From 9918693037dce8aa4bb6f08741b6812923486c18 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 19 Jun 2024 11:26:03 +0200 Subject: Merging upstream version 1.76.0+dfsg1. Signed-off-by: Daniel Baumann --- .../src/solve/project_goals/inherent_projection.rs | 50 -- .../src/solve/project_goals/mod.rs | 680 --------------------- .../src/solve/project_goals/opaques.rs | 85 --- .../src/solve/project_goals/weak_types.rs | 34 -- 4 files changed, 849 deletions(-) delete mode 100644 compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs delete mode 100644 compiler/rustc_trait_selection/src/solve/project_goals/mod.rs delete mode 100644 compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs delete mode 100644 compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs (limited to 'compiler/rustc_trait_selection/src/solve/project_goals') diff --git a/compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs b/compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs deleted file mode 100644 index 28fe59b7f..000000000 --- a/compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs +++ /dev/null @@ -1,50 +0,0 @@ -//! Computes a normalizes-to (projection) goal for inherent associated types, -//! `#![feature(inherent_associated_type)]`. Since astconv already determines -//! which impl the IAT is being projected from, we just: -//! 1. instantiate substs, -//! 2. equate the self type, and -//! 3. instantiate and register where clauses. -use rustc_middle::traits::solve::{Certainty, Goal, QueryResult}; -use rustc_middle::ty; - -use super::EvalCtxt; - -impl<'tcx> EvalCtxt<'_, 'tcx> { - pub(super) fn normalize_inherent_associated_type( - &mut self, - goal: Goal<'tcx, ty::ProjectionPredicate<'tcx>>, - ) -> QueryResult<'tcx> { - let tcx = self.tcx(); - let inherent = goal.predicate.projection_ty; - let expected = goal.predicate.term.ty().expect("inherent consts are treated separately"); - - let impl_def_id = tcx.parent(inherent.def_id); - let impl_substs = self.fresh_args_for_item(impl_def_id); - - // Equate impl header and add impl where clauses - self.eq( - goal.param_env, - inherent.self_ty(), - tcx.type_of(impl_def_id).instantiate(tcx, impl_substs), - )?; - - // Equate IAT with the RHS of the project goal - let inherent_substs = inherent.rebase_inherent_args_onto_impl(impl_substs, tcx); - self.eq( - goal.param_env, - expected, - tcx.type_of(inherent.def_id).instantiate(tcx, inherent_substs), - ) - .expect("expected goal term to be fully unconstrained"); - - // Check both where clauses on the impl and IAT - self.add_goals( - tcx.predicates_of(inherent.def_id) - .instantiate(tcx, inherent_substs) - .into_iter() - .map(|(pred, _)| goal.with(tcx, pred)), - ); - - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } -} diff --git a/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs b/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs deleted file mode 100644 index 240141065..000000000 --- a/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs +++ /dev/null @@ -1,680 +0,0 @@ -use crate::traits::{check_args_compatible, specialization_graph}; - -use super::assembly::{self, structural_traits}; -use super::EvalCtxt; -use rustc_hir::def::DefKind; -use rustc_hir::def_id::DefId; -use rustc_hir::LangItem; -use rustc_infer::traits::query::NoSolution; -use rustc_infer::traits::specialization_graph::LeafDef; -use rustc_infer::traits::Reveal; -use rustc_middle::traits::solve::{ - CandidateSource, CanonicalResponse, Certainty, Goal, QueryResult, -}; -use rustc_middle::traits::BuiltinImplSource; -use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams}; -use rustc_middle::ty::ProjectionPredicate; -use rustc_middle::ty::{self, Ty, TyCtxt}; -use rustc_middle::ty::{ToPredicate, TypeVisitableExt}; -use rustc_span::{sym, ErrorGuaranteed, DUMMY_SP}; - -mod inherent_projection; -mod opaques; -mod weak_types; - -impl<'tcx> EvalCtxt<'_, 'tcx> { - #[instrument(level = "debug", skip(self), ret)] - pub(super) fn compute_projection_goal( - &mut self, - goal: Goal<'tcx, ProjectionPredicate<'tcx>>, - ) -> QueryResult<'tcx> { - let def_id = goal.predicate.def_id(); - match self.tcx().def_kind(def_id) { - DefKind::AssocTy | DefKind::AssocConst => { - // To only compute normalization once for each projection we only - // assemble normalization candidates if the expected term is an - // unconstrained inference variable. - // - // Why: For better cache hits, since if we have an unconstrained RHS then - // there are only as many cache keys as there are (canonicalized) alias - // types in each normalizes-to goal. This also weakens inference in a - // forwards-compatible way so we don't use the value of the RHS term to - // affect candidate assembly for projections. - // - // E.g. for `::Assoc == u32` we recursively compute the goal - // `exists ::Assoc == U` and then take the resulting type for - // `U` and equate it with `u32`. This means that we don't need a separate - // projection cache in the solver, since we're piggybacking off of regular - // goal caching. - if self.term_is_fully_unconstrained(goal) { - match self.tcx().associated_item(def_id).container { - ty::AssocItemContainer::TraitContainer => { - let candidates = self.assemble_and_evaluate_candidates(goal); - self.merge_candidates(candidates) - } - ty::AssocItemContainer::ImplContainer => { - self.normalize_inherent_associated_type(goal) - } - } - } else { - self.set_normalizes_to_hack_goal(goal); - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } - } - DefKind::AnonConst => self.normalize_anon_const(goal), - DefKind::OpaqueTy => self.normalize_opaque_type(goal), - DefKind::TyAlias => self.normalize_weak_type(goal), - kind => bug!("unknown DefKind {} in projection goal: {goal:#?}", kind.descr(def_id)), - } - } - - #[instrument(level = "debug", skip(self), ret)] - fn normalize_anon_const( - &mut self, - goal: Goal<'tcx, ty::ProjectionPredicate<'tcx>>, - ) -> QueryResult<'tcx> { - if let Some(normalized_const) = self.try_const_eval_resolve( - goal.param_env, - ty::UnevaluatedConst::new( - goal.predicate.projection_ty.def_id, - goal.predicate.projection_ty.args, - ), - self.tcx() - .type_of(goal.predicate.projection_ty.def_id) - .no_bound_vars() - .expect("const ty should not rely on other generics"), - ) { - self.eq(goal.param_env, normalized_const, goal.predicate.term.ct().unwrap())?; - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } else { - self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS) - } - } -} - -impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> { - fn self_ty(self) -> Ty<'tcx> { - self.self_ty() - } - - fn trait_ref(self, tcx: TyCtxt<'tcx>) -> ty::TraitRef<'tcx> { - self.projection_ty.trait_ref(tcx) - } - - fn polarity(self) -> ty::ImplPolarity { - ty::ImplPolarity::Positive - } - - fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self { - self.with_self_ty(tcx, self_ty) - } - - fn trait_def_id(self, tcx: TyCtxt<'tcx>) -> DefId { - self.trait_def_id(tcx) - } - - fn probe_and_match_goal_against_assumption( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - assumption: ty::Clause<'tcx>, - then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>, - ) -> QueryResult<'tcx> { - if let Some(projection_pred) = assumption.as_projection_clause() { - if projection_pred.projection_def_id() == goal.predicate.def_id() { - let tcx = ecx.tcx(); - ecx.probe_misc_candidate("assumption").enter(|ecx| { - let assumption_projection_pred = - ecx.instantiate_binder_with_infer(projection_pred); - ecx.eq( - goal.param_env, - goal.predicate.projection_ty, - assumption_projection_pred.projection_ty, - )?; - ecx.eq(goal.param_env, goal.predicate.term, assumption_projection_pred.term) - .expect("expected goal term to be fully unconstrained"); - - // Add GAT where clauses from the trait's definition - ecx.add_goals( - tcx.predicates_of(goal.predicate.def_id()) - .instantiate_own(tcx, goal.predicate.projection_ty.args) - .map(|(pred, _)| goal.with(tcx, pred)), - ); - - then(ecx) - }) - } else { - Err(NoSolution) - } - } else { - Err(NoSolution) - } - } - - fn consider_impl_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, ProjectionPredicate<'tcx>>, - impl_def_id: DefId, - ) -> QueryResult<'tcx> { - let tcx = ecx.tcx(); - - let goal_trait_ref = goal.predicate.projection_ty.trait_ref(tcx); - let impl_trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap(); - let drcx = DeepRejectCtxt { treat_obligation_params: TreatParams::ForLookup }; - if !drcx.args_refs_may_unify(goal_trait_ref.args, impl_trait_ref.skip_binder().args) { - return Err(NoSolution); - } - - ecx.probe_trait_candidate(CandidateSource::Impl(impl_def_id)).enter(|ecx| { - let impl_args = ecx.fresh_args_for_item(impl_def_id); - let impl_trait_ref = impl_trait_ref.instantiate(tcx, impl_args); - - ecx.eq(goal.param_env, goal_trait_ref, impl_trait_ref)?; - - let where_clause_bounds = tcx - .predicates_of(impl_def_id) - .instantiate(tcx, impl_args) - .predicates - .into_iter() - .map(|pred| goal.with(tcx, pred)); - ecx.add_goals(where_clause_bounds); - - // Add GAT where clauses from the trait's definition - ecx.add_goals( - tcx.predicates_of(goal.predicate.def_id()) - .instantiate_own(tcx, goal.predicate.projection_ty.args) - .map(|(pred, _)| goal.with(tcx, pred)), - ); - - // In case the associated item is hidden due to specialization, we have to - // return ambiguity this would otherwise be incomplete, resulting in - // unsoundness during coherence (#105782). - let Some(assoc_def) = fetch_eligible_assoc_item_def( - ecx, - goal.param_env, - goal_trait_ref, - goal.predicate.def_id(), - impl_def_id, - )? - else { - return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); - }; - - let error_response = |ecx: &mut EvalCtxt<'_, 'tcx>, reason| { - let guar = tcx.sess.delay_span_bug(tcx.def_span(assoc_def.item.def_id), reason); - let error_term = match assoc_def.item.kind { - ty::AssocKind::Const => ty::Const::new_error( - tcx, - guar, - tcx.type_of(goal.predicate.def_id()) - .instantiate(tcx, goal.predicate.projection_ty.args), - ) - .into(), - ty::AssocKind::Type => Ty::new_error(tcx, guar).into(), - ty::AssocKind::Fn => unreachable!(), - }; - ecx.eq(goal.param_env, goal.predicate.term, error_term) - .expect("expected goal term to be fully unconstrained"); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }; - - if !assoc_def.item.defaultness(tcx).has_value() { - return error_response(ecx, "missing value for assoc item in impl"); - } - - // Getting the right args here is complex, e.g. given: - // - a goal ` as Trait>::Assoc` - // - the applicable impl `impl Trait for Vec` - // - and the impl which defines `Assoc` being `impl Trait for Vec` - // - // We first rebase the goal args onto the impl, going from `[Vec, i32, u64]` - // to `[u32, u64]`. - // - // And then map these args to the args of the defining impl of `Assoc`, going - // from `[u32, u64]` to `[u32, i32, u64]`. - let impl_args_with_gat = goal.predicate.projection_ty.args.rebase_onto( - tcx, - goal_trait_ref.def_id, - impl_args, - ); - let args = ecx.translate_args( - goal.param_env, - impl_def_id, - impl_args_with_gat, - assoc_def.defining_node, - ); - - if !check_args_compatible(tcx, assoc_def.item, args) { - return error_response( - ecx, - "associated item has mismatched generic item arguments", - ); - } - - // Finally we construct the actual value of the associated type. - let term = match assoc_def.item.kind { - ty::AssocKind::Type => tcx.type_of(assoc_def.item.def_id).map_bound(|ty| ty.into()), - ty::AssocKind::Const => { - if tcx.features().associated_const_equality { - bug!("associated const projection is not supported yet") - } else { - ty::EarlyBinder::bind( - ty::Const::new_error_with_message( - tcx, - tcx.type_of(assoc_def.item.def_id).instantiate_identity(), - DUMMY_SP, - "associated const projection is not supported yet", - ) - .into(), - ) - } - } - ty::AssocKind::Fn => unreachable!