From fd59d058ec10b5c4cca977240b1f82ac99482166 Mon Sep 17 00:00:00 2001 From: lcnr Date: Mon, 25 Jul 2022 19:27:52 +0200 Subject: [PATCH 1/3] `BoundVarReplacer`: trait object instead of 3 fns --- .../src/infer/canonical/substitute.rs | 30 ++-- .../src/infer/higher_ranked/mod.rs | 45 +++--- compiler/rustc_infer/src/infer/mod.rs | 75 ++++++---- compiler/rustc_middle/src/ty/fold.rs | 134 +++++++++--------- compiler/rustc_middle/src/ty/subst.rs | 8 ++ 5 files changed, 164 insertions(+), 128 deletions(-) diff --git a/compiler/rustc_infer/src/infer/canonical/substitute.rs b/compiler/rustc_infer/src/infer/canonical/substitute.rs index 45ed4b63009..34b6113427d 100644 --- a/compiler/rustc_infer/src/infer/canonical/substitute.rs +++ b/compiler/rustc_infer/src/infer/canonical/substitute.rs @@ -7,7 +7,7 @@ //! [c]: https://rust-lang.github.io/chalk/book/canonical_queries/canonicalization.html use crate::infer::canonical::{Canonical, CanonicalVarValues}; -use rustc_middle::ty::fold::TypeFoldable; +use rustc_middle::ty::fold::{FnMutDelegate, TypeFoldable}; use rustc_middle::ty::subst::GenericArgKind; use rustc_middle::ty::{self, TyCtxt}; @@ -71,21 +71,21 @@ where if var_values.var_values.is_empty() { value } else { - let fld_r = |br: ty::BoundRegion| match var_values.var_values[br.var].unpack() { - GenericArgKind::Lifetime(l) => l, - r => bug!("{:?} is a region but value is {:?}", br, r), + let delegate = FnMutDelegate { + regions: |br: ty::BoundRegion| match var_values.var_values[br.var].unpack() { + GenericArgKind::Lifetime(l) => l, + r => bug!("{:?} is a region but value is {:?}", br, r), + }, + types: |bound_ty: ty::BoundTy| match var_values.var_values[bound_ty.var].unpack() { + GenericArgKind::Type(ty) => ty, + r => bug!("{:?} is a type but value is {:?}", bound_ty, r), + }, + consts: |bound_ct: ty::BoundVar, _| match var_values.var_values[bound_ct].unpack() { + GenericArgKind::Const(ct) => ct, + c => bug!("{:?} is a const but value is {:?}", bound_ct, c), + }, }; - let fld_t = |bound_ty: ty::BoundTy| match var_values.var_values[bound_ty.var].unpack() { - GenericArgKind::Type(ty) => ty, - r => bug!("{:?} is a type but value is {:?}", bound_ty, r), - }; - - let fld_c = |bound_ct: ty::BoundVar, _| match var_values.var_values[bound_ct].unpack() { - GenericArgKind::Const(ct) => ct, - c => bug!("{:?} is a const but value is {:?}", bound_ct, c), - }; - - tcx.replace_escaping_bound_vars_uncached(value, fld_r, fld_t, fld_c) + tcx.replace_escaping_bound_vars_uncached(value, delegate) } } diff --git a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs index e543ae1fcda..ed257c144e0 100644 --- a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs +++ b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs @@ -4,6 +4,7 @@ use super::combine::CombineFields; use super::{HigherRankedType, InferCtxt}; use crate::infer::CombinedSnapshot; +use rustc_middle::ty::fold::FnMutDelegate; use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation}; use rustc_middle::ty::{self, Binder, TypeFoldable}; @@ -79,31 +80,31 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { let next_universe = self.create_next_universe(); - let fld_r = |br: ty::BoundRegion| { - self.tcx.mk_region(ty::RePlaceholder(ty::PlaceholderRegion { - universe: next_universe, - name: br.kind, - })) - }; - - let fld_t = |bound_ty: ty::BoundTy| { - self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType { - universe: next_universe, - name: bound_ty.var, - })) - }; - - let fld_c = |bound_var: ty::BoundVar, ty| { - self.tcx.mk_const(ty::ConstS { - kind: ty::ConstKind::Placeholder(ty::PlaceholderConst { + let