diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/select/mod.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/mod.rs | 165 |
1 files changed, 78 insertions, 87 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 08208cc60..23f7bdd15 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -32,8 +32,8 @@ use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_errors::Diagnostic; use rustc_hir as hir; use rustc_hir::def_id::DefId; +use rustc_infer::infer::BoundRegionConversionTime; use rustc_infer::infer::DefineOpaqueTypes; -use rustc_infer::infer::LateBoundRegionConversionTime; use rustc_infer::traits::TraitObligation; use rustc_middle::dep_graph::dep_kinds; use rustc_middle::dep_graph::DepNodeIndex; @@ -46,6 +46,7 @@ use rustc_middle::ty::GenericArgsRef; use rustc_middle::ty::{self, EarlyBinder, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate}; use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, TypeVisitableExt}; use rustc_span::symbol::sym; +use rustc_span::Symbol; use std::cell::{Cell, RefCell}; use std::cmp; @@ -59,13 +60,13 @@ mod candidate_assembly; mod confirmation; #[derive(Clone, Debug, Eq, PartialEq, Hash)] -pub enum IntercrateAmbiguityCause { - DownstreamCrate { trait_desc: String, self_desc: Option<String> }, - UpstreamCrateUpdate { trait_desc: String, self_desc: Option<String> }, - ReservationImpl { message: String }, +pub enum IntercrateAmbiguityCause<'tcx> { + DownstreamCrate { trait_ref: ty::TraitRef<'tcx>, self_ty: Option<Ty<'tcx>> }, + UpstreamCrateUpdate { trait_ref: ty::TraitRef<'tcx>, self_ty: Option<Ty<'tcx>> }, + ReservationImpl { message: Symbol }, } -impl IntercrateAmbiguityCause { +impl<'tcx> IntercrateAmbiguityCause<'tcx> { /// Emits notes when the overlap is caused by complex intercrate ambiguities. /// See #23980 for details. pub fn add_intercrate_ambiguity_hint(&self, err: &mut Diagnostic) { @@ -73,28 +74,32 @@ impl IntercrateAmbiguityCause { } pub fn intercrate_ambiguity_hint(&self) -> String { - match self { - IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc } => { - let self_desc = if let Some(ty) = self_desc { - format!(" for type `{ty}`") - } else { - String::new() - }; - format!("downstream crates may implement trait `{trait_desc}`{self_desc}") + with_no_trimmed_paths!(match self { + IntercrateAmbiguityCause::DownstreamCrate { trait_ref, self_ty } => { + format!( + "downstream crates may implement trait `{trait_desc}`{self_desc}", + trait_desc = trait_ref.print_trait_sugared(), + self_desc = if let Some(self_ty) = self_ty { + format!(" for type `{self_ty}`") + } else { + String::new() + } + ) } - IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_desc, self_desc } => { - let self_desc = if let Some(ty) = self_desc { - format!(" for type `{ty}`") - } else { - String::new() - }; + IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_ref, self_ty } => { format!( "upstream crates may add a new impl of trait `{trait_desc}`{self_desc} \ - in future versions" + in future versions", + trait_desc = trait_ref.print_trait_sugared(), + self_desc = if let Some(self_ty) = self_ty { + format!(" for type `{self_ty}`") + } else { + String::new() + } ) } - IntercrateAmbiguityCause::ReservationImpl { message } => message.clone(), - } + IntercrateAmbiguityCause::ReservationImpl { message } => message.to_string(), + }) } } @@ -114,7 +119,7 @@ pub struct SelectionContext<'cx, 'tcx> { /// We don't do his until we detect a coherence error because it can /// lead to false overflow results (#47139) and because always /// computing it may negatively impact performance. - intercrate_ambiguity_causes: Option<FxIndexSet<IntercrateAmbiguityCause>>, + intercrate_ambiguity_causes: Option<FxIndexSet<IntercrateAmbiguityCause<'tcx>>>, /// The mode that trait queries run in, which informs our error handling /// policy. In