Uplift TypeAndMut and ClosureKind to rustc_type_ir

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -378,3 +378,9 @@ pub struct IndicateAnonymousLifetime {
     pub count: usize,
     pub suggestion: String,
 }
+
+impl IntoDiagnosticArg for type_ir::ClosureKind {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(self.as_str().into())
+    }
+}

compiler/rustc_hir_typeck/src/closure.rs

@@ -141,7 +141,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         debug!(?sig, ?opt_kind);
 
         let closure_kind_ty = match opt_kind {
-            Some(kind) => kind.to_ty(self.tcx),
+            Some(kind) => Ty::from_closure_kind(self.tcx, kind),
 
             // Create a type variable (for now) to represent the closure kind.
             // It will be unified during the upvar inference phase (`upvar.rs`)

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -2018,7 +2018,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let new_def_id = self.probe(|_| {
                         let trait_ref = ty::TraitRef::new(
                             self.tcx,
-                            call_kind.to_def_id(self.tcx),
+                            self.tcx.fn_trait_kind_to_def_id(call_kind)?,
                             [
                                 callee_ty,
                                 self.next_ty_var(TypeVariableOrigin {

compiler/rustc_hir_typeck/src/upvar.rs

@@ -261,7 +261,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Unify the (as yet unbound) type variable in the closure
             // args with the kind we inferred.
             let closure_kind_ty = closure_args.as_closure().kind_ty();
-            self.demand_eqtype(span, closure_kind.to_ty(self.tcx), closure_kind_ty);
+            self.demand_eqtype(
+                span,
+                Ty::from_closure_kind(self.tcx, closure_kind),
+                closure_kind_ty,
+            );
 
             // If we have an origin, store it.
             if let Some(mut origin) = origin {

compiler/rustc_middle/src/middle/lang_items.rs

@@ -36,6 +36,17 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    /// Given a [`ty::ClosureKind`], get the [`DefId`] of its corresponding `Fn`-family
+    /// trait, if it is defined.
+    pub fn fn_trait_kind_to_def_id(self, kind: ty::ClosureKind) -> Option<DefId> {
+        let items = self.lang_items();
+        match kind {
+            ty::ClosureKind::Fn => items.fn_trait(),
+            ty::ClosureKind::FnMut => items.fn_mut_trait(),
+            ty::ClosureKind::FnOnce => items.fn_once_trait(),
+        }
+    }
+
     /// Returns `true` if `id` is a `DefId` of [`Fn`], [`FnMut`] or [`FnOnce`] traits.
     pub fn is_fn_trait(self, id: DefId) -> bool {
         self.fn_trait_kind_from_def_id(id).is_some()

compiler/rustc_middle/src/mir/type_foldable.rs

@@ -15,7 +15,6 @@ TrivialTypeTraversalImpls! {
     UserTypeAnnotationIndex,
     BorrowKind,
     CastKind,
-    hir::Movability,
     BasicBlock,
     SwitchTargets,
     CoroutineKind,

compiler/rustc_middle/src/ty/closure.rs

@@ -7,14 +7,13 @@ use std::fmt::Write;
 
 use crate::query::Providers;
 use rustc_data_structures::fx::FxIndexMap;
-use rustc_errors::{DiagnosticArgValue, IntoDiagnosticArg};
-use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::{self as hir, LangItem};
+use rustc_hir as hir;
+use rustc_hir::def_id::LocalDefId;
 use rustc_span::def_id::LocalDefIdMap;
 use rustc_span::symbol::Ident;
 use rustc_span::{Span, Symbol};
 
-use super::{Ty, TyCtxt};
+use super::TyCtxt;
 
 use self::BorrowKind::*;
 
@@ -73,72 +72,6 @@ pub type RootVariableMinCaptureList<'tcx> = FxIndexMap<hir::HirId, MinCaptureLis
 /// Part of `MinCaptureInformationMap`; List of `CapturePlace`s.
 pub type MinCaptureList<'tcx> = Vec<CapturedPlace<'tcx>>;
 
