Rollup of 7 pull requests

.github/workflows/ghcr.yml

@@ -48,10 +48,21 @@ jobs:
 
       - name: Mirror DockerHub
         run: |
-          # DockerHub image we want to mirror
-          image="ubuntu:22.04"
+          # List of DockerHub images to mirror to ghcr.io
+          images=(
+            # Mirrored because used by the mingw-check-tidy, which doesn't cache Docker images
+            "ubuntu:22.04"
+            # Mirrored because used by all linux CI jobs, including mingw-check-tidy
+            "moby/buildkit:buildx-stable-1"
+          )
 
-          # Mirror image from DockerHub to ghcr.io
-          ./crane copy \
-            docker.io/${image} \
-            ghcr.io/${{ github.repository_owner }}/${image}
+          # Mirror each image from DockerHub to ghcr.io
+          for img in "${images[@]}"; do
+            echo "Mirroring ${img}..."
+            # Remove namespace from the image if any.
+            # E.g. "moby/buildkit:buildx-stable-1" becomes "buildkit:buildx-stable-1"
+            dest_image=$(echo "${img}" | cut -d'/' -f2-)
+            ./crane copy \
+              "docker.io/${img}" \
+              "ghcr.io/${{ github.repository_owner }}/${dest_image}"
+          done

compiler/rustc_borrowck/src/polonius/loan_liveness.rs

@@ -9,16 +9,21 @@ use rustc_middle::ty::{RegionVid, TyCtxt};
 use rustc_mir_dataflow::points::PointIndex;
 
 use super::{LiveLoans, LocalizedOutlivesConstraintSet};
+use crate::constraints::OutlivesConstraint;
 use crate::dataflow::BorrowIndex;
 use crate::region_infer::values::LivenessValues;
+use crate::type_check::Locations;
 use crate::{BorrowSet, PlaceConflictBias, places_conflict};
 
-/// With the full graph of constraints, we can compute loan reachability, stop at kills, and trace
-/// loan liveness throughout the CFG.
+/// Compute loan reachability, stop at kills, and trace loan liveness throughout the CFG, by
+/// traversing the full graph of constraints that combines:
+/// - the localized constraints (the physical edges),
+/// - with the constraints that hold at all points (the logical edges).
 pub(super) fn compute_loan_liveness<'tcx>(
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
     liveness: &LivenessValues,
+    outlives_constraints: impl Iterator<Item = OutlivesConstraint<'tcx>>,
     borrow_set: &BorrowSet<'tcx>,
     localized_outlives_constraints: &LocalizedOutlivesConstraintSet,
 ) -> LiveLoans {
@@ -29,7 +34,11 @@ pub(super) fn compute_loan_liveness<'tcx>(
     // edges when visualizing the constraint graph anyways.
     let kills = collect_kills(body, tcx, borrow_set);
 
-    let graph = index_constraints(&localized_outlives_constraints);
+    // Create the full graph with the physical edges we've localized earlier, and the logical edges
+    // of constraints that hold at all points.
+    let logical_constraints =
+        outlives_constraints.filter(|c| matches!(c.locations, Locations::All(_)));
+    let graph = LocalizedConstraintGraph::new(&localized_outlives_constraints, logical_constraints);
     let mut visited = FxHashSet::default();
     let mut stack = Vec::new();
 
@@ -108,7 +117,7 @@ pub(super) fn compute_loan_liveness<'tcx>(
             let is_loan_killed =
                 kills.get(&current_location).is_some_and(|kills| kills.contains(&loan_idx));
 
-            for succ in outgoing_edges(&graph, node) {
+            for succ in graph.outgoing_edges(node) {
                 // If the loan is killed at this point, it is killed _on exit_. But only during
                 // forward traversal.
                 if is_loan_killed {
@@ -125,9 +134,17 @@ pub(super) fn compute_loan_liveness<'tcx>(
     live_loans
 }
 