delegate = FnMutDelegate { + regions: |br: ty::BoundRegion| { + self.tcx.mk_region(ty::RePlaceholder(ty::PlaceholderRegion { universe: next_universe, - name: ty::BoundConst { var: bound_var, ty }, - }), - ty, - }) + name: br.kind, + })) + }, + types: |bound_ty: ty::BoundTy| { + self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType { + universe: next_universe, + name: bound_ty.var, + })) + }, + consts: |bound_var: ty::BoundVar, ty| { + self.tcx.mk_const(ty::ConstS { + kind: ty::ConstKind::Placeholder(ty::PlaceholderConst { + universe: next_universe, + name: ty::BoundConst { var: bound_var, ty }, + }), + ty, + }) + }, }; - let result = self.tcx.replace_bound_vars_uncached(binder, fld_r, fld_t, fld_c); + let result = self.tcx.replace_bound_vars_uncached(binder, delegate); debug!(?next_universe, ?result); result } diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs index 0ac6e8c541b..21045a0585c 100644 --- a/compiler/rustc_infer/src/infer/mod.rs +++ b/compiler/rustc_infer/src/infer/mod.rs @@ -23,6 +23,7 @@ use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult}; use rustc_middle::traits::select; use rustc_middle::ty::abstract_const::{AbstractConst, FailureKind}; use rustc_middle::ty::error::{ExpectedFound, TypeError}; +use rustc_middle::ty::fold::BoundVarReplacerDelegate; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable}; use rustc_middle::ty::relate::RelateResult; use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef}; @@ -1564,32 +1565,56 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { return inner; } - let mut region_map = FxHashMap::default(); - let fld_r = |br: ty::BoundRegion| { - *region_map - .entry(br) - .or_insert_with(|| self.next_region_var(LateBoundRegion(span, br.kind, lbrct))) - }; + struct ToFreshVars<'a, 'tcx> { + infcx: &'a InferCtxt<'a, 'tcx>, + span: Span, + lbrct: LateBoundRegionConversionTime, + map: FxHashMap>, + } - let mut ty_map = FxHashMap::default(); - let fld_t = |bt: ty::BoundTy| { - *ty_map.entry(bt).or_insert_with(|| { - self.next_ty_var(TypeVariableOrigin { - kind: TypeVariableOriginKind::MiscVariable, - span, - }) - }) - }; - let mut ct_map = FxHashMap::default(); - let fld_c = |bc: ty::BoundVar, ty| { - *ct_map.entry(bc).or_insert_with(|| { - self.next_const_var( - ty, - ConstVariableOrigin { kind: ConstVariableOriginKind::MiscVariable, span }, - ) - }) - }; - self.tcx.replace_bound_vars_uncached(value, fld_r, fld_t, fld_c) + impl<'tcx> BoundVarReplacerDelegate<'tcx> for ToFreshVars<'_, 'tcx> { + fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> { + self.map + .entry(br.var) + .or_insert_with(|| { + self.infcx + .next_region_var(LateBoundRegion(self.span, br.kind, self.lbrct)) + .into() + }) + .expect_region() + } + fn replace_ty(&mut self, bt: ty::BoundTy) -> Ty<'tcx> { + self.map + .entry(bt.var) + .or_insert_with(|| { + self.infcx + .next_ty_var(TypeVariableOrigin { + kind: TypeVariableOriginKind::MiscVariable, + span: self.span, + }) + .into() + }) + .expect_ty() + } + fn replace_const(&mut self, bv: ty::BoundVar, ty: Ty<'tcx>) -> ty::Const<'tcx> { + self.map + .entry(bv) + .or_insert_with(|| { + self.infcx + .next_const_var( + ty, + ConstVariableOrigin { + kind: ConstVariableOriginKind::MiscVariable, + span: self.span, + }, + ) + .into() + }) + .expect_const() + } + } + let delegate = ToFreshVars { infcx: self, span, lbrct, map: Default::default() }; + self.tcx.replace_bound_vars_uncached(value, delegate) } /// See the [`region_constraints::RegionConstraintCollector::verify_generic_bound`] method. diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs index 878f31af00f..273604fc221 