Auto merge of #109442 - Nilstrieb:rollup-seb5xsa, r=Nilstrieb

Rollup of 10 pull requests

Successful merges:

 - #106434 (Document `Iterator::sum/product` for Option/Result)
 - #108326 (Implement read_buf for a few more types)
 - #108842 (Enforce non-lifetime-binders in supertrait preds are not object safe)
 - #108896 (new solver: make all goal evaluation able to be automatically rerun )
 - #109124 (Add `dist.compression-profile` option to control compression speed)
 - #109240 (Walk un-shifted nested `impl Trait` in trait when setting up default trait method assumptions)
 - #109385 (fix typo)
 - #109386 (add myself to mailmap)
 - #109390 (Custom MIR: Support aggregate expressions)
 - #109408 (not *all* retags might be explicit in Runtime MIR)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

.mailmap

@@ -29,6 +29,8 @@ Alexander Ronald Altman <alexanderaltman@me.com>
 Alexandre Martin <martin.alex32@hotmail.fr>
 Alexis Beingessner <a.beingessner@gmail.com>
 Alfie John <alfie@alfie.wtf> Alfie John <alfiej@fastmail.fm>
+Alona Enraght-Moony <code@alona.page> <nixon.emoony@gmail.com>
+Alona Enraght-Moony <code@alona.page> <nixon@caminus.local>
 Amos Onn <amosonn@gmail.com>
 Ana-Maria Mihalache <mihalacheana.maria@yahoo.com>
 Anatoly Ikorsky <aikorsky@gmail.com>
@@ -415,7 +417,6 @@ Nicolas Abram <abramlujan@gmail.com>
 Nicole Mazzuca <npmazzuca@gmail.com>
 Nif Ward <nif.ward@gmail.com>
 Nika Layzell <nika@thelayzells.com> <michael@thelayzells.com>
-Nixon Enraght-Moony <nixon.emoony@gmail.com>
 NODA Kai <nodakai@gmail.com>
 oliver <16816606+o752d@users.noreply.github.com>
 Oliver Middleton <olliemail27@gmail.com> <ollie27@users.noreply.github.com>

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -605,7 +605,7 @@ fn find_opaque_ty_constraints_for_tait(tcx: TyCtxt<'_>, def_id: LocalDefId) -> T
         found: Option<ty::OpaqueHiddenType<'tcx>>,
 
         /// In the presence of dead code, typeck may figure out a hidden type
-        /// while borrowck will now. We collect these cases here and check at
+        /// while borrowck will not. We collect these cases here and check at
         /// the end that we actually found a type that matches (modulo regions).
         typeck_types: Vec<ty::OpaqueHiddenType<'tcx>>,
     }

compiler/rustc_middle/src/mir/syntax.rs

@@ -78,7 +78,8 @@ pub enum MirPhase {
     ///    MIR, this is UB.
     ///  - Retags: If `-Zmir-emit-retag` is enabled, analysis MIR has "implicit" retags in the same way
     ///    that Rust itself has them. Where exactly these are is generally subject to change, and so we
-    ///    don't document this here. Runtime MIR has all retags explicit.
+    ///    don't document this here. Runtime MIR has most retags explicit (though implicit retags
+    ///    can still occur at `Rvalue::{Ref,AddrOf}`).
     ///  - Generator bodies: In analysis MIR, locals may actually be behind a pointer that user code has
     ///    access to. This occurs in generator bodies. Such locals do not behave like other locals,
     ///    because they eg may be aliased in surprising ways. Runtime MIR has no such special locals -
@@ -1165,7 +1166,7 @@ pub enum AggregateKind<'tcx> {
     Tuple,
 
     /// The second field is the variant index. It's equal to 0 for struct
-    /// and union expressions. The fourth field is
+    /// and union expressions. The last field is the
     /// active field number and is present only for union expressions
     /// -- e.g., for a union expression `SomeUnion { c: .. }`, the
     /// active field index would identity the field `c`

compiler/rustc_middle/src/traits/mod.rs

@@ -897,6 +897,9 @@ pub enum ObjectSafetyViolation {
     /// (e.g., `trait Foo : Bar<Self>`).
     SupertraitSelf(SmallVec<[Span; 1]>),
 
+    // Supertrait has a non-lifetime `for<T>` binder.
+    SupertraitNonLifetimeBinder(SmallVec<[Span; 1]>),
+
     /// Method has something illegal.
     Method(Symbol, MethodViolationCode, Span),
 
