Uplift super_combine

This commit is contained in:
Michael Goulet 2024-10-04 12:33:51 -04:00
parent 09da2ebd63
commit ce7a61b9d0
13 changed files with 376 additions and 305 deletions

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@ -11,6 +11,7 @@
use rustc_middle::traits::ObligationCause;
use rustc_middle::traits::query::NoSolution;
use rustc_middle::ty::fold::FnMutDelegate;
use rustc_middle::ty::relate::combine::InferCtxtCombineExt;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
use rustc_span::symbol::sym;
use rustc_span::{Span, Symbol};

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@ -1,22 +1,27 @@
///! Definition of `InferCtxtLike` from the librarified type layer.
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_middle::infer::unify_key::EffectVarValue;
use rustc_middle::traits::ObligationCause;
use rustc_middle::traits::solve::{Goal, NoSolution, SolverMode};
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::relate::combine::PredicateEmittingRelation;
use rustc_middle::ty::relate::{Relate, RelateResult};
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_span::DUMMY_SP;
use rustc_type_ir::InferCtxtLike;
use rustc_type_ir::relate::Relate;
use rustc_span::{DUMMY_SP, ErrorGuaranteed};
use super::{BoundRegionConversionTime, InferCtxt, SubregionOrigin};
impl<'tcx> InferCtxtLike for InferCtxt<'tcx> {
impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
type Interner = TyCtxt<'tcx>;
fn cx(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn next_trait_solver(&self) -> bool {
self.next_trait_solver
}
fn solver_mode(&self) -> ty::solve::SolverMode {
match self.intercrate {
true => SolverMode::Coherence,
@ -131,6 +136,59 @@ fn enter_forall<T: TypeFoldable<TyCtxt<'tcx>> + Copy, U>(
self.enter_forall(value, f)
}
fn equate_int_vids_raw(&self, a: rustc_type_ir::IntVid, b: rustc_type_ir::IntVid) {
self.inner.borrow_mut().int_unification_table().union(a, b);
}
fn equate_float_vids_raw(&self, a: rustc_type_ir::FloatVid, b: rustc_type_ir::FloatVid) {
self.inner.borrow_mut().float_unification_table().union(a, b);
}
fn equate_const_vids_raw(&self, a: rustc_type_ir::ConstVid, b: rustc_type_ir::ConstVid) {
self.inner.borrow_mut().const_unification_table().union(a, b);
}
fn equate_effect_vids_raw(&self, a: rustc_type_ir::EffectVid, b: rustc_type_ir::EffectVid) {
self.inner.borrow_mut().effect_unification_table().union(a, b);
}
fn instantiate_int_var_raw(
&self,
vid: rustc_type_ir::IntVid,
value: rustc_type_ir::IntVarValue,
) {
self.inner.borrow_mut().int_unification_table().union_value(vid, value);
}
fn instantiate_float_var_raw(
&self,
vid: rustc_type_ir::FloatVid,
value: rustc_type_ir::FloatVarValue,
) {
self.inner.borrow_mut().float_unification_table().union_value(vid, value);
}
fn instantiate_effect_var_raw(&self, vid: rustc_type_ir::EffectVid, value: ty::Const<'tcx>) {
self.inner
.borrow_mut()
.effect_unification_table()
.union_value(vid, EffectVarValue::Known(value));
}
fn instantiate_const_var_raw<R: PredicateEmittingRelation<Self>>(
&self,
relation: &mut R,
target_is_expected: bool,
target_vid: rustc_type_ir::ConstVid,
source_ct: ty::Const<'tcx>,
) -> RelateResult<'tcx, ()> {
self.instantiate_const_var(relation, target_is_expected, target_vid, source_ct)
}
fn set_tainted_by_errors(&self, e: ErrorGuaranteed) {
self.set_tainted_by_errors(e)
}
fn relate<T: Relate<TyCtxt<'tcx>>>(
&self,
param_env: ty::ParamEnv<'tcx>,
@ -154,6 +212,9 @@ fn eq_structurally_relating_aliases<T: Relate<TyCtxt<'tcx>>>(
fn shallow_resolve(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
self.shallow_resolve(ty)
}
fn shallow_resolve_const(&self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
self.shallow_resolve_const(ct)
}
fn resolve_vars_if_possible<T>(&self, value: T) -> T
where

