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Diffstat (limited to 'compiler/rustc_type_ir/src/sty.rs')
| -rw-r--r-- | compiler/rustc_type_ir/src/sty.rs | 1329 |
1 files changed, 1329 insertions, 0 deletions
diff --git a/compiler/rustc_type_ir/src/sty.rs b/compiler/rustc_type_ir/src/sty.rs new file mode 100644 index 000000000..74737e30b --- /dev/null +++ b/compiler/rustc_type_ir/src/sty.rs @@ -0,0 +1,1329 @@ +#![allow(rustc::usage_of_ty_tykind)] + +use std::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd}; +use std::{fmt, hash}; + +use crate::DebruijnIndex; +use crate::FloatTy; +use crate::IntTy; +use crate::Interner; +use crate::TyDecoder; +use crate::TyEncoder; +use crate::UintTy; +use crate::UniverseIndex; + +use self::RegionKind::*; +use self::TyKind::*; + +use rustc_data_structures::stable_hasher::HashStable; +use rustc_serialize::{Decodable, Decoder, Encodable}; + +/// Defines the kinds of types used by the type system. +/// +/// Types written by the user start out as `hir::TyKind` and get +/// converted to this representation using `AstConv::ast_ty_to_ty`. +#[rustc_diagnostic_item = "IrTyKind"] +pub enum TyKind<I: Interner> { + /// The primitive boolean type. Written as `bool`. + Bool, + + /// The primitive character type; holds a Unicode scalar value + /// (a non-surrogate code point). Written as `char`. + Char, + + /// A primitive signed integer type. For example, `i32`. + Int(IntTy), + + /// A primitive unsigned integer type. For example, `u32`. + Uint(UintTy), + + /// A primitive floating-point type. For example, `f64`. + Float(FloatTy), + + /// Algebraic data types (ADT). For example: structures, enumerations and unions. + /// + /// For example, the type `List<i32>` would be represented using the `AdtDef` + /// for `struct List<T>` and the substs `[i32]`. + /// + /// Note that generic parameters in fields only get lazily substituted + /// by using something like `adt_def.all_fields().map(|field| field.ty(tcx, substs))`. + Adt(I::AdtDef, I::SubstsRef), + + /// An unsized FFI type that is opaque to Rust. Written as `extern type T`. + Foreign(I::DefId), + + /// The pointee of a string slice. Written as `str`. + Str, + + /// An array with the given length. Written as `[T; N]`. + Array(I::Ty, I::Const), + + /// The pointee of an array slice. Written as `[T]`. + Slice(I::Ty), + + /// A raw pointer. Written as `*mut T` or `*const T` + RawPtr(I::TypeAndMut), + + /// A reference; a pointer with an associated lifetime. Written as + /// `&'a mut T` or `&'a T`. + Ref(I::Region, I::Ty, I::Mutability), + + /// The anonymous type of a function declaration/definition. Each + /// function has a unique type. + /// + /// For the function `fn foo() -> i32 { 3 }` this type would be + /// shown to the user as `fn() -> i32 {foo}`. + /// + /// For example the type of `bar` here: + /// ```rust + /// fn foo() -> i32 { 1 } + /// let bar = foo; // bar: fn() -> i32 {foo} + /// ``` + FnDef(I::DefId, I::SubstsRef), + + /// A pointer to a function. Written as `fn() -> i32`. + /// + /// Note that both functions and closures start out as either + /// [FnDef] or [Closure] which can be then be coerced to this variant. + /// + /// For example the type of `bar` here: + /// + /// ```rust + /// fn foo() -> i32 { 1 } + /// let bar: fn() -> i32 = foo; + /// ``` + FnPtr(I::PolyFnSig), + + /// A trait object. Written as `dyn for<'b> Trait<'b, Assoc = u32> + Send + 'a`. + Dynamic(I::ListBinderExistentialPredicate, I::Region), + + /// The anonymous type of a closure. Used to represent the type of `|a| a`. + /// + /// Closure substs contain both the - potentially substituted - generic parameters + /// of its parent and some synthetic parameters. See the documentation for + /// `ClosureSubsts` for more details. + Closure(I::DefId, I::SubstsRef), + + /// The anonymous type of a generator. Used to represent the type of + /// `|a| yield a`. + /// + /// For more info about generator substs, visit the documentation for + /// `GeneratorSubsts`. + Generator(I::DefId, I::SubstsRef, I::Movability), + + /// A type representing the types stored inside a generator. + /// This should only appear as part of the `GeneratorSubsts`. + /// + /// Note that the captured variables for generators are stored separately + /// using a tuple in the same way as for closures. + /// + /// Unlike upvars, the witness can reference lifetimes from + /// inside of the generator itself. To deal with them in + /// the type of the generator, we convert them to higher ranked + /// lifetimes bound by the witness itself. + /// + /// Looking at the following example, the witness for this generator + /// may end up as something like `for<'a> [Vec<i32>, &'a Vec<i32>]`: + /// + /// ```ignore UNSOLVED (ask @compiler-errors, should this error? can we just swap the yields?) + /// #![feature(generators)] + /// |a| { + /// let x = &vec![3]; + /// yield a; + /// yield x[0]; + /// } + /// # ; + /// ``` + GeneratorWitness(I::BinderListTy), + + /// The never type `!`. + Never, + + /// A tuple type. For example, `(i32, bool)`. + Tuple(I::ListTy), + + /// The projection of an associated type. For example, + /// `<T as Trait<..