-/// Represents the various closure traits in the language. This
-/// will determine the type of the environment (`self`, in the
-/// desugaring) argument that the closure expects.
-///
-/// You can get the environment type of a closure using
-/// `tcx.closure_env_ty()`.
-#[derive(Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
-#[derive(HashStable)]
-pub enum ClosureKind {
-    // Warning: Ordering is significant here! The ordering is chosen
-    // because the trait Fn is a subtrait of FnMut and so in turn, and
-    // hence we order it so that Fn < FnMut < FnOnce.
-    Fn,
-    FnMut,
-    FnOnce,
-}
-
-impl ClosureKind {
-    /// This is the initial value used when doing upvar inference.
-    pub const LATTICE_BOTTOM: ClosureKind = ClosureKind::Fn;
-
-    pub const fn as_str(self) -> &'static str {
-        match self {
-            ClosureKind::Fn => "Fn",
-            ClosureKind::FnMut => "FnMut",
-            ClosureKind::FnOnce => "FnOnce",
-        }
-    }
-
-    /// Returns `true` if a type that impls this closure kind
-    /// must also implement `other`.
-    pub fn extends(self, other: ty::ClosureKind) -> bool {
-        self <= other
-    }
-
-    /// Converts `self` to a [`DefId`] of the corresponding trait.
-    ///
-    /// Note: the inverse of this function is [`TyCtxt::fn_trait_kind_from_def_id`].
-    pub fn to_def_id(&self, tcx: TyCtxt<'_>) -> DefId {
-        tcx.require_lang_item(
-            match self {
-                ClosureKind::Fn => LangItem::Fn,
-                ClosureKind::FnMut => LangItem::FnMut,
-                ClosureKind::FnOnce => LangItem::FnOnce,
-            },
-            None,
-        )
-    }
-
-    /// Returns the representative scalar type for this closure kind.
-    /// See `Ty::to_opt_closure_kind` for more details.
-    pub fn to_ty<'tcx>(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
-        match self {
-            ClosureKind::Fn => tcx.types.i8,
-            ClosureKind::FnMut => tcx.types.i16,
-            ClosureKind::FnOnce => tcx.types.i32,
-        }
-    }
-}
-
-impl IntoDiagnosticArg for ClosureKind {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
-        DiagnosticArgValue::Str(self.as_str().into())
-    }
-}
-
 /// A composite describing a `Place` that is captured by a closure.
 #[derive(PartialEq, Clone, Debug, TyEncodable, TyDecodable, HashStable)]
 #[derive(TypeFoldable, TypeVisitable)]

compiler/rustc_middle/src/ty/context.rs

@@ -28,7 +28,7 @@ use crate::ty::{
     self, AdtDef, AdtDefData, AdtKind, Binder, Clause, Const, ConstData, GenericParamDefKind,
     ImplPolarity, List, ParamConst, ParamTy, PolyExistentialPredicate, PolyFnSig, Predicate,
     PredicateKind, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyVid,
-    TypeAndMut, Visibility,
+    Visibility,
 };
 use crate::ty::{GenericArg, GenericArgs, GenericArgsRef};
 use rustc_ast::{self as ast, attr};
@@ -88,7 +88,6 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type Term = ty::Term<'tcx>;
 
     type Binder<T> = Binder<'tcx, T>;
-    type TypeAndMut = TypeAndMut<'tcx>;
     type CanonicalVars = CanonicalVarInfos<'tcx>;
 
     type Ty = Ty<'tcx>;
@@ -128,12 +127,6 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type CoercePredicate = ty::CoercePredicate<'tcx>;
     type ClosureKind = ty::ClosureKind;
 