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@ -1,245 +0,0 @@
//! There are four type combiners: `TypeRelating`, `Lub`, and `Glb`,
//! and `NllTypeRelating` in rustc_borrowck, which is only used for NLL.
//!
//! Each implements the trait [TypeRelation] and contains methods for
//! combining two instances of various things and yielding a new instance.
//! These combiner methods always yield a `Result<T>`. To relate two
//! types, you can use `infcx.at(cause, param_env)` which then allows
//! you to use the relevant methods of [At](crate::infer::at::At).
//!
//! Combiners mostly do their specific behavior and then hand off the
//! bulk of the work to [InferCtxt::super_combine_tys] and
//! [InferCtxt::super_combine_consts].
//!
//! Combining two types may have side-effects on the inference contexts
//! which can be undone by using snapshots. You probably want to use
//! either [InferCtxt::commit_if_ok] or [InferCtxt::probe].
//!
//! On success, the LUB/GLB operations return the appropriate bound. The
//! return value of `Equate` or `Sub` shouldn't really be used.
use rustc_middle::bug;
use rustc_middle::infer::unify_key::EffectVarValue;
use rustc_middle::ty::error::{ExpectedFound, TypeError};
use rustc_middle::ty::{self, InferConst, IntType, Ty, TypeVisitableExt, UintType};
pub use rustc_next_trait_solver::relate::combine::*;
use tracing::debug;
use super::{RelateResult, StructurallyRelateAliases};
use crate::infer::{InferCtxt, relate};
impl<'tcx> InferCtxt<'tcx> {
pub fn super_combine_tys<R>(
&self,
relation: &mut R,
a: Ty<'tcx>,
b: Ty<'tcx>,
) -> RelateResult<'tcx, Ty<'tcx>>
where
R: PredicateEmittingRelation<InferCtxt<'tcx>>,
{
debug!("super_combine_tys::<{}>({:?}, {:?})", std::any::type_name::<R>(), a, b);
debug_assert!(!a.has_escaping_bound_vars());
debug_assert!(!b.has_escaping_bound_vars());
match (a.kind(), b.kind()) {
(&ty::Error(e), _) | (_, &ty::Error(e)) => {
self.set_tainted_by_errors(e);
return Ok(Ty::new_error(self.tcx, e));
}
// Relate integral variables to other types
(&ty::Infer(ty::IntVar(a_id)), &ty::Infer(ty::IntVar(b_id))) => {
self.inner.borrow_mut().int_unification_table().union(a_id, b_id);
Ok(a)
}
(&ty::Infer(ty::IntVar(v_id)), &ty::Int(v)) => {
self.unify_integral_variable(v_id, IntType(v));
Ok(b)
}
(&ty::Int(v), &ty::Infer(ty::IntVar(v_id))) => {
self.unify_integral_variable(v_id, IntType(v));
Ok(a)
}
(&ty::Infer(ty::IntVar(v_id)), &ty::Uint(v)) => {
self.unify_integral_variable(v_id, UintType(v));
Ok(b)
}
(&ty::Uint(v), &ty::Infer(ty::IntVar(v_id))) => {
self.unify_integral_variable(v_id, UintType(v));
Ok(a)
}
// Relate floating-point variables to other types
(&ty::Infer(ty::FloatVar(a_id)), &ty::Infer(ty::FloatVar(b_id))) => {
self.inner.borrow_mut().float_unification_table().union(a_id, b_id);
Ok(a)
}
(&ty::Infer(ty::FloatVar(v_id)), &ty::Float(v)) => {
self.unify_float_variable(v_id, ty::FloatVarValue::Known(v));
Ok(b)
}
(&ty::Float(v), &ty::Infer(ty::FloatVar(v_id))) => {
self.unify_float_variable(v_id, ty::FloatVarValue::Known(v));
Ok(a)
}
// We don't expect `TyVar` or `Fresh*` vars at this point with lazy norm.
(ty::Alias(..), ty::Infer(ty::TyVar(_))) | (ty::Infer(ty::TyVar(_)), ty::Alias(..))
if self.next_trait_solver() =>
{
bug!(
"We do not expect to encounter `TyVar` this late in combine \
-- they should have been handled earlier"
)
}
(_, ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)))
| (ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)), _)
if self.next_trait_solver() =>
{
bug!("We do not expect to encounter `Fresh` variables in the new solver")
}
(_, ty::Alias(..)) | (ty::Alias(..), _) if self.next_trait_solver() => {
