Rollup of 5 pull requests

RELEASES.md

@@ -68,15 +68,15 @@ Stabilized APIs
 - [`impl Default for std::collections::vec_deque::Iter`](https://doc.rust-lang.org/nightly/std/collections/vec_deque/struct.Iter.html#impl-Default-for-Iter%3C'_,+T%3E)
 - [`impl Default for std::collections::vec_deque::IterMut`](https://doc.rust-lang.org/nightly/std/collections/vec_deque/struct.IterMut.html#impl-Default-for-IterMut%3C'_,+T%3E)
 - [`Rc<T>::new_uninit`](https://doc.rust-lang.org/nightly/std/rc/struct.Rc.html#method.new_uninit)
-- [`Rc<T>::assume_init`](https://doc.rust-lang.org/nightly/std/rc/struct.Rc.html#method.assume_init)
+- [`Rc<MaybeUninit<T>>::assume_init`](https://doc.rust-lang.org/nightly/std/rc/struct.Rc.html#method.assume_init)
 - [`Rc<[T]>::new_uninit_slice`](https://doc.rust-lang.org/nightly/std/rc/struct.Rc.html#method.new_uninit_slice)
 - [`Rc<[MaybeUninit<T>]>::assume_init`](https://doc.rust-lang.org/nightly/std/rc/struct.Rc.html#method.assume_init-1)
 - [`Arc<T>::new_uninit`](https://doc.rust-lang.org/nightly/std/sync/struct.Arc.html#method.new_uninit)
-- [`Arc<T>::assume_init`](https://doc.rust-lang.org/nightly/std/sync/struct.Arc.html#method.assume_init)
+- [`Arc<MaybeUninit<T>>::assume_init`](https://doc.rust-lang.org/nightly/std/sync/struct.Arc.html#method.assume_init)
 - [`Arc<[T]>::new_uninit_slice`](https://doc.rust-lang.org/nightly/std/sync/struct.Arc.html#method.new_uninit_slice)
 - [`Arc<[MaybeUninit<T>]>::assume_init`](https://doc.rust-lang.org/nightly/std/sync/struct.Arc.html#method.assume_init-1)
 - [`Box<T>::new_uninit`](https://doc.rust-lang.org/nightly/std/boxed/struct.Box.html#method.new_uninit)
-- [`Box<T>::assume_init`](https://doc.rust-lang.org/nightly/std/boxed/struct.Box.html#method.assume_init)
+- [`Box<MaybeUninit<T>>::assume_init`](https://doc.rust-lang.org/nightly/std/boxed/struct.Box.html#method.assume_init)
 - [`Box<[T]>::new_uninit_slice`](https://doc.rust-lang.org/nightly/std/boxed/struct.Box.html#method.new_uninit_slice)
 - [`Box<[MaybeUninit<T>]>::assume_init`](https://doc.rust-lang.org/nightly/std/boxed/struct.Box.html#method.assume_init-1)
 - [`core::arch::x86_64::_bextri_u64`](https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bextri_u64.html)

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs

@@ -170,7 +170,7 @@ where
         //
         // We don't do so for `NormalizesTo` goals as we erased the expected term and
         // bailing with overflow here would prevent us from detecting a type-mismatch,
-        // causing a coherence error in diesel, see #131969. We still bail with verflow
+        // causing a coherence error in diesel, see #131969. We still bail with overflow
         // when later returning from the parent AliasRelate goal.
         if !self.is_normalizes_to_goal {
             let num_non_region_vars =

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs

@@ -291,7 +291,7 @@ where
             search_graph,
             nested_goals: NestedGoals::new(),
             tainted: Ok(()),
-            inspect: canonical_goal_evaluation.new_goal_evaluation_step(var_values, input),
+            inspect: canonical_goal_evaluation.new_goal_evaluation_step(var_values),
         };
 
         for &(key, ty) in &input.predefined_opaques_in_body.opaque_types {

compiler/rustc_next_trait_solver/src/solve/inspect/build.rs

@@ -13,7 +13,7 @@ use rustc_type_ir::{self as ty, Interner};
 use crate::delegate::SolverDelegate;
 use crate::solve::eval_ctxt::canonical;
 use crate::solve::{
-    CanonicalInput, Certainty, GenerateProofTree, Goal, GoalEvaluationKind, GoalSource, QueryInput,
+    CanonicalInput, Certainty, GenerateProofTree, Goal, GoalEvaluationKind, GoalSource,
     QueryResult, inspect,
 };
 
