Rollup of 6 pull requests

compiler/rustc_const_eval/src/transform/validate.rs

@@ -67,8 +67,8 @@ impl<'tcx> MirPass<'tcx> for Validator {
             unwind_edge_count: 0,
             reachable_blocks: traversal::reachable_as_bitset(body),
             storage_liveness,
-            place_cache: Vec::new(),
-            value_cache: Vec::new(),
+            place_cache: FxHashSet::default(),
+            value_cache: FxHashSet::default(),
         };
         checker.visit_body(body);
         checker.check_cleanup_control_flow();
@@ -95,8 +95,8 @@ struct TypeChecker<'a, 'tcx> {
     unwind_edge_count: usize,
     reachable_blocks: BitSet<BasicBlock>,
     storage_liveness: ResultsCursor<'a, 'tcx, MaybeStorageLive<'static>>,
-    place_cache: Vec<PlaceRef<'tcx>>,
-    value_cache: Vec<u128>,
+    place_cache: FxHashSet<PlaceRef<'tcx>>,
+    value_cache: FxHashSet<u128>,
 }
 
 impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
@@ -951,10 +951,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
 
                 self.value_cache.clear();
                 self.value_cache.extend(targets.iter().map(|(value, _)| value));
-                let all_len = self.value_cache.len();
-                self.value_cache.sort_unstable();
-                self.value_cache.dedup();
-                let has_duplicates = all_len != self.value_cache.len();
+                let has_duplicates = targets.iter().len() != self.value_cache.len();
                 if has_duplicates {
                     self.fail(
                         location,
@@ -987,16 +984,14 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 // passed by a reference to the callee. Consequently they must be non-overlapping.
                 // Currently this simply checks for duplicate places.
                 self.place_cache.clear();
-                self.place_cache.push(destination.as_ref());
+                self.place_cache.insert(destination.as_ref());
+                let mut has_duplicates = false;
                 for arg in args {
                     if let Operand::Move(place) = arg {
-                        self.place_cache.push(place.as_ref());
+                        has_duplicates |= !self.place_cache.insert(place.as_ref());
                     }
                 }
-                let all_len = self.place_cache.len();
-                let mut dedup = FxHashSet::default();
-                self.place_cache.retain(|p| dedup.insert(*p));
-                let has_duplicates = all_len != self.place_cache.len();
+
                 if has_duplicates {
                     self.fail(
                         location,

compiler/rustc_trait_selection/src/solve/eval_ctxt.rs

@@ -837,7 +837,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         }
     }
 
-    pub(super) fn can_define_opaque_ty(&mut self, def_id: LocalDefId) -> bool {
+    pub(super) fn can_define_opaque_ty(&self, def_id: LocalDefId) -> bool {
         self.infcx.opaque_type_origin(def_id).is_some()
     }
 

compiler/rustc_trait_selection/src/solve/eval_ctxt/select.rs

@@ -173,10 +173,18 @@ fn candidate_should_be_dropped_in_favor_of<'tcx>(
             victim_idx >= other_idx
         }
         (_, CandidateSource::ParamEnv(_)) => true,
+
+        (
+            CandidateSource::BuiltinImpl(BuiltinImplSource::Object),
+            CandidateSource::BuiltinImpl(BuiltinImplSource::Object),
+        ) => false,
+        (_, CandidateSource::BuiltinImpl(BuiltinImplSource::Object)) => true,
+
         (CandidateSource::Impl(victim_def_id), CandidateSource::Impl(other_def_id)) => {
             tcx.specializes((other_def_id, victim_def_id))
                 && other.result.value.certainty == Certainty::Yes
         }
+
         _ => false,
     }
 }

compiler/rustc_trait_selection/src/solve/normalize.rs

@@ -167,9 +167,7 @@ impl<'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for NormalizationFolder<'_, 'tcx> {
         // We don't normalize opaque types unless we have
         // `Reveal::All`, even if we're in the defining scope.
         let data = match *ty.kind() {
-            ty::Alias(kind, alias_ty) if kind != ty::Opaque || reveal == Reveal::UserFacing => {
-                alias_ty
-            }
+            ty::Alias(kind, alias_ty) if kind != ty::Opaque || reveal == Reveal::All => alias_ty,
             _ => return ty.try_super_fold_with(self),
         };
 

compiler/rustc_trait_selection/src/solve/trait_goals.rs

@@ -7,6 +7,7 @@ use rustc_hir::{LangItem, Movability};
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::util::supertraits;
 use rustc_middle::traits::solve::{CanonicalResponse, Certainty, Goal, QueryResult};
+use rustc_middle::traits::Reveal;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams, TreatProjections};
 use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt};
 use rustc_middle::ty::{TraitPredicate, TypeVisitableExt};
@@ -118,6 +119,32 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
             return result;
         }
 