match relation.structurally_relate_aliases() {
StructurallyRelateAliases::Yes => {
relate::structurally_relate_tys(relation, a, b)
}
StructurallyRelateAliases::No => {
relation.register_alias_relate_predicate(a, b);
Ok(a)
}
}
}
// All other cases of inference are errors
(&ty::Infer(_), _) | (_, &ty::Infer(_)) => {
Err(TypeError::Sorts(ExpectedFound::new(true, a, b)))
}
// During coherence, opaque types should be treated as *possibly*
// equal to any other type (except for possibly itself). This is an
// extremely heavy hammer, but can be relaxed in a forwards-compatible
// way later.
(&ty::Alias(ty::Opaque, _), _) | (_, &ty::Alias(ty::Opaque, _)) if self.intercrate => {
relation.register_predicates([ty::Binder::dummy(ty::PredicateKind::Ambiguous)]);
Ok(a)
}
_ => relate::structurally_relate_tys(relation, a, b),
}
}
pub fn super_combine_consts<R>(
&self,
relation: &mut R,
a: ty::Const<'tcx>,
b: ty::Const<'tcx>,
) -> RelateResult<'tcx, ty::Const<'tcx>>
where
R: PredicateEmittingRelation<InferCtxt<'tcx>>,
{
debug!("super_combine_consts::<{}>({:?}, {:?})", std::any::type_name::<R>(), a, b);
debug_assert!(!a.has_escaping_bound_vars());
debug_assert!(!b.has_escaping_bound_vars());
if a == b {
return Ok(a);
}
let a = self.shallow_resolve_const(a);
let b = self.shallow_resolve_const(b);
match (a.kind(), b.kind()) {
(
ty::ConstKind::Infer(InferConst::Var(a_vid)),
ty::ConstKind::Infer(InferConst::Var(b_vid)),
) => {
self.inner.borrow_mut().const_unification_table().union(a_vid, b_vid);
Ok(a)
}
(
ty::ConstKind::Infer(InferConst::EffectVar(a_vid)),
ty::ConstKind::Infer(InferConst::EffectVar(b_vid)),
) => {
self.inner.borrow_mut().effect_unification_table().union(a_vid, b_vid);
Ok(a)
}
// All other cases of inference with other variables are errors.
(
ty::ConstKind::Infer(InferConst::Var(_) | InferConst::EffectVar(_)),
ty::ConstKind::Infer(_),
)
| (
ty::ConstKind::Infer(_),
ty::ConstKind::Infer(InferConst::Var(_) | InferConst::EffectVar(_)),
) => {
bug!(
"tried to combine ConstKind::Infer/ConstKind::Infer(InferConst::Var): {a:?} and {b:?}"
)
}
(ty::ConstKind::Infer(InferConst::Var(vid)), _) => {
self.instantiate_const_var(relation, true, vid, b)?;
Ok(b)
}
(_, ty::ConstKind::Infer(InferConst::Var(vid))) => {
self.instantiate_const_var(relation, false, vid, a)?;
Ok(a)
}
(ty::ConstKind::Infer(InferConst::EffectVar(vid)), _) => {
Ok(self.unify_effect_variable(vid, b))
}
(_, ty::ConstKind::Infer(InferConst::EffectVar(vid))) => {
Ok(self.unify_effect_variable(vid, a))
}
(ty::ConstKind::Unevaluated(..), _) | (_, ty::ConstKind::Unevaluated(..))
if self.tcx.features().generic_const_exprs || self.next_trait_solver() =>
{
match relation.structurally_relate_aliases() {
StructurallyRelateAliases::No => {
relation.register_predicates([if self.next_trait_solver() {
ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Equate,
)
} else {
ty::PredicateKind::ConstEquate(a, b)
}]);
Ok(b)
}
StructurallyRelateAliases::Yes => {
relate::structurally_relate_consts(relation, a, b)
}
}
}
_ => relate::structurally_relate_consts(relation, a, b),
}
}
#[inline(always)]
fn unify_integral_variable(&self, vid: ty::IntVid, val: ty::IntVarValue) {
self.inner.borrow_mut().int_unification_table().union_value(vid, val);
}
#[inline(always)]
fn unify_float_variable(&self, vid: ty::FloatVid, val: ty::FloatVarValue) {
self.inner.borrow_mut().float_unification_table().union_value(vid, val);
}
fn unify_effect_variable(&self, vid: ty::EffectVid, val: ty::Const<'tcx>) -> ty::Const<'tcx> {
self.inner
.borrow_mut()
.effect_unification_table()
.union_value(vid, EffectVarValue::Known(val));
val
}
}

