Merging upstream version 1.74.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 42 insertions, 64 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index e3da87a22..bead8758a 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -436,8 +436,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 | ty::Ref(_, _, _)
                 | ty::Closure(_, _)
                 | ty::Generator(_, _, _)
-                | ty::GeneratorWitness(_)
-                | ty::GeneratorWitnessMIR(_, _)
+                | ty::GeneratorWitness(..)
                 | ty::Never
                 | ty::Tuple(_)
                 | ty::Error(_) => return true,
@@ -569,8 +568,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 | ty::Generator(..)
                 | ty::Never
                 | ty::Tuple(_)
-                | ty::GeneratorWitness(_)
-                | ty::GeneratorWitnessMIR(..) => {
+                | ty::GeneratorWitness(..) => {
                     // Only consider auto impls if there are no manual impls for the root of `self_ty`.
                     //
                     // For example, we only consider auto candidates for `&i32: Auto` if no explicit impl
@@ -946,8 +944,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::Tuple(_)
-            | ty::GeneratorWitness(_)
-            | ty::GeneratorWitnessMIR(..) => {
+            | ty::GeneratorWitness(..) => {
                 // These are built-in, and cannot have a custom `impl const Destruct`.
                 candidates.vec.push(ConstDestructCandidate(None));
             }
@@ -1020,8 +1017,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Dynamic(_, _, _)
             | ty::Closure(_, _)
             | ty::Generator(_, _, _)
-            | ty::GeneratorWitness(_)
-            | ty::GeneratorWitnessMIR(..)
+            | ty::GeneratorWitness(..)
             | ty::Never
             | ty::Alias(..)
             | ty::Param(_)
@@ -1083,7 +1079,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Never
             | ty::Tuple(..)
             | ty::Alias(..)
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 88d030033..08ee9c73b 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -535,6 +535,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let assoc_types: Vec<_> = tcx
             .associated_items(trait_predicate.def_id())
             .in_definition_order()
+            // Associated types that require `Self: Sized` do not show up in the built-in
+            // implementation of `Trait for dyn Trait`, and can be dropped here.
+            .filter(|item| !tcx.generics_require_sized_self(item.def_id))
             .filter_map(
                 |item| if item.kind == ty::AssocKind::Type { Some(item.def_id) } else { None },
             )
@@ -548,7 +551,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     obligation.cause.span,
                     "GATs in trait object shouldn't have been considered",
                 );
-                return Err(SelectionError::Unimplemented);
+                return Err(SelectionError::TraitNotObjectSafe(trait_predicate.trait_ref.def_id));
             }
 
             // This maybe belongs in wf, but that can't (doesn't) handle
@@ -1235,10 +1238,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     let generator = args.as_generator();
                     stack.extend([generator.tupled_upvars_ty(), generator.witness()]);
                 }
-                ty::GeneratorWitness(tys) => {
-                    stack.extend(tcx.erase_late_bound_regions(tys).to_vec());
-                }
-                ty::GeneratorWitnessMIR(def_id, args) => {
+                ty::GeneratorWitness(def_id, args) => {
                     let tcx = self.tcx();
                     stack.extend(tcx.generator_hidden_types(def_id).map(|bty| {
                         let ty = bty.instantiate(tcx, args);
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 19385e2d7..ec46a6769 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -35,7 +35,8 @@ use rustc_hir::def_id::DefId;
 use rustc_infer::infer::DefineOpaqueTypes;
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_infer::traits::TraitObligation;
-use rustc_middle::dep_graph::{DepKind, DepNodeIndex};
+use rustc_middle::dep_graph::dep_kinds;
+use rustc_middle::dep_graph::DepNodeIndex;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::fold::BottomUpFolder;
@@ -988,9 +989,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                 Err(_) => Ok(EvaluatedToErr),
                             }
                         }
-                        (Err(ErrorHandled::Reported(_)), _)
-                        | (_, Err(ErrorHandled::Reported(_))) => Ok(EvaluatedToErr),
-                        (Err(ErrorHandled::TooGeneric), _) | (_, Err(ErrorHandled::TooGeneric)) => {
+                        (Err(ErrorHandled::Reported(..)), _)
+                        | (_, Err(ErrorHandled::Reported(..))) => Ok(EvaluatedToErr),
+                        (Err(ErrorHandled::TooGeneric(..)), _)
+                        | (_, Err(ErrorHandled::TooGeneric(..))) => {
                             if c1.has_non_region_infer() || c2.has_non_region_infer() {
                                 Ok(EvaluatedToAmbig)
                             } else {
@@ -1415,7 +1417,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         OP: FnOnce(&mut Self) -> R,
     {
         let (result, dep_node) =
-            self.tcx().dep_graph.with_anon_task(self.tcx(), DepKind::TraitSelect, || op(self));
+            self.tcx().dep_graph.with_anon_task(self.tcx(), dep_kinds::TraitSelect, || op(self));
         self.tcx().dep_graph.read_index(dep_node);
         (result, dep_node)
     }
@@ -2110,7 +2112,6 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
             | ty::Ref(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Array(..)
             | ty::Closure(..)
             | ty::Never
@@ -2209,22 +2210,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 }
             }
 