100644 --- a/compiler/rustc_middle/src/ty/fold.rs +++ b/compiler/rustc_middle/src/ty/fold.rs @@ -370,6 +370,34 @@ impl<'a, 'tcx> TypeFolder<'tcx> for RegionFolder<'a, 'tcx> { /////////////////////////////////////////////////////////////////////////// // Bound vars replacer +pub trait BoundVarReplacerDelegate<'tcx> { + fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx>; + fn replace_ty(&mut self, bt: ty::BoundTy) -> Ty<'tcx>; + fn replace_const(&mut self, bv: ty::BoundVar, ty: Ty<'tcx>) -> ty::Const<'tcx>; +} + +pub struct FnMutDelegate { + pub regions: R, + pub types: T, + pub consts: C, +} +impl<'tcx, R, T, C> BoundVarReplacerDelegate<'tcx> for FnMutDelegate +where + R: FnMut(ty::BoundRegion) -> ty::Region<'tcx>, + T: FnMut(ty::BoundTy) -> Ty<'tcx>, + C: FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx>, +{ + fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> { + (self.regions)(br) + } + fn replace_ty(&mut self, bt: ty::BoundTy) -> Ty<'tcx> { + (self.types)(bt) + } + fn replace_const(&mut self, bv: ty::BoundVar, ty: Ty<'tcx>) -> ty::Const<'tcx> { + (self.consts)(bv, ty) + } +} + /// Replaces the escaping bound vars (late bound regions or bound types) in a type. struct BoundVarReplacer<'a, 'tcx> { tcx: TyCtxt<'tcx>, @@ -378,19 +406,12 @@ struct BoundVarReplacer<'a, 'tcx> { /// the ones we have visited. current_index: ty::DebruijnIndex, - fld_r: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a), - fld_t: &'a mut (dyn FnMut(ty::BoundTy) -> Ty<'tcx> + 'a), - fld_c: &'a mut (dyn FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx> + 'a), + delegate: &'a mut dyn BoundVarReplacerDelegate<'tcx>, } impl<'a, 'tcx> BoundVarReplacer<'a, 'tcx> { - fn new( - tcx: TyCtxt<'tcx>, - fld_r: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a), - fld_t: &'a mut (dyn FnMut(ty::BoundTy) -> Ty<'tcx> + 'a), - fld_c: &'a mut (dyn FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx> + 'a), - ) -> Self { - BoundVarReplacer { tcx, current_index: ty::INNERMOST, fld_r, fld_t, fld_c } + fn new(tcx: TyCtxt<'tcx>, delegate: &'a mut dyn BoundVarReplacerDelegate<'tcx>) -> Self { + BoundVarReplacer { tcx, current_index: ty::INNERMOST, delegate } } } @@ -412,7 +433,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for BoundVarReplacer<'a, 'tcx> { fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { match *t.kind() { ty::Bound(debruijn, bound_ty) if debruijn == self.current_index => { - let ty = (self.fld_t)(bound_ty); + let ty = self.delegate.replace_ty(bound_ty); ty::fold::shift_vars(self.tcx, ty, self.current_index.as_u32()) } _ if t.has_vars_bound_at_or_above(self.current_index) => t.super_fold_with(self), @@ -423,7 +444,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for BoundVarReplacer<'a, 'tcx> { fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { match *r { ty::ReLateBound(debruijn, br) if debruijn == self.current_index => { - let region = (self.fld_r)(br); + let region = self.delegate.replace_region(br); if let ty::ReLateBound(debruijn1, br) = *region { // If the callback returns a late-bound region, // that region should always use the INNERMOST @@ -442,7 +463,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for BoundVarReplacer<'a, 'tcx> { fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> { match ct.kind() { ty::ConstKind::Bound(debruijn, bound_const) if debruijn == self.current_index => { - let ct = (self.fld_c)(bound_const, ct.ty()); + let ct = self.delegate.replace_const(bound_const, ct.ty()); ty::fold::shift_vars(self.tcx, ct, self.current_index.as_u32()) } _ => ct.super_fold_with(self), @@ -486,19 +507,22 @@ impl<'tcx> TyCtxt<'tcx> { pub fn replace_late_bound_regions_uncached( self, value: Binder<'tcx, T>, - mut fld_r: F, + replace_regions: F, ) -> T where F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>, T: TypeFoldable<'tcx>, { - let mut fld_t = |b| bug!