diff options
Diffstat (limited to 'compiler/rustc_trait_selection')
3 files changed, 18 insertions, 152 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs index eb34cb10c68..a54eb80fedc 100644 --- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs +++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs @@ -9,7 +9,7 @@ use rustc_macros::extension; pub use rustc_middle::traits::query::NormalizationResult; use rustc_middle::ty::{ self, FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeSuperVisitable, - TypeVisitableExt, TypeVisitor, TypingMode, + TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode, }; use rustc_span::DUMMY_SP; use tracing::{debug, info, instrument}; @@ -127,7 +127,7 @@ struct MaxEscapingBoundVarVisitor { } impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for MaxEscapingBoundVarVisitor { - fn visit_binder<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) { + fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &ty::Binder<'tcx, T>) { self.outer_index.shift_in(1); t.super_visit_with(self); self.outer_index.shift_out(1); diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 3a2f9e8ca17..1b9b68fa980 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -1919,12 +1919,23 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // impl `impl<T: ?Sized> Any for T { .. }`. This really shouldn't exist but is // necessary due to #57893. We again arbitrarily prefer the applicable candidate // with the lowest index. + // + // We do not want to use these impls to guide inference in case a user-written impl + // may also apply. let object_bound = candidates .iter() .filter_map(|c| if let ObjectCandidate(i) = c.candidate { Some(i) } else { None }) .try_reduce(|c1, c2| if has_non_region_infer { None } else { Some(c1.min(c2)) }); match object_bound { - Some(Some(index)) => return Some(ObjectCandidate(index)), + Some(Some(index)) => { + return if has_non_region_infer + && candidates.iter().any(|c| matches!(c.candidate, ImplCandidate(_))) + { + None + } else { + Some(ObjectCandidate(index)) + }; + } Some(None) => {} None => return None, } diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs index 035fd38c48a..0723aebd5d2 100644 --- a/compiler/rustc_trait_selection/src/traits/util.rs +++ b/compiler/rustc_trait_selection/src/traits/util.rs @@ -1,4 +1,4 @@ -use std::collections::{BTreeMap, VecDeque}; +use std::collections::VecDeque; use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_hir::LangItem; @@ -9,6 +9,7 @@ use rustc_middle::bug; use rustc_middle::ty::{ self, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitableExt, }; +pub use rustc_next_trait_solver::placeholder::BoundVarReplacer; use rustc_span::Span; use smallvec::{SmallVec, smallvec}; use tracing::debug; @@ -212,158 +213,12 @@ pub fn with_replaced_escaping_bound_vars< } } -pub struct BoundVarReplacer<'a, 'tcx> { - infcx: &'a InferCtxt<'tcx>, - // These three maps track the bound variable that were replaced by placeholders. It might be - // nice to remove these since we already have the `kind` in the placeholder; we really just need - // the `var` (but we *could* bring that into scope if we were to track them as we pass them). - mapped_regions: FxIndexMap<ty::PlaceholderRegion, ty::BoundRegion>, - mapped_types: FxIndexMap<ty::PlaceholderType, ty::BoundTy>, - mapped_consts: BTreeMap<ty::PlaceholderConst, ty::BoundVar>, - // The current depth relative to *this* folding, *not* the entire normalization. In other words, - // the depth of binders we've passed here. - current_index: ty::DebruijnIndex, - // The `UniverseIndex` of the binding levels above us. These are optional, since we are lazy: - // we don't actually create a universe until we see a bound var we have to replace. - universe_indices: &'a mut Vec<Option<ty::UniverseIndex>>, -} - -impl<'a, 'tcx> BoundVarReplacer<'a, 'tcx> { - /// Returns `Some` if we *were* able to replace bound vars. If there are any bound vars that - /// use a binding level above `universe_indices.len()`, we fail. - pub fn replace_bound_vars<T: TypeFoldable<TyCtxt<'tcx>>>( - infcx: &'a InferCtxt<'tcx>, - universe_indices: &'a mut Vec<Option<ty::UniverseIndex>>, - value: T, - ) -> ( - T, - FxIndexMap<ty::PlaceholderRegion, ty::BoundRegion>, - FxIndexMap<ty::PlaceholderType, ty::BoundTy>, - BTreeMap<ty::PlaceholderConst, ty::BoundVar>, - ) { - let mapped_regions: FxIndexMap<ty::PlaceholderRegion, ty::BoundRegion> = - FxIndexMap::default(); - let mapped_types: FxIndexMap<ty::PlaceholderType, ty::BoundTy> = FxIndexMap::default(); - let mapped_consts: BTreeMap<ty::PlaceholderConst, ty::BoundVar> = BTreeMap::new(); - - let mut replacer = BoundVarReplacer { - infcx, - mapped_regions, - mapped_types, - mapped_consts, - current_index: ty::INNERMOST, - universe_indices, - }; - - let value = value.fold_with(&mut replacer); - - (value, replacer.mapped_regions, replacer.mapped_types, replacer.mapped_consts) - } - - fn universe_for(&mut self, debruijn: ty::DebruijnIndex) -> ty::UniverseIndex { - let infcx = self.infcx; - let index = - self.universe_indices.len() + self.current_index.as_usize() - debruijn.as_usize() - 1; - let universe = self.universe_indices[index].unwrap_or_else(|| { - for i in self.universe_indices.iter_mut().take(index + 1) { - *i = i.or_else(|| Some(infcx.create_next_universe())) - } - self.universe_indices[index].unwrap() - }); - universe - } -} - -impl<'tcx> TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'_, 'tcx> { - fn cx(&self) -> TyCtxt<'tcx> { - self.infcx.tcx - } - - fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>( - &mut self, - t: ty::Binder<'tcx, T>, - ) -> ty::Binder<'tcx, T> { - self.current_index.shift_in(1); - let t = t.super_fold_with(self); - self.current_index.shift_out(1); - t - } - - fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { - match r.kind() { - ty::ReBound(debruijn, _) - if debruijn.as_usize() - >= self.current_index.as_usize() + self.universe_indices.len() => - { - bug!( - "Bound vars {r:#?} outside of `self.universe_indices`: {:#?}", - self.universe_indices - ); - } - ty::ReBound(debruijn, br) if debruijn >= self.current_index => { - let universe = self.universe_for(debruijn); - let p = ty::PlaceholderRegion { universe, bound: br }; - self.mapped_regions.insert(p, br); - ty::Region::new_placeholder(self.infcx.tcx, p) - } - _ => r, - } - } - - fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { - match *t.kind() { - ty::Bound(debruijn, _) - if debruijn.as_usize() + 1 - > self.current_index.as_usize() + self.universe_indices.len() => - { - bug!( - "Bound vars {t:#?} outside of `self.universe_indices`: {:#?}", - self.universe_indices - ); - } - ty::Bound(debruijn, bound_ty) if debruijn >= self.current_index => { - let universe = self.universe_for(debruijn); - let p = ty::PlaceholderType { universe, bound: bound_ty }; - self.mapped_types.insert(p, bound_ty); - Ty::new_placeholder(self.infcx.tcx, p) - } - _ if t.has_vars_bound_at_or_above(self.current_index) => t.super_fold_with(self), - _ => t, - } - } - - fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> { - match ct.kind() { - ty::ConstKind::Bound(debruijn, _) - if debruijn.as_usize() + 1 - > self.current_index.as_usize() + self.universe_indices.len() => - { - bug!( - "Bound vars {ct:#?} outside of `self.universe_indices`: {:#?}", - self.universe_indices - ); - } - ty::ConstKind::Bound(debruijn, bound_const) if debruijn >= self.current_index => { - let universe = self.universe_for(debruijn); - let p = ty::PlaceholderConst { universe, bound: bound_const }; - self.mapped_consts.insert(p, bound_const); - ty::Const::new_placeholder(self.infcx.tcx, p) - } - _ => ct.super_fold_with(self), - } - } - - fn fold_predicate(&mut self, p: ty::Predicate<'tcx>) -> ty::Predicate<'tcx> { - if p.has_vars_bound_at_or_above(self.current_index) { p.super_fold_with(self) } else { p } - } -} - /// The inverse of [`BoundVarReplacer`]: replaces placeholders with the bound vars from which they came. pub struct PlaceholderReplacer<'a, 'tcx> { infcx: &'a InferCtxt<'tcx>, mapped_regions: FxIndexMap<ty::PlaceholderRegion, ty::BoundRegion>, mapped_types: FxIndexMap<ty::PlaceholderType, ty::BoundTy>, - mapped_consts: BTreeMap<ty::PlaceholderConst, ty::BoundVar>, + mapped_consts: FxIndexMap<ty::PlaceholderConst, ty::BoundVar>, universe_indices: &'a [Option<ty::UniverseIndex>], current_index: ty::DebruijnIndex, } @@ -373,7 +228,7 @@ impl<'a, 'tcx> PlaceholderReplacer<'a, 'tcx> { infcx: &'a InferCtxt<'tcx>, mapped_regions: FxIndexMap<ty::PlaceholderRegion, ty::BoundRegion>, mapped_types: FxIndexMap<ty::PlaceholderType, ty::BoundTy>, - mapped_consts: BTreeMap<ty::PlaceholderConst, ty::BoundVar>, + mapped_consts: FxIndexMap<ty::PlaceholderConst, ty::BoundVar>, universe_indices: &'a [Option<ty::UniverseIndex>], value: T, ) -> T { |