diff options
| -rw-r--r-- | compiler/rustc_middle/src/ty/fold.rs | 47 |
1 files changed, 24 insertions, 23 deletions
diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs index 2842b3c3102..d431d008ddf 100644 --- a/compiler/rustc_middle/src/ty/fold.rs +++ b/compiler/rustc_middle/src/ty/fold.rs @@ -407,6 +407,7 @@ where match *t.kind() { ty::Bound(debruijn, bound_ty) if debruijn == self.current_index => { let ty = self.delegate.replace_ty(bound_ty); + debug_assert!(!ty.has_vars_bound_above(ty::INNERMOST)); 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), @@ -437,6 +438,7 @@ where match ct.kind() { ty::ConstKind::Bound(debruijn, bound_const) if debruijn == self.current_index => { let ct = self.delegate.replace_const(bound_const, ct.ty()); + debug_assert!(!ct.has_vars_bound_above(ty::INNERMOST)); ty::fold::shift_vars(self.tcx, ct, self.current_index.as_u32()) } _ => ct.super_fold_with(self), @@ -697,14 +699,10 @@ impl<'tcx> TypeFolder<'tcx> for Shifter<'tcx> { fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { match *r { - ty::ReLateBound(debruijn, br) => { - if self.amount == 0 || debruijn < self.current_index { - r - } else { - let debruijn = debruijn.shifted_in(self.amount); - let shifted = ty::ReLateBound(debruijn, br); - self.tcx.mk_region(shifted) - } + ty::ReLateBound(debruijn, br) if debruijn >= self.current_index => { + let debruijn = debruijn.shifted_in(self.amount); + let shifted = ty::ReLateBound(debruijn, br); + self.tcx.mk_region(shifted) } _ => r, } @@ -712,31 +710,30 @@ impl<'tcx> TypeFolder<'tcx> for Shifter<'tcx> { fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { match *ty.kind() { - ty::Bound(debruijn, bound_ty) => { - if self.amount == 0 || debruijn < self.current_index { - ty - } else { - let debruijn = debruijn.shifted_in(self.amount); - self.tcx.mk_ty(ty::Bound(debruijn, bound_ty)) - } + ty::Bound(debruijn, bound_ty) if debruijn >= self.current_index => { + let debruijn = debruijn.shifted_in(self.amount); + self.tcx.mk_ty(ty::Bound(debruijn, bound_ty)) } - _ => ty.super_fold_with(self), + _ if ty.has_vars_bound_at_or_above(self.current_index) => ty.super_fold_with(self), + _ => ty, } } fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> { - if let ty::ConstKind::Bound(debruijn, bound_ct) = ct.kind() { - if self.amount == 0 || debruijn < self.current_index { - ct - } else { - let debruijn = debruijn.shifted_in(self.amount); - self.tcx.mk_const(ty::ConstKind::Bound(debruijn, bound_ct), ct.ty()) - } + if let ty::ConstKind::Bound(debruijn, bound_ct) = ct.kind() + && debruijn >= self.current_index + { + let debruijn = debruijn.shifted_in(self.amount); + self.tcx.mk_const(ty::ConstKind::Bound(debruijn, bound_ct), ct.ty()) } else { 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 } + } } pub fn shift_region<'tcx>( @@ -758,5 +755,9 @@ where { debug!("shift_vars(value={:?}, amount={})", value, amount); + if amount == 0 || !value.has_escaping_bound_vars() { + return value; + } + value.fold_with(&mut Shifter::new(tcx, amount)) } |