("unexpected bound ty in binder: {b:?}"); - let mut fld_c = |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"); let value = value.skip_binder(); if !value.has_escaping_bound_vars() { value } else { - let mut replacer = BoundVarReplacer::new(self, &mut fld_r, &mut fld_t, &mut fld_c); + let mut delegate = FnMutDelegate { + regions: replace_regions, + types: |b| bug!("unexpected bound ty in binder: {b:?}"), + consts: |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"), + }; + let mut replacer = BoundVarReplacer::new(self, &mut delegate); value.fold_with(&mut replacer) } } @@ -506,23 +530,15 @@ impl<'tcx> TyCtxt<'tcx> { /// Replaces all escaping bound vars. The `fld_r` closure replaces escaping /// bound regions; the `fld_t` closure replaces escaping bound types and the `fld_c` /// closure replaces escaping bound consts. - pub fn replace_escaping_bound_vars_uncached( + pub fn replace_escaping_bound_vars_uncached>( self, value: T, - mut fld_r: F, - mut fld_t: G, - mut fld_c: H, - ) -> T - where - F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>, - G: FnMut(ty::BoundTy) -> Ty<'tcx>, - H: FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx>, - T: TypeFoldable<'tcx>, - { + mut delegate: impl BoundVarReplacerDelegate<'tcx>, + ) -> T { if !value.has_escaping_bound_vars() { value } else { - let mut replacer = BoundVarReplacer::new(self, &mut fld_r, &mut fld_t, &mut fld_c); + let mut replacer = BoundVarReplacer::new(self, &mut delegate); value.fold_with(&mut replacer) } } @@ -530,20 +546,12 @@ impl<'tcx> TyCtxt<'tcx> { /// Replaces all types or regions bound by the given `Binder`. The `fld_r` /// closure replaces bound regions, the `fld_t` closure replaces bound /// types, and `fld_c` replaces bound constants. - pub fn replace_bound_vars_uncached( + pub fn replace_bound_vars_uncached>( self, value: Binder<'tcx, T>, - fld_r: F, - fld_t: G, - fld_c: H, - ) -> T - where - F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>, - G: FnMut(ty::BoundTy) -> Ty<'tcx>, - H: FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx>, - T: TypeFoldable<'tcx>, - { - self.replace_escaping_bound_vars_uncached(value.skip_binder(), fld_r, fld_t, fld_c) + delegate: impl BoundVarReplacerDelegate<'tcx>, + ) -> T { + self.replace_escaping_bound_vars_uncached(value.skip_binder(), delegate) } /// Replaces any late-bound regions bound in `value` with @@ -568,34 +576,28 @@ impl<'tcx> TyCtxt<'tcx> { where T: TypeFoldable<'tcx>, { + let shift_bv = |bv: ty::BoundVar| ty::BoundVar::from_usize(bv.as_usize() + bound_vars); self.replace_escaping_bound_vars_uncached( value, - |r| { - self.mk_region(ty::ReLateBound( - ty::INNERMOST, - ty::BoundRegion { - var: ty::BoundVar::from_usize(r.var.as_usize() + bound_vars), - kind: r.kind, - }, - )) - }, - |t| { - self.mk_ty(ty::Bound( - ty::INNERMOST, - ty::BoundTy { - var: ty::BoundVar::from_usize(t.var.as_usize() + bound_vars), - kind: t.kind, - }, - )) - }, - |c, ty| { - self.mk_const(ty::ConstS { - kind: ty::ConstKind::Bound( + FnMutDelegate { + regions: |r: ty::BoundRegion| { + self.mk_region(ty::ReLateBound( ty::INNERMOST, - ty::BoundVar::from_usize(c.as_usize() + bound_vars), - ), - ty, - }) + ty::BoundRegion { var: shift_bv(r.var), kind: r.kind }, + )) + }, + types: |t: ty::BoundTy| { + self.mk_ty(ty::Bound( + ty::INNERMOST, + ty::BoundTy { var: shift_bv(t.var), kind: t.kind }, + )) + }, + consts: |c, ty: Ty<'tcx>| { + self.mk_const(ty::ConstS { + kind: ty::ConstKind::Bound(ty::INNERMOST, shift_bv(c)), + ty, + }) + }, }, ) } diff --git a/compiler/rustc_middle/src/ty/subst.rs b/compiler/rustc_middle/src/ty/subst.rs index b4fa9837aed..6262aa18075 100644 --- a/compiler/rustc_middle/src/ty/subst.rs +++ b/compiler/rustc_middle/src/ty/subst.rs @@ -164,6 +164,14 @@ impl<'tcx> GenericArg<'tcx> { } } + /// Unpack the `GenericArg` as a region when it is known certainly to be a region. + pub fn expect_region(self) -> ty::Region<'tcx> { + match self.unpack() { + GenericArgKind::Lifetime(lt) => lt, + _ => bug!("expected a region, but found another kind"), + } + } + /// Unpack the `GenericArg` as a type when it is known certainly to be a type. /// This is true in cases where `Substs` is used in places where the kinds are known /// to be limited (e.g. in tuples, where the only parameters are type parameters). From c3fce8e9379069daf50ac393918ab6e60b57f4ca Mon Sep 17 00:00:00 2001 From: lcnr Date: Mon, 25 Jul 2022 20:24:13 +0200 Subject: [PATCH 2/3] anonymize all bound vars, not just regions --- .../src/infer/canonical/substitute.rs | 4 +- compiler/rustc_infer/src/traits/util.rs | 4 +- compiler/rustc_middle/src/ty/erase_regions.rs | 2 +- compiler/rustc_middle/src/ty/fold.rs | 57 +++++++++++++++++-- compiler/rustc_middle/src/ty/sty.rs | 23 ++++++++ compiler/rustc_typeck/src/check/dropck.rs | 4 +- .../anonymize-bound-vars.rs | 14 +++++ 7 files changed, 95 insertions(+), 13 deletions(-) create mode 100644 src/test/ui/generic-associated-types/anonymize-bound-vars.rs diff --git a/compiler/rustc_infer/src/infer/canonical/substitute.rs b/compiler/rustc_infer/src/infer/canonical/substitute.rs index 34b6113427d..9af7c3d4b9f 100644 --- a/compiler/rustc_infer/src/infer/canonical/substitute.rs +++ b/compiler/rustc_infer/src/infer/canonical/substitute.rs @@ -71,7 +71,7 @@ where if var_values.var_values.is_empty() { value } else { - let delegate = FnMutDelegate { + let mut delegate = FnMutDelegate { regions: |br: ty::BoundRegion| match var_values.var_values[br.var].unpack() { GenericArgKind::Lifetime(l) => l, r => bug!("{:?} is a region but value is {:?}", br, r), @@ -86,6 +86,6 @@ where }, }; - tcx.replace_escaping_bound_vars_uncached(value, delegate) + tcx.replace_escaping_bound_vars_uncached(value, &mut delegate) } } diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 38ff9343537..f5a1edf6d81 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -11,7 +11,7 @@ pub fn anonymize_predicate<'tcx>( tcx: TyCtxt<'tcx>, pred: ty::Predicate<'tcx>, ) -> ty::Predicate<'tcx> { - let new = tcx.anonymize_late_bound_regions(pred.kind()); + let new = tcx.anonymize_bound_vars(pred.kind()); tcx.reuse_or_mk_predicate(pred, new) } @@ -334,7 +334,7 @@ pub fn transitive_bounds_that_define_assoc_type<'tcx>( std::iter::from_fn(move || { while let Some(trait_ref) = stack.pop() { - let anon_trait_ref = tcx.anonymize_late_bound_regions(trait_ref); + let anon_trait_ref = tcx.anonymize_bound_vars(trait_ref); if visited.insert(anon_trait_ref) { let super_predicates = tcx.super_predicates_that_define_assoc_type(( trait_ref.def_id(), diff --git a/compiler/rustc_middle/src/ty/erase_regions.rs b/compiler/rustc_middle/src/ty/erase_regions.rs index f39fa363a16..3226950e79e 100644 --- a/compiler/rustc_middle/src/ty/erase_regions.rs +++ b/compiler/rustc_middle/src/ty/erase_regions.rs @@ -49,7 +49,7 @@ impl<'tcx> TypeFolder<'tcx> for RegionEraserVisitor<'tcx> { where T: TypeFoldable<'tcx>, { - let u = self.tcx.anonymize_late_bound_regions(t); + let u = self.tcx.anonymize_bound_vars(t); u.super_fold_with(self) } diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs index 273604fc221..a873465922f 100644 --- a/compiler/rustc_middle/src/ty/fold.rs +++ b/compiler/rustc_middle/src/ty/fold.rs @@ -44,7 +44,8 @@ //! - u.fold_with(folder) //! ``` use crate::mir; -use crate::ty::{self, Binder, Ty, TyCtxt, TypeVisitable}; +use crate::ty::{self, Binder, BoundTy, Ty, TyCtxt, TypeVisitable}; +use rustc_data_structures::fx::FxIndexMap; use rustc_hir::def_id::DefId; use std::collections::BTreeMap; @@ -533,12 +534,12 @@ impl<'tcx> TyCtxt<'tcx> { pub fn replace_escaping_bound_vars_uncached>( self, value: T, - mut delegate: impl BoundVarReplacerDelegate<'tcx>, + delegate: &mut impl BoundVarReplacerDelegate<'tcx>, ) -> T { if !value.has_escaping_bound_vars() { value } else { - let mut replacer = BoundVarReplacer::new(self, &mut delegate); + let mut replacer = BoundVarReplacer::new(self, delegate); value.fold_with(&mut replacer) } } @@ -549,9 +550,9 @@ impl<'tcx> TyCtxt<'tcx> { pub fn replace_bound_vars_uncached>( self, value: Binder<'tcx, T>, - delegate: impl BoundVarReplacerDelegate<'tcx>, + mut delegate: impl BoundVarReplacerDelegate<'tcx>, ) -> T { - self.replace_escaping_bound_vars_uncached(value.skip_binder(), delegate) + self.replace_escaping_bound_vars_uncached(value.skip_binder(), &mut delegate) } /// Replaces any late-bound regions bound in `value` with @@ -579,7 +580,7 @@ impl<'tcx> TyCtxt<'tcx> { let shift_bv = |bv: ty::BoundVar| ty::BoundVar::from_usize(bv.as_usize() + bound_vars); self.replace_escaping_bound_vars_uncached( value, - FnMutDelegate { + &mut FnMutDelegate { regions: |r: ty::BoundRegion| { self.mk_region(ty::ReLateBound( ty::INNERMOST, @@ -640,6 +641,50 @@ impl<'tcx> TyCtxt<'tcx> { ); Binder::bind_with_vars(inner, bound_vars) } + + /// Anonymize all bound variables in `value`, this is mostly used to improve caching. + pub fn anonymize_bound_vars(self, value: Binder<'tcx, T>) -> Binder<'tcx, T> + where + T: TypeFoldable<'tcx>, + { + struct Anonymize<'tcx> { + tcx: TyCtxt<'tcx>, + map: FxIndexMap, + } + impl<'tcx> BoundVarReplacerDelegate<'tcx> for Anonymize<'tcx> { + fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> { + let entry = self.map.entry(br.var); + let index = entry.index(); + let var = ty::BoundVar::from_usize(index); + let kind = entry + .or_insert_with(|| ty::BoundVariableKind::Region(ty::BrAnon(index as u32))) + .expect_region(); + let br = ty::BoundRegion { var, kind }; + self.tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)) + } + fn replace_ty(&mut self, bt: ty::BoundTy) -> Ty<'tcx> { + let entry = self.map.entry(bt.var); + let index = entry.index(); + let var = ty::BoundVar::from_usize(index); + let kind = entry + .or_insert_with(|| ty::BoundVariableKind::Ty(ty::BoundTyKind::Anon)) + .expect_ty(); + self.tcx.mk_ty(ty::Bound(ty::INNERMOST, BoundTy { var, kind })) + } + fn replace_const(&mut self, bv: ty::BoundVar, ty: Ty<'tcx>) -> ty::Const<'tcx> { + let entry = self.map.entry(bv); + let index = entry.index(); + let var = ty::BoundVar::from_usize(index); + let () = entry.or_insert_with(|| ty::BoundVariableKind::Const).expect_const(); + self.tcx.mk_const(ty::ConstS { ty, kind: ty::ConstKind::Bound(ty::INNERMOST, var) }) + } + } + + let mut delegate = Anonymize { tcx: self, map: Default::default() }; + let inner = self.replace_escaping_bound_vars_uncached(value.skip_binder(), &mut delegate); + let bound_vars = self.mk_bound_variable_kinds(delegate.map.into_values()); + Binder::bind_with_vars(inner, bound_vars) + } } /////////////////////////////////////////////////////////////////////////// diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index 9f622ad6cd2..a152ba843b4 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -976,6 +976,29 @@ pub enum BoundVariableKind { Const, } +impl BoundVariableKind { + pub fn expect_region(self) -> BoundRegionKind { + match self { + BoundVariableKind::Region(lt) => lt, + _ => bug!