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Fix handling of binders in canonicalization

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I'm looking forward to getting rid of this in favor of Chalk's implementation.
This commit is contained in:
Florian Diebold 2020-02-21 21:46:21 +01:00
parent 0dfbbaf03b
commit f126808b2e
1 changed files with 35 additions and 64 deletions
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99
crates/ra_hir_ty/src/infer/unify.rs
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@ -7,10 +7,7 @@ use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
use test_utils::tested_by;
use super::{InferenceContext, Obligation};
use crate::{
db::HirDatabase, utils::make_mut_slice, Canonical, InEnvironment, InferTy, ProjectionPredicate,
ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
};
use crate::{db::HirDatabase, Canonical, InEnvironment, InferTy, Substs, Ty, TypeCtor, TypeWalk};
impl<'a, D: HirDatabase> InferenceContext<'a, D> {
pub(super) fn canonicalizer<'b>(&'b mut self) -> Canonicalizer<'a, 'b, D>
@ -50,42 +47,38 @@ where
})
}
fn do_canonicalize_ty(&mut self, ty: Ty) -> Ty {
ty.fold(&mut |ty| match ty {
Ty::Infer(tv) => {
let inner = tv.to_inner();
if self.var_stack.contains(&inner) {
// recursive type
return tv.fallback_value();
fn do_canonicalize<T: TypeWalk>(&mut self, t: T, binders: usize) -> T {
t.fold_binders(
&mut |ty, binders| match ty {
Ty::Infer(tv) => {
let inner = tv.to_inner();
if self.var_stack.contains(&inner) {
// recursive type
return tv.fallback_value();
}
if let Some(known_ty) =
self.ctx.table.var_unification_table.inlined_probe_value(inner).known()
{
self.var_stack.push(inner);
let result = self.do_canonicalize(known_ty.clone(), binders);
self.var_stack.pop();
result
} else {
let root = self.ctx.table.var_unification_table.find(inner);
let free_var = match tv {
InferTy::TypeVar(_) => InferTy::TypeVar(root),
InferTy::IntVar(_) => InferTy::IntVar(root),
InferTy::FloatVar(_) => InferTy::FloatVar(root),
InferTy::MaybeNeverTypeVar(_) => InferTy::MaybeNeverTypeVar(root),
};
let position = self.add(free_var);
Ty::Bound((position + binders) as u32)
}
}
if let Some(known_ty) =
self.ctx.table.var_unification_table.inlined_probe_value(inner).known()
{
self.var_stack.push(inner);
let result = self.do_canonicalize_ty(known_ty.clone());
self.var_stack.pop();
result
} else {
let root = self.ctx.table.var_unification_table.find(inner);
let free_var = match tv {
InferTy::TypeVar(_) => InferTy::TypeVar(root),
InferTy::IntVar(_) => InferTy::IntVar(root),
InferTy::FloatVar(_) => InferTy::FloatVar(root),
InferTy::MaybeNeverTypeVar(_) => InferTy::MaybeNeverTypeVar(root),
};
let position = self.add(free_var);
Ty::Bound(position as u32)
}
}
_ => ty,
})
}
fn do_canonicalize_trait_ref(&mut self, mut trait_ref: TraitRef) -> TraitRef {
for ty in make_mut_slice(&mut trait_ref.substs.0) {
*ty = self.do_canonicalize_ty(ty.clone());
}
trait_ref
_ => ty,
},
binders,
)
}
fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
@ -95,28 +88,8 @@ where
}
}
fn do_canonicalize_projection_ty(&mut self, mut projection_ty: ProjectionTy) -> ProjectionTy {
for ty in make_mut_slice(&mut projection_ty.parameters.0) {
*ty = self.do_canonicalize_ty(ty.clone());
}
projection_ty
}
fn do_canonicalize_projection_predicate(
&mut self,
projection: ProjectionPredicate,
) -> ProjectionPredicate {
let ty = self.do_canonicalize_ty(projection.ty);
let projection_ty = self.do_canonicalize_projection_ty(projection.projection_ty);
ProjectionPredicate { ty, projection_ty }
}
// FIXME: add some point, we need to introduce a `Fold` trait that abstracts
// over all the things that can be canonicalized (like Chalk and rustc have)
pub(crate) fn canonicalize_ty(mut self, ty: Ty) -> Canonicalized<Ty> {
let result = self.do_canonicalize_ty(ty);
let result = self.do_canonicalize(ty, 0);
self.into_canonicalized(result)
}
@ -125,10 +98,8 @@ where
obligation: InEnvironment<Obligation>,
) -> Canonicalized<InEnvironment<Obligation>> {
let result = match obligation.value {
Obligation::Trait(tr) => Obligation::Trait(self.do_canonicalize_trait_ref(tr)),
Obligation::Projection(pr) => {
Obligation::Projection(self.do_canonicalize_projection_predicate(pr))
}
Obligation::Trait(tr) => Obligation::Trait(self.do_canonicalize(tr, 0)),
Obligation::Projection(pr) => Obligation::Projection(self.do_canonicalize(pr, 0)),
};
self.into_canonicalized(InEnvironment {
value: result,