diff options
Diffstat (limited to 'compiler/rustc_middle/src/ty/mod.rs')
| -rw-r--r-- | compiler/rustc_middle/src/ty/mod.rs | 333 |
1 files changed, 255 insertions, 78 deletions
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index a8d0dca37..aa8bfd317 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -53,7 +53,6 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{ExpnId, ExpnKind, Span}; use rustc_target::abi::{Align, FieldIdx, Integer, IntegerType, VariantIdx}; pub use rustc_target::abi::{ReprFlags, ReprOptions}; -use rustc_type_ir::WithCachedTypeInfo; pub use subst::*; pub use vtable::*; @@ -67,6 +66,10 @@ use std::{fmt, str}; pub use crate::ty::diagnostics::*; pub use rustc_type_ir::AliasKind::*; +pub use rustc_type_ir::ConstKind::{ + Bound as BoundCt, Error as ErrorCt, Expr as ExprCt, Infer as InferCt, Param as ParamCt, + Placeholder as PlaceholderCt, Unevaluated, Value, +}; pub use rustc_type_ir::DynKind::*; pub use rustc_type_ir::InferTy::*; pub use rustc_type_ir::RegionKind::*; @@ -82,7 +85,7 @@ pub use self::closure::{ CAPTURE_STRUCT_LOCAL, }; pub use self::consts::{ - Const, ConstData, ConstInt, ConstKind, Expr, InferConst, ScalarInt, UnevaluatedConst, ValTree, + Const, ConstData, ConstInt, Expr, InferConst, ScalarInt, UnevaluatedConst, ValTree, }; pub use self::context::{ tls, CtxtInterners, DeducedParamAttrs, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt, TyCtxtFeed, @@ -94,7 +97,7 @@ pub use self::rvalue_scopes::RvalueScopes; pub use self::sty::BoundRegionKind::*; pub use self::sty::{ AliasTy, Article, Binder, BoundRegion, BoundRegionKind, BoundTy, BoundTyKind, BoundVar, - BoundVariableKind, CanonicalPolyFnSig, ClosureSubsts, ClosureSubstsParts, ConstVid, + BoundVariableKind, CanonicalPolyFnSig, ClosureSubsts, ClosureSubstsParts, ConstKind, ConstVid, EarlyBoundRegion, ExistentialPredicate, ExistentialProjection, ExistentialTraitRef, FnSig, FreeRegion, GenSig, GeneratorSubsts, GeneratorSubstsParts, InlineConstSubsts, InlineConstSubstsParts, ParamConst, ParamTy, PolyExistentialPredicate, @@ -145,6 +148,7 @@ mod opaque_types; mod parameterized; mod rvalue_scopes; mod structural_impls; +#[cfg_attr(not(bootstrap), allow(hidden_glob_reexports))] mod sty; mod typeck_results; @@ -456,6 +460,11 @@ impl ty::EarlyBoundRegion { } } +/// A statement that can be proven by a trait solver. This includes things that may +/// show up in where clauses, such as trait predicates and projection predicates, +/// and also things that are emitted as part of type checking such as `ObjectSafe` +/// predicate which is emitted when a type is coerced to a trait object. +/// /// Use this rather than `PredicateKind`, whenever possible. #[derive(Clone, Copy, PartialEq, Eq, Hash, HashStable)] #[rustc_pass_by_value] @@ -487,11 +496,11 @@ impl<'tcx> Predicate<'tcx> { let kind = self .kind() .map_bound(|kind| match kind { - PredicateKind::Clause(Clause::Trait(TraitPredicate { + PredicateKind::Clause(ClauseKind::Trait(TraitPredicate { trait_ref, constness, polarity, - })) => Some(PredicateKind::Clause(Clause::Trait(TraitPredicate { + })) => Some(PredicateKind::Clause(ClauseKind::Trait(TraitPredicate { trait_ref, constness, polarity: polarity.flip()?, @@ -505,10 +514,10 @@ impl<'tcx> Predicate<'tcx> { } pub fn without_const(mut self, tcx: TyCtxt<'tcx>) -> Self { - if let PredicateKind::Clause(Clause::Trait(TraitPredicate { trait_ref, constness, polarity })) = self.kind().skip_binder() + if let PredicateKind::Clause(ClauseKind::Trait(TraitPredicate { trait_ref, constness, polarity })) = self.kind().skip_binder() && constness != BoundConstness::NotConst { - self = tcx.mk_predicate(self.kind().rebind(PredicateKind::Clause(Clause::Trait(TraitPredicate { + self = tcx.mk_predicate(self.kind().rebind(PredicateKind::Clause(ClauseKind::Trait(TraitPredicate { trait_ref, constness: BoundConstness::NotConst, polarity, @@ -520,10 +529,10 @@ impl<'tcx> Predicate<'tcx> { #[instrument(level = "debug", skip(tcx), ret)] pub fn is_coinductive(self, tcx: TyCtxt<'tcx>) -> bool { match self.kind().skip_binder() { - ty::PredicateKind::Clause(ty::Clause::Trait(data)) => { + ty::PredicateKind::Clause(ty::ClauseKind::Trait(data)) => { tcx.trait_is_coinductive(data.def_id()) } - ty::PredicateKind::WellFormed(_) => true, + ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(_)) => true, _ => false, } } @@ -536,21 +545,20 @@ impl<'tcx> Predicate<'tcx> { #[inline] pub fn allow_normalization(self) -> bool { match self.kind().skip_binder() { - PredicateKind::WellFormed(_) => false, - PredicateKind::Clause(Clause::Trait(_)) - | PredicateKind::Clause(Clause::RegionOutlives(_)) - | PredicateKind::Clause(Clause::TypeOutlives(_)) - | PredicateKind::Clause(Clause::Projection(_)) - | PredicateKind::Clause(Clause::ConstArgHasType(..)) + PredicateKind::Clause(ClauseKind::WellFormed(_)) => false, + PredicateKind::Clause(ClauseKind::Trait(_)) + | PredicateKind::Clause(ClauseKind::RegionOutlives(_)) + | PredicateKind::Clause(ClauseKind::TypeOutlives(_)) + | PredicateKind::Clause(ClauseKind::Projection(_)) + | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) | PredicateKind::AliasRelate(..) | PredicateKind::ObjectSafe(_) | PredicateKind::ClosureKind(_, _, _) | PredicateKind::Subtype(_) | PredicateKind::Coerce(_) - | PredicateKind::ConstEvaluatable(_) + | PredicateKind::Clause(ClauseKind::ConstEvaluatable(_)) | PredicateKind::ConstEquate(_, _) - | PredicateKind::Ambiguous - | PredicateKind::TypeWellFormedFromEnv(_) => true, + | PredicateKind::Ambiguous => true, } } } @@ -561,11 +569,77 @@ impl rustc_errors::IntoDiagnosticArg for Predicate<'_> { } } +impl rustc_errors::IntoDiagnosticArg for Clause<'_> { + fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> { + rustc_errors::DiagnosticArgValue::Str(std::borrow::Cow::Owned(self.to_string())) + } +} + +/// A subset of predicates which can be assumed by the trait solver. They show up in +/// an item's where clauses, hence the name `Clause`, and may either be user-written +/// (such as traits) or may be inserted during lowering. +#[derive(Clone, Copy, PartialEq, Eq, Hash, HashStable)] +#[rustc_pass_by_value] +pub struct Clause<'tcx>(Interned<'tcx, WithCachedTypeInfo<ty::Binder<'tcx, PredicateKind<'tcx>>>>); + +impl<'tcx> Clause<'tcx> { + pub fn as_predicate(self) -> Predicate<'tcx> { + Predicate(self.0) + } + + pub fn kind(self) -> Binder<'tcx, ClauseKind<'tcx>> { + self.0.internee.map_bound(|kind| match kind { + PredicateKind::Clause(clause) => clause, + _ => unreachable!(), + }) + } + + pub fn as_trait_clause(self) -> Option<Binder<'tcx, TraitPredicate<'tcx>>> { + let clause = self.kind(); + if let ty::ClauseKind::Trait(trait_clause) = clause.skip_binder() { + Some(clause.rebind(trait_clause)) + } else { + None + } + } + + pub fn as_projection_clause(self) -> Option<Binder<'tcx, ProjectionPredicate<'tcx>>> { + let clause = self.kind(); + if let ty::ClauseKind::Projection(projection_clause) = clause.skip_binder() { + Some(clause.rebind(projection_clause)) + } else { + None + } + } + + pub fn as_type_outlives_clause(self) -> Option<Binder<'tcx, TypeOutlivesPredicate<'tcx>>> { + let clause = self.kind(); + if let ty::ClauseKind::TypeOutlives(o) = clause.skip_binder() { + Some(clause.rebind(o)) + } else { + None + } + } + + pub fn as_region_outlives_clause(self) -> Option<Binder<'tcx, RegionOutlivesPredicate<'tcx>>> { + let clause = self.kind(); + if let ty::ClauseKind::RegionOutlives(o) = clause.skip_binder() { + Some(clause.rebind(o)) + } else { + None + } + } + + pub fn without_const(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + self.as_predicate().without_const(tcx).expect_clause() + } +} + #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] #[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] /// A clause is something that can appear in where bounds or be inferred /// by implied bounds. -pub enum Clause<'tcx> { +pub enum ClauseKind<'tcx> { /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be /// the `Self` type of the trait reference and `A`, `B`, and `C` /// would be the type parameters. @@ -584,16 +658,19 @@ pub enum Clause<'tcx> { /// Ensures that a const generic argument to a parameter `const N: u8` /// is of type `u8`. ConstArgHasType(Const<'tcx>, Ty<'tcx>), + + /// No syntax: `T` well-formed. + WellFormed(GenericArg<'tcx>), + + /// Constant initializer must evaluate successfully. + ConstEvaluatable(ty::Const<'tcx>), } #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] #[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub enum PredicateKind<'tcx> { /// Prove a clause - Clause(Clause<'tcx>), - - /// No syntax: `T` well-formed. - WellFormed(GenericArg<'tcx>), + Clause(ClauseKind<'tcx>), /// Trait must be object-safe. ObjectSafe(DefId), @@ -620,22 +697,14 @@ pub enum PredicateKind<'tcx> { /// logic. Coerce(CoercePredicate<'tcx>), - /// Constant initializer must evaluate successfully. - ConstEvaluatable(ty::Const<'tcx>), - /// Constants must be equal. The first component is the const that is expected. ConstEquate(Const<'tcx>, Const<'tcx>), - /// Represents a type found in the environment that we can use for implied bounds. - /// - /// Only used for Chalk. - TypeWellFormedFromEnv(Ty<'tcx>), - /// A marker predicate that is always ambiguous. /// Used for coherence to mark opaque types as possibly equal to each other but ambiguous. Ambiguous, - /// Separate from `Clause::Projection` which is used for normalization in new solver. + /// Separate from `ClauseKind::Projection` which is used for normalization in new solver. /// This predicate requires two terms to be equal to eachother. /// /// Only used for new solver @@ -672,7 +741,7 @@ pub struct CratePredicatesMap<'tcx> { pub predicates: FxHashMap<DefId, &'tcx [(Clause<'tcx>, Span)]>, } -impl<'tcx> Predicate<'tcx> { +impl<'tcx> Clause<'tcx> { /// Performs a substitution suitable for going from a /// poly-trait-ref to supertraits that must hold if that /// poly-trait-ref holds. This is slightly different from a normal @@ -682,7 +751,7 @@ impl<'tcx> Predicate<'tcx> { self, tcx: TyCtxt<'tcx>, trait_ref: &ty::PolyTraitRef<'tcx>, - ) -> Predicate<'tcx> { + ) -> Clause<'tcx> { // The interaction between HRTB and supertraits is not entirely // obvious. Let me walk you (and myself) through an example. // @@ -764,11 +833,17 @@ impl<'tcx> Predicate<'tcx> { let shifted_pred = tcx.shift_bound_var_indices(trait_bound_vars.len(), bound_pred.skip_binder()); // 2) Self: Bar1<'a, '^0.1> -> T: Bar1<'^0.0, '^0.1> - let new = EarlyBinder(shifted_pred).subst(tcx, trait_ref.skip_binder().substs); + let new = EarlyBinder::bind(shifted_pred).subst(tcx, trait_ref.skip_binder().substs); // 3) ['x] + ['b] -> ['x, 'b] let bound_vars = tcx.mk_bound_variable_kinds_from_iter(trait_bound_vars.iter().chain(pred_bound_vars)); - tcx.reuse_or_mk_predicate(self, ty::Binder::bind_with_vars(new, bound_vars)) + + // FIXME: Is it really perf sensitive to use reuse_or_mk_predicate here? + tcx.reuse_or_mk_predicate( + self.as_predicate(), + ty::Binder::bind_with_vars(PredicateKind::Clause(new), bound_vars), + ) + .expect_clause() } } @@ -1189,13 +1264,41 @@ impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> { } } -impl<'tcx> ToPredicate<'tcx> for