diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
4 files changed, 154 insertions, 14 deletions
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index 14639039ae9..7ba87e180d0 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -737,7 +737,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { applied_do_not_recommend = true; } } - if let Some((parent_cause, _parent_pred)) = base_cause.parent() { + if let Some(parent_cause) = base_cause.parent() { base_cause = parent_cause.clone(); } else { break; @@ -797,7 +797,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { trait_ref.skip_binder().args.type_at(1).to_opt_closure_kind() && !found_kind.extends(expected_kind) { - if let Some((_, Some(parent))) = obligation.cause.code().parent() { + if let Some((_, Some(parent))) = obligation.cause.code().parent_with_predicate() { // If we have a derived obligation, then the parent will be a `AsyncFn*` goal. trait_ref = parent.to_poly_trait_ref(); } else if let &ObligationCauseCode::FunctionArg { arg_hir_id, .. } = @@ -945,7 +945,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { let Some(typeck) = &self.typeck_results else { return false; }; - let Some((ObligationCauseCode::QuestionMark, Some(y))) = obligation.cause.code().parent() + let Some((ObligationCauseCode::QuestionMark, Some(y))) = + obligation.cause.code().parent_with_predicate() else { return false; }; @@ -1198,7 +1199,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { let mut code = obligation.cause.code(); let mut pred = obligation.predicate.as_trait_clause(); - while let Some((next_code, next_pred)) = code.parent() { + while let Some((next_code, next_pred)) = code.parent_with_predicate() { if let Some(pred) = pred { self.enter_forall(pred, |pred| { diag.note(format!( @@ -2114,7 +2115,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { let mut code = obligation.cause.code(); let mut trait_pred = trait_predicate; let mut peeled = false; - while let Some((parent_code, parent_trait_pred)) = code.parent() { + while let Some((parent_code, parent_trait_pred)) = code.parent_with_predicate() { code = parent_code; if let Some(parent_trait_pred) = parent_trait_pred { trait_pred = parent_trait_pred; diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs index 007a220ae69..9d85ca1dd4d 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs @@ -464,7 +464,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { // Get the root obligation, since the leaf obligation we have may be unhelpful (#87437) let mut real_trait_pred = trait_pred; - while let Some((parent_code, parent_trait_pred)) = code.parent() { + while let Some((parent_code, parent_trait_pred)) = code.parent_with_predicate() { code = parent_code; if let Some(parent_trait_pred) = parent_trait_pred { real_trait_pred = parent_trait_pred; @@ -1447,7 +1447,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { let mut span = obligation.cause.span; let mut trait_pred = trait_pred; let mut code = obligation.cause.code(); - while let Some((c, Some(parent_trait_pred))) = code.parent() { + while let Some((c, Some(parent_trait_pred))) = code.parent_with_predicate() { // We want the root obligation, in order to detect properly handle // `for _ in &mut &mut vec![] {}`. code = c; @@ -3470,6 +3470,59 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { ) }); } + ObligationCauseCode::ImplDerivedHost(ref data) => { + let self_ty = + self.resolve_vars_if_possible(data.derived.parent_host_pred.self_ty()); + let msg = format!( + "required for `{self_ty}` to implement `{} {}`", + data.derived.parent_host_pred.skip_binder().constness, + data.derived + .parent_host_pred + .map_bound(|pred| pred.trait_ref) + .print_only_trait_path(), + ); + match tcx.hir().get_if_local(data.impl_def_id) { + Some(Node::Item(hir::Item { + kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }), + .. + })) => { + let mut spans = vec![self_ty.span]; + spans.extend(of_trait.as_ref().map(|t| t.path.span)); + let mut spans: MultiSpan = spans.into(); + spans.push_span_label(data.span, "unsatisfied trait bound introduced here"); + err.span_note(spans, msg); + } + _ => { + err.note(msg); + } + } + ensure_sufficient_stack(|| { + self.note_obligation_cause_code( + body_id, + err, + data.derived.parent_host_pred, + param_env, + &data.derived.parent_code, + obligated_types, + seen_requirements, + long_ty_file, + ) + }); + } + ObligationCauseCode::BuiltinDerivedHost(ref data) => { + ensure_sufficient_stack(|| { + self.note_obligation_cause_code( + body_id, + err, + data.parent_host_pred, + param_env, + &data.parent_code, + obligated_types, + seen_requirements, + long_ty_file, + ) + }); + } ObligationCauseCode::WellFormedDerived(ref data) => { let parent_trait_ref = self.resolve_vars_if_possible(data.parent_trait_pred); let parent_predicate = parent_trait_ref; diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs index c79a8abca20..7db0f2bb5a7 100644 --- a/compiler/rustc_trait_selection/src/solve/fulfill.rs +++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs @@ -430,6 +430,7 @@ impl<'tcx> BestObligation<'tcx> { matches!