From d5d485ef9289589332893f2c0ad96cb366afe9d6 Mon Sep 17 00:00:00 2001
From: Florian Diebold <florian.diebold@freiheit.com>
Date: Sun, 28 Jun 2020 21:17:27 +0200
Subject: Implement Chalk variable kinds
This means we need to keep track of the kinds (general/int/float) of variables
in `Canonical`, which requires some more ceremony. (It also exposes some places
where we're not really dealing with canonicalization correctly -- another thing
to be cleaned up when we switch to using Chalk's types directly.)
Should fix the last remaining issue of #2534.
---
crates/ra_hir_ty/src/autoderef.rs | 15 ++++----
crates/ra_hir_ty/src/infer/unify.rs | 55 ++++++++++++++++++++--------
crates/ra_hir_ty/src/lib.rs | 22 +++++++++--
crates/ra_hir_ty/src/method_resolution.rs | 32 ++++++++--------
crates/ra_hir_ty/src/tests/traits.rs | 18 +++++++++
crates/ra_hir_ty/src/traits.rs | 16 ++------
crates/ra_hir_ty/src/traits/chalk/mapping.rs | 43 +++++++++++++++-------
7 files changed, 135 insertions(+), 66 deletions(-)
(limited to 'crates/ra_hir_ty/src')
diff --git a/crates/ra_hir_ty/src/autoderef.rs b/crates/ra_hir_ty/src/autoderef.rs
index 1b0f84c5c..c727012c6 100644
--- a/crates/ra_hir_ty/src/autoderef.rs
+++ b/crates/ra_hir_ty/src/autoderef.rs
@@ -37,7 +37,7 @@ pub(crate) fn deref(
ty: InEnvironment<&Canonical<Ty>>,
) -> Option<Canonical<Ty>> {
if let Some(derefed) = ty.value.value.builtin_deref() {
- Some(Canonical { value: derefed, num_vars: ty.value.num_vars })
+ Some(Canonical { value: derefed, kinds: ty.value.kinds.clone() })
} else {
deref_by_trait(db, krate, ty)
}
@@ -68,8 +68,8 @@ fn deref_by_trait(
// Check that the type implements Deref at all
let trait_ref = TraitRef { trait_: deref_trait, substs: parameters.clone() };
- let implements_goal = super::Canonical {
- num_vars: ty.value.num_vars,
+ let implements_goal = Canonical {
+ kinds: ty.value.kinds.clone(),
value: InEnvironment {
value: Obligation::Trait(trait_ref),
environment: ty.environment.clone(),
@@ -81,7 +81,7 @@ fn deref_by_trait(
// Now do the assoc type projection
let projection = super::traits::ProjectionPredicate {
- ty: Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.num_vars)),
+ ty: Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.kinds.len())),
projection_ty: super::ProjectionTy { associated_ty: target, parameters },
};
@@ -89,7 +89,8 @@ fn deref_by_trait(
let in_env = InEnvironment { value: obligation, environment: ty.environment };
- let canonical = super::Canonical { num_vars: 1 + ty.value.num_vars, value: in_env };
+ let canonical =
+ Canonical::new(in_env, ty.value.kinds.iter().copied().chain(Some(super::TyKind::General)));
let solution = db.trait_solve(krate, canonical)?;
@@ -110,7 +111,7 @@ fn deref_by_trait(
// assumptions will be broken. We would need to properly introduce
// new variables in that case
- for i in 1..vars.0.num_vars {
+ for i in 1..vars.0.kinds.len() {
if vars.0.value[i - 1] != Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, i - 1))
{
warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.value, solution);
@@ -119,7 +120,7 @@ fn deref_by_trait(
}
Some(Canonical {
value: vars.0.value[vars.0.value.len() - 1].clone(),
- num_vars: vars.0.num_vars,
+ kinds: vars.0.kinds.clone(),
})
}
Solution::Ambig(_) => {
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index 269495ca0..2e895d911 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -9,7 +9,7 @@ use test_utils::mark;
use super::{InferenceContext, Obligation};
use crate::{
BoundVar, Canonical, DebruijnIndex, GenericPredicate, InEnvironment, InferTy, Substs, Ty,
- TypeCtor, TypeWalk,
+ TyKind, TypeCtor, TypeWalk,
};
impl<'a> InferenceContext<'a> {
@@ -86,10 +86,20 @@ where
}
fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
- Canonicalized {
- value: Canonical { value: result, num_vars: self.free_vars.len() },
- free_vars: self.free_vars,
- }
+ let kinds = self
+ .free_vars
+ .iter()
+ .map(|v| match v {
+ // mapping MaybeNeverTypeVar to the same kind as general ones
+ // should be fine, because as opposed to int or float type vars,
+ // they don't restrict what kind of type can go into them, they
+ // just affect fallback.