("expected a region, but found another kind"), + } + } + + pub fn expect_ty(self) -> BoundTyKind { + match self { + BoundVariableKind::Ty(ty) => ty, + _ => bug!("expected a type, but found another kind"), + } + } + + pub fn expect_const(self) { + match self { + BoundVariableKind::Const => (), + _ => bug!("expected a const, but found another kind"), + } + } +} + /// Binder is a binder for higher-ranked lifetimes or types. It is part of the /// compiler's representation for things like `for<'a> Fn(&'a isize)` /// (which would be represented by the type `PolyTraitRef == diff --git a/compiler/rustc_typeck/src/check/dropck.rs b/compiler/rustc_typeck/src/check/dropck.rs index 72095c40807..321064ec0fc 100644 --- a/compiler/rustc_typeck/src/check/dropck.rs +++ b/compiler/rustc_typeck/src/check/dropck.rs @@ -318,8 +318,8 @@ impl<'tcx> TypeRelation<'tcx> for SimpleEqRelation<'tcx> { // Anonymizing the LBRs is necessary to solve (Issue #59497). // After we do so, it should be totally fine to skip the binders. - let anon_a = self.tcx.anonymize_late_bound_regions(a); - let anon_b = self.tcx.anonymize_late_bound_regions(b); + let anon_a = self.tcx.anonymize_bound_vars(a); + let anon_b = self.tcx.anonymize_bound_vars(b); self.relate(anon_a.skip_binder(), anon_b.skip_binder())?; Ok(a) diff --git a/src/test/ui/generic-associated-types/anonymize-bound-vars.rs b/src/test/ui/generic-associated-types/anonymize-bound-vars.rs new file mode 100644 index 00000000000..1ec9c69989a --- /dev/null +++ b/src/test/ui/generic-associated-types/anonymize-bound-vars.rs @@ -0,0 +1,14 @@ +// check-pass +// +// regression test for #98702 +#![feature(generic_associated_types)] + +trait Foo { + type Assoc; +} + +impl Foo for () { + type Assoc = [T; 2*2]; +} + +fn main() {} From 1436fa9e90a180d0985cef9fe79b556106c967ae Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 28 Jul 2022 16:55:15 +0200 Subject: [PATCH 3/3] optimize bound vars replacement :3 --- .../src/infer/canonical/substitute.rs | 4 +- compiler/rustc_middle/src/ty/fold.rs | 40 ++++++++++--------- 2 files changed, 24 insertions(+), 20 deletions(-) diff --git a/compiler/rustc_infer/src/infer/canonical/substitute.rs b/compiler/rustc_infer/src/infer/canonical/substitute.rs index 9af7c3d4b9f..34b6113427d 100644 --- a/compiler/rustc_infer/src/infer/canonical/substitute.rs +++ b/compiler/rustc_infer/src/infer/canonical/substitute.rs @@ -71,7 +71,7 @@ where if var_values.var_values.is_empty() { value } else { - let mut delegate = FnMutDelegate { + let delegate = FnMutDelegate { regions: |br: ty::BoundRegion| match var_values.var_values[br.var].unpack() { GenericArgKind::Lifetime(l) => l, r => bug!("{:?} is a region but value is {:?}", br, r), @@ -86,6 +86,6 @@ where }, }; - tcx.replace_escaping_bound_vars_uncached(value, &mut delegate) + tcx.replace_escaping_bound_vars_uncached(value, delegate) } } diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs index a873465922f..5e96e278b9c 100644 --- a/compiler/rustc_middle/src/ty/fold.rs +++ b/compiler/rustc_middle/src/ty/fold.rs @@ -400,23 +400,26 @@ where } /// Replaces the escaping bound vars (late bound regions or bound types) in a type. -struct BoundVarReplacer<'a, 'tcx> { +struct BoundVarReplacer<'tcx, D> { tcx: TyCtxt<'tcx>, /// As with `RegionFolder`, represents