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emit `AliasEq` when relating type and const aliases

This commit is contained in:
Boxy 2023-02-10 14:29:28 +00:00
parent 23ab2464be
commit 1f89e2aef2
12 changed files with 157 additions and 147 deletions
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6
compiler/rustc_borrowck/src/type_check/relate_tys.rs
View File

@ -1,4 +1,4 @@
use rustc_infer::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate};
use rustc_infer::infer::nll_relate::{TypeRelating, TypeRelatingDelegate};
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_infer::traits::PredicateObligations;
use rustc_middle::mir::ConstraintCategory;
@ -140,10 +140,6 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
);
}
fn normalization() -> NormalizationStrategy {
NormalizationStrategy::Eager
}
fn forbid_inference_vars() -> bool {
true
}

6
compiler/rustc_infer/src/infer/canonical/query_response.rs
View File

@ -12,7 +12,7 @@ use crate::infer::canonical::{
Canonical, CanonicalQueryResponse, CanonicalVarValues, Certainty, OriginalQueryValues,
QueryOutlivesConstraint, QueryRegionConstraints, QueryResponse,
};
use crate::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate};
use crate::infer::nll_relate::{TypeRelating, TypeRelatingDelegate};
use crate::infer::region_constraints::{Constraint, RegionConstraintData};
use crate::infer::{InferCtxt, InferOk, InferResult, NllRegionVariableOrigin};
use crate::traits::query::{Fallible, NoSolution};
@ -717,10 +717,6 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> {
});
}
fn normalization() -> NormalizationStrategy {
NormalizationStrategy::Eager
}
fn forbid_inference_vars() -> bool {
true
}