+ InferTy::TypeVar(_) | InferTy::MaybeNeverTypeVar(_) => TyKind::General,
+ InferTy::IntVar(_) => TyKind::Integer,
+ InferTy::FloatVar(_) => TyKind::Float,
+ })
+ .collect();
+ Canonicalized { value: Canonical { value: result, kinds }, free_vars: self.free_vars }
}
pub(crate) fn canonicalize_ty(mut self, ty: Ty) -> Canonicalized<Ty> {
@@ -131,26 +141,41 @@ impl<T> Canonicalized<T> {
ty
}
- pub fn apply_solution(&self, ctx: &mut InferenceContext<'_>, solution: Canonical<Vec<Ty>>) {
+ pub fn apply_solution(&self, ctx: &mut InferenceContext<'_>, solution: Canonical<Substs>) {
// the solution may contain new variables, which we need to convert to new inference vars
- let new_vars = Substs((0..solution.num_vars).map(|_| ctx.table.new_type_var()).collect());
+ let new_vars = Substs(
+ solution
+ .kinds
+ .iter()
+ .map(|k| match k {
+ TyKind::General => ctx.table.new_type_var(),
+ TyKind::Integer => ctx.table.new_integer_var(),
+ TyKind::Float => ctx.table.new_float_var(),
+ })
+ .collect(),
+ );
for (i, ty) in solution.value.into_iter().enumerate() {
let var = self.free_vars[i];
// eagerly replace projections in the type; we may be getting types
// e.g. from where clauses where this hasn't happened yet
- let ty = ctx.normalize_associated_types_in(ty.subst_bound_vars(&new_vars));
+ let ty = ctx.normalize_associated_types_in(ty.clone().subst_bound_vars(&new_vars));
ctx.table.unify(&Ty::Infer(var), &ty);
}
}
}
-pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
+pub fn unify(tys: &Canonical<(Ty, Ty)>) -> Option<Substs> {
let mut table = InferenceTable::new();
- let num_vars = ty1.num_vars.max(ty2.num_vars);
- let vars =
- Substs::builder(num_vars).fill(std::iter::repeat_with(|| table.new_type_var())).build();
- let ty1_with_vars = ty1.value.clone().subst_bound_vars(&vars);
- let ty2_with_vars = ty2.value.clone().subst_bound_vars(&vars);
+ let vars = Substs(
+ tys.kinds
+ .iter()
+ // we always use type vars here because we want everything to
+ // fallback to Unknown in the end (kind of hacky, as below)
+ .map(|_| table.new_type_var())
+ .collect(),
+ );
+ let ty1_with_vars = tys.value.0.clone().subst_bound_vars(&vars);
+ let ty2_with_vars = tys.value.1.clone().subst_bound_vars(&vars);
if !table.unify(&ty1_with_vars, &ty2_with_vars) {
return None;
}
@@ -162,7 +187,7 @@ pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
}
}
Some(
- Substs::builder(ty1.num_vars)
+ Substs::builder(tys.kinds.len())
.fill(vars.iter().map(|v| table.resolve_ty_completely(v.clone())))
.build(),
)
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index c9513b752..7f3f5e771 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -662,13 +662,27 @@ impl TypeWalk for GenericPredicate {
/// Basically a claim (currently not validated / checked) that the contained
/// type / trait ref contains no inference variables; any inference variables it
-/// contained have been replaced by bound variables, and `num_vars` tells us how
-/// many there are. This is used to erase irrelevant differences between types
-/// before using them in queries.
+/// contained have been replaced by bound variables, and `kinds` tells us how
+/// many there are and whether they were normal or float/int variables. This is
+/// used to erase irrelevant differences between types before using them in
+/// queries.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Canonical<T> {
pub value: T,
- pub num_vars: usize,
+ pub kinds: Arc<[TyKind]>,
+}
+
+impl<T> Canonical<T> {
+ pub fn new(value: T, kinds: impl IntoIterator<Item = TyKind>) -> Self {
+ Self { value, kinds: kinds.into_iter().collect() }
+ }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum TyKind {
+ General,
+ Integer,
+ Float,
}
/// A function signature as seen by type inference: Several parameter types and
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index c19519cf1..c3edd6885 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -2,7 +2,7 @@
//! For details about how this works in rustc, see the method lookup page in the
//! [rustc guide](https://rust-lang.github.io/rustc-guide/method-lookup.html)
//! and the corresponding code mostly in librustc_typeck/check/method/probe.rs.