Clause<'tcx> { +impl<'tcx> ToPredicate<'tcx> for ClauseKind<'tcx> { #[inline(always)] fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { tcx.mk_predicate(ty::Binder::dummy(ty::PredicateKind::Clause(self))) } } +impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, ClauseKind<'tcx>> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { + tcx.mk_predicate(self.map_bound(ty::PredicateKind::Clause)) + } +} + +impl<'tcx> ToPredicate<'tcx> for Clause<'tcx> { + #[inline(always)] + fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { + self.as_predicate() + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for ClauseKind<'tcx> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + tcx.mk_predicate(Binder::dummy(ty::PredicateKind::Clause(self))).expect_clause() + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for Binder<'tcx, ClauseKind<'tcx>> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + tcx.mk_predicate(self.map_bound(|clause| ty::PredicateKind::Clause(clause))).expect_clause() + } +} + impl<'tcx> ToPredicate<'tcx> for TraitRef<'tcx> { #[inline(always)] fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { @@ -1203,6 +1306,29 @@ impl<'tcx> ToPredicate<'tcx> for TraitRef<'tcx> { } } +impl<'tcx> ToPredicate<'tcx, TraitPredicate<'tcx>> for TraitRef<'tcx> { + #[inline(always)] + fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> TraitPredicate<'tcx> { + self.without_const() + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for TraitRef<'tcx> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + let p: Predicate<'tcx> = self.to_predicate(tcx); + p.expect_clause() + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for TraitPredicate<'tcx> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + let p: Predicate<'tcx> = self.to_predicate(tcx); + p.expect_clause() + } +} + impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, TraitRef<'tcx>> { #[inline(always)] fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { @@ -1211,6 +1337,14 @@ impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, TraitRef<'tcx>> { } } +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for Binder<'tcx, TraitRef<'tcx>> { + #[inline(always)] + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + let pred: PolyTraitPredicate<'tcx> = self.to_predicate(tcx); + pred.to_predicate(tcx) + } +} + impl<'tcx> ToPredicate<'tcx, PolyTraitPredicate<'tcx>> for Binder<'tcx, TraitRef<'tcx>> { #[inline(always)] fn to_predicate(self, _: TyCtxt<'tcx>) -> PolyTraitPredicate<'tcx> { @@ -1236,31 +1370,45 @@ impl<'tcx> ToPredicate<'tcx, PolyTraitPredicate<'tcx>> for TraitPredicate<'tcx> impl<'tcx> ToPredicate<'tcx> for PolyTraitPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { - self.map_bound(|p| PredicateKind::Clause(Clause::Trait(p))).to_predicate(tcx) + self.map_bound(|p| PredicateKind::Clause(ClauseKind::Trait(p))).to_predicate(tcx) + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for PolyTraitPredicate<'tcx> { + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + let p: Predicate<'tcx> = self.to_predicate(tcx); + p.expect_clause() } } impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { - self.map_bound(|p| PredicateKind::Clause(Clause::RegionOutlives(p))).to_predicate(tcx) + self.map_bound(|p| PredicateKind::Clause(ClauseKind::RegionOutlives(p))).to_predicate(tcx) } } impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { - self.map_bound(|p| PredicateKind::Clause(Clause::TypeOutlives(p))).to_predicate(tcx) + self.map_bound(|p| PredicateKind::Clause(ClauseKind::TypeOutlives(p))).to_predicate(tcx) } } impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { - self.map_bound(|p| PredicateKind::Clause(Clause::Projection(p))).to_predicate(tcx) + self.map_bound(|p| PredicateKind::Clause(ClauseKind::Projection(p))).to_predicate(tcx) + } +} + +impl<'tcx> ToPredicate<'tcx, Clause<'tcx>> for