-            ty::GeneratorWitness(binder) => {
-                let witness_tys = binder.skip_binder();
-                for witness_ty in witness_tys.iter() {
-                    let resolved = self.infcx.shallow_resolve(witness_ty);
-                    if resolved.is_ty_var() {
-                        return Ambiguous;
-                    }
-                }
-                // (*) binder moved here
-                let all_vars = self.tcx().mk_bound_variable_kinds_from_iter(
-                    obligation.predicate.bound_vars().iter().chain(binder.bound_vars().iter()),
-                );
-                Where(ty::Binder::bind_with_vars(witness_tys.to_vec(), all_vars))
-            }
-
-            ty::GeneratorWitnessMIR(def_id, ref args) => {
+            ty::GeneratorWitness(def_id, ref args) => {
                 let hidden_types = bind_generator_hidden_types_above(
                     self.infcx,
                     def_id,
@@ -2329,12 +2315,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 t.rebind([ty].into_iter().chain(iter::once(witness)).collect())
             }
 
-            ty::GeneratorWitness(types) => {
-                debug_assert!(!types.has_escaping_bound_vars());
-                types.map_bound(|types| types.to_vec())
-            }
-
-            ty::GeneratorWitnessMIR(def_id, ref args) => {
+            ty::GeneratorWitness(def_id, ref args) => {
                 bind_generator_hidden_types_above(self.infcx, def_id, args, t.bound_vars())
             }
 
@@ -2346,14 +2327,15 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
             }
 
             ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => {
-                let ty = self.tcx().type_of(def_id);
-                if ty.skip_binder().references_error() {
-                    return Err(SelectionError::OpaqueTypeAutoTraitLeakageUnknown(def_id));
-                }
                 // We can resolve the `impl Trait` to its concrete type,
                 // which enforces a DAG between the functions requiring
                 // the auto trait bounds in question.
-                t.rebind(vec![ty.instantiate(self.tcx(), args)])
+                match self.tcx().type_of_opaque(def_id) {
+                    Ok(ty) => t.rebind(vec![ty.instantiate(self.tcx(), args)]),
+                    Err(_) => {
+                        return Err(SelectionError::OpaqueTypeAutoTraitLeakageUnknown(def_id));
+                    }
+                }
             }
         })
     }
@@ -3093,32 +3075,33 @@ fn bind_generator_hidden_types_above<'tcx>(
         .generator_hidden_types(def_id)
         // Deduplicate tys to avoid repeated work.
         .filter(|bty| seen_tys.insert(*bty))
-        .map(|bty| {
-            let mut ty = bty.instantiate(tcx, args);
-
+        .map(|mut bty| {
             // Only remap erased regions if we use them.
             if considering_regions {
-                ty = tcx.fold_regions(ty, |r, current_depth| match r.kind() {
-                    ty::ReErased => {
-                        let br = ty::BoundRegion {
-                            var: ty::BoundVar::from_u32(counter),
-                            kind: ty::BrAnon(None),
-                        };
-                        counter += 1;
-                        ty::Region::new_late_bound(tcx, current_depth, br)
-                    }
-                    r => bug!("unexpected region: {r:?}"),
+                bty = bty.map_bound(|ty| {
+                    tcx.fold_regions(ty, |r, current_depth| match r.kind() {
+                        ty::ReErased => {
+                            let br = ty::BoundRegion {
+                                var: ty::BoundVar::from_u32(counter),
+                                kind: ty::BrAnon,
+                            };
+                            counter += 1;
+                            ty::Region::new_late_bound(tcx, current_depth, br)
+                        }
+                        r => bug!("unexpected region: {r:?}"),
+                    })
                 })
             }
 
-            ty
+            bty.instantiate(tcx, args)
         })
         .collect();
     if considering_regions {
         debug_assert!(!hidden_types.has_erased_regions());
     }
-    let bound_vars = tcx.mk_bound_variable_kinds_from_iter(bound_vars.iter().chain(
-        (num_bound_variables..counter).map(|_| ty::BoundVariableKind::Region(ty::BrAnon(None))),
-    ));
+    let bound_vars =
+        tcx.mk_bound_variable_kinds_from_iter(bound_vars.iter().chain(
+            (num_bound_variables..counter).map(|_| ty::BoundVariableKind::Region(ty::BrAnon)),
+        ));
     ty::Binder::bind_with_vars(hidden_types, bound_vars)
 }