-/// The localized constraint graph is currently the per-node map of its physical edges. In the
-/// future, we'll add logical edges to model constraints that hold at all points in the CFG.
-type LocalizedConstraintGraph = FxHashMap<LocalizedNode, FxIndexSet<LocalizedNode>>;
+/// The localized constraint graph indexes the physical and logical edges to compute a given node's
+/// successors during traversal.
+struct LocalizedConstraintGraph {
+    /// The actual, physical, edges we have recorded for a given node.
+    edges: FxHashMap<LocalizedNode, FxIndexSet<LocalizedNode>>,
+
+    /// The logical edges representing the outlives constraints that hold at all points in the CFG,
+    /// which we don't localize to avoid creating a lot of unnecessary edges in the graph. Some CFGs
+    /// can be big, and we don't need to create such a physical edge for every point in the CFG.
+    logical_edges: FxHashMap<RegionVid, FxIndexSet<RegionVid>>,
+}
 
 /// A node in the graph to be traversed, one of the two vertices of a localized outlives constraint.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
@@ -136,24 +153,44 @@ struct LocalizedNode {
     point: PointIndex,
 }
 
-/// Traverses the constraints and returns the indexable graph of edges per node.
-fn index_constraints(constraints: &LocalizedOutlivesConstraintSet) -> LocalizedConstraintGraph {
-    let mut edges = LocalizedConstraintGraph::default();
-    for constraint in &constraints.outlives {
-        let source = LocalizedNode { region: constraint.source, point: constraint.from };
-        let target = LocalizedNode { region: constraint.target, point: constraint.to };
-        edges.entry(source).or_default().insert(target);
-    }
+impl LocalizedConstraintGraph {
+    /// Traverses the constraints and returns the indexed graph of edges per node.
+    fn new<'tcx>(
+        constraints: &LocalizedOutlivesConstraintSet,
+        logical_constraints: impl Iterator<Item = OutlivesConstraint<'tcx>>,
+    ) -> Self {
+        let mut edges: FxHashMap<_, FxIndexSet<_>> = FxHashMap::default();
+        for constraint in &constraints.outlives {
+            let source = LocalizedNode { region: constraint.source, point: constraint.from };
+            let target = LocalizedNode { region: constraint.target, point: constraint.to };
+            edges.entry(source).or_default().insert(target);
+        }
 
-    edges
-}
+        let mut logical_edges: FxHashMap<_, FxIndexSet<_>> = FxHashMap::default();
+        for constraint in logical_constraints {
+            logical_edges.entry(constraint.sup).or_default().insert(constraint.sub);
+        }
+
+        LocalizedConstraintGraph { edges, logical_edges }
+    }
 
-/// Returns the outgoing edges of a given node, not its transitive closure.
-fn outgoing_edges(
-    graph: &LocalizedConstraintGraph,
-    node: LocalizedNode,
-) -> impl Iterator<Item = LocalizedNode> + use<'_> {
-    graph.get(&node).into_iter().flat_map(|edges| edges.iter().copied())
+    /// Returns the outgoing edges of a given node, not its transitive closure.
+    fn outgoing_edges(&self, node: LocalizedNode) -> impl Iterator<Item = LocalizedNode> + use<'_> {
+        // The outgoing edges are:
+        // - the physical edges present at this node,
+        // - the materialized logical edges that exist virtually at all points for this node's
+        //   region, localized at this point.
+        let physical_edges =
+            self.edges.get(&node).into_iter().flat_map(|targets| targets.iter().copied());
+        let materialized_edges =
+            self.logical_edges.get(&node.region).into_iter().flat_map(move |targets| {
+                targets
+                    .iter()
+                    .copied()
+                    .map(move |target| LocalizedNode { point: node.point, region: target })
+            });
+        physical_edges.chain(materialized_edges)
+    }
 }
 
 /// Traverses the MIR and collects kills.

