diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/solve/trait_goals.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/solve/trait_goals.rs | 168 |
1 files changed, 97 insertions, 71 deletions
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs index abd11a15a..f722f2813 100644 --- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs +++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs @@ -78,16 +78,17 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { }) } - fn consider_implied_clause( + fn probe_and_match_goal_against_assumption( ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, assumption: ty::Predicate<'tcx>, - requirements: impl IntoIterator<Item = Goal<'tcx, ty::Predicate<'tcx>>>, + then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>, ) -> QueryResult<'tcx> { if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred() && poly_trait_pred.def_id() == goal.predicate.def_id() + && poly_trait_pred.polarity() == goal.predicate.polarity { - // FIXME: Constness and polarity + // FIXME: Constness ecx.probe(|ecx| { let assumption_trait_pred = ecx.instantiate_binder_with_infer(poly_trait_pred); @@ -96,57 +97,21 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { goal.predicate.trait_ref, assumption_trait_pred.trait_ref, )?; - ecx.add_goals(requirements); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + then(ecx) }) } else { Err(NoSolution) } } - fn consider_object_bound_candidate( + fn consider_auto_trait_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, - assumption: ty::Predicate<'tcx>, ) -> QueryResult<'tcx> { - if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred() - && poly_trait_pred.def_id() == goal.predicate.def_id() - { - // FIXME: Constness and polarity - ecx.probe(|ecx| { - let assumption_trait_pred = - ecx.instantiate_binder_with_infer(poly_trait_pred); - ecx.eq( - goal.param_env, - goal.predicate.trait_ref, - assumption_trait_pred.trait_ref, - )?; - - let tcx = ecx.tcx(); - let ty::Dynamic(bounds, _, _) = *goal.predicate.self_ty().kind() else { - bug!("expected object type in `consider_object_bound_candidate`"); - }; - ecx.add_goals( - structural_traits::predicates_for_object_candidate( - &ecx, - goal.param_env, - goal.predicate.trait_ref, - bounds, - ) - .into_iter() - .map(|pred| goal.with(tcx, pred)), - ); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }) - } else { - Err(NoSolution) + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); } - } - fn consider_auto_trait_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { if let Some(result) = ecx.disqualify_auto_trait_candidate_due_to_possible_impl(goal) { return result; } @@ -161,6 +126,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); ecx.probe(|ecx| { @@ -176,6 +145,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.probe_and_evaluate_goal_for_constituent_tys( goal, structural_traits::instantiate_constituent_tys_for_sized_trait, @@ -186,6 +159,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.probe_and_evaluate_goal_for_constituent_tys( goal, structural_traits::instantiate_constituent_tys_for_copy_clone_trait, @@ -196,14 +173,22 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { - if goal.predicate.self_ty().has_non_region_infer() { - return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); } + // The regions of a type don't affect the size of the type let tcx = ecx.tcx(); - let self_ty = tcx.erase_regions(goal.predicate.self_ty()); + // We should erase regions from both the param-env and type, since both + // may have infer regions. Specifically, after canonicalizing and instantiating, + // early bound regions turn into region vars in both the new and old solver. + let key = tcx.erase_regions(goal.param_env.and(goal.predicate.self_ty())); + // But if there are inference variables, we have to wait until it's resolved. + if key.has_non_region_infer() { + return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); + } - if let Ok(layout) = tcx.layout_of(goal.param_env.and(self_ty)) + if let Ok(layout) = tcx.layout_of(key) && layout.layout.is_pointer_like(&tcx.data_layout) { // FIXME: We could make this faster by making a no-constraints response @@ -217,6 +202,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if let ty::FnPtr(..) = goal.predicate.self_ty().kind() { ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } else { @@ -229,6 +218,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { goal: Goal<'tcx, Self>, goal_kind: ty::ClosureKind, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); let tupled_inputs_and_output = match structural_traits::extract_tupled_inputs_and_output_from_callable( @@ -242,12 +235,13 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); } }; - let output_is_sized_pred = tupled_inputs_and_output - .map_bound(|(_, output)| tcx.at(DUMMY_SP).mk_trait_ref(LangItem::Sized, [output])); + let output_is_sized_pred = tupled_inputs_and_output.map_bound(|(_, output)| { + ty::TraitRef::from_lang_item(tcx, LangItem::Sized, DUMMY_SP, [output]) + }); let pred = tupled_inputs_and_output .map_bound(|(inputs, _)| { - tcx.mk_trait_ref(goal.predicate.def_id(), [goal.predicate.self_ty(), inputs]) + ty::TraitRef::new(tcx, goal.predicate.def_id(), [goal.predicate.self_ty(), inputs]) }) .to_predicate(tcx); // A built-in `Fn` impl only holds if the output is