("we should never project to a fn"), - }; - - ecx.eq(goal.param_env, goal.predicate.term, term.instantiate(tcx, args)) - .expect("expected goal term to be fully unconstrained"); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }) - } - - /// Fail to normalize if the predicate contains an error, alternatively, we could normalize to `ty::Error` - /// and succeed. Can experiment with this to figure out what results in better error messages. - fn consider_error_guaranteed_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - _guar: ErrorGuaranteed, - ) -> QueryResult<'tcx> { - Err(NoSolution) - } - - fn consider_auto_trait_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - ecx.tcx().sess.delay_span_bug( - ecx.tcx().def_span(goal.predicate.def_id()), - "associated types not allowed on auto traits", - ); - Err(NoSolution) - } - - fn consider_trait_alias_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("trait aliases do not have associated types: {:?}", goal); - } - - fn consider_builtin_sized_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`Sized` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_copy_clone_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`Copy`/`Clone` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_pointer_like_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`PointerLike` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_fn_ptr_trait_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`FnPtr` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_fn_trait_candidates( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - goal_kind: ty::ClosureKind, - ) -> QueryResult<'tcx> { - let tcx = ecx.tcx(); - let tupled_inputs_and_output = - match structural_traits::extract_tupled_inputs_and_output_from_callable( - tcx, - goal.predicate.self_ty(), - goal_kind, - )? { - Some(tupled_inputs_and_output) => tupled_inputs_and_output, - None => { - return ecx - .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); - } - }; - 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, output)| ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new( - tcx, - goal.predicate.def_id(), - [goal.predicate.self_ty(), inputs], - ), - term: output.into(), - }) - .to_predicate(tcx); - - // A built-in `Fn` impl only holds if the output is sized. - // (FIXME: technically we only need to check this if the type is a fn ptr...) - Self::consider_implied_clause(ecx, goal, pred, [goal.with(tcx, output_is_sized_pred)]) - } - - fn consider_builtin_tuple_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`Tuple` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_pointee_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - let tcx = ecx.tcx(); - ecx.probe_misc_candidate("builtin pointee").enter(|ecx| { - let metadata_ty = match goal.predicate.self_ty().kind() { - ty::Bool - | ty::Char - | ty::Int(..) - | ty::Uint(..) - | ty::Float(..) - | ty::Array(..) - | ty::RawPtr(..) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Closure(..) - | ty::Infer(ty::IntVar(..) | ty::FloatVar(..)) - | ty::Coroutine(..) - | ty::CoroutineWitness(..) - | ty::Never - | ty::Foreign(..) => tcx.types.unit, - - ty::Error(e) => Ty::new_error(tcx, *e), - - ty::Str | ty::Slice(_) => tcx.types.usize, - - ty::Dynamic(_, _, _) => { - let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, None); - tcx.type_of(dyn_metadata) - .instantiate(tcx, &[ty::GenericArg::from(goal.predicate.self_ty())]) - } - - ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => { - // FIXME(ptr_metadata): It would also be possible to return a `Ok(Ambig)` with no constraints. - let sized_predicate = ty::TraitRef::from_lang_item( - tcx, - LangItem::Sized, - DUMMY_SP, - [ty::GenericArg::from(goal.predicate.self_ty())], - ); - ecx.add_goal(goal.with(tcx, sized_predicate)); - tcx.types.unit - } - - ty::Adt(def, args) if def.is_struct() => match def.non_enum_variant().tail_opt() { - None => tcx.types.unit, - Some(field_def) => { - let self_ty = field_def.ty(tcx, args); - ecx.add_goal(goal.with(tcx, goal.predicate.with_self_ty(tcx, self_ty))); - return ecx - .evaluate_added_goals_and_make_canonical_response(Certainty::Yes); - } - }, - ty::Adt(_, _) => tcx.types.unit, - - ty::Tuple(elements) => match elements.last() { - None => tcx.types.unit, - Some(&self_ty) => { - ecx.add_goal(goal.with(tcx, goal.predicate.with_self_ty(tcx, self_ty))); - return ecx - .evaluate_added_goals_and_make_canonical_response(Certainty::Yes); - } - }, - - ty::Infer( - ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_), - ) - | ty::Bound(..) => bug!( - "unexpected self ty `{:?}` when normalizing `::Metadata`", - goal.predicate.self_ty() - ), - }; - - ecx.eq(goal.param_env, goal.predicate.term, metadata_ty.into()) - .expect("expected goal term to be fully unconstrained"); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }) - } - - fn consider_builtin_future_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - let self_ty = goal.predicate.self_ty(); - let ty::Coroutine(def_id, args, _) = *self_ty.kind() else { - return Err(NoSolution); - }; - - // Coroutines are not futures unless they come from `async` desugaring - let tcx = ecx.tcx(); - if !tcx.coroutine_is_async(def_id) { - return Err(NoSolution); - } - - let term = args.as_coroutine().return_ty().into(); - - Self::consider_implied_clause( - ecx, - goal, - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new(ecx.tcx(), goal.predicate.def_id(), [self_ty]), - term, - } - .to_predicate(tcx), - // Technically, we need to check that the future type is Sized, - // but that's already proven by the coroutine being WF. - [], - ) - } - - fn consider_builtin_iterator_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - let self_ty = goal.predicate.self_ty(); - let ty::Coroutine(def_id, args, _) = *self_ty.kind() else { - return Err(NoSolution); - }; - - // Coroutines are not Iterators unless they come from `gen` desugaring - let tcx = ecx.tcx(); - if !tcx.coroutine_is_gen(def_id) { - return Err(NoSolution); - } - - let term = args.as_coroutine().yield_ty().into(); - - Self::consider_implied_clause( - ecx, - goal, - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new(ecx.tcx(), goal.predicate.def_id(), [self_ty]), - term, - } - .to_predicate(tcx), - // Technically, we need to check that the iterator type is Sized, - // but that's already proven by the generator being WF. - [], - ) - } - - fn consider_builtin_coroutine_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - let self_ty = goal.predicate.self_ty(); - let ty::Coroutine(def_id, args, _) = *self_ty.kind() else { - return Err(NoSolution); - }; - - // `async`-desugared coroutines do not implement the coroutine trait - let tcx = ecx.tcx(); - if !tcx.is_general_coroutine(def_id) { - return Err(NoSolution); - } - - let coroutine = args.as_coroutine(); - - let name = tcx.associated_item(goal.predicate.def_id()).name; - let term = if name == sym::Return { - coroutine.return_ty().into() - } else if name == sym::Yield { - coroutine.yield_ty().into() - } else { - bug!("unexpected associated item `<{self_ty} as Coroutine>::{name}`") - }; - - Self::consider_implied_clause( - ecx, - goal, - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new( - ecx.tcx(), - goal.predicate.def_id(), - [self_ty, coroutine.resume_ty()], - ), - term, - } - .to_predicate(tcx), - // Technically, we need to check that the coroutine type is Sized, - // but that's already proven by the coroutine being WF. - [], - ) - } - - fn consider_unsize_to_dyn_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`Unsize` does not have an associated type: {:?