is the top of the lattice, + // so we don't need to look on the other predicates. + return Ok(EvaluatedToErr); + } else { + result = cmp::max(result, eval); } - Ok(result) - } - } - - /// Evaluates the predicates using the new solver when `-Ztrait-solver=next` is enabled - fn evaluate_predicates_recursively_in_new_solver( - &mut self, - predicates: impl IntoIterator<Item = PredicateObligation<'tcx>>, - ) -> Result<EvaluationResult, OverflowError> { - let mut fulfill_cx = crate::solve::FulfillmentCtxt::new(self.infcx); - fulfill_cx.register_predicate_obligations(self.infcx, predicates); - // True errors - // FIXME(-Ztrait-solver=next): Overflows are reported as ambig here, is that OK? - if !fulfill_cx.select_where_possible(self.infcx).is_empty() { - return Ok(EvaluatedToErr); } - if !fulfill_cx.select_all_or_error(self.infcx).is_empty() { - return Ok(EvaluatedToAmbig); - } - // Regions and opaques are handled in the `evaluation_probe` by looking at the snapshot - Ok(EvaluatedToOk) + Ok(result) } #[instrument( @@ -636,6 +611,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { previous_stack: TraitObligationStackList<'o, 'tcx>, obligation: PredicateObligation<'tcx>, ) -> Result<EvaluationResult, OverflowError> { + debug_assert!(!self.infcx.next_trait_solver()); // `previous_stack` stores a `TraitObligation`, while `obligation` is // a `PredicateObligation`. These are distinct types, so we can't // use any `Option` combinator method that would force them to be @@ -1179,6 +1155,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { &mut self, stack: &TraitObligationStack<'o, 'tcx>, ) -> Result<EvaluationResult, OverflowError> { + debug_assert!(!self.infcx.next_trait_solver()); // In intercrate mode, whenever any of the generics are unbound, // there can always be an impl. Even if there are no impls in // this crate, perhaps the type would be unified with diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index 86c7fc45ff7..0ae6b181519 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -302,6 +302,16 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> { } fn normalize(self, infcx: &InferCtxt<'tcx>) -> Vec<traits::PredicateObligation<'tcx>> { + // Do not normalize `wf` obligations with the new solver. + // + // The current deep normalization routine with the new solver does not + // handle ambiguity and the new solver correctly deals with unnnormalized goals. + // If the user relies on normalized types, e.g. for `fn implied_outlives_bounds`, + // it is their responsibility to normalize while avoiding ambiguity. + if infcx.next_trait_solver() { + return self.out; + } + let cause = self.cause(traits::WellFormed(None)); let param_env = self.param_env; let mut obligations = Vec::with_capacity(self.out.len()); |