diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/fulfill.rs')
-rw-r--r-- | compiler/rustc_trait_selection/src/traits/fulfill.rs | 84 |
1 files changed, 41 insertions, 43 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index a81fef60a..a417e1440 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -25,10 +25,9 @@ use super::Unimplemented; use super::{FulfillmentError, FulfillmentErrorCode}; use super::{ObligationCause, PredicateObligation}; -use crate::traits::error_reporting::InferCtxtExt as _; use crate::traits::project::PolyProjectionObligation; use crate::traits::project::ProjectionCacheKeyExt as _; -use crate::traits::query::evaluate_obligation::InferCtxtExt as _; +use crate::traits::query::evaluate_obligation::InferCtxtExt; impl<'tcx> ForestObligation for PendingPredicateObligation<'tcx> { /// Note that we include both the `ParamEnv` and the `Predicate`, @@ -103,7 +102,7 @@ impl<'a, 'tcx> FulfillmentContext<'tcx> { } /// Attempts to select obligations using `selcx`. - fn select(&mut self, selcx: &mut SelectionContext<'a, 'tcx>) -> Vec<FulfillmentError<'tcx>> { + fn select(&mut self, selcx: SelectionContext<'a, 'tcx>) -> Vec<FulfillmentError<'tcx>> { let span = debug_span!("select", obligation_forest_size = ?self.predicates.len()); let _enter = span.enter(); @@ -138,7 +137,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { #[instrument(level = "debug", skip(self, infcx, param_env, cause))] fn normalize_projection_type( &mut self, - infcx: &InferCtxt<'_, 'tcx>, + infcx: &InferCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, projection_ty: ty::ProjectionTy<'tcx>, cause: ObligationCause<'tcx>, @@ -166,7 +165,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { fn register_predicate_obligation( &mut self, - infcx: &InferCtxt<'_, 'tcx>, + infcx: &InferCtxt<'tcx>, obligation: PredicateObligation<'tcx>, ) { // this helps to reduce duplicate errors, as well as making @@ -183,7 +182,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { .register_obligation(PendingPredicateObligation { obligation, stalled_on: vec![] }); } - fn select_all_or_error(&mut self, infcx: &InferCtxt<'_, 'tcx>) -> Vec<FulfillmentError<'tcx>> { + fn select_all_or_error(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> { { let errors = self.select_where_possible(infcx); if !errors.is_empty() { @@ -194,12 +193,9 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { self.predicates.to_errors(CodeAmbiguity).into_iter().map(to_fulfillment_error).collect() } - fn select_where_possible( - &mut self, - infcx: &InferCtxt<'_, 'tcx>, - ) -> Vec<FulfillmentError<'tcx>> { - let mut selcx = SelectionContext::new(infcx); - self.select(&mut selcx) + fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>> { + let selcx = SelectionContext::new(infcx); + self.select(selcx) } fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> { @@ -211,8 +207,8 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { } } -struct FulfillProcessor<'a, 'b, 'tcx> { - selcx: &'a mut SelectionContext<'b, 'tcx>, +struct FulfillProcessor<'a, 'tcx> { + selcx: SelectionContext<'a, 'tcx>, } fn mk_pending(os: Vec<PredicateObligation<'_>>) -> Vec<PendingPredicateObligation<'_>> { @@ -221,9 +217,10 @@ fn mk_pending(os: Vec<PredicateObligation<'_>>) -> Vec<PendingPredicateObligatio .collect() } -impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { +impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> { type Obligation = PendingPredicateObligation<'tcx>; type Error = FulfillmentErrorCode<'tcx>; + type OUT = Outcome<Self::Obligation, Self::Error>; /// Identifies whether a predicate obligation needs processing. /// @@ -279,7 +276,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { debug!(?obligation, "pre-resolve"); - if obligation.predicate.has_infer_types_or_consts() { + if obligation.predicate.has_non_region_infer() { obligation.predicate = self.selcx.infcx().resolve_vars_if_possible(obligation.predicate); } @@ -291,7 +288,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { if obligation.predicate.has_projections() { let mut obligations = Vec::new(); let predicate = crate::traits::project::try_normalize_with_depth_to( - self.selcx, + &mut self.selcx, obligation.param_env, obligation.cause.clone(), obligation.recursion_depth + 1, @@ -358,7 +355,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { } ty::PredicateKind::RegionOutlives(data) => { - if infcx.considering_regions || data.has_placeholders() { + if infcx.considering_regions { infcx.region_outlives_predicate(&obligation.cause, Binder::dummy(data)); } @@ -479,9 +476,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { Err(NotConstEvaluatable::MentionsInfer) => { pending_obligation.stalled_on.clear(); pending_obligation.stalled_on.extend( - uv.substs - .iter() - .filter_map(TyOrConstInferVar::maybe_from_generic_arg), + uv.walk().filter_map(TyOrConstInferVar::maybe_from_generic_arg), ); ProcessResult::Unchanged } @@ -495,19 +490,20 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { } ty::PredicateKind::ConstEquate(c1, c2) => { + assert!