87
compiler/rustc_infer/src/infer/combine.rs
View File

@ -38,8 +38,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
use rustc_middle::ty::subst::SubstsRef;
use rustc_middle::ty::{
self, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
TypeVisitable,
self, AliasKind, FallibleTypeFolder, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable,
TypeSuperFoldable, TypeVisitable,
};
use rustc_middle::ty::{IntType, UintType};
use rustc_span::{Span, DUMMY_SP};
@ -74,7 +74,7 @@ impl<'tcx> InferCtxt<'tcx> {
b: Ty<'tcx>,
) -> RelateResult<'tcx, Ty<'tcx>>
where
R: TypeRelation<'tcx>,
R: ObligationEmittingRelation<'tcx>,
{
let a_is_expected = relation.a_is_expected();
@ -122,6 +122,15 @@ impl<'tcx> InferCtxt<'tcx> {
Err(TypeError::Sorts(ty::relate::expected_found(relation, a, b)))
}
(ty::Alias(AliasKind::Projection, _), _) if self.tcx.trait_solver_next() => {
relation.register_type_equate_obligation(a.into(), b.into());
Ok(b)
}
(_, ty::Alias(AliasKind::Projection, _)) if self.tcx.trait_solver_next() => {
relation.register_type_equate_obligation(b.into(), a.into());
Ok(a)
}
_ => ty::relate::super_relate_tys(relation, a, b),
}
}
@ -133,7 +142,7 @@ impl<'tcx> InferCtxt<'tcx> {
b: ty::Const<'tcx>,
) -> RelateResult<'tcx, ty::Const<'tcx>>
where
R: ConstEquateRelation<'tcx>,
R: ObligationEmittingRelation<'tcx>,
{
debug!("{}.consts({:?}, {:?})", relation.tag(), a, b);
if a == b {
@ -169,7 +178,7 @@ impl<'tcx> InferCtxt<'tcx> {
// FIXME(#59490): Need to remove the leak check to accommodate
// escaping bound variables here.
if !a.has_escaping_bound_vars() && !b.has_escaping_bound_vars() {
relation.const_equate_obligation(a, b);
relation.register_const_equate_obligation(a, b);
}
return Ok(b);
}
@ -177,7 +186,7 @@ impl<'tcx> InferCtxt<'tcx> {
// FIXME(#59490): Need to remove the leak check to accommodate
// escaping bound variables here.
if !a.has_escaping_bound_vars() && !b.has_escaping_bound_vars() {
relation.const_equate_obligation(a, b);
relation.register_const_equate_obligation(a, b);
}
return Ok(a);
}
@ -435,32 +444,21 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
Ok(Generalization { ty, needs_wf })
}
pub fn add_const_equate_obligation(
pub fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.obligations.extend(obligations.into_iter());
}
pub fn register_predicates(
&mut self,
a_is_expected: bool,
a: ty::Const<'tcx>,
b: ty::Const<'tcx>,
obligations: impl IntoIterator<Item = impl ToPredicate<'tcx>>,
) {
let predicate = if a_is_expected {
ty::PredicateKind::ConstEquate(a, b)
} else {
ty::PredicateKind::ConstEquate(b, a)
};
self.obligations.push(Obligation::new(
self.tcx(),
self.trace.cause.clone(),
self.param_env,
ty::Binder::dummy(predicate),
));
self.obligations.extend(obligations.into_iter().map(|to_pred| {
Obligation::new(self.infcx.tcx, self.trace.cause.clone(), self.param_env, to_pred)
}))
}
pub fn mark_ambiguous(&mut self) {
self.obligations.push(Obligation::new(
self.tcx(),
self.trace.cause.clone(),
self.param_env,
ty::Binder::dummy(ty::PredicateKind::Ambiguous),
));
self.register_predicates([ty::Binder::dummy(ty::PredicateKind::Ambiguous)]);
}
}
@ -775,11 +773,42 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
}
}
pub trait ConstEquateRelation<'tcx>: TypeRelation<'tcx> {
pub trait ObligationEmittingRelation<'tcx>: TypeRelation<'tcx> {
/// Register obligations that must hold in order for this relation to hold
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>);
/// Register predicates that must hold in order for this relation to hold. Uses
/// a default obligation cause, [`ObligationEmittingRelation::register_obligations`] should
/// be used if control over the obligaton causes is required.
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ToPredicate<'tcx>>,
);
/// Register an obligation that both constants must be equal to each other.
///
/// If they aren't equal then the relation doesn't hold.
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>);
fn register_const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) };
self.register_predicates([ty::Binder::dummy(if self.tcx().trait_solver_next() {
ty::PredicateKind::AliasEq(a.into(), b.into())
} else {
ty::PredicateKind::ConstEquate(a, b)
})]);
}
/// Register an obligation that both types must be equal to each other.
///
/// If they aren't equal then the relation doesn't hold.
fn register_type_equate_obligation(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) {
let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) };
self.register_predicates([ty::Binder::dummy(ty::PredicateKind::AliasEq(
a.into(),
b.into(),
))]);
}
}
fn int_unification_error<'tcx>(

17
compiler/rustc_infer/src/infer/equate.rs
View File

@ -1,4 +1,6 @@
use super::combine::{CombineFields, ConstEquateRelation, RelationDir};
use crate::traits::PredicateObligations;
use super::combine::{CombineFields, ObligationEmittingRelation, RelationDir};
use super::Subtype;
use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
@ -198,8 +200,15 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> {
}
}
impl<'tcx> ConstEquateRelation<'tcx> for Equate<'_, '_, 'tcx> {
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
self.fields.add_const_equate_obligation(self.a_is_expected, a, b);
impl<'tcx> ObligationEmittingRelation<'tcx> for Equate<'_, '_, 'tcx> {
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
self.fields.register_predicates(obligations);
}
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.fields.register_obligations(obligations);
}
}