the index of a binder *just outside* /// the ones we have visited. current_index: ty::DebruijnIndex, - delegate: &'a mut dyn BoundVarReplacerDelegate<'tcx>, + delegate: D, } -impl<'a, 'tcx> BoundVarReplacer<'a, 'tcx> { - fn new(tcx: TyCtxt<'tcx>, delegate: &'a mut dyn BoundVarReplacerDelegate<'tcx>) -> Self { +impl<'tcx, D: BoundVarReplacerDelegate<'tcx>> BoundVarReplacer<'tcx, D> { + fn new(tcx: TyCtxt<'tcx>, delegate: D) -> Self { BoundVarReplacer { tcx, current_index: ty::INNERMOST, delegate } } } -impl<'a, 'tcx> TypeFolder<'tcx> for BoundVarReplacer<'a, 'tcx> { +impl<'tcx, D> TypeFolder<'tcx> for BoundVarReplacer<'tcx, D> +where + D: BoundVarReplacerDelegate<'tcx>, +{ fn tcx<'b>(&'b self) -> TyCtxt<'tcx> { self.tcx } @@ -452,7 +455,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for BoundVarReplacer<'a, 'tcx> { // debruijn index. Then we adjust it to the // correct depth. assert_eq!(debruijn1, ty::INNERMOST); - self.tcx.mk_region(ty::ReLateBound(debruijn, br)) + self.tcx.reuse_or_mk_region(region, ty::ReLateBound(debruijn, br)) } else { region } @@ -518,12 +521,12 @@ impl<'tcx> TyCtxt<'tcx> { if !value.has_escaping_bound_vars() { value } else { - let mut delegate = FnMutDelegate { + let delegate = FnMutDelegate { regions: replace_regions, types: |b| bug!("unexpected bound ty in binder: {b:?}"), consts: |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"), }; - let mut replacer = BoundVarReplacer::new(self, &mut delegate); + let mut replacer = BoundVarReplacer::new(self, delegate); value.fold_with(&mut replacer) } } @@ -534,7 +537,7 @@ impl<'tcx> TyCtxt<'tcx> { pub fn replace_escaping_bound_vars_uncached>( self, value: T, - delegate: &mut impl BoundVarReplacerDelegate<'tcx>, + delegate: impl BoundVarReplacerDelegate<'tcx>, ) -> T { if !value.has_escaping_bound_vars() { value @@ -550,9 +553,9 @@ impl<'tcx> TyCtxt<'tcx> { pub fn replace_bound_vars_uncached>( self, value: Binder<'tcx, T>, - mut delegate: impl BoundVarReplacerDelegate<'tcx>, + delegate: impl BoundVarReplacerDelegate<'tcx>, ) -> T { - self.replace_escaping_bound_vars_uncached(value.skip_binder(), &mut delegate) + self.replace_escaping_bound_vars_uncached(value.skip_binder(), delegate) } /// Replaces any late-bound regions bound in `value` with @@ -580,7 +583,7 @@ impl<'tcx> TyCtxt<'tcx> { let shift_bv = |bv: ty::BoundVar| ty::BoundVar::from_usize(bv.as_usize() + bound_vars); self.replace_escaping_bound_vars_uncached( value, - &mut FnMutDelegate { + FnMutDelegate { regions: |r: ty::BoundRegion| { self.mk_region(ty::ReLateBound( ty::INNERMOST, @@ -647,11 +650,11 @@ impl<'tcx> TyCtxt<'tcx> { where T: TypeFoldable<'tcx>, { - struct Anonymize<'tcx> { + struct Anonymize<'a, 'tcx> { tcx: TyCtxt<'tcx>, - map: FxIndexMap, + map: &'a mut FxIndexMap, } - impl<'tcx> BoundVarReplacerDelegate<'tcx> for Anonymize<'tcx> { + impl<'tcx> BoundVarReplacerDelegate<'tcx> for Anonymize<'_, 'tcx> { fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> { let entry = self.map.entry(br.var); let index = entry.index(); @@ -680,9 +683,10 @@ impl<'tcx> TyCtxt<'tcx> { } } - let mut delegate = Anonymize { tcx: self, map: Default::default() }; - let inner = self.replace_escaping_bound_vars_uncached(value.skip_binder(), &mut delegate); - let bound_vars = self.mk_bound_variable_kinds(delegate.map.into_values()); + let mut map = Default::default(); + let delegate = Anonymize { tcx: self, map: &mut map }; + let inner = self.replace_escaping_bound_vars_uncached(value.skip_binder(), delegate); + let bound_vars = self.mk_bound_variable_kinds(map.into_values()); Binder::bind_with_vars(inner, bound_vars) } }