essence, canonicalized queries need their errors propagated @@ -217,8 +222,8 @@ pub enum TreatInductiveCycleAs { impl From<TreatInductiveCycleAs> for EvaluationResult { fn from(treat: TreatInductiveCycleAs) -> EvaluationResult { match treat { - TreatInductiveCycleAs::Ambig => EvaluatedToUnknown, - TreatInductiveCycleAs::Recur => EvaluatedToRecur, + TreatInductiveCycleAs::Ambig => EvaluatedToAmbigStackDependent, + TreatInductiveCycleAs::Recur => EvaluatedToErrStackDependent, } } } @@ -270,7 +275,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// Gets the intercrate ambiguity causes collected since tracking /// was enabled and disables tracking at the same time. If /// tracking is not enabled, just returns an empty vector. - pub fn take_intercrate_ambiguity_causes(&mut self) -> FxIndexSet<IntercrateAmbiguityCause> { + pub fn take_intercrate_ambiguity_causes( + &mut self, + ) -> FxIndexSet<IntercrateAmbiguityCause<'tcx>> { assert!(self.is_intercrate()); self.intercrate_ambiguity_causes.take().unwrap_or_default() } @@ -367,7 +374,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, '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)?; + self.check_recursion_limit(stack.obligation, stack.obligation)?; // Check the cache. Note that we freshen the trait-ref // separately rather than using `stack.fresh_trait_ref` -- @@ -416,7 +423,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let mut no_candidates_apply = true; for c in candidate_set.vec.iter() { - if self.evaluate_candidate(stack, &c)?.may_apply() { + if self.evaluate_candidate(stack, c)?.may_apply() { no_candidates_apply = false; break; } @@ -428,19 +435,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ); if !trait_ref.references_error() { let self_ty = trait_ref.self_ty(); - let (trait_desc, self_desc) = with_no_trimmed_paths!({ - let trait_desc = trait_ref.print_only_trait_path().to_string(); - let self_desc = - self_ty.has_concrete_skeleton().then(|| self_ty.to_string()); - (trait_desc, self_desc) - }); + let self_ty = self_ty.has_concrete_skeleton().then(|| self_ty); let cause = if let Conflict::Upstream = conflict { - IntercrateAmbiguityCause::UpstreamCrateUpdate { - trait_desc, - self_desc, - } + IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_ref, self_ty } } else { - IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc } + IntercrateAmbiguityCause::DownstreamCrate { trait_ref, self_ty } }; debug!(?cause, "evaluate_stack: pushing cause"); self.intercrate_ambiguity_causes.as_mut().unwrap().insert(cause); @@ -799,7 +798,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // A global type with no free lifetimes or generic parameters // outlives anything. if pred.0.has_free_regions() - || pred.0.has_late_bound_regions() + || pred.0.has_bound_regions() || pred.0.has_non_region_infer() || pred.0.has_non_region_infer() { @@ -885,19 +884,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } - ty::PredicateKind::ClosureKind(_, closure_args, kind) => { - match self.infcx.closure_kind(closure_args) { - Some(closure_kind) => { - if closure_kind.extends(kind) { - Ok(EvaluatedToOk) - } else { - Ok(EvaluatedToErr) - } - } - None => Ok(EvaluatedToAmbig), - } - } - ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(uv)) => { match const_evaluatable::is_const_evaluatable( self.infcx, @@ -1004,8 +990,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } } + ty::PredicateKind::NormalizesTo(..) => { + bug!("NormalizesTo is only used by the new solver") + } ty::PredicateKind::AliasRelate(..) => { - bug!("AliasRelate is only used for new solver") + bug!