@@ -919,6 +922,9 @@ impl ObjectSafetyViolation {
                         .into()
                 }
             }
+            ObjectSafetyViolation::SupertraitNonLifetimeBinder(_) => {
+                format!("where clause cannot reference non-lifetime `for<...>` variables").into()
+            }
             ObjectSafetyViolation::Method(name, MethodViolationCode::StaticMethod(_), _) => {
                 format!("associated function `{}` has no `self` parameter", name).into()
             }
@@ -969,7 +975,9 @@ impl ObjectSafetyViolation {
 
     pub fn solution(&self, err: &mut Diagnostic) {
         match self {
-            ObjectSafetyViolation::SizedSelf(_) | ObjectSafetyViolation::SupertraitSelf(_) => {}
+            ObjectSafetyViolation::SizedSelf(_)
+            | ObjectSafetyViolation::SupertraitSelf(_)
+            | ObjectSafetyViolation::SupertraitNonLifetimeBinder(..) => {}
             ObjectSafetyViolation::Method(
                 name,
                 MethodViolationCode::StaticMethod(Some((add_self_sugg, make_sized_sugg))),
@@ -1023,7 +1031,8 @@ impl ObjectSafetyViolation {
         // diagnostics use a `note` instead of a `span_label`.
         match self {
             ObjectSafetyViolation::SupertraitSelf(spans)
-            | ObjectSafetyViolation::SizedSelf(spans) => spans.clone(),
+            | ObjectSafetyViolation::SizedSelf(spans)
+            | ObjectSafetyViolation::SupertraitNonLifetimeBinder(spans) => spans.clone(),
             ObjectSafetyViolation::AssocConst(_, span)
             | ObjectSafetyViolation::GAT(_, span)
             | ObjectSafetyViolation::Method(_, _, span)

compiler/rustc_middle/src/ty/fold.rs

@@ -51,9 +51,7 @@ where
 // Region folder
 
 impl<'tcx> TyCtxt<'tcx> {
-    /// Folds the escaping and free regions in `value` using `f`, and
-    /// sets `skipped_regions` to true if any late-bound region was found
-    /// and skipped.
+    /// Folds the escaping and free regions in `value` using `f`.
     pub fn fold_regions<T>(
         self,
         value: T,
@@ -64,17 +62,6 @@ impl<'tcx> TyCtxt<'tcx> {
     {
         value.fold_with(&mut RegionFolder::new(self, &mut f))
     }
-
-    pub fn super_fold_regions<T>(
-        self,
-        value: T,
-        mut f: impl FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
-    ) -> T
-    where
-        T: TypeSuperFoldable<TyCtxt<'tcx>>,
-    {
-        value.super_fold_with(&mut RegionFolder::new(self, &mut f))
-    }
 }
 
 /// Folds over the substructure of a type, visiting its component

compiler/rustc_mir_build/src/build/custom/parse/instruction.rs

@@ -166,6 +166,28 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> {
                 let cast_kind = mir_cast_kind(source_ty, expr.ty);
                 Ok(Rvalue::Cast(cast_kind, source, expr.ty))
             },
+            ExprKind::Tuple { fields } => Ok(
+                Rvalue::Aggregate(
+                    Box::new(AggregateKind::Tuple),
+                    fields.iter().map(|e| self.parse_operand(*e)).collect::<Result<_, _>>()?
+                )
+            ),
+            ExprKind::Array { fields } => {
+                let elem_ty = expr.ty.builtin_index().expect("ty must be an array");
+                Ok(Rvalue::Aggregate(
+                    Box::new(AggregateKind::Array(elem_ty)),
+                    fields.iter().map(|e| self.parse_operand(*e)).collect::<Result<_, _>>()?
+                ))
+            },
+            ExprKind::Adt(box AdtExpr{ adt_def, variant_index, substs, fields, .. }) => {
+                let is_union = adt_def.is_union();
+                let active_field_index = is_union.then(|| fields[0].name.index());
+
+                Ok(Rvalue::Aggregate(
+                    Box::new(AggregateKind::Adt(adt_def.did(), *variant_index, substs, None, active_field_index)),
+                    fields.iter().map(|f| self.parse_operand(f.expr)).collect::<Result<_, _>>()?
+                ))
+            },
             _ => self.parse_operand(expr_id).map(Rvalue::Use),
         )
     }

compiler/rustc_trait_selection/src/solve/assembly.rs

@@ -224,7 +224,9 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         if goal.predicate.self_ty().is_ty_var() {
             return vec![Candidate {
                 source: CandidateSource::BuiltinImpl,
-                result: self.make_canonical_response(Certainty::AMBIGUOUS).unwrap(),
+                result: self
+                    .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)
+                    .unwrap(),
             }];
         }
 