-    fn ty_and_mut_to_parts(
-        TypeAndMut { ty, mutbl }: TypeAndMut<'tcx>,
-    ) -> (Self::Ty, ty::Mutability) {
-        (ty, mutbl)
-    }
-
     fn mk_canonical_var_infos(self, infos: &[ty::CanonicalVarInfo<Self>]) -> Self::CanonicalVars {
         self.mk_canonical_var_infos(infos)
     }

compiler/rustc_middle/src/ty/mod.rs

@@ -75,7 +75,7 @@ pub use self::binding::BindingMode;
 pub use self::binding::BindingMode::*;
 pub use self::closure::{
     is_ancestor_or_same_capture, place_to_string_for_capture, BorrowKind, CaptureInfo,
-    CapturedPlace, ClosureKind, ClosureTypeInfo, MinCaptureInformationMap, MinCaptureList,
+    CapturedPlace, ClosureTypeInfo, MinCaptureInformationMap, MinCaptureList,
     RootVariableMinCaptureList, UpvarCapture, UpvarId, UpvarPath, CAPTURE_STRUCT_LOCAL,
 };
 pub use self::consts::{Const, ConstData, ConstInt, Expr, ScalarInt, UnevaluatedConst, ValTree};

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1680,7 +1680,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
         self.wrap_binder(&sig, |sig, cx| {
             define_scoped_cx!(cx);
 
-            p!(print(kind), "(");
+            p!(write("{kind}("));
             for (i, arg) in sig.inputs()[0].tuple_fields().iter().enumerate() {
                 if i > 0 {
                     p!(", ");
@@ -2754,6 +2754,10 @@ forward_display_to_print! {
 define_print! {
     (self, cx):
 
+    ty::TypeAndMut<'tcx> {
+        p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
+    }
+
     ty::ClauseKind<'tcx> {
         match *self {
             ty::ClauseKind::Trait(ref data) => {
@@ -2799,10 +2803,6 @@ define_print_and_forward_display! {
         p!("{{", comma_sep(self.iter()), "}}")
     }
 
-    ty::TypeAndMut<'tcx> {
-        p!(write("{}", self.mutbl.prefix_str()), print(self.ty))
-    }
-
     ty::ExistentialTraitRef<'tcx> {
         // Use a type that can't appear in defaults of type parameters.
         let dummy_self = Ty::new_fresh(cx.tcx(),0);
@@ -2943,10 +2943,6 @@ define_print_and_forward_display! {
         }
     }
 
-    ty::ClosureKind {
-        p!(write("{}", self.as_str()))
-    }
-
     ty::Predicate<'tcx> {
         p!(print(self.kind()))
     }

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -440,7 +440,6 @@ TrivialTypeTraversalImpls! {
 // interners).
 TrivialTypeTraversalAndLiftImpls! {
     ::rustc_hir::def_id::DefId,
-    ::rustc_hir::Mutability,
     ::rustc_hir::Unsafety,
     ::rustc_target::spec::abi::Abi,
     crate::ty::ClosureKind,

compiler/rustc_middle/src/ty/sty.rs

@@ -42,23 +42,18 @@ use rustc_type_ir::PredicateKind as IrPredicateKind;
 use rustc_type_ir::RegionKind as IrRegionKind;
 use rustc_type_ir::TyKind as IrTyKind;
 use rustc_type_ir::TyKind::*;
+use rustc_type_ir::TypeAndMut as IrTypeAndMut;
 
 use super::GenericParamDefKind;
 
-// Re-export the `TyKind` from `rustc_type_ir` here for convenience
+// Re-export and re-parameterize some `I = TyCtxt<'tcx>` types here
 #[rustc_diagnostic_item = "TyKind"]
 pub type TyKind<'tcx> = IrTyKind<TyCtxt<'tcx>>;
 pub type RegionKind<'tcx> = IrRegionKind<TyCtxt<'tcx>>;
 pub type ConstKind<'tcx> = IrConstKind<TyCtxt<'tcx>>;
 pub type PredicateKind<'tcx> = IrPredicateKind<TyCtxt<'tcx>>;
 pub type ClauseKind<'tcx> = IrClauseKind<TyCtxt<'tcx>>;
-
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
-#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)]
-pub struct TypeAndMut<'tcx> {
-    pub ty: Ty<'tcx>,
-    pub mutbl: hir::Mutability,
-}
+pub type TypeAndMut<'tcx> = IrTypeAndMut<TyCtxt<'tcx>>;
 
