diff options
| -rw-r--r-- | src/librustc_mir/borrow_check/nll/type_check/relate_tys.rs | 101 |
1 files changed, 42 insertions, 59 deletions
diff --git a/src/librustc_mir/borrow_check/nll/type_check/relate_tys.rs b/src/librustc_mir/borrow_check/nll/type_check/relate_tys.rs index 130b4b31d08..d919c5c02c6 100644 --- a/src/librustc_mir/borrow_check/nll/type_check/relate_tys.rs +++ b/src/librustc_mir/borrow_check/nll/type_check/relate_tys.rs @@ -10,15 +10,13 @@ use borrow_check::nll::constraints::{ConstraintCategory, OutlivesConstraint}; use borrow_check::nll::type_check::{BorrowCheckContext, Locations}; -use borrow_check::nll::universal_regions::UniversalRegions; -use borrow_check::nll::ToRegionVid; use rustc::infer::canonical::{Canonical, CanonicalVarInfos}; use rustc::infer::{InferCtxt, NLLRegionVariableOrigin}; use rustc::traits::query::Fallible; use rustc::ty::fold::{TypeFoldable, TypeVisitor}; use rustc::ty::relate::{self, Relate, RelateResult, TypeRelation}; use rustc::ty::subst::Kind; -use rustc::ty::{self, CanonicalTy, CanonicalVar, RegionVid, Ty, TyCtxt}; +use rustc::ty::{self, CanonicalTy, CanonicalVar, Ty, TyCtxt}; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::indexed_vec::IndexVec; @@ -122,10 +120,10 @@ struct TypeRelating<'cx, 'bccx: 'cx, 'gcx: 'tcx, 'tcx: 'bccx> { /// /// This field stores the instantiations for late-bound regions in /// the `a` type. - a_scopes: Vec<BoundRegionScope>, + a_scopes: Vec<BoundRegionScope<'tcx>>, /// Same as `a_scopes`, but for the `b` type. - b_scopes: Vec<BoundRegionScope>, + b_scopes: Vec<BoundRegionScope<'tcx>>, /// Where (and why) is this relation taking place? locations: Locations, @@ -152,13 +150,13 @@ struct TypeRelating<'cx, 'bccx: 'cx, 'gcx: 'tcx, 'tcx: 'bccx> { #[derive(Clone, Debug)] struct ScopesAndKind<'tcx> { - scopes: Vec<BoundRegionScope>, + scopes: Vec<BoundRegionScope<'tcx>>, kind: Kind<'tcx>, } #[derive(Clone, Debug, Default)] -struct BoundRegionScope { - map: FxHashMap<ty::BoundRegion, RegionVid>, +struct BoundRegionScope<'tcx> { + map: FxHashMap<ty::BoundRegion, ty::Region<'tcx>>, } #[derive(Copy, Clone)] @@ -204,7 +202,7 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelating<'cx, 'bccx, 'gcx, 'tcx> { &mut self, value: &ty::Binder<impl TypeFoldable<'tcx>>, universally_quantified: UniversallyQuantified, - ) -> BoundRegionScope { + ) -> BoundRegionScope<'tcx> { let mut scope = BoundRegionScope::default(); value.skip_binder().visit_with(&mut ScopeInstantiator { infcx: self.infcx, @@ -227,8 +225,8 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelating<'cx, 'bccx, 'gcx, 'tcx> { debruijn: ty::DebruijnIndex, br: &ty::BoundRegion, first_free_index: ty::DebruijnIndex, - scopes: &[BoundRegionScope], - ) -> RegionVid { + scopes: &[BoundRegionScope<'tcx>], + ) -> ty::Region<'tcx> { // The debruijn index is a "reverse index" into the // scopes listing. So when we have INNERMOST (0), we // want the *last* scope pushed, and so forth. @@ -245,28 +243,25 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelating<'cx, 'bccx, 'gcx, 'tcx> { /// with. Otherwise just return `r`. fn replace_bound_region( &self, - universal_regions: &UniversalRegions<'tcx>, r: ty::Region<'tcx>, first_free_index: ty::DebruijnIndex, - scopes: &[BoundRegionScope], - ) -> RegionVid { - match r { - ty::ReLateBound(debruijn, br) => { - Self::lookup_bound_region(*debruijn, br, first_free_index, scopes) - } - - ty::ReVar(v) => *v, - - _ => universal_regions.to_region_vid(r), + scopes: &[BoundRegionScope<'tcx>], + ) -> ty::Region<'tcx> { + if let ty::ReLateBound(debruijn, br) = r { + Self::lookup_bound_region(*debruijn, br, first_free_index, scopes) + } else { + r } } /// Push a new outlives requirement into our output set of /// constraints. - fn push_outlives(&mut self, sup: RegionVid, sub: RegionVid) { + fn push_outlives(&mut self, sup: ty::Region<'tcx>, sub: ty::Region<'tcx>) { debug!