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Remove failed and review comments
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@jackh726
jackh726 committed Jul 15, 2021
1 parent 09978bd commit cf001dc
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Showing 2 changed files with 69 additions and 99 deletions.
142 changes: 56 additions & 86 deletions compiler/rustc_trait_selection/src/traits/project.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -315,9 +315,11 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> {
fn fold<T: TypeFoldable<'tcx>>(&mut self, value: T) -> T {
let value = self.selcx.infcx().resolve_vars_if_possible(value);

if value.has_escaping_bound_vars() {
bug!("Normalizing without wrapping in a `Binder`");
}
assert!(
!value.has_escaping_bound_vars(),
"Normalizing {:?} without wrapping in a `Binder`",
value
);

if !value.has_projections() { value } else { value.fold_with(self) }
}
Expand Down Expand Up @@ -427,40 +429,36 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
// give up and fall back to pretending like we never tried!

let infcx = self.selcx.infcx();
let replaced =
let (data, mapped_regions, mapped_types, mapped_consts) =
BoundVarReplacer::replace_bound_vars(infcx, &mut self.universes, data);
if let Some((data, mapped_regions, mapped_types, mapped_consts)) = replaced {
let normalized_ty = opt_normalize_projection_type(
self.selcx,
self.param_env,
data,
self.cause.clone(),
self.depth,
&mut self.obligations,
)
.ok()
.flatten()
.unwrap_or_else(|| ty);

let normalized_ty = PlaceholderReplacer::replace_placeholders(
infcx,
mapped_regions,
mapped_types,
mapped_consts,
&self.universes,
normalized_ty,
);
debug!(
?self.depth,
?ty,
?normalized_ty,
obligations.len = ?self.obligations.len(),
"AssocTypeNormalizer: normalized type"
);
normalized_ty
} else {
ty
}
let normalized_ty = opt_normalize_projection_type(
self.selcx,
self.param_env,
data,
self.cause.clone(),
self.depth,
&mut self.obligations,
)
.ok()
.flatten()
.unwrap_or_else(|| ty);

let normalized_ty = PlaceholderReplacer::replace_placeholders(
infcx,
mapped_regions,
mapped_types,
mapped_consts,
&self.universes,
normalized_ty,
);
debug!(
?self.depth,
?ty,
?normalized_ty,
obligations.len = ?self.obligations.len(),
"AssocTypeNormalizer: normalized type"
);
normalized_ty
}

_ => ty,
Expand Down Expand Up @@ -491,14 +489,6 @@ pub struct BoundVarReplacer<'me, 'tcx> {
// 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: &'me mut Vec<Option<ty::UniverseIndex>>,
// FIXME: So, this is a less-than-ideal solution to a problem we want to solve eventually. Ideally, we
// shouldn't need to worry about bound vars for which we haven't passed (`self.current_index`)
// or that we don't explicitly know about (`self.universe_indices`). This is true for
// `AssocTypeNormalizer` but not `QueryNormalizer` currently. When we can always know about
// any binding levels above us, we can remove this. (The alternative would be
// `outer_exclusive_binder`, but that only exists on `Ty`. Otherwise, we would have to visit
// through the `T`, which we specifically want to avoid not being lazy.)
failed: bool,
}

impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> {
Expand All @@ -508,12 +498,12 @@ impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> {
infcx: &'me InferCtxt<'me, 'tcx>,
universe_indices: &'me mut Vec<Option<ty::UniverseIndex>>,
value: T,
) -> Option<(
) -> (
T,
BTreeMap<ty::PlaceholderRegion, ty::BoundRegion>,
BTreeMap<ty::PlaceholderType, ty::BoundTy>,
BTreeMap<ty::PlaceholderConst<'tcx>, ty::BoundVar>,
)> {
) {
let mapped_regions: BTreeMap<ty::PlaceholderRegion, ty::BoundRegion> = BTreeMap::new();
let mapped_types: BTreeMap<ty::PlaceholderType, ty::BoundTy> = BTreeMap::new();
let mapped_consts: BTreeMap<ty::PlaceholderConst<'tcx>, ty::BoundVar> = BTreeMap::new();
Expand All @@ -525,14 +515,24 @@ impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> {
mapped_consts,
current_index: ty::INNERMOST,
universe_indices,
failed: false,
};

let value = value.super_fold_with(&mut replacer);