}", goal) - } - - fn consider_structural_builtin_unsize_candidates( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> Vec<(CanonicalResponse<'tcx>, BuiltinImplSource)> { - bug!("`Unsize` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_discriminant_kind_candidate( - ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - let self_ty = goal.predicate.self_ty(); - let discriminant_ty = match *self_ty.kind() { - ty::Bool - | ty::Char - | ty::Int(..) - | ty::Uint(..) - | ty::Float(..) - | ty::Array(..) - | ty::RawPtr(..) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Closure(..) - | ty::Infer(ty::IntVar(..) | ty::FloatVar(..)) - | ty::Coroutine(..) - | ty::CoroutineWitness(..) - | ty::Never - | ty::Foreign(..) - | ty::Adt(_, _) - | ty::Str - | ty::Slice(_) - | ty::Dynamic(_, _, _) - | ty::Tuple(_) - | ty::Error(_) => self_ty.discriminant_ty(ecx.tcx()), - - // We do not call `Ty::discriminant_ty` on alias, param, or placeholder - // types, which return `::Discriminant` - // (or ICE in the case of placeholders). Projecting a type to itself - // is never really productive. - ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => { - return Err(NoSolution); - } - - ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) - | ty::Bound(..) => bug!( - "unexpected self ty `{:?}` when normalizing `::Discriminant`", - goal.predicate.self_ty() - ), - }; - - ecx.probe_misc_candidate("builtin discriminant kind").enter(|ecx| { - ecx.eq(goal.param_env, goal.predicate.term, discriminant_ty.into()) - .expect("expected goal term to be fully unconstrained"); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }) - } - - fn consider_builtin_destruct_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`Destruct` does not have an associated type: {:?}", goal); - } - - fn consider_builtin_transmute_candidate( - _ecx: &mut EvalCtxt<'_, 'tcx>, - goal: Goal<'tcx, Self>, - ) -> QueryResult<'tcx> { - bug!("`BikeshedIntrinsicFrom` does not have an associated type: {:?}", goal) - } -} - -/// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code. -/// -/// FIXME: We should merge these 3 implementations as it's likely that they otherwise -/// diverge. -#[instrument(level = "debug", skip(ecx, param_env), ret)] -fn fetch_eligible_assoc_item_def<'tcx>( - ecx: &EvalCtxt<'_, 'tcx>, - param_env: ty::ParamEnv<'tcx>, - goal_trait_ref: ty::TraitRef<'tcx>, - trait_assoc_def_id: DefId, - impl_def_id: DefId, -) -> Result, NoSolution> { - let node_item = specialization_graph::assoc_def(ecx.tcx(), impl_def_id, trait_assoc_def_id) - .map_err(|ErrorGuaranteed { .. }| NoSolution)?; - - let eligible = if node_item.is_final() { - // Non-specializable items are always projectable. - true - } else { - // Only reveal a specializable default if we're past type-checking - // and the obligation is monomorphic, otherwise passes such as - // transmute checking and polymorphic MIR optimizations could - // get a result which isn't correct for all monomorphizations. - if param_env.reveal() == Reveal::All { - let poly_trait_ref = ecx.resolve_vars_if_possible(goal_trait_ref); - !poly_trait_ref.still_further_specializable() - } else { - debug!(?node_item.item.def_id, "not eligible due to default"); - false - } - }; - - if eligible { Ok(Some(node_item)) } else { Ok(None) } -} diff --git a/compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs b/compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs deleted file mode 100644 index ebd129f32..000000000 --- a/compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs +++ /dev/null @@ -1,85 +0,0 @@ -//! Computes a normalizes-to (projection) goal for opaque types. This goal -//! behaves differently depending on the param-env's reveal mode and whether -//! the opaque is in a defining scope. -use rustc_middle::traits::query::NoSolution; -use rustc_middle::traits::solve::{Certainty, Goal, QueryResult}; -use rustc_middle::traits::Reveal; -use rustc_middle::ty; -use rustc_middle::ty::util::NotUniqueParam; - -use