sized. @@ -259,6 +253,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if let ty::Tuple(..) = goal.predicate.self_ty().kind() { ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } else { @@ -268,8 +266,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { fn consider_builtin_pointee_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, - _goal: Goal<'tcx, Self>, + goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -277,6 +279,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let ty::Generator(def_id, _, _) = *goal.predicate.self_ty().kind() else { return Err(NoSolution); }; @@ -297,6 +303,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let self_ty = goal.predicate.self_ty(); let ty::Generator(def_id, substs, _) = *self_ty.kind() else { return Err(NoSolution); @@ -312,10 +322,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { Self::consider_implied_clause( ecx, goal, - ty::Binder::dummy( - tcx.mk_trait_ref(goal.predicate.def_id(), [self_ty, generator.resume_ty()]), - ) - .to_predicate(tcx), + ty::TraitRef::new(tcx, goal.predicate.def_id(), [self_ty, generator.resume_ty()]) + .to_predicate(tcx), // Technically, we need to check that the generator types are Sized, // but that's already proven by the generator being WF. [], @@ -326,6 +334,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); let a_ty = goal.predicate.self_ty(); let b_ty = goal.predicate.trait_ref.substs.type_at(1); @@ -346,7 +358,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { // Can only unsize to an object-safe type if data .principal_def_id() - .map_or(false, |def_id| !tcx.check_is_object_safe(def_id)) + .is_some_and(|def_id| !tcx.check_is_object_safe(def_id)) { return Err(NoSolution); } @@ -360,9 +372,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { data.iter().map(|pred| goal.with(tcx, pred.with_self_ty(tcx, a_ty))), ); // The type must be Sized to be unsized. - ecx.add_goal( - goal.with(tcx, ty::Binder::dummy(tcx.mk_trait_ref(sized_def_id, [a_ty]))), - ); + ecx.add_goal(goal.with(tcx, ty::TraitRef::new(tcx, sized_def_id, [a_ty]))); // The type must outlive the lifetime of the `dyn` we're unsizing into. ecx.add_goal( goal.with(tcx, ty::Binder::dummy(ty::OutlivesPredicate(a_ty, region))), @@ -411,9 +421,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx.eq(goal.param_env, unsized_a_ty, b_ty)?; ecx.add_goal(goal.with( tcx, - ty::Binder::dummy( - tcx.mk_trait_ref(goal.predicate.def_id(), [a_tail_ty, b_tail_ty]), - ), + ty::TraitRef::new(tcx, goal.predicate.def_id(), [a_tail_ty, b_tail_ty]), )); ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -432,9 +440,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { // Similar to ADTs, require that the rest of the fields are equal. ecx.add_goal(goal.with( tcx, - ty::Binder::dummy( - tcx.mk_trait_ref(goal.predicate.def_id(), [*a_last_ty, *b_last_ty]), - ), + ty::TraitRef::new(tcx, goal.predicate.def_id(), [*a_last_ty, *b_last_ty]), )); ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -447,6 +453,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> Vec<CanonicalResponse<'tcx>> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return vec![]; + } + let tcx = ecx.tcx(); let a_ty = goal.predicate.self_ty(); @@ -521,8 +531,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { fn consider_builtin_discriminant_kind_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, - _goal: Goal<'tcx, Self>, + goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + // `DiscriminantKind` is automatically implemented for every type. ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -531,6 +545,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if !goal.param_env.is_const() { // `Destruct` is automatically implemented for every type in // non-const environments. @@ -545,6 +563,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + // `rustc_transmute` does not have support for type or const params if goal.has_non_region_placeholders() { return Err(NoSolution); @@ -591,12 +613,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { Some(self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)) } - // These types cannot be structurally decomposed into constitutent + // These types cannot be structurally decomposed into constituent // types, and therefore have no built-in auto impl. ty::Dynamic(..) | ty::Param(..) | ty::Foreign(..) - | ty::Alias(ty::Projection, ..) + | ty::Alias(ty::Projection | ty::Inherent, ..) | ty::Placeholder(..) => Some(Err(NoSolution)), ty::Infer(_) | ty::Bound(_, _) => bug!("unexpected type `{self_ty}`"), @@ -645,12 +667,16 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { // FIXME: Handling opaques here is kinda sus. Especially because we // simplify them to PlaceholderSimplifiedType. | ty::Alias(ty::Opaque, _) => { - if let Some(def_id) = self.tcx().find_map_relevant_impl( + let mut disqualifying_impl = None; + self.tcx().for_each_relevant_impl_treating_projections( goal.predicate.def_id(), goal.predicate.self_ty(), TreatProjections::NextSolverLookup, - Some, - ) { + |impl_def_id| { + disqualifying_impl = Some(impl_def_id); + }, + ); + if let Some(def_id) = disqualifying_impl { debug!(?def_id, ?goal, "disqualified auto-trait implementation"); // No need to actually consider the candidate here, // since we do that in `consider_impl_candidate`. |