("AliasRelate is only used by the new solver") } ty::PredicateKind::Ambiguous => Ok(EvaluatedToAmbig), ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => { @@ -1237,15 +1226,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { if unbound_input_types && stack.iter().skip(1).any(|prev| { stack.obligation.param_env == prev.obligation.param_env - && self.match_fresh_trait_refs( - stack.fresh_trait_pred, - prev.fresh_trait_pred, - prev.obligation.param_env, - ) + && self.match_fresh_trait_refs(stack.fresh_trait_pred, prev.fresh_trait_pred) }) { debug!("evaluate_stack --> unbound argument, recursive --> giving up",); - return Ok(EvaluatedToUnknown); + return Ok(EvaluatedToAmbigStackDependent); } match self.candidate_from_obligation(stack) { @@ -1464,20 +1449,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { if let ImplCandidate(def_id) = candidate { if let ty::ImplPolarity::Reservation = tcx.impl_polarity(def_id) { if let Some(intercrate_ambiguity_clauses) = &mut self.intercrate_ambiguity_causes { - let value = tcx + let message = tcx .get_attr(def_id, sym::rustc_reservation_impl) .and_then(|a| a.value_str()); - if let Some(value) = value { + if let Some(message) = message { debug!( "filter_reservation_impls: \ reservation impl ambiguity on {:?}", def_id ); - intercrate_ambiguity_clauses.insert( - IntercrateAmbiguityCause::ReservationImpl { - message: value.to_string(), - }, - ); + intercrate_ambiguity_clauses + .insert(IntercrateAmbiguityCause::ReservationImpl { message }); } } return Ok(None); @@ -1751,7 +1733,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let mut nested_obligations = Vec::new(); let infer_predicate = self.infcx.instantiate_binder_with_fresh_vars( obligation.cause.span, - LateBoundRegionConversionTime::HigherRankedType, + BoundRegionConversionTime::HigherRankedType, env_predicate, ); let infer_projection = if potentially_unnormalized_candidates { @@ -1841,7 +1823,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // the param_env so that it can be given the lowest priority. See // #50825 for the motivation for this. let is_global = - |cand: &ty::PolyTraitPredicate<'tcx>| cand.is_global() && !cand.has_late_bound_vars(); + |cand: &ty::PolyTraitPredicate<'tcx>| cand.is_global() && !cand.has_bound_vars(); // (*) Prefer `BuiltinCandidate { has_nested: false }`, `PointeeCandidate`, // `DiscriminantKindCandidate`, `ConstDestructCandidate` @@ -1879,7 +1861,9 @@ impl<'tcx> SelectionContext<'_, 'tcx> { } // Drop otherwise equivalent non-const fn pointer candidates - (FnPointerCandidate { .. }, FnPointerCandidate { is_const: false }) => DropVictim::Yes, + (FnPointerCandidate { .. }, FnPointerCandidate { fn_host_effect }) => { + DropVictim::drop_if(*fn_host_effect == self.tcx().consts.true_) + } ( ParamCandidate(ref other_cand), @@ -1889,6 +1873,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate @@ -1896,7 +1881,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | BuiltinCandidate { .. } | TraitAliasCandidate | ObjectCandidate(_) - | ProjectionCandidate(..), + | ProjectionCandidate(_), ) => { // We have a where clause so don't go around looking // for impls. Arbitrarily give param candidates priority @@ -1906,7 +1891,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // here (see issue #50825). DropVictim::drop_if(!is_global(other_cand)) } - (ObjectCandidate(_) | ProjectionCandidate(..), ParamCandidate(ref victim_cand)) => { + (ObjectCandidate(_) | ProjectionCandidate(_), ParamCandidate(ref victim_cand)) => { // Prefer these to a global where-clause bound // (see issue #50825). if is_global(victim_cand) { DropVictim::Yes } else { DropVictim::No } @@ -1918,6 +1903,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate @@ -1933,26 +1919,27 @@ impl<'tcx> SelectionContext<'_, 'tcx> { ) } - (ProjectionCandidate(i, _), ProjectionCandidate(j, _)) + (ProjectionCandidate(i), ProjectionCandidate(j)) | (ObjectCandidate(i), ObjectCandidate(j)) => { // Arbitrarily pick the lower numbered candidate for backwards // compatibility reasons. Don't let this affect inference. DropVictim::drop_if(i < j && !has_non_region_infer) } - (ObjectCandidate(_), ProjectionCandidate(..)) - | (ProjectionCandidate(..), ObjectCandidate(_)) => { + (ObjectCandidate(_), ProjectionCandidate(_)) + | (ProjectionCandidate(_), ObjectCandidate(_)) => { bug!