>>::N`. + Projection(I::ProjectionTy), + + /// Opaque (`impl Trait`) type found in a return type. + /// + /// The `DefId` comes either from + /// * the `impl Trait` ast::Ty node, + /// * or the `type Foo = impl Trait` declaration + /// + /// For RPIT the substitutions are for the generics of the function, + /// while for TAIT it is used for the generic parameters of the alias. + /// + /// During codegen, `tcx.type_of(def_id)` can be used to get the underlying type. + Opaque(I::DefId, I::SubstsRef), + + /// A type parameter; for example, `T` in `fn f<T>(x: T) {}`. + Param(I::ParamTy), + + /// Bound type variable, used to represent the `'a` in `for<'a> fn(&'a ())`. + /// + /// For canonical queries, we replace inference variables with bound variables, + /// so e.g. when checking whether `&'_ (): Trait<_>` holds, we canonicalize that to + /// `for<'a, T> &'a (): Trait<T>` and then convert the introduced bound variables + /// back to inference variables in a new inference context when inside of the query. + /// + /// See the `rustc-dev-guide` for more details about + /// [higher-ranked trait bounds][1] and [canonical queries][2]. + /// + /// [1]: https://rustc-dev-guide.rust-lang.org/traits/hrtb.html + /// [2]: https://rustc-dev-guide.rust-lang.org/traits/canonical-queries.html + Bound(DebruijnIndex, I::BoundTy), + + /// A placeholder type, used during higher ranked subtyping to instantiate + /// bound variables. + Placeholder(I::PlaceholderType), + + /// A type variable used during type checking. + /// + /// Similar to placeholders, inference variables also live in a universe to + /// correctly deal with higher ranked types. Though unlike placeholders, + /// that universe is stored in the `InferCtxt` instead of directly + /// inside of the type. + Infer(I::InferTy), + + /// A placeholder for a type which could not be computed; this is + /// propagated to avoid useless error messages. + Error(I::DelaySpanBugEmitted), +} + +impl<I: Interner> TyKind<I> { + #[inline] + pub fn is_primitive(&self) -> bool { + matches!(self, Bool | Char | Int(_) | Uint(_) | Float(_)) + } +} + +// This is manually implemented for `TyKind` because `std::mem::discriminant` +// returns an opaque value that is `PartialEq` but not `PartialOrd` +#[inline] +const fn tykind_discriminant<I: Interner>(value: &TyKind<I>) -> usize { + match value { + Bool => 0, + Char => 1, + Int(_) => 2, + Uint(_) => 3, + Float(_) => 4, + Adt(_, _) => 5, + Foreign(_) => 6, + Str => 7, + Array(_, _) => 8, + Slice(_) => 9, + RawPtr(_) => 10, + Ref(_, _, _) => 11, + FnDef(_, _) => 12, + FnPtr(_) => 13, + Dynamic(_, _) => 14, + Closure(_, _) => 15, + Generator(_, _, _) => 16, + GeneratorWitness(_) => 17, + Never => 18, + Tuple(_) => 19, + Projection(_) => 20, + Opaque(_, _) => 21, + Param(_) => 22, + Bound(_, _) => 23, + Placeholder(_) => 24, + Infer(_) => 25, + Error(_) => 26, + } +} + +// This is manually implemented because a derive would require `I: Clone` +impl<I: Interner> Clone for TyKind<I> { + fn clone(&self) -> Self { + match self { + Bool => Bool, + Char => Char, + Int(i) => Int(i.clone()), + Uint(u) => Uint(u.clone()), + Float(f) => Float(f.clone()), + Adt(d, s) => Adt(d.clone(), s.clone()), + Foreign(d) => Foreign(d.clone()), + Str => Str, + Array(t, c) => Array(t.clone(), c.clone()), + Slice(t) => Slice(t.clone()), + RawPtr(t) => RawPtr(t.clone()), + Ref(r, t, m) => Ref(r.clone(), t.clone(), m.clone()), + FnDef(d, s) => FnDef(d.clone(), s.clone()), + FnPtr(s) => FnPtr(s.clone()), + Dynamic(p, r) => Dynamic(p.clone(), r.clone()), + Closure(d, s) => Closure(d.clone(), s.clone()), + Generator(d, s, m) => Generator(d.clone(), s.clone(), m.clone()), + GeneratorWitness(g) => GeneratorWitness(g.clone()), + Never => Never, + Tuple(t) => Tuple(t.clone()), + Projection(p) => Projection(p.clone()), + Opaque(d, s) => Opaque(d.clone(), s.clone()), + Param(p) => Param(p.clone()), + Bound(d, b) => Bound(d.clone(), b.clone()), + Placeholder(p) => Placeholder(p.clone()), + Infer(t) => Infer(t.clone()), + Error(e) => Error(e.clone()), + } + } +} + +// This is manually implemented because a derive would require `I: PartialEq` +impl<I: Interner> PartialEq for TyKind<I> { + #[inline] + fn eq(&self, other: &TyKind<I>) -> bool { + let __self_vi = tykind_discriminant(self); + let __arg_1_vi = tykind_discriminant(other); + if __self_vi == __arg_1_vi { + match (&*self, &*other) { + (&Int(ref __self_0), &Int(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Uint(ref __self_0), &Uint(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Float(ref __self_0), &Float(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Adt(ref __self_0, ref __self_1), &Adt(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&Foreign(ref __self_0), &Foreign(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Array(ref __self_0, ref __self_1), &Array(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&Slice(ref __self_0), &Slice(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&RawPtr(ref __self_0), &RawPtr(ref __arg_1_0)) => __self_0 == __arg_1_0, + ( + &Ref(ref __self_0, ref __self_1, ref __self_2), + &Ref(ref __arg_1_0, ref __arg_1_1, ref __arg_1_2), + ) => __self_0 == __arg_1_0 && __self_1 == __arg_1_1 && __self_2 == __arg_1_2, + (&FnDef(ref __self_0, ref __self_1), &FnDef(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&FnPtr(ref __self_0), &FnPtr(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Dynamic(ref __self_0, ref __self_1), &Dynamic(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&Closure(ref __self_0, ref __self_1), &Closure(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + ( + &Generator(ref __self_0, ref __self_1, ref __self_2), + &Generator(ref __arg_1_0, ref __arg_1_1, ref __arg_1_2), + ) => __self_0 == __arg_1_0 && __self_1 == __arg_1_1 && __self_2 == __arg_1_2, + (&GeneratorWitness(ref __self_0), &GeneratorWitness(ref __arg_1_0)) => { + __self_0 == __arg_1_0 + } + (&Tuple(ref __self_0), &Tuple(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Projection(ref __self_0), &Projection(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Opaque(ref __self_0, ref __self_1), &Opaque(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&Param(ref __self_0), &Param(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Bound(ref __self_0, ref __self_1), &Bound(ref __arg_1_0, ref __arg_1_1)) => { + __self_0 == __arg_1_0 && __self_1 == __arg_1_1 + } + (&Placeholder(ref __self_0), &Placeholder(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Infer(ref __self_0), &Infer(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&Error(ref __self_0), &Error(ref __arg_1_0)) => __self_0 == __arg_1_0, + _ => true, + } + } else { + false + } + } +} + +// This is manually implemented because a derive would require `I: Eq` +impl<I: Interner> Eq for TyKind<I> {} + +// This is manually implemented because a derive would require `I: PartialOrd` +impl<I: Interner> PartialOrd for TyKind<I> { + #[inline] + fn partial_cmp(&self, other: &TyKind<I>) -> Option<Ordering> { + Some(Ord::cmp(self, other)) + } +} + +// This is manually implemented because a derive would require `I: Ord` +impl<I: Interner> Ord for TyKind<I> { + #[inline] + fn cmp(&self, other: &TyKind<I>) -> Ordering { + let __self_vi = tykind_discriminant(self); + let __arg_1_vi = tykind_discriminant(other); + if __self_vi == __arg_1_vi { + match (&*self, &*other) { + (&Int(ref __self_0), &Int(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Uint(ref __self_0), &Uint(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Float(ref __self_0), &Float(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Adt(ref __self_0, ref __self_1), &Adt(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&Foreign(ref __self_0), &Foreign(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Array(ref __self_0, ref __self_1), &Array(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&Slice(ref __self_0), &Slice(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&RawPtr(ref __self_0), &RawPtr(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + ( + &Ref(ref __self_0, ref __self_1, ref __self_2), + &Ref(ref __arg_1_0, ref __arg_1_1, ref __arg_1_2), + ) => match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => match Ord::cmp(__self_1, __arg_1_1) { + Ordering::Equal => Ord::cmp(__self_2, __arg_1_2), + cmp => cmp, + }, + cmp => cmp, + }, + (&FnDef(ref __self_0, ref __self_1), &FnDef(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&FnPtr(ref __self_0), &FnPtr(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Dynamic(ref __self_0, ref __self_1), &Dynamic(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&Closure(ref __self_0, ref __self_1), &Closure(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + ( + &Generator(ref __self_0, ref __self_1, ref __self_2), + &Generator(ref __arg_1_0, ref __arg_1_1, ref __arg_1_2), + ) => match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => match Ord::cmp(__self_1, __arg_1_1) { + Ordering::Equal => Ord::cmp(__self_2, __arg_1_2), + cmp => cmp, + }, + cmp => cmp, + }, + (&GeneratorWitness(ref __self_0), &GeneratorWitness(ref __arg_1_0)) => { + Ord::cmp(__self_0, __arg_1_0) + } + (&Tuple(ref __self_0), &Tuple(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Projection(ref __self_0), &Projection(ref __arg_1_0)) => { + Ord::cmp(__self_0, __arg_1_0) + } + (&Opaque(ref __self_0, ref __self_1), &Opaque(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&Param(ref __self_0), &Param(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Bound(ref __self_0, ref __self_1), &Bound(ref __arg_1_0, ref __arg_1_1)) => { + match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + } + } + (&Placeholder(ref __self_0), &Placeholder(ref __arg_1_0)) => { + Ord::cmp(__self_0, __arg_1_0) + } + (&Infer(ref __self_0), &Infer(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&Error(ref __self_0), &Error(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + _ => Ordering::Equal, + } + } else { + Ord::cmp(&__self_vi, &__arg_1_vi) + } + } +} + +// This is manually implemented because a derive would require `I: Hash` +impl<I: Interner> hash::Hash for TyKind<I> { + fn hash<__H: hash::Hasher>(&self, state: &mut __H) -> () { + match (&*self,) { + (&Int(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Uint(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Float(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Adt(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Foreign(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Array(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Slice(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&RawPtr(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Ref(ref __self_0, ref __self_1, ref __self_2),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state); + hash::Hash::hash(__self_2, state) + } + (&FnDef(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&FnPtr(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Dynamic(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Closure(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Generator(ref __self_0, ref __self_1, ref __self_2),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state); + hash::Hash::hash(__self_2, state) + } + (&GeneratorWitness(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Tuple(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Projection(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Opaque(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Param(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Bound(ref __self_0, ref __self_1),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&Placeholder(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Infer(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&Error(ref __self_0),) => { + hash::Hash::hash(&tykind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + _ => hash::Hash::hash(&tykind_discriminant(self), state), + } + } +} + +// This is manually implemented because a derive would require `I: Debug` +impl<I: Interner> fmt::Debug for TyKind<I> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + use std::fmt::*; + match self { + Bool => Formatter::write_str(f, "Bool"), + Char => Formatter::write_str(f, "Char"), + Int(f0) => Formatter::debug_tuple_field1_finish(f, "Int", f0), + Uint(f0) => Formatter::debug_tuple_field1_finish(f, "Uint", f0), + Float(f0) => Formatter::debug_tuple_field1_finish(f, "Float", f0), + Adt(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Adt", f0, f1), + Foreign(f0) => Formatter::debug_tuple_field1_finish(f, "Foreign", f0), + Str => Formatter::write_str(f, "Str"), + Array(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Array", f0, f1), + Slice(f0) => Formatter::debug_tuple_field1_finish(f, "Slice", f0), + RawPtr(f0) => Formatter::debug_tuple_field1_finish(f, "RawPtr", f0), + Ref(f0, f1, f2) => Formatter::debug_tuple_field3_finish(f, "Ref", f0, f1, f2), + FnDef(f0, f1) => Formatter::debug_tuple_field2_finish(f, "FnDef", f0, f1), + FnPtr(f0) => Formatter::debug_tuple_field1_finish(f, "FnPtr", f0), + Dynamic(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Dynamic", f0, f1), + Closure(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Closure", f0, f1), + Generator(f0, f1, f2) => { + Formatter::debug_tuple_field3_finish(f, "Generator", f0, f1, f2) + } + GeneratorWitness(f0) => Formatter::debug_tuple_field1_finish(f, "GeneratorWitness", f0), + Never => Formatter::write_str(f, "Never"), + Tuple(f0) => Formatter::debug_tuple_field1_finish(f, "Tuple", f0), + Projection(f0) => Formatter::debug_tuple_field1_finish(f, "Projection", f0), + Opaque(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Opaque", f0, f1), + Param(f0) => Formatter::debug_tuple_field1_finish(f, "Param", f0), + Bound(f0, f1) => Formatter::debug_tuple_field2_finish(f, "Bound", f0, f1), + Placeholder(f0) => Formatter::debug_tuple_field1_finish(f, "Placeholder", f0), + Infer(f0) => Formatter::debug_tuple_field1_finish(f, "Infer", f0), + TyKind::Error(f0) => Formatter::debug_tuple_field1_finish(f, "Error", f0), + } + } +} + +// This is manually implemented because a derive would require `I: Encodable` +impl<I: Interner, E: TyEncoder> Encodable<E> for TyKind<I> +where + I::DelaySpanBugEmitted: Encodable<E>, + I::AdtDef: Encodable<E>, + I::SubstsRef: Encodable<E>, + I::DefId: Encodable<E>, + I::Ty: Encodable<E>, + I::Const: Encodable<E>, + I::Region: Encodable<E>, + I::TypeAndMut: Encodable<E>, + I::Mutability: Encodable<E>, + I::Movability: Encodable<E>, + I::PolyFnSig: Encodable<E>, + I::ListBinderExistentialPredicate: Encodable<E>, + I::BinderListTy: Encodable<E>, + I::ListTy: Encodable<E>, + I::ProjectionTy: Encodable<E>, + I::ParamTy: Encodable<E>, + I::BoundTy: Encodable<E>, + I::PlaceholderType: Encodable<E>, + I::InferTy: Encodable<E>, + I::DelaySpanBugEmitted: Encodable<E>, + I::PredicateKind: Encodable<E>, + I::AllocId: Encodable<E>, +{ + fn encode(&self, e: &mut E) { + let disc = tykind_discriminant(self); + match self { + Bool => e.emit_enum_variant(disc, |_| {}), + Char => e.emit_enum_variant(disc, |_| {}), + Int(i) => e.emit_enum_variant(disc, |e| { + i.encode(e); + }), + Uint(u) => e.emit_enum_variant(disc, |e| { + u.encode(e); + }), + Float(f) => e.emit_enum_variant(disc, |e| { + f.encode(e); + }), + Adt(adt, substs) => e.emit_enum_variant(disc, |e| { + adt.encode(e); + substs.encode(e); + }), + Foreign(def_id) => e.emit_enum_variant(disc, |e| { + def_id.encode(e); + }), + Str => e.emit_enum_variant(disc, |_| {}), + Array(t, c) => e.emit_enum_variant(disc, |e| { + t.encode(e); + c.encode(e); + }), + Slice(t) => e.emit_enum_variant(disc, |e| { + t.encode(e); + }), + RawPtr(tam) => e.emit_enum_variant(disc, |e| { + tam.encode(e); + }), + Ref(r, t, m) => e.emit_enum_variant(disc, |e| { + r.encode(e); + t.encode(e); + m.encode(e); + }), + FnDef(def_id, substs) => e.emit_enum_variant(disc, |e| { + def_id.encode(e); + substs.encode(e); + }), + FnPtr(polyfnsig) => e.emit_enum_variant(disc, |e| { + polyfnsig.encode(e); + }), + Dynamic(l, r) => e.emit_enum_variant(disc, |e| { + l.encode(e); + r.encode(e); + }), + Closure(def_id, substs) => e.emit_enum_variant(disc, |e| { + def_id.encode(e); + substs.encode(e); + }), + Generator(def_id, substs, m) => e.emit_enum_variant(disc, |e| { + def_id.encode(e); + substs.encode(e); + m.encode(e); + }), + GeneratorWitness(b) => e.emit_enum_variant(disc, |e| { + b.encode(e); + }), + Never => e.emit_enum_variant(disc, |_| {}), + Tuple(substs) => e.emit_enum_variant(disc, |e| { + substs.encode(e); + }), + Projection(p) => e.emit_enum_variant(disc, |e| { + p.encode(e); + }), + Opaque(def_id, substs) => e.emit_enum_variant(disc, |e| { + def_id.encode(e); + substs.encode(e); + }), + Param(p) => e.emit_enum_variant(disc, |e| { + p.encode(e); + }), + Bound(d, b) => e.emit_enum_variant(disc, |e| { + d.encode(e); + b.encode(e); + }), + Placeholder(p) => e.emit_enum_variant(disc, |e| { + p.encode(e); + }), + Infer(i) => e.emit_enum_variant(disc, |e| { + i.encode(e); + }), + Error(d) => e.emit_enum_variant(disc, |e| { + d.encode(e); + }), + } + } +} + +// This is manually implemented because a derive would require `I: Decodable` +impl<I: Interner, D: TyDecoder<I = I>> Decodable<D> for TyKind<I> +where + I::DelaySpanBugEmitted: Decodable<D>, + I::AdtDef: Decodable<D>, + I::SubstsRef: Decodable<D>, + I::DefId: Decodable<D>, + I::Ty: Decodable<D>, + I::Const: Decodable<D>, + I::Region: Decodable<D>, + I::TypeAndMut: Decodable<D>, + I::Mutability: Decodable<D>, + I::Movability: Decodable<D>, + I::PolyFnSig: Decodable<D>, + I::ListBinderExistentialPredicate: Decodable<D>, + I::BinderListTy: Decodable<D>, + I::ListTy: Decodable<D>, + I::ProjectionTy: Decodable<D>, + I::ParamTy: Decodable<D>, + I::BoundTy: Decodable<D>, + I::PlaceholderType: Decodable<D>, + I::InferTy: Decodable<D>, + I::DelaySpanBugEmitted: Decodable<D>, + I::PredicateKind: Decodable<D>, + I::AllocId: Decodable<D>, +{ + fn decode(d: &mut D) -> Self { + match Decoder::read_usize(d) { + 0 => Bool, + 1 => Char, + 2 => Int(Decodable::decode(d)), + 3 => Uint(Decodable::decode(d)), + 4 => Float(Decodable::decode(d)), + 5 => Adt(Decodable::decode(d), Decodable::decode(d)), + 6 => Foreign(Decodable::decode(d)), + 7 => Str, + 8 => Array(Decodable::decode(d), Decodable::decode(d)), + 9 => Slice(Decodable::decode(d)), + 10 => RawPtr(Decodable::decode(d)), + 11 => Ref(Decodable::decode(d), Decodable::decode(d), Decodable::decode(d)), + 12 => FnDef(Decodable::decode(d), Decodable::decode(d)), + 13 => FnPtr(Decodable::decode(d)), + 14 => Dynamic(Decodable::decode(d), Decodable::decode(d)), + 15 => Closure(Decodable::decode(d), Decodable::decode(d)), + 16 => Generator(Decodable::decode(d), Decodable::decode(d), Decodable::decode(d)), + 17 => GeneratorWitness(Decodable::decode(d)), + 18 => Never, + 19 => Tuple(Decodable::decode(d)), + 20 => Projection(Decodable::decode(d)), + 21 => Opaque(Decodable::decode(d), Decodable::decode(d)), + 22 => Param(Decodable::decode(d)), + 23 => Bound(Decodable::decode(d), Decodable::decode(d)), + 24 => Placeholder(Decodable::decode(d)), + 25 => Infer(Decodable::decode(d)), + 26 => Error(Decodable::decode(d)), + _ => panic!( + "{}", + format!( + "invalid enum variant tag while decoding `{}`, expected 0..{}", + "TyKind", 27, + ) + ), + } + } +} + +// This is not a derived impl because a derive would require `I: HashStable` +#[allow(rustc::usage_of_ty_tykind)] +impl<CTX, I: Interner> HashStable<CTX> for TyKind<I> +where + I::AdtDef: HashStable<CTX>, + I::DefId: HashStable<CTX>, + I::SubstsRef: HashStable<CTX>, + I::Ty: HashStable<CTX>, + I::Const: HashStable<CTX>, + I::TypeAndMut: HashStable<CTX>, + I::PolyFnSig: HashStable<CTX>, + I::ListBinderExistentialPredicate: HashStable<CTX>, + I::Region: HashStable<CTX>, + I::Movability: HashStable<CTX>, + I::Mutability: HashStable<CTX>, + I::BinderListTy: HashStable<CTX>, + I::ListTy: HashStable<CTX>, + I::ProjectionTy: HashStable<CTX>, + I::BoundTy: HashStable<CTX>, + I::ParamTy: HashStable<CTX>, + I::PlaceholderType: HashStable<CTX>, + I::InferTy: HashStable<CTX>, + I::DelaySpanBugEmitted: HashStable<CTX>, +{ + #[inline] + fn hash_stable( + &self, + __hcx: &mut CTX, + __hasher: &mut rustc_data_structures::stable_hasher::StableHasher, + ) { + std::mem::discriminant(self).hash_stable(__hcx, __hasher); + match self { + Bool => {} + Char => {} + Int(i) => { + i.hash_stable(__hcx, __hasher); + } + Uint(u) => { + u.hash_stable(__hcx, __hasher); + } + Float(f) => { + f.hash_stable(__hcx, __hasher); + } + Adt(adt, substs) => { + adt.hash_stable(__hcx, __hasher); + substs.hash_stable(__hcx, __hasher); + } + Foreign(def_id) => { + def_id.hash_stable(__hcx, __hasher); + } + Str => {} + Array(t, c) => { + t.hash_stable(__hcx, __hasher); + c.hash_stable(__hcx, __hasher); + } + Slice(t) => { + t.hash_stable(__hcx, __hasher); + } + RawPtr(tam) => { + tam.hash_stable(__hcx, __hasher); + } + Ref(r, t, m) => { + r.hash_stable(__hcx, __hasher); + t.hash_stable(__hcx, __hasher); + m.hash_stable(__hcx, __hasher); + } + FnDef(def_id, substs) => { + def_id.hash_stable(__hcx, __hasher); + substs.hash_stable(__hcx, __hasher); + } + FnPtr(polyfnsig) => { + polyfnsig.hash_stable(__hcx, __hasher); + } + Dynamic(l, r) => { + l.hash_stable(__hcx, __hasher); + r.hash_stable(__hcx, __hasher); + } + Closure(def_id, substs) => { + def_id.hash_stable(__hcx, __hasher); + substs.hash_stable(__hcx, __hasher); + } + Generator(def_id, substs, m) => { + def_id.hash_stable(__hcx, __hasher); + substs.hash_stable(__hcx, __hasher); + m.hash_stable(__hcx, __hasher); + } + GeneratorWitness(b) => { + b.hash_stable(__hcx, __hasher); + } + Never => {} + Tuple(substs) => { + substs.hash_stable(__hcx, __hasher); + } + Projection(p) => { + p.hash_stable(__hcx, __hasher); + } + Opaque(def_id, substs) => { + def_id.hash_stable(__hcx, __hasher); + substs.hash_stable(__hcx, __hasher); + } + Param(p) => { + p.hash_stable(__hcx, __hasher); + } + Bound(d, b) => { + d.hash_stable(__hcx, __hasher); + b.hash_stable(__hcx, __hasher); + } + Placeholder(p) => { + p.hash_stable(__hcx, __hasher); + } + Infer(i) => { + i.hash_stable(__hcx, __hasher); + } + Error(d) => { + d.hash_stable(__hcx, __hasher); + } + } + } +} + +/// Representation of regions. Note that the NLL checker uses a distinct +/// representation of regions. For this reason, it internally replaces all the +/// regions with inference variables -- the index of the variable is then used +/// to index into internal NLL data structures. See `rustc_const_eval::borrow_check` +/// module for more information. +/// +/// Note: operations are on the wrapper `Region` type, which is interned, +/// rather than this type. +/// +/// ## The Region lattice within a given function +/// +/// In general, the region lattice looks like +/// +/// ```text +/// static ----------+-----...------+ (greatest) +/// | | | +/// early-bound and | | +/// free regions | | +/// | | | +/// | | | +/// empty(root) placeholder(U1) | +/// | / | +/// | / placeholder(Un) +/// empty(U1) -- / +/// | / +/// ... / +/// | / +/// empty(Un) -------- (smallest) +/// ``` +/// +/// Early-bound/free regions are the named lifetimes in scope from the +/// function declaration. They have relationships to one another +/// determined based on the declared relationships from the +/// function. +/// +/// Note that inference variables and bound regions are not included +/// in this diagram. In the case of inference variables, they should +/// be inferred to some other region from the diagram. In the case of +/// bound regions, they are excluded because they don't make sense to +/// include -- the diagram indicates the relationship between free +/// regions. +/// +/// ## Inference variables +/// +/// During region inference, we sometimes create inference variables, +/// represented as `ReVar`. These will be inferred by the code in +/// `infer::lexical_region_resolve` to some free region from the +/// lattice above (the minimal region that meets the +/// constraints). +/// +/// During NLL checking, where regions are defined differently, we +/// also use `ReVar` -- in that case, the index is used to index into +/// the NLL region checker's data structures. The variable may in fact +/// represent either a free region or an inference variable, in that +/// case. +/// +/// ## Bound Regions +/// +/// These are regions that are stored behind a binder and must be substituted +/// with some concrete region before being used. There are two kind of +/// bound regions: early-bound, which are bound in an item's `Generics`, +/// and are substituted by an `InternalSubsts`, and late-bound, which are part of +/// higher-ranked types (e.g., `for<'a> fn(&'a ())`), and are substituted by +/// the likes of `liberate_late_bound_regions`. The distinction exists +/// because higher-ranked lifetimes aren't supported in all places. See [1][2]. +/// +/// Unlike `Param`s, bound regions are not supposed to exist "in the wild" +/// outside their binder, e.g., in types passed to type inference, and +/// should first be substituted (by placeholder regions, free regions, +/// or region variables). +/// +/// ## Placeholder and Free Regions +/// +/// One often wants to work with bound regions without knowing their precise +/// identity. For example, when checking a function, the lifetime of a borrow +/// can end up being assigned to some region parameter. In these cases, +/// it must be ensured that bounds on the region can't be accidentally +/// assumed without being checked. +/// +/// To do this, we replace the bound regions with placeholder markers, +/// which don't satisfy any relation not explicitly provided. +/// +/// There are two kinds of placeholder regions in rustc: `ReFree` and +/// `RePlaceholder`. When checking an item's body, `ReFree` is supposed +/// to be used. These also support explicit bounds: both the internally-stored +/// *scope*, which the region is assumed to outlive, as well as other +/// relations stored in the `FreeRegionMap`. Note that these relations +/// aren't checked when you `make_subregion` (or `eq_types`), only by +/// `resolve_regions_and_report_errors`. +/// +/// When working with higher-ranked types, some region relations aren't +/// yet known, so you can't just call `resolve_regions_and_report_errors`. +/// `RePlaceholder` is designed for this