22
compiler/rustc_infer/src/infer/glb.rs
View File

@ -1,12 +1,11 @@
//! Greatest lower bound. See [`lattice`].
use super::combine::CombineFields;
use super::combine::{CombineFields, ObligationEmittingRelation};
use super::lattice::{self, LatticeDir};
use super::InferCtxt;
use super::Subtype;
use crate::infer::combine::ConstEquateRelation;
use crate::traits::{ObligationCause, PredicateObligation};
use crate::traits::{ObligationCause, PredicateObligations};
use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
use rustc_middle::ty::{self, Ty, TyCtxt};
@ -136,10 +135,6 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Glb<'combine, 'infcx,
&self.fields.trace.cause
}
fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>) {
self.fields.obligations.extend(obligations)
}
fn relate_bound(&mut self, v: Ty<'tcx>, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, ()> {
let mut sub = self.fields.sub(self.a_is_expected);
sub.relate(v, a)?;
@ -152,8 +147,15 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Glb<'combine, 'infcx,
}
}
impl<'tcx> ConstEquateRelation<'tcx> for Glb<'_, '_, 'tcx> {
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
self.fields.add_const_equate_obligation(self.a_is_expected, a, b);
impl<'tcx> ObligationEmittingRelation<'tcx> for Glb<'_, '_, 'tcx> {
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
self.fields.register_predicates(obligations);
}
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.fields.register_obligations(obligations);
}
}

11
compiler/rustc_infer/src/infer/lattice.rs
View File

@ -17,11 +17,12 @@
//!
//! [lattices]: https://en.wikipedia.org/wiki/Lattice_(order)
use super::combine::ObligationEmittingRelation;
use super::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use super::InferCtxt;
use crate::traits::{ObligationCause, PredicateObligation};
use rustc_middle::ty::relate::{RelateResult, TypeRelation};
use crate::traits::ObligationCause;
use rustc_middle::ty::relate::RelateResult;
use rustc_middle::ty::TyVar;
use rustc_middle::ty::{self, Ty};
@ -30,13 +31,11 @@ use rustc_middle::ty::{self, Ty};
///
/// GLB moves "down" the lattice (to smaller values); LUB moves
/// "up" the lattice (to bigger values).
pub trait LatticeDir<'f, 'tcx>: TypeRelation<'tcx> {
pub trait LatticeDir<'f, 'tcx>: ObligationEmittingRelation<'tcx> {
fn infcx(&self) -> &'f InferCtxt<'tcx>;
fn cause(&self) -> &ObligationCause<'tcx>;
fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>);
fn define_opaque_types(&self) -> bool;
// Relates the type `v` to `a` and `b` such that `v` represents
@ -113,7 +112,7 @@ where
| (_, &ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }))
if this.define_opaque_types() && def_id.is_local() =>
{
this.add_obligations(
this.register_obligations(
infcx
.handle_opaque_type(a, b, this.a_is_expected(), this.cause(), this.param_env())?
.obligations,

28
compiler/rustc_infer/src/infer/lub.rs
View File

@ -1,12 +1,11 @@
//! Least upper bound. See [`lattice`].
use super::combine::CombineFields;
use super::combine::{CombineFields, ObligationEmittingRelation};
use super::lattice::{self, LatticeDir};
use super::InferCtxt;
use super::Subtype;
use crate::infer::combine::ConstEquateRelation;
use crate::traits::{ObligationCause, PredicateObligation};
use crate::traits::{ObligationCause, PredicateObligations};
use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
use rustc_middle::ty::{self, Ty, TyCtxt};
@ -127,12 +126,6 @@ impl<'tcx> TypeRelation<'tcx> for Lub<'_, '_, 'tcx> {
}
}
impl<'tcx> ConstEquateRelation<'tcx> for Lub<'_, '_, 'tcx> {
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
self.fields.add_const_equate_obligation(self.a_is_expected, a, b);
}
}
impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx, 'tcx> {
fn infcx(&self) -> &'infcx InferCtxt<'tcx> {
self.fields.infcx
@ -142,10 +135,6 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx,
&self.fields.trace.cause
}
fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>) {
self.fields.obligations.extend(obligations)
}
fn relate_bound(&mut self, v: Ty<'tcx>, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, ()> {
let mut sub = self.fields.sub(self.a_is_expected);
sub.relate(a, v)?;
@ -157,3 +146,16 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx,
self.fields.define_opaque_types
}
}
impl<'tcx> ObligationEmittingRelation<'tcx> for Lub<'_, '_, 'tcx> {
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
self.fields.register_predicates(obligations);
}
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.fields.register_obligations(obligations)
}
}

