diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/type_check/relate_tys.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/context.rs | 69 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/relate/combine.rs | 245 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/relate/generalize.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/relate/lattice.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/relate/mod.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_infer/src/infer/relate/type_relating.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_next_trait_solver/src/lib.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_next_trait_solver/src/relate.rs | 15 | ||||
| -rw-r--r-- | compiler/rustc_next_trait_solver/src/relate/combine.rs | 34 | ||||
| -rw-r--r-- | compiler/rustc_type_ir/src/infer_ctxt.rs | 37 | ||||
| -rw-r--r-- | compiler/rustc_type_ir/src/relate.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_type_ir/src/relate/combine.rs | 255 |
13 files changed, 376 insertions, 305 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/relate_tys.rs b/compiler/rustc_borrowck/src/type_check/relate_tys.rs index bf079e813f1..e72c21e8fad 100644 --- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs +++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs @@ -11,6 +11,7 @@ use rustc_middle::span_bug; 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}; diff --git a/compiler/rustc_infer/src/infer/context.rs b/compiler/rustc_infer/src/infer/context.rs index c06836edcfb..10b22c98a0d 100644 --- a/compiler/rustc_infer/src/infer/context.rs +++ b/compiler/rustc_infer/src/infer/context.rs @@ -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 @@ impl<'tcx> InferCtxtLike for InferCtxt<'tcx> { 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 @@ impl<'tcx> InferCtxtLike for InferCtxt<'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 diff --git a/compiler/rustc_infer/src/infer/relate/combine.rs b/compiler/rustc_infer/src/infer/relate/combine.rs deleted file mode 100644 index f879fbc5578..00000000000 --- a/compiler/rustc_infer/src/infer/relate/combine.rs +++ /dev/null @@ -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 - } -} diff --git a/compiler/rustc_infer/src/infer/relate/generalize.rs b/compiler/rustc_infer/src/infer/relate/generalize.rs index 726a2296d11..7049444db9b 100644 --- a/compiler/rustc_infer/src/infer/relate/generalize.rs +++ b/compiler/rustc_infer/src/infer/relate/generalize.rs @@ -183,7 +183,7 @@ impl<'tcx> 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, diff --git a/compiler/rustc_infer/src/infer/relate/lattice.rs b/compiler/rustc_infer/src/infer/relate/lattice.rs index 8cec312abf7..fc208a08471 100644 --- a/compiler/rustc_infer/src/infer/relate/lattice.rs +++ b/compiler/rustc_infer/src/infer/relate/lattice.rs @@ -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; diff --git a/compiler/rustc_infer/src/infer/relate/mod.rs b/compiler/rustc_infer/src/infer/relate/mod.rs index baab5bb274a..e156f72d78d 100644 --- a/compiler/rustc_infer/src/infer/relate/mod.rs +++ b/compiler/rustc_infer/src/infer/relate/mod.rs @@ -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; diff --git a/compiler/rustc_infer/src/infer/relate/type_relating.rs b/compiler/rustc_infer/src/infer/relate/type_relating.rs index d99acabb825..d2dc4589103 100644 --- a/compiler/rustc_infer/src/infer/relate/type_relating.rs +++ b/compiler/rustc_infer/src/infer/relate/type_relating.rs @@ -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, }; diff --git a/compiler/rustc_next_trait_solver/src/lib.rs b/compiler/rustc_next_trait_solver/src/lib.rs index ca140500e2c..de74ac32804 100644 --- a/compiler/rustc_next_trait_solver/src/lib.rs +++ b/compiler/rustc_next_trait_solver/src/lib.rs @@ -12,6 +12,5 @@ pub mod canonicalizer; pub mod coherence; pub mod delegate; -pub mod relate; pub mod resolve; pub mod solve; diff --git a/compiler/rustc_next_trait_solver/src/relate.rs b/compiler/rustc_next_trait_solver/src/relate.rs deleted file mode 100644 index db819961bbd..00000000000 --- a/compiler/rustc_next_trait_solver/src/relate.rs +++ /dev/null @@ -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, -} diff --git a/compiler/rustc_next_trait_solver/src/relate/combine.rs b/compiler/rustc_next_trait_solver/src/relate/combine.rs deleted file mode 100644 index 96968327d8e..00000000000 --- a/compiler/rustc_next_trait_solver/src/relate/combine.rs +++ /dev/null @@ -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); -} diff --git a/compiler/rustc_type_ir/src/infer_ctxt.rs b/compiler/rustc_type_ir/src/infer_ctxt.rs index 1d0b2345b80..2f6476c6e23 100644 --- a/compiler/rustc_type_ir/src/infer_ctxt.rs +++ b/compiler/rustc_type_ir/src/infer_ctxt.rs @@ -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 @@ pub trait InferCtxtLike: Sized { 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 @@ pub trait InferCtxtLike: Sized { &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 diff --git a/compiler/rustc_type_ir/src/relate.rs b/compiler/rustc_type_ir/src/relate.rs index 9c725f34d8e..8e5d917e915 100644 --- a/compiler/rustc_type_ir/src/relate.rs +++ b/compiler/rustc_type_ir/src/relate.rs @@ -9,8 +9,22 @@ use crate::fold::TypeFoldable; 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` diff --git a/compiler/rustc_type_ir/src/relate/combine.rs b/compiler/rustc_type_ir/src/relate/combine.rs new file mode 100644 index 00000000000..9dfcde609c7 --- /dev/null +++ b/compiler/rustc_type_ir/src/relate/combine.rs @@ -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), + } + } +} |