( nested_goal.source(), GoalSource::ImplWhereBound + | GoalSource::AliasBoundConstCondition | GoalSource::InstantiateHigherRanked | GoalSource::AliasWellFormed ) && match self.consider_ambiguities { @@ -491,8 +492,11 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> { // for normalizes-to. let pred_kind = goal.goal().predicate.kind(); let child_mode = match pred_kind.skip_binder() { - ty::PredicateKind::Clause(ty::ClauseKind::Trait(parent_trait_pred)) => { - ChildMode::Trait(pred_kind.rebind(parent_trait_pred)) + ty::PredicateKind::Clause(ty::ClauseKind::Trait(pred)) => { + ChildMode::Trait(pred_kind.rebind(pred)) + } + ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(pred)) => { + ChildMode::Host(pred_kind.rebind(pred)) } ty::PredicateKind::NormalizesTo(normalizes_to) if matches!( @@ -521,7 +525,7 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> { let obligation; match (child_mode, nested_goal.source()) { - (ChildMode::Trait(_), GoalSource::Misc) => { + (ChildMode::Trait(_) | ChildMode::Host(_), GoalSource::Misc) => { continue; } (ChildMode::Trait(parent_trait_pred), GoalSource::ImplWhereBound) => { @@ -534,11 +538,25 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> { )); impl_where_bound_count += 1; } + ( + ChildMode::Host(parent_host_pred), + GoalSource::ImplWhereBound | GoalSource::AliasBoundConstCondition, + ) => { + obligation = make_obligation(derive_host_cause( + tcx, + candidate.kind(), + self.obligation.cause.clone(), + impl_where_bound_count, + parent_host_pred, + )); + impl_where_bound_count += 1; + } // Skip over a higher-ranked predicate. (_, GoalSource::InstantiateHigherRanked) => { obligation = self.obligation.clone(); } - (ChildMode::PassThrough, _) | (_, GoalSource::AliasWellFormed) => { + (ChildMode::PassThrough, _) + | (_, GoalSource::AliasWellFormed | GoalSource::AliasBoundConstCondition) => { obligation = make_obligation(self.obligation.cause.clone()); } } @@ -592,6 +610,10 @@ enum ChildMode<'tcx> { // and skip all `GoalSource::Misc`, which represent useless obligations // such as alias-eq which may not hold. Trait(ty::PolyTraitPredicate<'tcx>), + // Try to derive an `ObligationCause::{ImplDerived,BuiltinDerived}`, + // and skip all `GoalSource::Misc`, which represent useless obligations + // such as alias-eq which may not hold. + Host(ty::Binder<'tcx, ty::HostEffectPredicate<'tcx>>), // Skip trying to derive an `ObligationCause` from this obligation, and // report *all* sub-obligations as if they came directly from the parent // obligation. @@ -633,3 +655,52 @@ fn derive_cause<'tcx>( }; cause } + +fn derive_host_cause<'tcx>( + tcx: TyCtxt<'tcx>, + candidate_kind: inspect::ProbeKind<TyCtxt<'tcx>>, + mut cause: ObligationCause<'tcx>, + idx: usize, + parent_host_pred: ty::Binder<'tcx, ty::HostEffectPredicate<'tcx>>, +) -> ObligationCause<'tcx> { + match candidate_kind { + inspect::ProbeKind::TraitCandidate { + source: CandidateSource::Impl(impl_def_id), + result: _, + } => { + if let Some((_, span)) = tcx + .predicates_of(impl_def_id) + .instantiate_identity(tcx) + .into_iter() + .chain(tcx.const_conditions(impl_def_id).instantiate_identity(tcx).into_iter().map( + |(trait_ref, span)| { + ( + trait_ref.to_host_effect_clause( + tcx, + parent_host_pred.skip_binder().constness, + ), + span, + ) + }, + )) + .nth(idx) + { + cause = + cause.derived_host_cause(parent_host_pred, |derived| { + ObligationCauseCode::ImplDerivedHost(Box::new( + traits::ImplDerivedHostCause { derived, impl_def_id, span }, + )) + }) + } + } + inspect::ProbeKind::TraitCandidate { + source: CandidateSource::BuiltinImpl(..), + result: _, + } => { + cause = + cause.derived_host_cause(parent_host_pred, ObligationCauseCode::BuiltinDerivedHost); + } + _ => {} + }; + cause +} diff --git a/compiler/rustc_trait_selection/src/traits/effects.rs b/compiler/rustc_trait_selection/src/traits/effects.rs index 91484ef99db..0ac24eb54e7 100644 --- a/compiler/rustc_trait_selection/src/traits/effects.rs +++ b/compiler/rustc_trait_selection/src/traits/effects.rs @@ -1,6 +1,8 @@ use rustc_hir as hir; use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes}; -use rustc_infer::traits::{ImplSource, Obligation, PredicateObligation}; +use rustc_infer::traits::{ + ImplDerivedHostCause, ImplSource, Obligation, ObligationCauseCode, PredicateObligation, +}; use rustc_middle::span_bug; use rustc_middle::ty::fast_reject::DeepRejectCtxt; use rustc_middle::ty::{self, TypingMode}; @@ -248,9 +250,22 @@ fn evaluate_host_effect_from_selection_candiate<'tcx>( tcx.const_conditions(impl_.impl_def_id) .instantiate(tcx, impl_.args) .into_iter() - .map(|(trait_ref, _)| { - obligation.with( + .map(|(trait_ref, span)| { + Obligation::new( tcx, + obligation.cause.clone().derived_host_cause( + ty::Binder::dummy(obligation.predicate), + |derived| { + ObligationCauseCode::ImplDerivedHost(Box::new( + ImplDerivedHostCause { + derived, + impl_def_id: impl_.impl_def_id, + span, + }, + )) + }, + ), + obligation.param_env, trait_ref .to_host_effect_clause(tcx, obligation.predicate.constness), ) |