Auto merge of rust-lang#124982 - compiler-errors:uplift-trait-ref, r=…

…lcnr

Uplift `TraitRef` into `rustc_type_ir`

Emotional rollercoaster

r? lcnr

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -22,6 +22,7 @@ use rustc_middle::mir::{
     Operand, Place, PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind, Terminator,
     TerminatorKind, VarBindingForm,
 };
+use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::{
     self, suggest_constraining_type_params, PredicateKind, ToPredicate, Ty, TyCtxt,
     TypeSuperVisitable, TypeVisitor,

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -532,8 +532,11 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
 
         if let PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy) = context {
             let tcx = self.tcx();
-            let trait_ref =
-                ty::TraitRef::from_lang_item(tcx, LangItem::Copy, self.last_span, [place_ty.ty]);
+            let trait_ref = ty::TraitRef::new(
+                tcx,
+                tcx.require_lang_item(LangItem::Copy, Some(self.last_span)),
+                [place_ty.ty],
+            );
 
             // To have a `Copy` operand, the type `T` of the
             // value must be `Copy`. Note that we prove that `T: Copy`,
@@ -1273,10 +1276,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 
                 self.check_rvalue(body, rv, location);
                 if !self.unsized_feature_enabled() {
-                    let trait_ref = ty::TraitRef::from_lang_item(
+                    let trait_ref = ty::TraitRef::new(
                         tcx,
-                        LangItem::Sized,
-                        self.last_span,
+                        tcx.require_lang_item(LangItem::Sized, Some(self.last_span)),
                         [place_ty],
                     );
                     self.prove_trait_ref(
@@ -1925,8 +1927,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         Operand::Move(place) => {
                             // Make sure that repeated elements implement `Copy`.
                             let ty = place.ty(body, tcx).ty;
-                            let trait_ref =
-                                ty::TraitRef::from_lang_item(tcx, LangItem::Copy, span, [ty]);
+                            let trait_ref = ty::TraitRef::new(
+                                tcx,
+                                tcx.require_lang_item(LangItem::Copy, Some(span)),
+                                [ty],
+                            );
 
                             self.prove_trait_ref(
                                 trait_ref,
@@ -1939,7 +1944,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
 
             &Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, ty) => {
-                let trait_ref = ty::TraitRef::from_lang_item(tcx, LangItem::Sized, span, [ty]);
+                let trait_ref = ty::TraitRef::new(
+                    tcx,
+                    tcx.require_lang_item(LangItem::Sized, Some(span)),
+                    [ty],
+                );
 
                 self.prove_trait_ref(
                     trait_ref,
@@ -1952,7 +1961,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             Rvalue::ShallowInitBox(operand, ty) => {
                 self.check_operand(operand, location);
 
-                let trait_ref = ty::TraitRef::from_lang_item(tcx, LangItem::Sized, span, [*ty]);
+                let trait_ref = ty::TraitRef::new(
+                    tcx,
+                    tcx.require_lang_item(LangItem::Sized, Some(span)),
+                    [*ty],
+                );
 
                 self.prove_trait_ref(
                     trait_ref,
@@ -2050,10 +2063,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 
                     CastKind::PointerCoercion(PointerCoercion::Unsize) => {
                         let &ty = ty;
-                        let trait_ref = ty::TraitRef::from_lang_item(
+                        let trait_ref = ty::TraitRef::new(
                             tcx,
-                            LangItem::CoerceUnsized,
-                            span,
+                            tcx.require_lang_item(LangItem::CoerceUnsized, Some(span)),
                             [op.ty(body, tcx), ty],
                         );
 

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -8,7 +8,7 @@ use rustc_hir::def_id::DefId;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{ImplSource, Obligation, ObligationCause};
 use rustc_middle::mir::{self, CallSource};
-use rustc_middle::ty::print::with_no_trimmed_paths;
+use rustc_middle::ty::print::{with_no_trimmed_paths, PrintTraitRefExt as _};
 use rustc_middle::ty::{
     self, suggest_constraining_type_param, Closure, FnDef, FnPtr, GenericArgKind, GenericArgsRef,
     Param, TraitRef, Ty,

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -94,6 +94,12 @@ into_diag_arg_using_display!(
     ErrCode,
 );
 