crate::solve::{EvalCtxt, SolverMode}; - -impl<'tcx> EvalCtxt<'_, 'tcx> { - pub(super) fn normalize_opaque_type( - &mut self, - goal: Goal<'tcx, ty::ProjectionPredicate<'tcx>>, - ) -> QueryResult<'tcx> { - let tcx = self.tcx(); - let opaque_ty = goal.predicate.projection_ty; - let expected = goal.predicate.term.ty().expect("no such thing as an opaque const"); - - match (goal.param_env.reveal(), self.solver_mode()) { - (Reveal::UserFacing, SolverMode::Normal) => { - let Some(opaque_ty_def_id) = opaque_ty.def_id.as_local() else { - return Err(NoSolution); - }; - // FIXME: at some point we should call queries without defining - // new opaque types but having the existing opaque type definitions. - // This will require moving this below "Prefer opaques registered already". - if !self.can_define_opaque_ty(opaque_ty_def_id) { - return Err(NoSolution); - } - // FIXME: This may have issues when the args contain aliases... - match self.tcx().uses_unique_placeholders_ignoring_regions(opaque_ty.args) { - Err(NotUniqueParam::NotParam(param)) if param.is_non_region_infer() => { - return self.evaluate_added_goals_and_make_canonical_response( - Certainty::AMBIGUOUS, - ); - } - Err(_) => { - return Err(NoSolution); - } - Ok(()) => {} - } - // Prefer opaques registered already. - let opaque_type_key = - ty::OpaqueTypeKey { def_id: opaque_ty_def_id, args: opaque_ty.args }; - let matches = - self.unify_existing_opaque_tys(goal.param_env, opaque_type_key, expected); - if !matches.is_empty() { - if let Some(response) = self.try_merge_responses(&matches) { - return Ok(response); - } else { - return self.flounder(&matches); - } - } - // Otherwise, define a new opaque type - self.insert_hidden_type(opaque_type_key, goal.param_env, expected)?; - self.add_item_bounds_for_hidden_type( - opaque_ty.def_id, - opaque_ty.args, - goal.param_env, - expected, - ); - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } - (Reveal::UserFacing, SolverMode::Coherence) => { - // An impossible opaque type bound is the only way this goal will fail - // e.g. assigning `impl Copy := NotCopy` - self.add_item_bounds_for_hidden_type( - opaque_ty.def_id, - opaque_ty.args, - goal.param_env, - expected, - ); - self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS) - } - (Reveal::All, _) => { - // FIXME: Add an assertion that opaque type storage is empty. - let actual = tcx.type_of(opaque_ty.def_id).instantiate(tcx, opaque_ty.args); - self.eq(goal.param_env, expected, actual)?; - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } - } - } -} diff --git a/compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs b/compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs deleted file mode 100644 index 54de32cf6..000000000 --- a/compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs +++ /dev/null @@ -1,34 +0,0 @@ -//! Computes a normalizes-to (projection) goal for inherent associated types, -//! `#![feature(lazy_type_alias)]` and `#![feature(type_alias_impl_trait)]`. -//! -//! Since a weak alias is not ambiguous, this just computes the `type_of` of -//! the alias and registers the where-clauses of the type alias. -use rustc_middle::traits::solve::{Certainty, Goal, QueryResult}; -use rustc_middle::ty; - -use super::EvalCtxt; - -impl<'tcx> EvalCtxt<'_, 'tcx> { - pub(super) fn normalize_weak_type( - &mut self, - goal: Goal<'tcx, ty::ProjectionPredicate<'tcx>>, - ) -> QueryResult<'tcx> { - let tcx = self.tcx(); - let weak_ty = goal.predicate.projection_ty; - let expected = goal.predicate.term.ty().expect("no such thing as a const alias"); - - let actual = tcx.type_of(weak_ty.def_id).instantiate(tcx, weak_ty.args); - self.eq(goal.param_env, expected, actual)?; - - // Check where clauses - self.add_goals( - tcx.predicates_of(weak_ty.def_id) - .instantiate(tcx, weak_ty.args) - .predicates - .into_iter() - .map(|pred| goal.with(tcx, pred)), - ); - - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } -} -- cgit v1.2.3