("push_outlives({:?}: {:?})", sup, sub); if let Some(borrowck_context) = &mut self.borrowck_context { + let sub = borrowck_context.universal_regions.to_region_vid(sub); + let sup = borrowck_context.universal_regions.to_region_vid(sup); borrowck_context .constraints .outlives_constraints @@ -316,10 +311,7 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelating<'cx, 'bccx, 'gcx, 'tcx> { return result; } - fn generalize_value( - &self, - kind: Kind<'tcx>, - ) -> Kind<'tcx> { + fn generalize_value(&self, kind: Kind<'tcx>) -> Kind<'tcx> { TypeGeneralizer { type_rel: self, first_free_index: ty::INNERMOST, @@ -397,37 +389,30 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelation<'cx, 'gcx, 'tcx> a: ty::Region<'tcx>, b: ty::Region<'tcx>, ) -> RelateResult<'tcx, ty::Region<'tcx>> { - if let Some(&mut BorrowCheckContext { - universal_regions, .. - }) = self.borrowck_context - { - if let ty::ReCanonical(var) = a { - self.relate_var(*var, b.into())?; - return Ok(a); - } + if let ty::ReCanonical(var) = a { + self.relate_var(*var, b.into())?; + return Ok(a); + } - debug!( - "regions(a={:?}, b={:?}, variance={:?})", - a, b, self.ambient_variance - ); + debug!( + "regions(a={:?}, b={:?}, variance={:?})", + a, b, self.ambient_variance + ); - let v_a = - self.replace_bound_region(universal_regions, a, ty::INNERMOST, &self.a_scopes); - let v_b = - self.replace_bound_region(universal_regions, b, ty::INNERMOST, &self.b_scopes); + let v_a = self.replace_bound_region(a, ty::INNERMOST, &self.a_scopes); + let v_b = self.replace_bound_region(b, ty::INNERMOST, &self.b_scopes); - debug!("regions: v_a = {:?}", v_a); - debug!("regions: v_b = {:?}", v_b); + debug!("regions: v_a = {:?}", v_a); + debug!("regions: v_b = {:?}", v_b); - if self.ambient_covariance() { - // Covariance: a <= b. Hence, `b: a`. - self.push_outlives(v_b, v_a); - } + if self.ambient_covariance() { + // Covariance: a <= b. Hence, `b: a`. + self.push_outlives(v_b, v_a); + } - if self.ambient_contravariance() { - // Contravariant: b <= a. Hence, `a: b`. - self.push_outlives(v_a, v_b); - } + if self.ambient_contravariance() { + // Contravariant: b <= a. Hence, `a: b`. + self.push_outlives(v_a, v_b); } Ok(a) @@ -527,10 +512,8 @@ impl<'cx, 'bccx, 'gcx, 'tcx> TypeRelation<'cx, 'gcx, 'tcx> // Reset ambient variance to contravariance. See the // covariant case above for an explanation. - let variance = ::std::mem::replace( - &mut self.ambient_variance, - ty::Variance::Contravariant, - ); + let variance = + ::std::mem::replace(&mut self.ambient_variance, ty::Variance::Contravariant); self.relate(a.skip_binder(), b.skip_binder())?; @@ -556,7 +539,7 @@ struct ScopeInstantiator<'cx, 'gcx: 'tcx, 'tcx: 'cx> { // The debruijn index of the scope we are instantiating. target_index: ty::DebruijnIndex, universally_quantified: UniversallyQuantified, - bound_region_scope: &'cx mut BoundRegionScope, + bound_region_scope: &'cx mut BoundRegionScope<'tcx>, } impl<'cx, 'gcx, 'tcx> TypeVisitor<'tcx> for ScopeInstantiator<'cx, 'gcx, 'tcx> { @@ -583,7 +566,7 @@ impl<'cx, 'gcx, 'tcx> TypeVisitor<'tcx> for ScopeInstantiator<'cx, 'gcx, 'tcx> { } else { NLLRegionVariableOrigin::Existential }; - infcx.next_nll_region_var(origin).to_region_vid() + infcx.next_nll_region_var(origin) }); } |