+impl<I: rustc_type_ir::Interner> IntoDiagArg for rustc_type_ir::TraitRef<I> {
+    fn into_diag_arg(self) -> DiagArgValue {
+        self.to_string().into_diag_arg()
+    }
+}
+
 into_diag_arg_for_number!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize);
 
 impl IntoDiagArg for bool {

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -14,6 +14,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::infer::{self, RegionResolutionError};
 use rustc_infer::traits::Obligation;
 use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
+use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::{self, suggest_constraining_type_params, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;

compiler/rustc_hir_analysis/src/coherence/unsafety.rs

@@ -3,6 +3,7 @@
 
 use rustc_errors::{codes::*, struct_span_code_err};
 use rustc_hir::Unsafety;
+use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::{ImplPolarity::*, ImplTraitHeader, TraitDef, TyCtxt};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::ErrorGuaranteed;

compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs

@@ -5,6 +5,7 @@ use rustc_errors::{codes::*, struct_span_code_err};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TyCtxt};
 use rustc_span::symbol::Ident;
 use rustc_span::{ErrorGuaranteed, Span, Symbol};

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -17,6 +17,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_infer::traits::FulfillmentError;
 use rustc_middle::query::Key;
+use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::{self, suggest_constraining_type_param};
 use rustc_middle::ty::{AdtDef, Ty, TyCtxt, TypeVisitableExt};

compiler/rustc_hir_typeck/src/coercion.rs

@@ -758,10 +758,9 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             self.tcx,
             self.cause.clone(),
             self.param_env,
-            ty::TraitRef::from_lang_item(
+            ty::TraitRef::new(
                 self.tcx,
-                hir::LangItem::PointerLike,
-                self.cause.span,
+                self.tcx.require_lang_item(hir::LangItem::PointerLike, Some(self.cause.span)),
                 [a],
             ),
         ));

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -25,7 +25,9 @@ use rustc_hir::{ExprKind, Node, QPath};
 use rustc_infer::infer::{self, RegionVariableOrigin};
 use rustc_middle::ty::fast_reject::DeepRejectCtxt;
 use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
-use rustc_middle::ty::print::{with_crate_prefix, with_forced_trimmed_paths};
+use rustc_middle::ty::print::{
+    with_crate_prefix, with_forced_trimmed_paths, PrintTraitRefExt as _,
+};
 use rustc_middle::ty::IsSuggestable;
 use rustc_middle::ty::{self, GenericArgKind, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::DefIdSet;

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -70,7 +70,7 @@ use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
 use rustc_macros::extension;
 use rustc_middle::dep_graph::DepContext;
-use rustc_middle::ty::print::{with_forced_trimmed_paths, PrintError};
+use rustc_middle::ty::print::{with_forced_trimmed_paths, PrintError, PrintTraitRefExt as _};
 use rustc_middle::ty::relate::{self, RelateResult, TypeRelation};
 use rustc_middle::ty::ToPredicate;
 use rustc_middle::ty::{

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs

@@ -12,7 +12,7 @@ use rustc_errors::{Diag, IntoDiagArg};
 use rustc_hir::def::Namespace;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::error::ExpectedFound;
-use rustc_middle::ty::print::{FmtPrinter, Print, RegionHighlightMode};
+use rustc_middle::ty::print::{FmtPrinter, Print, PrintTraitRefExt as _, RegionHighlightMode};
 use rustc_middle::ty::GenericArgsRef;
 use rustc_middle::ty::{self, RePlaceholder, Region, TyCtxt};
 

compiler/rustc_lint/src/context.rs

@@ -30,7 +30,7 @@ use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::bug;
 use rustc_middle::middle::privacy::EffectiveVisibilities;
 use rustc_middle::ty::layout::{LayoutError, LayoutOfHelpers, TyAndLayout};
-use rustc_middle::ty::print::{with_no_trimmed_paths, PrintError};
+use rustc_middle::ty::print::{with_no_trimmed_paths, PrintError, PrintTraitRefExt as _};
 use rustc_middle::ty::{self, print::Printer, GenericArg, RegisteredTools, Ty, TyCtxt};
 use rustc_session::lint::{BuiltinLintDiag, LintExpectationId};
 use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId};

compiler/rustc_macros/src/lift.rs

@@ -41,7 +41,7 @@ pub fn lift_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStre
 
     s.add_impl_generic(newtcx);
     s.bound_impl(
-        quote!(::rustc_middle::ty::Lift<'__lifted>),
+        quote!(::rustc_middle::ty::Lift<::rustc_middle::ty::TyCtxt<'__lifted>>),
         quote! {
             type Lifted = #lifted;
 