1
compiler/rustc_infer/src/infer/mod.rs
View File

@ -4,6 +4,7 @@ pub use self::LateBoundRegionConversionTime::*;
pub use self::RegionVariableOrigin::*;
pub use self::SubregionOrigin::*;
pub use self::ValuePairs::*;
pub use combine::ObligationEmittingRelation;
use self::opaque_types::OpaqueTypeStorage;
pub(crate) use self::undo_log::{InferCtxtUndoLogs, Snapshot, UndoLog};

89
compiler/rustc_infer/src/infer/nll_relate/mod.rs
View File

@ -21,11 +21,10 @@
//! thing we relate in chalk are basically domain goals and their
//! constituents)
use crate::infer::combine::ConstEquateRelation;
use crate::infer::InferCtxt;
use crate::infer::{ConstVarValue, ConstVariableValue};
use crate::infer::{TypeVariableOrigin, TypeVariableOriginKind};
use crate::traits::{Obligation, PredicateObligation};
use crate::traits::{Obligation, PredicateObligations};
use rustc_data_structures::fx::FxHashMap;
use rustc_middle::traits::ObligationCause;
use rustc_middle::ty::error::TypeError;
@ -36,11 +35,7 @@ use rustc_span::Span;
use std::fmt::Debug;
use std::ops::ControlFlow;
#[derive(PartialEq)]
pub enum NormalizationStrategy {
Lazy,
Eager,
}
use super::combine::ObligationEmittingRelation;
pub struct TypeRelating<'me, 'tcx, D>
where
@ -92,7 +87,7 @@ pub trait TypeRelatingDelegate<'tcx> {
info: ty::VarianceDiagInfo<'tcx>,
);
fn register_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>);
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>);
/// Creates a new universe index. Used when instantiating placeholders.
fn create_next_universe(&mut self) -> ty::UniverseIndex;
@ -125,9 +120,6 @@ pub trait TypeRelatingDelegate<'tcx> {
/// relation stating that `'?0: 'a`).
fn generalize_existential(&mut self, universe: ty::UniverseIndex) -> ty::Region<'tcx>;
/// Define the normalization strategy to use, eager or lazy.
fn normalization() -> NormalizationStrategy;
/// Enables some optimizations if we do not expect inference variables
/// in the RHS of the relation.
fn forbid_inference_vars() -> bool;
@ -265,38 +257,6 @@ where
self.delegate.push_outlives(sup, sub, info);
}
/// Relate a projection type and some value type lazily. This will always
/// succeed, but we push an additional `ProjectionEq` goal depending
/// on the value type:
/// - if the value type is any type `T` which is not a projection, we push
/// `ProjectionEq(projection = T)`.
/// - if the value type is another projection `other_projection`, we create
/// a new inference variable `?U` and push the two goals
/// `ProjectionEq(projection = ?U)`, `ProjectionEq(other_projection = ?U)`.
fn relate_projection_ty(
&mut self,
projection_ty: ty::AliasTy<'tcx>,
value_ty: Ty<'tcx>,
) -> Ty<'tcx> {
use rustc_span::DUMMY_SP;
match *value_ty.kind() {
ty::Alias(ty::Projection, other_projection_ty) => {
let var = self.infcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::MiscVariable,
span: DUMMY_SP,
});
// FIXME(lazy-normalization): This will always ICE, because the recursive
// call will end up in the _ arm below.
self.relate_projection_ty(projection_ty, var);
self.relate_projection_ty(other_projection_ty, var);
var
}
_ => bug!("should never be invoked with eager normalization"),
}
}
/// Relate a type inference variable with a value type. This works
/// by creating a "generalization" G of the value where all the
/// lifetimes are replaced with fresh inference values. This
@ -335,12 +295,6 @@ where
return Ok(value_ty);
}
ty::Alias(ty::Projection, projection_ty)
if D::normalization() == NormalizationStrategy::Lazy =>
{
return Ok(self.relate_projection_ty(projection_ty, self.infcx.tcx.mk_ty_var(vid)));
}
_ => (),
}
@ -627,18 +581,6 @@ where
self.relate_opaques(a, b)
}
(&ty::Alias(ty::Projection, projection_ty), _)
if D::normalization() == NormalizationStrategy::Lazy =>
{
Ok(self.relate_projection_ty(projection_ty, b))
}
(_, &ty::Alias(ty::Projection, projection_ty))
if D::normalization() == NormalizationStrategy::Lazy =>
{
Ok(self.relate_projection_ty(projection_ty, a))
}
_ => {
debug!(?a, ?b, ?self.ambient_variance);
@ -813,17 +755,26 @@ where
}
}
impl<'tcx, D> ConstEquateRelation<'tcx> for TypeRelating<'_, 'tcx, D>
impl<'tcx, D> ObligationEmittingRelation<'tcx> for TypeRelating<'_, 'tcx, D>
where
D: TypeRelatingDelegate<'tcx>,
{
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
self.delegate.register_obligations(vec![Obligation::new(
self.tcx(),
ObligationCause::dummy(),
self.param_env(),
ty::Binder::dummy(ty::PredicateKind::ConstEquate(a, b)),
)]);
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
self.delegate.register_obligations(
obligations
.into_iter()
.map(|to_pred| {
Obligation::new(self.tcx(), ObligationCause::dummy(), self.param_env(), to_pred)
})
.collect(),
);
}
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.delegate.register_obligations(obligations);
}
}