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@ -183,7 +183,7 @@ pub fn instantiate_ty_var<R: PredicateEmittingRelation<InferCtxt<'tcx>>>(
///
/// See `tests/ui/const-generics/occurs-check/` for more examples where this is relevant.
#[instrument(level = "debug", skip(self, relation))]
pub(super) fn instantiate_const_var<R: PredicateEmittingRelation<InferCtxt<'tcx>>>(
pub(crate) fn instantiate_const_var<R: PredicateEmittingRelation<InferCtxt<'tcx>>>(
&self,
relation: &mut R,
target_is_expected: bool,

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@ -18,6 +18,7 @@
//! [lattices]: https://en.wikipedia.org/wiki/Lattice_(order)
use rustc_middle::traits::solve::Goal;
use rustc_middle::ty::relate::combine::InferCtxtCombineExt;
use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
use rustc_middle::ty::{self, Ty, TyCtxt, TyVar, TypeVisitableExt};
use rustc_span::Span;

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@ -3,12 +3,10 @@
//! As well as the implementation of `Relate` for interned things (`Ty`/`Const`/etc).
pub use rustc_middle::ty::relate::RelateResult;
pub use rustc_next_trait_solver::relate::*;
pub use self::combine::PredicateEmittingRelation;
pub use rustc_type_ir::relate::combine::PredicateEmittingRelation;
pub use rustc_type_ir::relate::*;
#[allow(hidden_glob_reexports)]
pub(super) mod combine;
mod generalize;
mod higher_ranked;
pub(super) mod lattice;

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@ -1,4 +1,5 @@
use rustc_middle::traits::solve::Goal;
use rustc_middle::ty::relate::combine::InferCtxtCombineExt;
use rustc_middle::ty::relate::{
Relate, RelateResult, TypeRelation, relate_args_invariantly, relate_args_with_variances,
};

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@ -12,6 +12,5 @@
pub mod canonicalizer;
pub mod coherence;
pub mod delegate;
pub mod relate;
pub mod resolve;
pub mod solve;

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@ -1,15 +0,0 @@
pub use rustc_type_ir::relate::*;
pub mod combine;
/// Whether aliases should be related structurally or not. Used
/// to adjust the behavior of generalization and combine.
///
/// This should always be `No` unless in a few special-cases when
/// instantiating canonical responses and in the new solver. Each
/// such case should have a comment explaining why it is used.
#[derive(Debug, Copy, Clone)]
pub enum StructurallyRelateAliases {
Yes,
No,
}

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@ -1,34 +0,0 @@
pub use rustc_type_ir::relate::*;
use rustc_type_ir::solve::Goal;
use rustc_type_ir::{InferCtxtLike, Interner, Upcast};
use super::StructurallyRelateAliases;
pub trait PredicateEmittingRelation<Infcx, I = <Infcx as InferCtxtLike>::Interner>:
TypeRelation<I>
where
Infcx: InferCtxtLike<Interner = I>,
I: Interner,
{
fn span(&self) -> I::Span;
fn param_env(&self) -> I::ParamEnv;
/// Whether aliases should be related structurally. This is pretty much
/// always `No` unless you're equating in some specific locations of the
/// new solver. See the comments in these use-cases for more details.
fn structurally_relate_aliases(&self) -> StructurallyRelateAliases;
/// Register obligations that must hold in order for this relation to hold
fn register_goals(&mut self, obligations: impl IntoIterator<Item = Goal<I, I::Predicate>>);
/// Register predicates that must hold in order for this relation to hold.
/// This uses the default `param_env` of the obligation.
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item: Upcast<I, I::Predicate>>,
);
/// Register `AliasRelate` obligation(s) that both types must be related to each other.
fn register_alias_relate_predicate(&mut self, a: I::Ty, b: I::Ty);
}