( + self.selcx.tcx().features().generic_const_exprs, + "`ConstEquate` without a feature gate: {c1:?} {c2:?}", + ); debug!(?c1, ?c2, "equating consts"); - let tcx = self.selcx.tcx(); - if tcx.features().generic_const_exprs { - // FIXME: we probably should only try to unify abstract constants - // if the constants depend on generic parameters. - // - // Let's just see where this breaks :shrug: - if let (ty::ConstKind::Unevaluated(a), ty::ConstKind::Unevaluated(b)) = - (c1.kind(), c2.kind()) - { - if infcx.try_unify_abstract_consts(a, b, obligation.param_env) { - return ProcessResult::Changed(vec![]); - } + // FIXME: we probably should only try to unify abstract constants + // if the constants depend on generic parameters. + // + // Let's just see where this breaks :shrug: + if let (ty::ConstKind::Unevaluated(a), ty::ConstKind::Unevaluated(b)) = + (c1.kind(), c2.kind()) + { + if infcx.try_unify_abstract_consts(a, b, obligation.param_env) { + return ProcessResult::Changed(vec![]); } } @@ -569,7 +565,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { ) } (Err(ErrorHandled::TooGeneric), _) | (_, Err(ErrorHandled::TooGeneric)) => { - if c1.has_infer_types_or_consts() || c2.has_infer_types_or_consts() { + if c1.has_non_region_infer() || c2.has_non_region_infer() { ProcessResult::Unchanged } else { // Two different constants using generic parameters ~> error. @@ -594,19 +590,21 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { &mut self, cycle: I, _marker: PhantomData<&'c PendingPredicateObligation<'tcx>>, - ) where + ) -> Result<(), FulfillmentErrorCode<'tcx>> + where I: Clone + Iterator<Item = &'c PendingPredicateObligation<'tcx>>, { if self.selcx.coinductive_match(cycle.clone().map(|s| s.obligation.predicate)) { debug!("process_child_obligations: coinductive match"); + Ok(()) } else { let cycle: Vec<_> = cycle.map(|c| c.obligation.clone()).collect(); - self.selcx.infcx().report_overflow_error_cycle(&cycle); + Err(FulfillmentErrorCode::CodeCycle(cycle)) } } } -impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { +impl<'a, 'tcx> FulfillProcessor<'a, 'tcx> { #[instrument(level = "debug", skip(self, obligation, stalled_on))] fn process_trait_obligation( &mut self, @@ -641,7 +639,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { // information about the types in the trait. stalled_on.clear(); stalled_on.extend(substs_infer_vars( - self.selcx, + &self.selcx, trait_obligation.predicate.map_bound(|pred| pred.trait_ref.substs), )); @@ -693,12 +691,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { } } - match project::poly_project_and_unify_type(self.selcx, &project_obligation) { + match project::poly_project_and_unify_type(&mut self.selcx, &project_obligation) { ProjectAndUnifyResult::Holds(os) => ProcessResult::Changed(mk_pending(os)), ProjectAndUnifyResult::FailedNormalization => { stalled_on.clear(); stalled_on.extend(substs_infer_vars( - self.selcx, + &self.selcx, project_obligation.predicate.map_bound(|pred| pred.projection_ty.substs), )); ProcessResult::Unchanged @@ -716,7 +714,7 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> { /// Returns the set of inference variables contained in `substs`. fn substs_infer_vars<'a, 'tcx>( - selcx: &mut SelectionContext<'a, 'tcx>, + selcx: &SelectionContext<'a, 'tcx>, substs: ty::Binder<'tcx, SubstsRef<'tcx>>, ) -> impl Iterator<Item = TyOrConstInferVar<'tcx>> { selcx @@ -724,11 +722,11 @@ fn substs_infer_vars<'a, 'tcx>( .resolve_vars_if_possible(substs) .skip_binder() // ok because this check doesn't care about regions .iter() - .filter(|arg| arg.has_infer_types_or_consts()) + .filter(|arg| arg.has_non_region_infer()) .flat_map(|arg| { let mut walker = arg.walk(); while let Some(c) = walker.next() { - if !c.has_infer_types_or_consts() { + if !c.has_non_region_infer() { walker.visited.remove(&c); walker.skip_current_subtree(); } |