18
compiler/rustc_infer/src/infer/sub.rs
View File

@ -1,8 +1,7 @@
use super::combine::{CombineFields, RelationDir};
use super::SubregionOrigin;
use super::{ObligationEmittingRelation, SubregionOrigin};
use crate::infer::combine::ConstEquateRelation;
use crate::traits::Obligation;
use crate::traits::{Obligation, PredicateObligations};
use rustc_middle::ty::relate::{Cause, Relate, RelateResult, TypeRelation};
use rustc_middle::ty::visit::TypeVisitable;
use rustc_middle::ty::TyVar;
@ -228,8 +227,15 @@ impl<'tcx> TypeRelation<'tcx> for Sub<'_, '_, 'tcx> {
}
}
impl<'tcx> ConstEquateRelation<'tcx> for Sub<'_, '_, 'tcx> {
fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) {
self.fields.add_const_equate_obligation(self.a_is_expected, a, b);
impl<'tcx> ObligationEmittingRelation<'tcx> for Sub<'_, '_, 'tcx> {
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
self.fields.register_predicates(obligations);
}
fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) {
self.fields.register_obligations(obligations);
}
}

4
compiler/rustc_middle/src/ty/context.rs
View File

@ -2230,6 +2230,10 @@ impl<'tcx> TyCtxt<'tcx> {
})
)
}
pub fn trait_solver_next(self) -> bool {
self.sess.opts.unstable_opts.trait_solver == rustc_session::config::TraitSolver::Next
}
}
impl<'tcx> TyCtxtAt<'tcx> {

15
compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs
View File

@ -1,5 +1,7 @@
use crate::infer::InferCtxt;
use rustc_infer::infer::ObligationEmittingRelation;
use rustc_infer::traits::PredicateObligations;
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
use rustc_middle::ty::{self, Ty, TyCtxt};
@ -88,3 +90,16 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> {
Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?))
}
}
impl<'tcx> ObligationEmittingRelation<'tcx> for CollectAllMismatches<'_, 'tcx> {
fn register_obligations(&mut self, _obligations: PredicateObligations<'tcx>) {
// FIXME(deferred_projection_equality)
}
fn register_predicates(
&mut self,
_obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>,
) {
// FIXME(deferred_projection_equality)
}
}