 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, TyEncodable, TyDecodable, Copy)]
 #[derive(HashStable)]
@@ -2816,6 +2811,15 @@ impl<'tcx> Ty<'tcx> {
         }
     }
 
+    /// Inverse of [`Ty::to_opt_closure_kind`].
+    pub fn from_closure_kind(tcx: TyCtxt<'tcx>, kind: ty::ClosureKind) -> Ty<'tcx> {
+        match kind {
+            ty::ClosureKind::Fn => tcx.types.i8,
+            ty::ClosureKind::FnMut => tcx.types.i16,
+            ty::ClosureKind::FnOnce => tcx.types.i32,
+        }
+    }
+
     /// Fast path helper for testing if a type is `Sized`.
     ///
     /// Returning true means the type is known to be sized. Returning

compiler/rustc_type_ir/src/interner.rs

@@ -3,8 +3,8 @@ use std::fmt::Debug;
 use std::hash::Hash;
 
 use crate::{
-    BoundVar, CanonicalVarInfo, ConstKind, DebruijnIndex, DebugWithInfcx, Mutability, RegionKind,
-    TyKind, UniverseIndex,
+    BoundVar, CanonicalVarInfo, ConstKind, DebruijnIndex, DebugWithInfcx, RegionKind, TyKind,
+    UniverseIndex,
 };
 
 pub trait Interner: Sized {
@@ -20,7 +20,6 @@ pub trait Interner: Sized {
     type Term: Copy + Debug + Hash + Ord;
 
     type Binder<T>;
-    type TypeAndMut: Copy + Debug + Hash + Ord;
     type CanonicalVars: Copy + Debug + Hash + Eq + IntoIterator<Item = CanonicalVarInfo<Self>>;
 
     // Kinds of tys
@@ -81,8 +80,6 @@ pub trait Interner: Sized {
     type CoercePredicate: Copy + Debug + Hash + Eq;
     type ClosureKind: Copy + Debug + Hash + Eq;
 
-    fn ty_and_mut_to_parts(ty_and_mut: Self::TypeAndMut) -> (Self::Ty, Mutability);
-
     fn mk_canonical_var_infos(self, infos: &[CanonicalVarInfo<Self>]) -> Self::CanonicalVars;
 
     // FIXME: We should not have all these constructors on `Interner`, but as functions on some trait.

compiler/rustc_type_ir/src/lib.rs

@@ -359,3 +359,45 @@ rustc_index::newtype_index! {
     #[gate_rustc_only]
     pub struct BoundVar {}
 }
+
+/// Represents the various closure traits in the language. This
+/// will determine the type of the environment (`self`, in the
+/// desugaring) argument that the closure expects.
+///
+/// You can get the environment type of a closure using
+/// `tcx.closure_env_ty()`.
+#[derive(Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash, Debug)]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
+pub enum ClosureKind {
+    // Warning: Ordering is significant here! The ordering is chosen
+    // because the trait Fn is a subtrait of FnMut and so in turn, and
+    // hence we order it so that Fn < FnMut < FnOnce.
+    Fn,
+    FnMut,
+    FnOnce,
+}
+
+impl ClosureKind {
+    /// This is the initial value used when doing upvar inference.
+    pub const LATTICE_BOTTOM: ClosureKind = ClosureKind::Fn;
+
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            ClosureKind::Fn => "Fn",
+            ClosureKind::FnMut => "FnMut",
+            ClosureKind::FnOnce => "FnOnce",
+        }
+    }
+
+    /// Returns `true` if a type that impls this closure kind
+    /// must also implement `other`.
+    pub fn extends(self, other: ClosureKind) -> bool {
+        self <= other
+    }
+}
+
+impl fmt::Display for ClosureKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.as_str().fmt(f)
+    }
+}

compiler/rustc_type_ir/src/macros.rs

@@ -51,4 +51,6 @@ TrivialTypeTraversalImpls! {
     crate::DebruijnIndex,
     crate::AliasRelationDirection,
     crate::UniverseIndex,
+    crate::Mutability,
+    crate::Movability,
 }