PolyProjectionPredicate<'tcx> { + fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Clause<'tcx> { + let p: Predicate<'tcx> = self.to_predicate(tcx); + p.expect_clause() } } impl<'tcx> ToPredicate<'tcx> for TraitPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { - PredicateKind::Clause(Clause::Trait(self)).to_predicate(tcx) + PredicateKind::Clause(ClauseKind::Trait(self)).to_predicate(tcx) } } @@ -1268,63 +1416,76 @@ impl<'tcx> Predicate<'tcx> { pub fn to_opt_poly_trait_pred(self) -> Option<PolyTraitPredicate<'tcx>> { let predicate = self.kind(); match predicate.skip_binder() { - PredicateKind::Clause(Clause::Trait(t)) => Some(predicate.rebind(t)), - PredicateKind::Clause(Clause::Projection(..)) - | PredicateKind::Clause(Clause::ConstArgHasType(..)) + PredicateKind::Clause(ClauseKind::Trait(t)) => Some(predicate.rebind(t)), + PredicateKind::Clause(ClauseKind::Projection(..)) + | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) - | PredicateKind::Clause(Clause::RegionOutlives(..)) - | PredicateKind::WellFormed(..) + | PredicateKind::Clause(ClauseKind::RegionOutlives(..)) + | PredicateKind::Clause(ClauseKind::WellFormed(..)) | PredicateKind::ObjectSafe(..) | PredicateKind::ClosureKind(..) - | PredicateKind::Clause(Clause::TypeOutlives(..)) - | PredicateKind::ConstEvaluatable(..) + | PredicateKind::Clause(ClauseKind::TypeOutlives(..)) + | PredicateKind::Clause(ClauseKind::ConstEvaluatable(..)) | PredicateKind::ConstEquate(..) - | PredicateKind::Ambiguous - | PredicateKind::TypeWellFormedFromEnv(..) => None, + | PredicateKind::Ambiguous => None, } } pub fn to_opt_poly_projection_pred(self) -> Option<PolyProjectionPredicate<'tcx>> { let predicate = self.kind(); match predicate.skip_binder() { - PredicateKind::Clause(Clause::Projection(t)) => Some(predicate.rebind(t)), - PredicateKind::Clause(Clause::Trait(..)) - | PredicateKind::Clause(Clause::ConstArgHasType(..)) + PredicateKind::Clause(ClauseKind::Projection(t)) => Some(predicate.rebind(t)), + PredicateKind::Clause(ClauseKind::Trait(..)) + | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) - | PredicateKind::Clause(Clause::RegionOutlives(..)) - | PredicateKind::WellFormed(..) + | PredicateKind::Clause(ClauseKind::RegionOutlives(..)) + | PredicateKind::Clause(ClauseKind::WellFormed(..)) | PredicateKind::ObjectSafe(..) | PredicateKind::ClosureKind(..) - | PredicateKind::Clause(Clause::TypeOutlives(..)) - | PredicateKind::ConstEvaluatable(..) + | PredicateKind::Clause(ClauseKind::TypeOutlives(..)) + | PredicateKind::Clause(ClauseKind::ConstEvaluatable(..)) | PredicateKind::ConstEquate(..) - | PredicateKind::Ambiguous - | PredicateKind::TypeWellFormedFromEnv(..) => None, + | PredicateKind::Ambiguous => None, } } pub fn to_opt_type_outlives(self) -> Option<PolyTypeOutlivesPredicate<'tcx>> { let predicate = self.kind(); match predicate.skip_binder() { - PredicateKind::Clause(Clause::TypeOutlives(data)) => Some(predicate.rebind(data)), - PredicateKind::Clause(Clause::Trait(..)) - | PredicateKind::Clause(Clause::ConstArgHasType(..)) - | PredicateKind::Clause(Clause::Projection(..)) + PredicateKind::Clause(ClauseKind::TypeOutlives(data)) => Some(predicate.rebind(data)), + PredicateKind::Clause(ClauseKind::Trait(..)) + | PredicateKind::Clause(ClauseKind::ConstArgHasType(..)) + | PredicateKind::Clause(ClauseKind::Projection(..)) | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) - | PredicateKind::Clause(Clause::RegionOutlives(..)) - | PredicateKind::WellFormed(..) + | PredicateKind::Clause(ClauseKind::RegionOutlives(..)) + | PredicateKind::Clause(ClauseKind::WellFormed(..)) | PredicateKind::ObjectSafe(..) | PredicateKind::ClosureKind(..) - | PredicateKind::ConstEvaluatable(..) + | PredicateKind::Clause(ClauseKind::ConstEvaluatable(..)) | PredicateKind::ConstEquate(..) - | PredicateKind::Ambiguous - | PredicateKind::TypeWellFormedFromEnv(..) => None, + | PredicateKind::Ambiguous => None, + } + } + + /// Matches a `PredicateKind::Clause` and turns it into a `Clause`, otherwise returns `None`. + pub fn as_clause(self) -> Option<Clause<'tcx>> { + match self.kind().skip_binder() { + PredicateKind::Clause(..) => Some(self.expect_clause()), + _ => None, + } + } + + /// Assert that the predicate is a clause. + pub fn expect_clause(self) -> Clause<'tcx> { + match self.kind().skip_binder() { + PredicateKind::Clause(..) => Clause(self.0), + _ => bug!("{self} is not a clause"), } } } @@ -1350,7 +1511,7 @@ impl<'tcx> Predicate<'tcx> { /// [usize:Bar<isize>]]`. #[derive(Clone, Debug, TypeFoldable, TypeVisitable)] pub struct InstantiatedPredicates<'tcx> { - pub predicates: Vec<Predicate<'tcx>>, + pub predicates: Vec<Clause<'tcx>>, pub spans: Vec<Span>, } @@ -1369,9 +1530,9 @@ impl<'tcx> InstantiatedPredicates<'tcx> { } impl<'tcx> IntoIterator for InstantiatedPredicates<'tcx> { - type Item = (Predicate<'tcx>, Span); + type Item = (Clause<'tcx>, Span); - type IntoIter = std::iter::Zip<std::vec::IntoIter<Predicate<'tcx>>, std::vec::IntoIter<Span>>; + type IntoIter = std::iter::Zip<std::vec::IntoIter<Clause<'tcx>>, std::vec::IntoIter<Span>>; fn into_iter(self) -> Self::IntoIter { debug_assert_eq!(self.predicates.len(), self.spans.len()); @@ -1380,10 +1541,10 @@ impl<'tcx> IntoIterator for InstantiatedPredicates<'tcx> { } impl<'a, 'tcx> IntoIterator for &'a InstantiatedPredicates<'tcx> { - type Item = (Predicate<'tcx>, Span); + type Item = (Clause<'tcx>, Span); type IntoIter = std::iter::Zip< - std::iter::Copied<std::slice::Iter<'a, Predicate<'tcx>>>, + std::iter::Copied<std::slice::Iter<'a, Clause<'tcx>>>, std::iter::Copied<std::slice::Iter<'a, Span>>, >; @@ -1496,7 +1657,7 @@ impl<'tcx> OpaqueHiddenType<'tcx> { /// identified by both a universe, as well as a name residing within that universe. Distinct bound /// regions/types/consts within the same universe simply have an unknown relationship to one /// another. -#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)] +#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)] #[derive(HashStable, TyEncodable, TyDecodable)] pub struct Placeholder<T> { pub universe: UniverseIndex, @@ -1533,7 +1694,7 @@ pub struct ParamEnv<'tcx> { /// want `Reveal::All`. /// /// Note: This is packed, use the reveal() method to access it. - packed: CopyTaggedPtr<&'tcx List<Predicate<'tcx>>, ParamTag, true>, + packed: CopyTaggedPtr<&'tcx List<Clause<'tcx>>, ParamTag, true>, } #[derive(Copy, Clone)] @@ -1599,7 +1760,7 @@ impl<'tcx> ParamEnv<'tcx> { } #[inline] - pub fn caller_bounds(self) -> &'tcx List<Predicate<'tcx>> { + pub fn caller_bounds(self) -> &'tcx List<Clause<'tcx>> { self.packed.pointer() } @@ -1633,7 +1794,7 @@ impl<'tcx> ParamEnv<'tcx> { /// Construct a trait environment with the given set of predicates. #[inline] pub fn new( - caller_bounds: &'tcx List<Predicate<'tcx>>, + caller_bounds: &'tcx List<Clause<'tcx>>, reveal: Reveal, constness: hir::Constness, ) -> Self { @@ -1874,6 +2035,22 @@ impl VariantDef { &self.fields[FieldIdx::from_u32(0)] } + + /// Returns the last field in this variant, if present. + #[inline] + pub fn tail_opt(&self) -> Option<&FieldDef> { + self.fields.raw.last() + } + + /// Returns the last field in this variant. + /// + /// # Panics + /// + /// Panics, if the variant has no fields. + #[inline] + pub fn tail(&self) -> &FieldDef { + self.tail_opt().expect("expected unsized ADT to have a tail field") + } } impl PartialEq for VariantDef { |