+        // Don't call `type_of` on a local TAIT that's in the defining scope,
+        // since that may require calling `typeck` on the same item we're
+        // currently type checking, which will result in a fatal cycle that
+        // ideally we want to avoid, since we can make progress on this goal
+        // via an alias bound or a locally-inferred hidden type instead.
+        //
+        // Also, don't call `type_of` on a TAIT in `Reveal::All` mode, since
+        // we already normalize the self type in
+        // `assemble_candidates_after_normalizing_self_ty`, and we'd
+        // just be registering an identical candidate here.
+        //
+        // Returning `Err(NoSolution)` here is ok in `SolverMode::Coherence`
+        // since we'll always be registering an ambiguous candidate in
+        // `assemble_candidates_after_normalizing_self_ty` due to normalizing
+        // the TAIT.
+        if let ty::Alias(ty::Opaque, opaque_ty) = goal.predicate.self_ty().kind() {
+            if matches!(goal.param_env.reveal(), Reveal::All)
+                || opaque_ty
+                    .def_id
+                    .as_local()
+                    .is_some_and(|def_id| ecx.can_define_opaque_ty(def_id))
+            {
+                return Err(NoSolution);
+            }
+        }
+
         ecx.probe_and_evaluate_goal_for_constituent_tys(
             goal,
             structural_traits::instantiate_constituent_tys_for_auto_trait,

library/std/src/io/buffered/bufreader.rs

@@ -53,7 +53,7 @@ pub struct BufReader<R: ?Sized> {
 }
 
 impl<R: Read> BufReader<R> {
-    /// Creates a new `BufReader<R>` with a default buffer capacity. The default is currently 8 KB,
+    /// Creates a new `BufReader<R>` with a default buffer capacity. The default is currently 8 KiB,
     /// but may change in the future.
     ///
     /// # Examples

library/std/src/io/buffered/bufwriter.rs

@@ -81,7 +81,7 @@ pub struct BufWriter<W: ?Sized + Write> {
 }
 
 impl<W: Write> BufWriter<W> {
-    /// Creates a new `BufWriter<W>` with a default buffer capacity. The default is currently 8 KB,
+    /// Creates a new `BufWriter<W>` with a default buffer capacity. The default is currently 8 KiB,
     /// but may change in the future.
     ///
     /// # Examples

tests/ui/dyn-star/param-env-region-infer.current.stderr

@@ -1,5 +1,5 @@
 error[E0282]: type annotations needed
-  --> $DIR/param-env-region-infer.rs:16:10
+  --> $DIR/param-env-region-infer.rs:18:10
    |
 LL |     t as _
    |          ^ cannot infer type

tests/ui/dyn-star/param-env-region-infer.next.stderr

@@ -0,0 +1,29 @@
+error[E0391]: cycle detected when computing type of `make_dyn_star::{opaque#0}`
+  --> $DIR/param-env-region-infer.rs:16:60
+   |
+LL | fn make_dyn_star<'a, T: PointerLike + Debug + 'a>(t: T) -> impl PointerLike + Debug + 'a {
+   |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires type-checking `make_dyn_star`...
+  --> $DIR/param-env-region-infer.rs:16:1
+   |
+LL | fn make_dyn_star<'a, T: PointerLike + Debug + 'a>(t: T) -> impl PointerLike + Debug + 'a {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: ...which requires computing layout of `make_dyn_star::{opaque#0}`...
+   = note: ...which requires normalizing `make_dyn_star::{opaque#0}`...
+   = note: ...which again requires computing type of `make_dyn_star::{opaque#0}`, completing the cycle
+note: cycle used when checking item types in top-level module
+  --> $DIR/param-env-region-infer.rs:10:1
+   |
+LL | / #![feature(dyn_star, pointer_like_trait)]
+LL | | #![allow(incomplete_features)]
+LL | |
+LL | | use std::fmt::Debug;
+...  |
+LL | |
+LL | | fn main() {}
+   | |____________^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.

tests/ui/dyn-star/param-env-region-infer.rs

@@ -1,6 +1,7 @@
 // revisions: current next
-//[next] compile-flags: -Ztrait-solver=next
-//[next] check-pass
+// Need `-Zdeduplicate-diagnostics=yes` because the number of cycle errors
+// emitted is for some horrible reason platform-specific.
+//[next] compile-flags: -Ztrait-solver=next -Zdeduplicate-diagnostics=yes
 // incremental
 