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@ -1,5 +1,6 @@
use crate::fold::TypeFoldable;
use crate::relate::Relate;
use crate::relate::combine::PredicateEmittingRelation;
use crate::relate::{Relate, RelateResult};
use crate::solve::{Goal, NoSolution, SolverMode};
use crate::{self as ty, Interner};
@ -7,6 +8,14 @@ pub trait InferCtxtLike: Sized {
type Interner: Interner;
fn cx(&self) -> Self::Interner;
/// Whether the new trait solver is enabled. This only exists because rustc
/// shares code between the new and old trait solvers; for all other users,
/// this should always be true. If this is unknowingly false and you try to
/// use the new trait solver, things will break badly.
fn next_trait_solver(&self) -> bool {
true
}
fn solver_mode(&self) -> SolverMode;
fn universe(&self) -> ty::UniverseIndex;
@ -58,6 +67,28 @@ fn enter_forall<T: TypeFoldable<Self::Interner> + Copy, U>(
f: impl FnOnce(T) -> U,
) -> U;
fn equate_int_vids_raw(&self, a: ty::IntVid, b: ty::IntVid);
fn equate_float_vids_raw(&self, a: ty::FloatVid, b: ty::FloatVid);
fn equate_const_vids_raw(&self, a: ty::ConstVid, b: ty::ConstVid);
fn equate_effect_vids_raw(&self, a: ty::EffectVid, b: ty::EffectVid);
fn instantiate_int_var_raw(&self, vid: ty::IntVid, value: ty::IntVarValue);
fn instantiate_float_var_raw(&self, vid: ty::FloatVid, value: ty::FloatVarValue);
fn instantiate_effect_var_raw(
&self,
vid: ty::EffectVid,
value: <Self::Interner as Interner>::Const,
);
fn instantiate_const_var_raw<R: PredicateEmittingRelation<Self>>(
&self,
relation: &mut R,
target_is_expected: bool,
target_vid: ty::ConstVid,
source_ct: <Self::Interner as Interner>::Const,
) -> RelateResult<Self::Interner, ()>;
fn set_tainted_by_errors(&self, e: <Self::Interner as Interner>::ErrorGuaranteed);
fn relate<T: Relate<Self::Interner>>(
&self,
param_env: <Self::Interner as Interner>::ParamEnv,
@ -77,6 +108,10 @@ fn shallow_resolve(
&self,
ty: <Self::Interner as Interner>::Ty,
) -> <Self::Interner as Interner>::Ty;
fn shallow_resolve_const(
&self,
ty: <Self::Interner as Interner>::Const,
) -> <Self::Interner as Interner>::Const;
fn resolve_vars_if_possible<T>(&self, value: T) -> T
where

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@ -9,8 +9,22 @@
use crate::inherent::*;
use crate::{self as ty, Interner};
pub mod combine;
pub type RelateResult<I, T> = Result<T, TypeError<I>>;
/// Whether aliases should be related structurally or not. Used
/// to adjust the behavior of generalization and combine.
///
/// This should always be `No` unless in a few special-cases when
/// instantiating canonical responses and in the new solver. Each
/// such case should have a comment explaining why it is used.
#[derive(Debug, Copy, Clone)]
pub enum StructurallyRelateAliases {
Yes,
No,
}
/// Extra information about why we ended up with a particular variance.
/// This is only used to add more information to error messages, and
/// has no effect on soundness. While choosing the 'wrong' `VarianceDiagInfo`

