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Use TypeVisitor::BreakTy in HasEscapingVarsVisitor

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This commit is contained in:
LeSeulArtichaut 2020-11-05 19:39:48 +01:00
parent 29b140a1c3
commit 44f7d8fcf6
1 changed files with 11 additions and 4 deletions
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15
compiler/rustc_middle/src/ty/fold.rs
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@ -818,6 +818,9 @@ where
value.fold_with(&mut Shifter::new(tcx, amount))
}
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
struct FoundEscapingVars;
/// An "escaping var" is a bound var whose binder is not part of `t`. A bound var can be a
/// bound region or a bound type.
///
@ -849,6 +852,8 @@ struct HasEscapingVarsVisitor {
}
impl<'tcx> TypeVisitor<'tcx> for HasEscapingVarsVisitor {
type BreakTy = FoundEscapingVars;
fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> ControlFlow<Self::BreakTy> {
self.outer_index.shift_in(1);
let result = t.super_visit_with(self);
@ -863,7 +868,7 @@ impl<'tcx> TypeVisitor<'tcx> for HasEscapingVarsVisitor {
// `outer_exclusive_binder` is always 1 higher than the
// content in `t`). Therefore, `t` has some escaping vars.
if t.outer_exclusive_binder > self.outer_index {
ControlFlow::BREAK
ControlFlow::Break(FoundEscapingVars)
} else {
ControlFlow::CONTINUE
}
@ -874,7 +879,7 @@ impl<'tcx> TypeVisitor<'tcx> for HasEscapingVarsVisitor {
// of outer index, then it escapes the binders we have
// visited.
if r.bound_at_or_above_binder(self.outer_index) {
ControlFlow::BREAK
ControlFlow::Break(FoundEscapingVars)
} else {
ControlFlow::CONTINUE
}
@ -887,14 +892,16 @@ impl<'tcx> TypeVisitor<'tcx> for HasEscapingVarsVisitor {
// const, as it has types/regions embedded in a lot of other
// places.
match ct.val {
ty::ConstKind::Bound(debruijn, _) if debruijn >= self.outer_index => ControlFlow::BREAK,
ty::ConstKind::Bound(debruijn, _) if debruijn >= self.outer_index => {
ControlFlow::Break(FoundEscapingVars)
}
_ => ct.super_visit_with(self),
}
}
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<Self::BreakTy> {
if predicate.inner.outer_exclusive_binder > self.outer_index {
ControlFlow::BREAK
ControlFlow::Break(FoundEscapingVars)
} else {
ControlFlow::CONTINUE
}