("Have both object and projection candidate") } // Arbitrarily give projection and object candidates priority. ( - ObjectCandidate(_) | ProjectionCandidate(..), + ObjectCandidate(_) | ProjectionCandidate(_), ImplCandidate(..) | AutoImplCandidate | ClosureCandidate { .. } | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate @@ -1968,13 +1955,14 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate | TraitUpcastingUnsizeCandidate(_) | BuiltinCandidate { .. } | TraitAliasCandidate, - ObjectCandidate(_) | ProjectionCandidate(..), + ObjectCandidate(_) | ProjectionCandidate(_), ) => DropVictim::No, (&ImplCandidate(other_def), &ImplCandidate(victim_def)) => { @@ -2075,6 +2063,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate @@ -2086,6 +2075,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | CoroutineCandidate | FutureCandidate | IteratorCandidate + | AsyncIteratorCandidate | FnPointerCandidate { .. } | BuiltinObjectCandidate | BuiltinUnsizeCandidate @@ -2218,7 +2208,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { } } - ty::CoroutineWitness(def_id, ref args) => { + ty::CoroutineWitness(def_id, args) => { let hidden_types = bind_coroutine_hidden_types_above( self.infcx, def_id, @@ -2307,23 +2297,23 @@ impl<'tcx> SelectionContext<'_, 'tcx> { ty::Array(element_ty, _) | ty::Slice(element_ty) => t.rebind(vec![element_ty]), - ty::Tuple(ref tys) => { + ty::Tuple(tys) => { // (T1, ..., Tn) -- meets any bound that all of T1...Tn meet t.rebind(tys.iter().collect()) } - ty::Closure(_, ref args) => { + ty::Closure(_, args) => { let ty = self.infcx.shallow_resolve(args.as_closure().tupled_upvars_ty()); t.rebind(vec![ty]) } - ty::Coroutine(_, ref args, _) => { + ty::Coroutine(_, args, _) => { let ty = self.infcx.shallow_resolve(args.as_coroutine().tupled_upvars_ty()); let witness = args.as_coroutine().witness(); t.rebind([ty].into_iter().chain(iter::once(witness)).collect()) } - ty::CoroutineWitness(def_id, ref args) => { + ty::CoroutineWitness(def_id, args) => { bind_coroutine_hidden_types_above(self.infcx, def_id, args, t.bound_vars()) } @@ -2436,7 +2426,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // the placeholder trait ref may fail due the Generalizer relation // raising a CyclicalTy error due to a sub_root_var relation // for a variable being generalized... - let guar = self.infcx.tcx.sess.delay_span_bug( + let guar = self.infcx.tcx.sess.span_delayed_bug( obligation.cause.span, format!( "Impl {impl_def_id:?} was matchable against {obligation:?} but now is not" @@ -2638,9 +2628,8 @@ impl<'tcx> SelectionContext<'_, 'tcx> { &self, previous: ty::PolyTraitPredicate<'tcx>, current: ty::PolyTraitPredicate<'tcx>, - param_env: ty::ParamEnv<'tcx>, ) -> bool { - let mut matcher = MatchAgainstFreshVars::new(self.tcx(), param_env); + let mut matcher = MatchAgainstFreshVars::new(self.tcx()); matcher.relate(previous, current).is_ok() } @@ -2668,6 +2657,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { &mut self, obligation: &PolyTraitObligation<'tcx>, args: GenericArgsRef<'tcx>, + fn_host_effect: ty::Const<'tcx>, ) -> ty::PolyTraitRef<'tcx> { let closure_sig = args.as_closure().sig(); @@ -2688,6 +2678,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { self_ty, closure_sig, util::TupleArgumentsFlag::No, + fn_host_effect, ) .map_bound(|(trait_ref, _)| trait_ref) } @@ -3103,7 +3094,7 @@ fn bind_coroutine_hidden_types_above<'tcx>( kind: ty::BrAnon, }; counter += 1; - ty::Region::new_late_bound(tcx, current_depth, br) + ty::Region::new_bound(tcx, current_depth, br) } r => bug!("unexpected region: {r:?}"), }) |