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@ -0,0 +1,255 @@
use tracing::debug;
use super::{
ExpectedFound, RelateResult, StructurallyRelateAliases, TypeRelation,
structurally_relate_consts, structurally_relate_tys,
};
use crate::error::TypeError;
use crate::inherent::*;
use crate::solve::{Goal, SolverMode};
use crate::visit::TypeVisitableExt as _;
use crate::{self as ty, InferCtxtLike, Interner, Upcast};
pub trait PredicateEmittingRelation<Infcx, I = <Infcx as InferCtxtLike>::Interner>:
TypeRelation<I>
where
Infcx: InferCtxtLike<Interner = I>,
I: Interner,
{
fn span(&self) -> I::Span;
fn param_env(&self) -> I::ParamEnv;
/// Whether aliases should be related structurally. This is pretty much
/// always `No` unless you're equating in some specific locations of the
/// new solver. See the comments in these use-cases for more details.
fn structurally_relate_aliases(&self) -> StructurallyRelateAliases;
/// Register obligations that must hold in order for this relation to hold
fn register_goals(&mut self, obligations: impl IntoIterator<Item = Goal<I, I::Predicate>>);
/// Register predicates that must hold in order for this relation to hold.
/// This uses the default `param_env` of the obligation.
fn register_predicates(
&mut self,
obligations: impl IntoIterator<Item: Upcast<I, I::Predicate>>,
);
/// Register `AliasRelate` obligation(s) that both types must be related to each other.
fn register_alias_relate_predicate(&mut self, a: I::Ty, b: I::Ty);
}
pub trait InferCtxtCombineExt<I: Interner>: InferCtxtLike {
fn super_combine_tys<R>(&self, relation: &mut R, a: I::Ty, b: I::Ty) -> RelateResult<I, I::Ty>
where
R: PredicateEmittingRelation<Self>;
fn super_combine_consts<R>(
&self,
relation: &mut R,
a: I::Const,
b: I::Const,
) -> RelateResult<I, I::Const>
where
R: PredicateEmittingRelation<Self>;
}
impl<I: Interner, Infcx: InferCtxtLike<Interner = I>> InferCtxtCombineExt<I> for Infcx {
fn super_combine_tys<R>(&self, relation: &mut R, a: I::Ty, b: I::Ty) -> RelateResult<I, I::Ty>
where
R: PredicateEmittingRelation<Infcx>,
{
debug!("super_combine_tys::<{}>({:?}, {:?})", std::any::type_name::<R>(), a, b);
debug_assert!(!a.has_escaping_bound_vars());
debug_assert!(!b.has_escaping_bound_vars());
match (a.kind(), b.kind()) {
(ty::Error(e), _) | (_, ty::Error(e)) => {
self.set_tainted_by_errors(e);
return Ok(Ty::new_error(self.cx(), e));
}
// Relate integral variables to other types
(ty::Infer(ty::IntVar(a_id)), ty::Infer(ty::IntVar(b_id))) => {
self.equate_int_vids_raw(a_id, b_id);
Ok(a)
}
(ty::Infer(ty::IntVar(v_id)), ty::Int(v)) => {
self.instantiate_int_var_raw(v_id, ty::IntVarValue::IntType(v));
Ok(b)
}
(ty::Int(v), ty::Infer(ty::IntVar(v_id))) => {
self.instantiate_int_var_raw(v_id, ty::IntVarValue::IntType(v));
Ok(a)
}
(ty::Infer(ty::IntVar(v_id)), ty::Uint(v)) => {
self.instantiate_int_var_raw(v_id, ty::IntVarValue::UintType(v));
Ok(b)
}
(ty::Uint(v), ty::Infer(ty::IntVar(v_id))) => {
self.instantiate_int_var_raw(v_id, ty::IntVarValue::UintType(v));
Ok(a)
}
// Relate floating-point variables to other types
(ty::Infer(ty::FloatVar(a_id)), ty::Infer(ty::FloatVar(b_id))) => {
self.equate_float_vids_raw(a_id, b_id);
Ok(a)
}
(ty::Infer(ty::FloatVar(v_id)), ty::Float(v)) => {
self.instantiate_float_var_raw(v_id, ty::FloatVarValue::Known(v));
Ok(b)
}
(ty::Float(v), ty::Infer(ty::FloatVar(v_id))) => {
self.instantiate_float_var_raw(v_id, ty::FloatVarValue::Known(v));
Ok(a)
}
// We don't expect `TyVar` or `Fresh*` vars at this point with lazy norm.
(ty::Alias(..), ty::Infer(ty::TyVar(_))) | (ty::Infer(ty::TyVar(_)), ty::Alias(..))