compiler/rustc_middle/src/macros.rs

@@ -57,7 +57,7 @@ macro_rules! span_bug {
 macro_rules! TrivialLiftImpls {
     ($($ty:ty),+ $(,)?) => {
         $(
-            impl<'tcx> $crate::ty::Lift<'tcx> for $ty {
+            impl<'tcx> $crate::ty::Lift<$crate::ty::TyCtxt<'tcx>> for $ty {
                 type Lifted = Self;
                 fn lift_to_tcx(self, _: $crate::ty::TyCtxt<'tcx>) -> Option<Self> {
                     Some(self)

compiler/rustc_middle/src/ty/consts.rs

@@ -8,7 +8,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::LocalDefId;
 use rustc_macros::{HashStable, TyDecodable, TyEncodable};
 use rustc_type_ir::ConstKind as IrConstKind;
-use rustc_type_ir::{ConstTy, IntoKind, TypeFlags, WithCachedTypeInfo};
+use rustc_type_ir::{TypeFlags, WithCachedTypeInfo};
 
 mod int;
 mod kind;
@@ -30,7 +30,7 @@ rustc_data_structures::static_assert_size!(ConstKind<'_>, 32);
 #[rustc_pass_by_value]
 pub struct Const<'tcx>(pub(super) Interned<'tcx, WithCachedTypeInfo<ConstData<'tcx>>>);
 
-impl<'tcx> IntoKind for Const<'tcx> {
+impl<'tcx> rustc_type_ir::inherent::IntoKind for Const<'tcx> {
     type Kind = ConstKind<'tcx>;
 
     fn kind(self) -> ConstKind<'tcx> {
@@ -48,12 +48,6 @@ impl<'tcx> rustc_type_ir::visit::Flags for Const<'tcx> {
     }
 }
 
-impl<'tcx> ConstTy<TyCtxt<'tcx>> for Const<'tcx> {
-    fn ty(self) -> Ty<'tcx> {
-        self.ty()
-    }
-}
-
 /// Typed constant value.
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[derive(HashStable, TyEncodable, TyDecodable)]
@@ -180,7 +174,7 @@ impl<'tcx> Const<'tcx> {
     }
 }
 
-impl<'tcx> rustc_type_ir::new::Const<TyCtxt<'tcx>> for Const<'tcx> {
+impl<'tcx> rustc_type_ir::inherent::Const<TyCtxt<'tcx>> for Const<'tcx> {
     fn new_anon_bound(
         tcx: TyCtxt<'tcx>,
         debruijn: ty::DebruijnIndex,
@@ -189,6 +183,10 @@ impl<'tcx> rustc_type_ir::new::Const<TyCtxt<'tcx>> for Const<'tcx> {
     ) -> Self {
         Const::new_bound(tcx, debruijn, var, ty)
     }
+
+    fn ty(self) -> Ty<'tcx> {
+        self.ty()
+    }
 }
 
 impl<'tcx> Const<'tcx> {

compiler/rustc_middle/src/ty/context.rs

@@ -4,6 +4,8 @@
 
 pub mod tls;
 
+pub use rustc_type_ir::lift::Lift;
+
 use crate::arena::Arena;
 use crate::dep_graph::{DepGraph, DepKindStruct};
 use crate::infer::canonical::{CanonicalParamEnvCache, CanonicalVarInfo, CanonicalVarInfos};
@@ -138,6 +140,19 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     fn mk_canonical_var_infos(self, infos: &[ty::CanonicalVarInfo<Self>]) -> Self::CanonicalVars {
         self.mk_canonical_var_infos(infos)
     }
+
+    type GenericsOf = &'tcx ty::Generics;
+    fn generics_of(self, def_id: DefId) -> &'tcx ty::Generics {
+        self.generics_of(def_id)
+    }
+
+    fn check_and_mk_args(
+        self,
+        def_id: DefId,
+        args: impl IntoIterator<Item: Into<ty::GenericArg<'tcx>>>,
+    ) -> ty::GenericArgsRef<'tcx> {
+        self.check_and_mk_args(def_id, args)
+    }
 }
 
 type InternedSet<'tcx, T> = ShardedHashMap<InternedInSet<'tcx, T>, ()>;
@@ -917,7 +932,7 @@ impl<'tcx> TyCtxt<'tcx> {
         )
     }
 