purpose. In these contexts, +/// there's also the risk that some inference variable laying around will +/// get unified with your placeholder region: if you want to check whether +/// `for<'a> Foo<'_>: 'a`, and you substitute your bound region `'a` +/// with a placeholder region `'%a`, the variable `'_` would just be +/// instantiated to the placeholder region `'%a`, which is wrong because +/// the inference variable is supposed to satisfy the relation +/// *for every value of the placeholder region*. To ensure that doesn't +/// happen, you can use `leak_check`. This is more clearly explained +/// by the [rustc dev guide]. +/// +/// [1]: https://smallcultfollowing.com/babysteps/blog/2013/10/29/intermingled-parameter-lists/ +/// [2]: https://smallcultfollowing.com/babysteps/blog/2013/11/04/intermingled-parameter-lists/ +/// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/hrtb.html +pub enum RegionKind<I: Interner> { + /// Region bound in a type or fn declaration which will be + /// substituted 'early' -- that is, at the same time when type + /// parameters are substituted. + ReEarlyBound(I::EarlyBoundRegion), + + /// Region bound in a function scope, which will be substituted when the + /// function is called. + ReLateBound(DebruijnIndex, I::BoundRegion), + + /// When checking a function body, the types of all arguments and so forth + /// that refer to bound region parameters are modified to refer to free + /// region parameters. + ReFree(I::FreeRegion), + + /// Static data that has an "infinite" lifetime. Top in the region lattice. + ReStatic, + + /// A region variable. Should not exist outside of type inference. + ReVar(I::RegionVid), + + /// A placeholder region -- basically, the higher-ranked version of `ReFree`. + /// Should not exist outside of type inference. + RePlaceholder(I::PlaceholderRegion), + + /// Empty lifetime is for data that is never accessed. We tag the + /// empty lifetime with a universe -- the idea is that we don't + /// want `exists<'a> { forall<'b> { 'b: 'a } }` to be satisfiable. + /// Therefore, the `'empty` in a universe `U` is less than all + /// regions visible from `U`, but not less than regions not visible + /// from `U`. + ReEmpty(UniverseIndex), + + /// Erased region, used by trait selection, in MIR and during codegen. + ReErased, +} + +// This is manually implemented for `RegionKind` because `std::mem::discriminant` +// returns an opaque value that is `PartialEq` but not `PartialOrd` +#[inline] +const fn regionkind_discriminant<I: Interner>(value: &RegionKind<I>) -> usize { + match value { + ReEarlyBound(_) => 0, + ReLateBound(_, _) => 1, + ReFree(_) => 2, + ReStatic => 3, + ReVar(_) => 4, + RePlaceholder(_) => 5, + ReEmpty(_) => 6, + ReErased => 7, + } +} + +// This is manually implemented because a derive would require `I: Copy` +impl<I: Interner> Copy for RegionKind<I> +where + I::EarlyBoundRegion: Copy, + I::BoundRegion: Copy, + I::FreeRegion: Copy, + I::RegionVid: Copy, + I::PlaceholderRegion: Copy, +{ +} + +// This is manually implemented because a derive would require `I: Clone` +impl<I: Interner> Clone for RegionKind<I> { + fn clone(&self) -> Self { + match self { + ReEarlyBound(a) => ReEarlyBound(a.clone()), + ReLateBound(a, b) => ReLateBound(a.clone(), b.clone()), + ReFree(a) => ReFree(a.clone()), + ReStatic => ReStatic, + ReVar(a) => ReVar(a.clone()), + RePlaceholder(a) => RePlaceholder(a.clone()), + ReEmpty(a) => ReEmpty(a.clone()), + ReErased => ReErased, + } + } +} + +// This is manually implemented because a derive would require `I: PartialEq` +impl<I: Interner> PartialEq for RegionKind<I> { + #[inline] + fn eq(&self, other: &RegionKind<I>) -> bool { + let __self_vi = regionkind_discriminant(self); + let __arg_1_vi = regionkind_discriminant(other); + if __self_vi == __arg_1_vi { + match (&*self, &*other) { + (&ReEarlyBound(ref __self_0), &ReEarlyBound(ref __arg_1_0)) => { + __self_0 == __arg_1_0 + } + ( + &ReLateBound(ref __self_0, ref __self_1), + &ReLateBound(ref __arg_1_0, ref __arg_1_1), + ) => __self_0 == __arg_1_0 && __self_1 == __arg_1_1, + (&ReFree(ref __self_0), &ReFree(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&ReStatic, &ReStatic) => true, + (&ReVar(ref __self_0), &ReVar(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&RePlaceholder(ref __self_0), &RePlaceholder(ref __arg_1_0)) => { + __self_0 == __arg_1_0 + } + (&ReEmpty(ref __self_0), &ReEmpty(ref __arg_1_0)) => __self_0 == __arg_1_0, + (&ReErased, &ReErased) => true, + _ => true, + } + } else { + false + } + } +} + +// This is manually implemented because a derive would require `I: Eq` +impl<I: Interner> Eq for RegionKind<I> {} + +// This is manually implemented because a derive would require `I: PartialOrd` +impl<I: Interner> PartialOrd for RegionKind<I> { + #[inline] + fn partial_cmp(&self, other: &RegionKind<I>) -> Option<Ordering> { + Some(Ord::cmp(self, other)) + } +} + +// This is manually implemented because a derive would require `I: Ord` +impl<I: Interner> Ord for RegionKind<I> { + #[inline] + fn cmp(&self, other: &RegionKind<I>) -> Ordering { + let __self_vi = regionkind_discriminant(self); + let __arg_1_vi = regionkind_discriminant(other); + if __self_vi == __arg_1_vi { + match (&*self, &*other) { + (&ReEarlyBound(ref __self_0), &ReEarlyBound(ref __arg_1_0)) => { + Ord::cmp(__self_0, __arg_1_0) + } + ( + &ReLateBound(ref __self_0, ref __self_1), + &ReLateBound(ref __arg_1_0, ref __arg_1_1), + ) => match Ord::cmp(__self_0, __arg_1_0) { + Ordering::Equal => Ord::cmp(__self_1, __arg_1_1), + cmp => cmp, + }, + (&ReFree(ref __self_0), &ReFree(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&ReStatic, &ReStatic) => Ordering::Equal, + (&ReVar(ref __self_0), &ReVar(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&RePlaceholder(ref __self_0), &RePlaceholder(ref __arg_1_0)) => { + Ord::cmp(__self_0, __arg_1_0) + } + (&ReEmpty(ref __self_0), &ReEmpty(ref __arg_1_0)) => Ord::cmp(__self_0, __arg_1_0), + (&ReErased, &ReErased) => Ordering::Equal, + _ => Ordering::Equal, + } + } else { + Ord::cmp(&__self_vi, &__arg_1_vi) + } + } +} + +// This is manually implemented because a derive would require `I: Hash` +impl<I: Interner> hash::Hash for RegionKind<I> { + fn hash<__H: hash::Hasher>(&self, state: &mut __H) -> () { + match (&*self,) { + (&ReEarlyBound(ref __self_0),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&ReLateBound(ref __self_0, ref __self_1),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state); + hash::Hash::hash(__self_1, state) + } + (&ReFree(ref __self_0),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&ReStatic,) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + } + (&ReVar(ref __self_0),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&RePlaceholder(ref __self_0),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&ReEmpty(ref __self_0),) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + hash::Hash::hash(__self_0, state) + } + (&ReErased,) => { + hash::Hash::hash(®ionkind_discriminant(self), state); + } + } + } +} + +// This is manually implemented because a derive would require `I: Debug` +impl<I: Interner> fmt::Debug for RegionKind<I> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + ReEarlyBound(ref data) => write!(f, "ReEarlyBound({:?})", data), + + ReLateBound(binder_id, ref bound_region) => { + write!(f, "ReLateBound({:?}, {:?})", binder_id, bound_region) + } + + ReFree(ref fr) => fr.fmt(f), + + ReStatic => write!(f, "ReStatic"), + + ReVar(ref vid) => vid.fmt(f), + + RePlaceholder(placeholder) => write!(f, "RePlaceholder({:?})", placeholder), + + ReEmpty(ui) => write!(f, "ReEmpty({:?})", ui), + + ReErased => write!(f, "ReErased"), + } + } +} + +// This is manually implemented because a derive would require `I: Encodable` +impl<I: Interner, E: TyEncoder> Encodable<E> for RegionKind<I> +where + I::EarlyBoundRegion: Encodable<E>, + I::BoundRegion: Encodable<E>, + I::FreeRegion: Encodable<E>, + I::RegionVid: Encodable<E>, + I::PlaceholderRegion: Encodable<E>, +{ + fn encode(&self, e: &mut E) { + let disc = regionkind_discriminant(self); + match self { + ReEarlyBound(a) => e.emit_enum_variant(disc, |e| { + a.encode(e); + }), + ReLateBound(a, b) => e.emit_enum_variant(disc, |e| { + a.encode(e); + b.encode(e); + }), + ReFree(a) => e.emit_enum_variant(disc, |e| { + a.encode(e); + }), + ReStatic => e.emit_enum_variant(disc, |_| {}), + ReVar(a) => e.emit_enum_variant(disc, |e| { + a.encode(e); + }), + RePlaceholder(a) => e.emit_enum_variant(disc, |e| { + a.encode(e); + }), + ReEmpty(a) => e.emit_enum_variant(disc, |e| { + a.encode(e); + }), + ReErased => e.emit_enum_variant(disc, |_| {}), + } + } +} + +// This is manually implemented because a derive would require `I: Decodable` +impl<I: Interner, D: TyDecoder<I = I>> Decodable<D> for RegionKind<I> +where + I::EarlyBoundRegion: Decodable<D>, + I::BoundRegion: Decodable<D>, + I::FreeRegion: Decodable<D>, + I::RegionVid: Decodable<D>, + I::PlaceholderRegion: Decodable<D>, +{ + fn decode(d: &mut D) -> Self { + match Decoder::read_usize(d) { + 0 => ReEarlyBound(Decodable::decode(d)), + 1 => ReLateBound(Decodable::decode(d), Decodable::decode(d)), + 2 => ReFree(Decodable::decode(d)), + 3 => ReStatic, + 4 => ReVar(Decodable::decode(d)), + 5 => RePlaceholder(Decodable::decode(d)), + 6 => ReEmpty(Decodable::decode(d)), + 7 => ReErased, + _ => panic!( + "{}", + format!( + "invalid enum variant tag while decoding `{}`, expected 0..{}", + "RegionKind", 8, + ) + ), + } + } +} + +// This is not a derived impl because a derive would require `I: HashStable` +impl<CTX, I: Interner> HashStable<CTX> for RegionKind<I> +where + I::EarlyBoundRegion: HashStable<CTX>, + I::BoundRegion: HashStable<CTX>, + I::FreeRegion: HashStable<CTX>, + I::RegionVid: HashStable<CTX>, + I::PlaceholderRegion: HashStable<CTX>, +{ + #[inline] + fn hash_stable( + &self, + hcx: &mut CTX, + hasher: &mut rustc_data_structures::stable_hasher::StableHasher, + ) { + std::mem::discriminant(self).hash_stable(hcx, hasher); + match self { + ReErased | ReStatic => { + // No variant fields to hash for these ... + } + ReEmpty(universe) => { + universe.hash_stable(hcx, hasher); + } + ReLateBound(db, br) => { + db.hash_stable(hcx, hasher); + br.hash_stable(hcx, hasher); + } + ReEarlyBound(eb) => { + eb.hash_stable(hcx, hasher); + } + ReFree(ref free_region) => { + free_region.hash_stable(hcx, hasher); + } + RePlaceholder(p) => { + p.hash_stable(hcx, hasher); + } + ReVar(reg) => { + reg.hash_stable(hcx, hasher); + } + } + } +} |