 // checks that we don't ICE if there are region inference variables in the environment
@@ -13,6 +14,7 @@ use std::fmt::Debug;
 use std::marker::PointerLike;
 
 fn make_dyn_star<'a, T: PointerLike + Debug + 'a>(t: T) -> impl PointerLike + Debug + 'a {
+    //[next]~^ ERROR cycle detected when computing
     t as _
     //[current]~^ ERROR type annotations needed
 }

tests/ui/impl-trait/reveal-during-codegen.rs

@@ -0,0 +1,11 @@
+// build-pass
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
+
+fn test() -> Option<impl Sized> {
+    Some("")
+}
+
+fn main() {
+    test();
+}

tests/ui/issues/issue-67552.rs

@@ -1,6 +1,7 @@
 // build-fail
 // compile-flags: -Copt-level=0
 // normalize-stderr-test: ".nll/" -> "/"
+// ignore-compare-mode-next-solver (hangs)
 
 fn main() {
     rec(Empty);

tests/ui/issues/issue-67552.stderr

@@ -1,11 +1,11 @@
 error: reached the recursion limit while instantiating `rec::<&mut &mut &mut &mut &mut ...>`
-  --> $DIR/issue-67552.rs:29:9
+  --> $DIR/issue-67552.rs:30:9
    |
 LL |         rec(identity(&mut it))
    |         ^^^^^^^^^^^^^^^^^^^^^^
    |
 note: `rec` defined here
-  --> $DIR/issue-67552.rs:22:1
+  --> $DIR/issue-67552.rs:23:1
    |
 LL | / fn rec<T>(mut it: T)
 LL | | where

tests/ui/recursion/issue-95134.rs

@@ -3,6 +3,7 @@
 // compile-flags: -Copt-level=0
 // dont-check-failure-status
 // dont-check-compiler-stderr
+// ignore-compare-mode-next-solver (hangs)
 
 pub fn encode_num<Writer: ExampleWriter>(n: u32, mut writer: Writer) -> Result<(), Writer::Error> {
     if n > 15 {

tests/ui/traits/new-solver/dont-type_of-tait-in-defining-scope.not_send.stderr

@@ -0,0 +1,16 @@
+error[E0283]: type annotations needed: cannot satisfy `Foo: Send`
+  --> $DIR/dont-type_of-tait-in-defining-scope.rs:16:5
+   |
+LL |     needs_send::<Foo>();
+   |     ^^^^^^^^^^^^^^^^^
+   |
+   = note: cannot satisfy `Foo: Send`
+note: required by a bound in `needs_send`
+  --> $DIR/dont-type_of-tait-in-defining-scope.rs:13:18
+   |
+LL | fn needs_send<T: Send>() {}
+   |                  ^^^^ required by this bound in `needs_send`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0283`.

tests/ui/traits/new-solver/dont-type_of-tait-in-defining-scope.rs

@@ -0,0 +1,22 @@
+// revisions: is_send not_send
+// compile-flags: -Ztrait-solver=next
+//[is_send] check-pass
+
+#![feature(type_alias_impl_trait)]
+
+#[cfg(is_send)]
+type Foo = impl Send;
+
+#[cfg(not_send)]
+type Foo = impl Sized;
+
+fn needs_send<T: Send>() {}
+
+fn test() {
+    needs_send::<Foo>();
+    //[not_send]~^ ERROR type annotations needed: cannot satisfy `Foo: Send`
+}
+
+fn main() {
+    let _: Foo = ();
+}

tests/ui/traits/new-solver/dyn-any-dont-prefer-impl.rs

@@ -0,0 +1,13 @@
+// compile-flags: -Ztrait-solver=next
+// check-pass
+
+use std::any::Any;
+
+fn needs_usize(_: &usize) {}
+
+fn main() {
+    let x: &dyn Any = &1usize;
+    if let Some(x) = x.downcast_ref::<usize>() {
+        needs_usize(x);
+    }
+}

tests/ui/type-alias-impl-trait/issue-109054.rs

@@ -0,0 +1,22 @@
+// edition:2021
+
+#![feature(type_alias_impl_trait)]
+
+struct CallMe;
+
+type ReturnType<'a> = impl std::future::Future<Output = u32> + 'a;
+type FnType = impl Fn(&u32) -> ReturnType;
+
+impl std::ops::Deref for CallMe {
+    type Target = FnType;
+
+    fn deref(&self) -> &Self::Target {
+        fn inner(val: &u32) -> ReturnType {
+            async move { *val * 2 }
+        }
+
+        &inner //~ ERROR: expected generic lifetime parameter, found `'_`
+    }
+}
+
+fn main() {}

tests/ui/type-alias-impl-trait/issue-109054.stderr

@@ -0,0 +1,12 @@
+error[E0792]: expected generic lifetime parameter, found `'_`
+  --> $DIR/issue-109054.rs:18:9
+   |
+LL | type ReturnType<'a> = impl std::future::Future<Output = u32> + 'a;
+   |                 -- this generic parameter must be used with a generic lifetime parameter
+...
+LL |         &inner
+   |         ^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0792`.