-    pub fn lift<T: Lift<'tcx>>(self, value: T) -> Option<T::Lifted> {
+    pub fn lift<T: Lift<TyCtxt<'tcx>>>(self, value: T) -> Option<T::Lifted> {
         value.lift_to_tcx(self)
     }
 
@@ -1524,31 +1539,9 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-/// A trait implemented for all `X<'a>` types that can be safely and
-/// efficiently converted to `X<'tcx>` as long as they are part of the
-/// provided `TyCtxt<'tcx>`.
-/// This can be done, for example, for `Ty<'tcx>` or `GenericArgsRef<'tcx>`
-/// by looking them up in their respective interners.
-///
-/// However, this is still not the best implementation as it does
-/// need to compare the components, even for interned values.
-/// It would be more efficient if `TypedArena` provided a way to
-/// determine whether the address is in the allocated range.
-///
-/// `None` is returned if the value or one of the components is not part
-/// of the provided context.
-/// For `Ty`, `None` can be returned if either the type interner doesn't
-/// contain the `TyKind` key or if the address of the interned
-/// pointer differs. The latter case is possible if a primitive type,
-/// e.g., `()` or `u8`, was interned in a different context.
-pub trait Lift<'tcx>: fmt::Debug {
-    type Lifted: fmt::Debug + 'tcx;
-    fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted>;
-}
-
 macro_rules! nop_lift {
     ($set:ident; $ty:ty => $lifted:ty) => {
-        impl<'a, 'tcx> Lift<'tcx> for $ty {
+        impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for $ty {
             type Lifted = $lifted;
             fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 // Assert that the set has the right type.
@@ -1583,7 +1576,7 @@ macro_rules! nop_lift {
 
 macro_rules! nop_list_lift {
     ($set:ident; $ty:ty => $lifted:ty) => {
-        impl<'a, 'tcx> Lift<'tcx> for &'a List<$ty> {
+        impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for &'a List<$ty> {
             type Lifted = &'tcx List<$lifted>;
             fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 // Assert that the set has the right type.
@@ -1621,7 +1614,7 @@ nop_list_lift! {args; GenericArg<'a> => GenericArg<'tcx>}
 
 macro_rules! nop_slice_lift {
     ($ty:ty => $lifted:ty) => {
-        impl<'a, 'tcx> Lift<'tcx> for &'a [$ty] {
+        impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for &'a [$ty] {
             type Lifted = &'tcx [$lifted];
             fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
                 if self.is_empty() {

compiler/rustc_middle/src/ty/generic_args.rs

@@ -39,6 +39,16 @@ pub struct GenericArg<'tcx> {
     marker: PhantomData<(Ty<'tcx>, ty::Region<'tcx>, ty::Const<'tcx>)>,
 }
 
+impl<'tcx> rustc_type_ir::inherent::GenericArgs<TyCtxt<'tcx>> for ty::GenericArgsRef<'tcx> {
+    fn type_at(self, i: usize) -> Ty<'tcx> {
+        self.type_at(i)
+    }
+
+    fn identity_for_item(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
+        GenericArgs::identity_for_item(tcx, def_id)
+    }
+}
+
 #[cfg(parallel_compiler)]
 unsafe impl<'tcx> rustc_data_structures::sync::DynSend for GenericArg<'tcx> where
     &'tcx (Ty<'tcx>, ty::Region<'tcx>, ty::Const<'tcx>): rustc_data_structures::sync::DynSend
@@ -205,7 +215,7 @@ impl<'tcx> GenericArg<'tcx> {
     }
 }
 
-impl<'a, 'tcx> Lift<'tcx> for GenericArg<'a> {
+impl<'a, 'tcx> Lift<TyCtxt<'tcx>> for GenericArg<'a> {
     type Lifted = GenericArg<'tcx>;
 
     fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {

compiler/rustc_middle/src/ty/generics.rs

@@ -145,6 +145,12 @@ pub struct Generics {
     pub host_effect_index: Option<usize>,
 }
 
+impl<'tcx> rustc_type_ir::inherent::GenericsOf<TyCtxt<'tcx>> for &'tcx Generics {
+    fn count(&self) -> usize {
+        self.parent_count + self.own_params.len()
+    }
+}
+
 impl<'tcx> Generics {
     /// Looks through the generics and all parents to find the index of the
     /// given param def-id. This is in comparison to the `param_def_id_to_index`