-use std::sync::Arc;
+use std::{iter, sync::Arc};
use arrayvec::ArrayVec;
use hir_def::{
@@ -17,7 +17,8 @@ use rustc_hash::{FxHashMap, FxHashSet};
use super::Substs;
use crate::{
autoderef, db::HirDatabase, primitive::FloatBitness, utils::all_super_traits, ApplicationTy,
- Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
+ Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TyKind, TypeCtor,
+ TypeWalk,
};
/// This is used as a key for indexing impls.
@@ -377,7 +378,7 @@ fn iterate_method_candidates_with_autoref(
return true;
}
let refed = Canonical {
- num_vars: deref_chain[0].num_vars,
+ kinds: deref_chain[0].kinds.clone(),
value: Ty::apply_one(TypeCtor::Ref(Mutability::Shared), deref_chain[0].value.clone()),
};
if iterate_method_candidates_by_receiver(
@@ -393,7 +394,7 @@ fn iterate_method_candidates_with_autoref(
return true;
}
let ref_muted = Canonical {
- num_vars: deref_chain[0].num_vars,
+ kinds: deref_chain[0].kinds.clone(),
value: Ty::apply_one(TypeCtor::Ref(Mutability::Mut), deref_chain[0].value.clone()),
};
if iterate_method_candidates_by_receiver(
@@ -612,18 +613,19 @@ pub(crate) fn inherent_impl_substs(
// we create a var for each type parameter of the impl; we need to keep in
// mind here that `self_ty` might have vars of its own
let vars = Substs::build_for_def(db, impl_id)
- .fill_with_bound_vars(DebruijnIndex::INNERMOST, self_ty.num_vars)
+ .fill_with_bound_vars(DebruijnIndex::INNERMOST, self_ty.kinds.len())
.build();
let self_ty_with_vars = db.impl_self_ty(impl_id).subst(&vars);
- let self_ty_with_vars =
- Canonical { num_vars: vars.len() + self_ty.num_vars, value: self_ty_with_vars };
- let substs = super::infer::unify(&self_ty_with_vars, self_ty);
+ let mut kinds = self_ty.kinds.to_vec();
+ kinds.extend(iter::repeat(TyKind::General).take(vars.len()));
+ let tys = Canonical { kinds: kinds.into(), value: (self_ty_with_vars, self_ty.value.clone()) };
+ let substs = super::infer::unify(&tys);
// We only want the substs for the vars we added, not the ones from self_ty.
// Also, if any of the vars we added are still in there, we replace them by
// Unknown. I think this can only really happen if self_ty contained
// Unknown, and in that case we want the result to contain Unknown in those
// places again.
- substs.map(|s| fallback_bound_vars(s.suffix(vars.len()), self_ty.num_vars))
+ substs.map(|s| fallback_bound_vars(s.suffix(vars.len()), self_ty.kinds.len()))
}
/// This replaces any 'free' Bound vars in `s` (i.e. those with indices past
@@ -683,15 +685,15 @@ fn generic_implements_goal(
trait_: TraitId,
self_ty: Canonical<Ty>,
) -> Canonical<InEnvironment<super::Obligation>> {
- let num_vars = self_ty.num_vars;
+ let mut kinds = self_ty.kinds.to_vec();
let substs = super::Substs::build_for_def(db, trait_)
.push(self_ty.value)
- .fill_with_bound_vars(DebruijnIndex::INNERMOST, num_vars)
+ .fill_with_bound_vars(DebruijnIndex::INNERMOST, kinds.len())
.build();
- let num_vars = substs.len() - 1 + self_ty.num_vars;
+ kinds.extend(iter::repeat(TyKind::General).take(substs.len() - 1));
let trait_ref = TraitRef { trait_, substs };
let obligation = super::Obligation::Trait(trait_ref);
- Canonical { num_vars, value: InEnvironment::new(env, obligation) }
+ Canonical { kinds: kinds.into(), value: InEnvironment::new(env, obligation) }
}
fn autoderef_method_receiver(
@@ -704,9 +706,9 @@ fn autoderef_method_receiver(
if let Some(Ty::Apply(ApplicationTy { ctor: TypeCtor::Array, parameters })) =
deref_chain.last().map(|ty| &ty.value)
{
- let num_vars = deref_chain.last().unwrap().num_vars;
+ let kinds = deref_chain.last().unwrap().kinds.clone();
let unsized_ty = Ty::apply(TypeCtor::Slice, parameters.clone());
- deref_chain.push(Canonical { value: unsized_ty, num_vars })
+ deref_chain.push(Canonical { value: unsized_ty, kinds })
}
deref_chain
}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 01c919a7e..766790576 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -3029,3 +3029,21 @@ fn infer_dyn_fn_output() {
"###
);
}
+
+#[test]
+fn variable_kinds() {
+ check_types(
+ r#"
+trait Trait<T> { fn get(self, t: T) -> T; }
+struct S;
+impl Trait<u128> for S {}
+impl Trait<f32> for S {}
+fn test() {
+ S.get(1);
+ //^^^^^^^^ u128
+ S.get(1.);
+ //^^^^^^^^ f32
+}
+ "#,
+ );
+}
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 6f43c3a22..2a6d7faef 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -1,5 +1,5 @@
//! Trait solving using Chalk.