@@ -261,37 +263,26 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         let &ty::Alias(ty::Projection, projection_ty) = goal.predicate.self_ty().kind() else {
             return
         };
-        self.probe(|this| {
-            let normalized_ty = this.next_ty_infer();
+
+        self.probe(|ecx| {
+            let normalized_ty = ecx.next_ty_infer();
             let normalizes_to_goal = goal.with(
                 tcx,
                 ty::Binder::dummy(ty::ProjectionPredicate {
                     projection_ty,
                     term: normalized_ty.into(),
                 }),
             );
-            let normalization_certainty = match this.evaluate_goal(normalizes_to_goal) {
-                Ok((_, certainty)) => certainty,
-                Err(NoSolution) => return,
-            };
-            let normalized_ty = this.resolve_vars_if_possible(normalized_ty);
-
-            // NOTE: Alternatively we could call `evaluate_goal` here and only have a `Normalized` candidate.
-            // This doesn't work as long as we use `CandidateSource` in winnowing.
-            let goal = goal.with(tcx, goal.predicate.with_self_ty(tcx, normalized_ty));
-            let normalized_candidates = this.assemble_and_evaluate_candidates(goal);
-            for mut normalized_candidate in normalized_candidates {
-                normalized_candidate.result =
-                    normalized_candidate.result.unchecked_map(|mut response| {
-                        // FIXME: This currently hides overflow in the normalization step of the self type
-                        // which is probably wrong. Maybe `unify_and` should actually keep overflow as
-                        // we treat it as non-fatal anyways.
-                        response.certainty = response.certainty.unify_and(normalization_certainty);
-                        response
-                    });
-                candidates.push(normalized_candidate);
+            ecx.add_goal(normalizes_to_goal);
+            if let Ok(_) = ecx.try_evaluate_added_goals() {
+                let normalized_ty = ecx.resolve_vars_if_possible(normalized_ty);
+
+                // NOTE: Alternatively we could call `evaluate_goal` here and only have a `Normalized` candidate.
+                // This doesn't work as long as we use `CandidateSource` in winnowing.
+                let goal = goal.with(tcx, goal.predicate.with_self_ty(tcx, normalized_ty));
+                candidates.extend(ecx.assemble_and_evaluate_candidates(goal));
             }
-        })
+        });
     }
 
     fn assemble_impl_candidates<G: GoalKind<'tcx>>(
@@ -516,7 +507,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
                 } else {
                     Certainty::AMBIGUOUS
                 };
-                return self.make_canonical_response(certainty);
+                return self.evaluate_added_goals_and_make_canonical_response(certainty);
             }
         }
 
@@ -538,14 +529,16 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         }
     }
 
-    fn discard_reservation_impl(&self, mut candidate: Candidate<'tcx>) -> Candidate<'tcx> {
+    fn discard_reservation_impl(&mut self, mut candidate: Candidate<'tcx>) -> Candidate<'tcx> {
         if let CandidateSource::Impl(def_id) = candidate.source {
             if let ty::ImplPolarity::Reservation = self.tcx().impl_polarity(def_id) {
                 debug!("Selected reservation impl");
                 // We assemble all candidates inside of a probe so by
                 // making a new canonical response here our result will
                 // have no constraints.
-                candidate.result = self.make_canonical_response(Certainty::AMBIGUOUS).unwrap();
+                candidate.result = self
+                    .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)
+                    .unwrap();
             }
         }
 

compiler/rustc_trait_selection/src/solve/canonical/mod.rs

@@ -48,7 +48,13 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
     /// - `external_constraints`: additional constraints which aren't expressable
     ///   using simple unification of inference variables.
     #[instrument(level = "debug", skip(self))]
-    pub(super) fn make_canonical_response(&self, certainty: Certainty) -> QueryResult<'tcx> {
+    pub(super) fn evaluate_added_goals_and_make_canonical_response(
+        &mut self,
+        certainty: Certainty,
+    ) -> QueryResult<'tcx> {
+        let goals_certainty = self.try_evaluate_added_goals()?;
+        let certainty = certainty.unify_and(goals_certainty);
+
         let external_constraints = self.compute_external_query_constraints()?;
 
         let response = Response { var_values: self.var_values, external_constraints, certainty };
@@ -209,7 +215,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             // FIXME: To deal with #105787 I also expect us to emit nested obligations here at
             // some point. We can figure out how to deal with this once we actually have
             // an ICE.
-            let nested_goals = self.eq(param_env, orig, response)?;
+            let nested_goals = self.eq_and_get_goals(param_env, orig, response)?;
             assert!(nested_goals.is_empty(), "{nested_goals:?}");
         }