(!replacer.failed).then(|| {
(value, replacer.mapped_regions, replacer.mapped_types, replacer.mapped_consts)
})
(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() - debruijn.as_usize() + self.current_index.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
}
}

Expand All @@ -557,20 +557,10 @@ impl TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> {
if debruijn.as_usize() + 1
> self.current_index.as_usize() + self.universe_indices.len() =>
{
self.failed = true;
r
bug!("Bound vars outside of `self.universe_indices`");
}
ty::ReLateBound(debruijn, br) if debruijn >= self.current_index => {
let infcx = self.infcx;
let index = self.universe_indices.len() - debruijn.as_usize()
+ self.current_index.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()
});
let universe = self.universe_for(debruijn);
let p = ty::PlaceholderRegion { universe, name: br.kind };
self.mapped_regions.insert(p.clone(), br);
self.infcx.tcx.mk_region(ty::RePlaceholder(p))
Expand All @@ -585,20 +575,10 @@ impl TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> {
if debruijn.as_usize() + 1
> self.current_index.as_usize() + self.universe_indices.len() =>
{
self.failed = true;
t
bug!("Bound vars outside of `self.universe_indices`");
}
ty::Bound(debruijn, bound_ty) if debruijn >= self.current_index => {
let infcx = self.infcx;
let index = self.universe_indices.len() - debruijn.as_usize()
+ self.current_index.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()
});
let universe = self.universe_for(debruijn);
let p = ty::PlaceholderType { universe, name: bound_ty.var };
self.mapped_types.insert(p.clone(), bound_ty);
self.infcx.tcx.mk_ty(ty::Placeholder(p))
Expand All @@ -614,22 +594,12 @@ impl TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> {
if debruijn.as_usize() + 1
> self.current_index.as_usize() + self.universe_indices.len() =>
{
self.failed = true;
ct
bug!("Bound vars outside of `self.universe_indices`");
}
ty::Const { val: ty::ConstKind::Bound(debruijn, bound_const), ty }
if debruijn >= self.current_index =>
{
let infcx = self.infcx;
let index = self.universe_indices.len() - debruijn.as_usize()
+ self.current_index.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()
});
let universe = self.universe_for(debruijn);
let p = ty::PlaceholderConst {
universe,
name: ty::BoundConst { var: bound_const, ty },
Expand Down
26 changes: 13 additions & 13 deletions compiler/rustc_trait_selection/src/traits/query/normalize.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -226,21 +226,21 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
// to return `ty` because there are bound vars that we aren't yet handling in a more
// complete way.

// `BoundVarReplacer` can't handle escaping bound vars. Ideally, we want this before even calling
// `QueryNormalizer`, but some const-generics tests pass escaping bound vars.
// Also, use `ty` so we get that sweet `outer_exclusive_binder` optimization
assert!(!ty.has_vars_bound_at_or_above(ty::DebruijnIndex::from_usize(
self.universes.len()
)));

let tcx = self.infcx.tcx;
let infcx = self.infcx;
let replaced = crate::traits::project::BoundVarReplacer::replace_bound_vars(
infcx,
&mut self.universes,
data,
);
let (data, mapped_regions, mapped_types, mapped_consts) = match replaced {
Some(r) => r,
None => {
bug!("{:?} {:?}", data, self.universes);
//self.error = true;
//return ty.super_fold_with(self);
}
};
let (data, mapped_regions, mapped_types, mapped_consts) =
crate::traits::project::BoundVarReplacer::replace_bound_vars(
infcx,
&mut self.universes,
data,
);
let data = data.super_fold_with(self);

let mut orig_values = OriginalQueryValues::default();
Expand Down

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