-use std::{panic, sync::Arc};
+use std::sync::Arc;
use chalk_ir::cast::Cast;
use hir_def::{
@@ -8,7 +8,7 @@ use hir_def::{
use ra_db::{impl_intern_key, salsa, CrateId};
use ra_prof::profile;
-use crate::{db::HirDatabase, DebruijnIndex};
+use crate::{db::HirDatabase, DebruijnIndex, Substs};
use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
@@ -190,15 +190,7 @@ fn solution_from_chalk(
solution: chalk_solve::Solution<Interner>,
) -> Solution {
let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<Interner>>| {
- let value = subst
- .value
- .iter(&Interner)
- .map(|p| match p.ty(&Interner) {
- Some(ty) => from_chalk(db, ty.clone()),
- None => unimplemented!(),
- })
- .collect();
- let result = Canonical { value, num_vars: subst.binders.len(&Interner) };
+ let result = from_chalk(db, subst);
SolutionVariables(result)
};
match solution {
@@ -222,7 +214,7 @@ fn solution_from_chalk(
}
#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct SolutionVariables(pub Canonical<Vec<Ty>>);
+pub struct SolutionVariables(pub Canonical<Substs>);
#[derive(Clone, Debug, PartialEq, Eq)]
/// A (possible) solution for a proposed goal.
diff --git a/crates/ra_hir_ty/src/traits/chalk/mapping.rs b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
index ac82ea831..433d6aa03 100644
--- a/crates/ra_hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
@@ -17,7 +17,7 @@ use crate::{
primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness},
traits::{builtin, AssocTyValue, Canonical, Impl, Obligation},
ApplicationTy, CallableDef, GenericPredicate, InEnvironment, OpaqueTy, OpaqueTyId,
- ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
+ ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TyKind, TypeCtor,
};
use super::interner::*;
@@ -555,22 +555,39 @@ where
type Chalk = chalk_ir::Canonical<T::Chalk>;
fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
- let parameter = chalk_ir::CanonicalVarKind::new(
- chalk_ir::VariableKind::Ty(chalk_ir::TyKind::General),
- chalk_ir::UniverseIndex::ROOT,
- );
+ let kinds = self
+ .kinds
+ .iter()
+ .map(|k| match k {
+ TyKind::General => chalk_ir::TyKind::General,
+ TyKind::Integer => chalk_ir::TyKind::Integer,
+ TyKind::Float => chalk_ir::TyKind::Float,
+ })
+ .map(|tk| {
+ chalk_ir::CanonicalVarKind::new(
+ chalk_ir::VariableKind::Ty(tk),
+ chalk_ir::UniverseIndex::ROOT,
+ )
+ });
let value = self.value.to_chalk(db);
- chalk_ir::Canonical {
- value,
- binders: chalk_ir::CanonicalVarKinds::from(&Interner, vec![parameter; self.num_vars]),
- }
+ chalk_ir::Canonical { value, binders: chalk_ir::CanonicalVarKinds::from(&Interner, kinds) }
}
fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
- Canonical {
- num_vars: canonical.binders.len(&Interner),
- value: from_chalk(db, canonical.value),
- }
+ let kinds = canonical
+ .binders
+ .iter(&Interner)
+ .map(|k| match k.kind {
+ chalk_ir::VariableKind::Ty(tk) => match tk {
+ chalk_ir::TyKind::General => TyKind::General,
+ chalk_ir::TyKind::Integer => TyKind::Integer,
+ chalk_ir::TyKind::Float => TyKind::Float,
+ },
+ chalk_ir::VariableKind::Lifetime => panic!("unexpected lifetime from Chalk"),
+ chalk_ir::VariableKind::Const(_) => panic!("unexpected const from Chalk"),
+ })
+ .collect();
+ Canonical { kinds, value: from_chalk(db, canonical.value) }
}
}
--
cgit v1.2.3