@@ -119,6 +119,9 @@ impl<I: Interner> WipCanonicalGoalEvaluation<I> {
     }
 }
 
+/// This only exists during proof tree building and does not have
+/// a corresponding struct in `inspect`. We need this to track a
+/// bunch of metadata about the current evaluation.
 #[derive_where(PartialEq, Eq, Debug; I: Interner)]
 struct WipCanonicalGoalEvaluationStep<I: Interner> {
     /// Unlike `EvalCtxt::var_values`, we append a new
@@ -128,7 +131,6 @@ struct WipCanonicalGoalEvaluationStep<I: Interner> {
     /// This is necessary as we otherwise don't unify these
     /// vars when instantiating multiple `CanonicalState`.
     var_values: Vec<I::GenericArg>,
-    instantiated_goal: QueryInput<I, I::Predicate>,
     probe_depth: usize,
     evaluation: WipProbe<I>,
 }
@@ -145,16 +147,12 @@ impl<I: Interner> WipCanonicalGoalEvaluationStep<I> {
         current
     }
 
-    fn finalize(self) -> inspect::CanonicalGoalEvaluationStep<I> {
+    fn finalize(self) -> inspect::Probe<I> {
         let evaluation = self.evaluation.finalize();
         match evaluation.kind {
-            inspect::ProbeKind::Root { .. } => (),
+            inspect::ProbeKind::Root { .. } => evaluation,
             _ => unreachable!("unexpected root evaluation: {evaluation:?}"),
         }
-        inspect::CanonicalGoalEvaluationStep {
-            instantiated_goal: self.instantiated_goal,
-            evaluation,
-        }
     }
 }
 
@@ -328,11 +326,9 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
     pub(crate) fn new_goal_evaluation_step(
         &mut self,
         var_values: ty::CanonicalVarValues<I>,
-        instantiated_goal: QueryInput<I, I::Predicate>,
     ) -> ProofTreeBuilder<D> {
         self.nested(|| WipCanonicalGoalEvaluationStep {
             var_values: var_values.var_values.to_vec(),
-            instantiated_goal,
             evaluation: WipProbe {
                 initial_num_var_values: var_values.len(),
                 steps: vec![],

compiler/rustc_trait_selection/src/solve/inspect/analyse.rs

@@ -344,7 +344,7 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
         };
 
         let mut nested_goals = vec![];
-        self.candidates_recur(&mut candidates, &mut nested_goals, &last_eval_step.evaluation);
+        self.candidates_recur(&mut candidates, &mut nested_goals, &last_eval_step);
 
         candidates
     }

compiler/rustc_type_ir/src/solve/inspect.rs

@@ -23,9 +23,7 @@ use std::hash::Hash;
 use derive_where::derive_where;
 use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
 
-use crate::solve::{
-    CandidateSource, CanonicalInput, Certainty, Goal, GoalSource, QueryInput, QueryResult,
-};
+use crate::solve::{CandidateSource, CanonicalInput, Certainty, Goal, GoalSource, QueryResult};
 use crate::{Canonical, CanonicalVarValues, Interner};
 
 /// Some `data` together with information about how they relate to the input
@@ -69,15 +67,10 @@ pub struct CanonicalGoalEvaluation<I: Interner> {
 #[derive_where(PartialEq, Eq, Hash, Debug; I: Interner)]
 pub enum CanonicalGoalEvaluationKind<I: Interner> {
     Overflow,
-    Evaluation { final_revision: CanonicalGoalEvaluationStep<I> },
-}
-
-#[derive_where(PartialEq, Eq, Hash, Debug; I: Interner)]
-pub struct CanonicalGoalEvaluationStep<I: Interner> {
-    pub instantiated_goal: QueryInput<I, I::Predicate>,
-
-    /// The actual evaluation of the goal, always `ProbeKind::Root`.
-    pub evaluation: Probe<I>,
+    Evaluation {
+        /// This is always `ProbeKind::Root`.
+        final_revision: Probe<I>,
+    },
 }
 