if self.next_trait_solver() =>
{
panic!(
"We do not expect to encounter `TyVar` this late in combine \
-- they should have been handled earlier"
)
}
(_, ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)))
| (ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)), _)
if self.next_trait_solver() =>
{
panic!("We do not expect to encounter `Fresh` variables in the new solver")
}
(_, ty::Alias(..)) | (ty::Alias(..), _) if self.next_trait_solver() => {
match relation.structurally_relate_aliases() {
StructurallyRelateAliases::Yes => structurally_relate_tys(relation, a, b),
StructurallyRelateAliases::No => {
relation.register_alias_relate_predicate(a, b);
Ok(a)
}
}
}
// All other cases of inference are errors
(ty::Infer(_), _) | (_, ty::Infer(_)) => {
Err(TypeError::Sorts(ExpectedFound::new(true, a, b)))
}
(ty::Alias(ty::Opaque, _), _) | (_, ty::Alias(ty::Opaque, _)) => {
match self.solver_mode() {
SolverMode::Normal => {
assert!(!self.next_trait_solver());
structurally_relate_tys(relation, a, b)
}
// During coherence, opaque types should be treated as *possibly*
// equal to any other type (except for possibly itself). This is an
// extremely heavy hammer, but can be relaxed in a forwards-compatible
// way later.
SolverMode::Coherence => {
relation
.register_predicates([ty::Binder::dummy(ty::PredicateKind::Ambiguous)]);
Ok(a)
}
}
}
_ => structurally_relate_tys(relation, a, b),
}
}
fn super_combine_consts<R>(
&self,
relation: &mut R,
a: I::Const,
b: I::Const,
) -> RelateResult<I, I::Const>
where
R: PredicateEmittingRelation<Infcx>,
{
debug!("super_combine_consts::<{}>({:?}, {:?})", std::any::type_name::<R>(), a, b);
debug_assert!(!a.has_escaping_bound_vars());
debug_assert!(!b.has_escaping_bound_vars());
if a == b {
return Ok(a);
}
let a = self.shallow_resolve_const(a);
let b = self.shallow_resolve_const(b);
match (a.kind(), b.kind()) {
(
ty::ConstKind::Infer(ty::InferConst::Var(a_vid)),
ty::ConstKind::Infer(ty::InferConst::Var(b_vid)),
) => {
self.equate_const_vids_raw(a_vid, b_vid);
Ok(a)
}
(
ty::ConstKind::Infer(ty::InferConst::EffectVar(a_vid)),
ty::ConstKind::Infer(ty::InferConst::EffectVar(b_vid)),
) => {
self.equate_effect_vids_raw(a_vid, b_vid);
Ok(a)
}
// All other cases of inference with other variables are errors.
(
ty::ConstKind::Infer(ty::InferConst::Var(_) | ty::InferConst::EffectVar(_)),
ty::ConstKind::Infer(_),
)
| (
ty::ConstKind::Infer(_),
ty::ConstKind::Infer(ty::InferConst::Var(_) | ty::InferConst::EffectVar(_)),
) => {
panic!(
"tried to combine ConstKind::Infer/ConstKind::Infer(InferConst::Var): {a:?} and {b:?}"
)
}
(ty::ConstKind::Infer(ty::InferConst::Var(vid)), _) => {
self.instantiate_const_var_raw(relation, true, vid, b)?;
Ok(b)
}
(_, ty::ConstKind::Infer(ty::InferConst::Var(vid))) => {
self.instantiate_const_var_raw(relation, false, vid, a)?;
Ok(a)
}
(ty::ConstKind::Infer(ty::InferConst::EffectVar(vid)), _) => {
self.instantiate_effect_var_raw(vid, b);
Ok(b)
}
(_, ty::ConstKind::Infer(ty::InferConst::EffectVar(vid))) => {
self.instantiate_effect_var_raw(vid, a);
Ok(a)
}
(ty::ConstKind::Unevaluated(..), _) | (_, ty::ConstKind::Unevaluated(..))
if self.cx().features().generic_const_exprs() || self.next_trait_solver() =>
{
match relation.structurally_relate_aliases() {
StructurallyRelateAliases::No => {
relation.register_predicates([if self.next_trait_solver() {
ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Equate,
)
} else {
ty::PredicateKind::ConstEquate(a, b)
}]);
Ok(b)
}
StructurallyRelateAliases::Yes => structurally_relate_consts(relation, a, b),
}
}
_ => structurally_relate_consts(relation, a, b),
}
}
}