 /// A self-contained computation during trait solving. This either

library/alloc/src/rc.rs

@@ -2312,7 +2312,16 @@ impl<T: Default> Default for Rc<T> {
     /// ```
     #[inline]
     fn default() -> Rc<T> {
-        Rc::new(Default::default())
+        unsafe {
+            Self::from_inner(
+                Box::leak(Box::write(Box::new_uninit(), RcInner {
+                    strong: Cell::new(1),
+                    weak: Cell::new(1),
+                    value: T::default(),
+                }))
+                .into(),
+            )
+        }
     }
 }
 

library/alloc/src/sync.rs

@@ -3447,13 +3447,16 @@ impl<T: Default> Default for Arc<T> {
     /// assert_eq!(*x, 0);
     /// ```
     fn default() -> Arc<T> {
-        let x = Box::into_raw(Box::write(Box::new_uninit(), ArcInner {
-            strong: atomic::AtomicUsize::new(1),
-            weak: atomic::AtomicUsize::new(1),
-            data: T::default(),
-        }));
-        // SAFETY: `Box::into_raw` consumes the `Box` and never returns null
-        unsafe { Self::from_inner(NonNull::new_unchecked(x)) }
+        unsafe {
+            Self::from_inner(
+                Box::leak(Box::write(Box::new_uninit(), ArcInner {
+                    strong: atomic::AtomicUsize::new(1),
+                    weak: atomic::AtomicUsize::new(1),
+                    data: T::default(),
+                }))
+                .into(),
+            )
+        }
     }
 }
 

library/core/tests/lib.rs

@@ -17,11 +17,14 @@
 #![feature(clone_to_uninit)]
 #![feature(const_align_of_val_raw)]
 #![feature(const_align_offset)]
+#![feature(const_bigint_helper_methods)]
 #![feature(const_black_box)]
+#![feature(const_eval_select)]
 #![feature(const_hash)]
 #![feature(const_heap)]
 #![feature(const_likely)]
 #![feature(const_nonnull_new)]
+#![feature(const_num_midpoint)]
 #![feature(const_option_ext)]
 #![feature(const_pin_2)]
 #![feature(const_pointer_is_aligned)]
@@ -46,6 +49,7 @@
 #![feature(get_many_mut)]
 #![feature(hasher_prefixfree_extras)]
 #![feature(hashmap_internals)]
+#![feature(inline_const_pat)]
 #![feature(int_roundings)]
 #![feature(ip)]
 #![feature(ip_from)]
@@ -104,6 +108,37 @@
 #![deny(fuzzy_provenance_casts)]
 #![deny(unsafe_op_in_unsafe_fn)]
 
+/// Version of `assert_matches` that ignores fancy runtime printing in const context and uses structural equality.
+macro_rules! assert_eq_const_safe {
+    ($left:expr, $right:expr$(, $($arg:tt)+)?) => {
+        {
+            fn runtime() {
+                assert_eq!($left, $right, $($arg)*);
+            }
+            const fn compiletime() {
+                assert!(matches!($left, const { $right }));
+            }
+            core::intrinsics::const_eval_select((), compiletime, runtime)
+        }
+    };
+}
+
+/// Creates a test for runtime and a test for constant-time.
+macro_rules! test_runtime_and_compiletime {
+    ($(
+        $(#[$attr:meta])*
+        fn $test:ident() $block:block
+    )*) => {
+        $(
+            $(#[$attr])*
+            #[test]
+            fn $test() $block
+            $(#[$attr])*
+            const _: () = $block;
+        )*
+    }
+}
+
 mod alloc;
 mod any;
 mod array;