compiler/rustc_borrowck/src/polonius/mod.rs

@@ -130,6 +130,7 @@ impl PoloniusContext {
             tcx,
             body,
             regioncx.liveness_constraints(),
+            regioncx.outlives_constraints(),
             borrow_set,
             &localized_outlives_constraints,
         );

compiler/rustc_borrowck/src/polonius/typeck_constraints.rs

@@ -22,23 +22,11 @@ pub(super) fn convert_typeck_constraints<'tcx>(
     for outlives_constraint in outlives_constraints {
         match outlives_constraint.locations {
             Locations::All(_) => {
-                // For now, turn logical constraints holding at all points into physical edges at
-                // every point in the graph.
-                // FIXME: encode this into *traversal* instead.
-                for (block, bb) in body.basic_blocks.iter_enumerated() {
-                    let statement_count = bb.statements.len();
-                    for statement_index in 0..=statement_count {
-                        let current_location = Location { block, statement_index };
-                        let current_point = liveness.point_from_location(current_location);
-
-                        localized_outlives_constraints.push(LocalizedOutlivesConstraint {
-                            source: outlives_constraint.sup,
-                            from: current_point,
-                            target: outlives_constraint.sub,
-                            to: current_point,
-                        });
-                    }
-                }
+                // We don't turn constraints holding at all points into physical edges at every
+                // point in the graph. They are encoded into *traversal* instead: a given node's
+                // successors will combine these logical edges with the regular, physical, localized
+                // edges.
+                continue;
             }
 
             Locations::Single(location) => {

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -1481,22 +1481,31 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// Test if this value might be null.
     /// If the machine does not support ptr-to-int casts, this is conservative.
     pub fn scalar_may_be_null(&self, scalar: Scalar<M::Provenance>) -> InterpResult<'tcx, bool> {
-        interp_ok(match scalar.try_to_scalar_int() {
-            Ok(int) => int.is_null(),
+        match scalar.try_to_scalar_int() {
+            Ok(int) => interp_ok(int.is_null()),
             Err(_) => {
-                // Can only happen during CTFE.
+                // We can't cast this pointer to an integer. Can only happen during CTFE.
                 let ptr = scalar.to_pointer(self)?;
                 match self.ptr_try_get_alloc_id(ptr, 0) {
                     Ok((alloc_id, offset, _)) => {
-                        let size = self.get_alloc_info(alloc_id).size;
-                        // If the pointer is out-of-bounds, it may be null.
-                        // Note that one-past-the-end (offset == size) is still inbounds, and never null.
-                        offset > size
+                        let info = self.get_alloc_info(alloc_id);
+                        // If the pointer is in-bounds (including "at the end"), it is definitely not null.
+                        if offset <= info.size {
+                            return interp_ok(false);
+                        }
+                        // If the allocation is N-aligned, and the offset is not divisible by N,
+                        // then `base + offset` has a non-zero remainder after division by `N`,
+                        // which means `base + offset` cannot be null.
+                        if offset.bytes() % info.align.bytes() != 0 {
+                            return interp_ok(false);
+                        }
+                        // We don't know enough, this might be null.
+                        interp_ok(true)
                     }
                     Err(_offset) => bug!("a non-int scalar is always a pointer"),
                 }
             }
-        })
+        }
     }
 
     /// Turning a "maybe pointer" into a proper pointer (and some information

library/core/src/num/f128.rs

@@ -504,7 +504,6 @@ impl f128 {
     ///
     /// ```rust
     /// #![feature(f128)]
-    /// #![feature(float_next_up_down)]
     /// # // FIXME(f16_f128): remove when `eqtf2` is available
     /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
@@ -516,13 +515,15 @@ impl f128 {
     /// # }
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextUp`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
+    #[doc(alias = "nextUp")]
     #[unstable(feature = "f128", issue = "116909")]
-    // #[unstable(feature = "float_next_up_down", issue = "91399")]
     pub const fn next_up(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here
@@ -558,7 +559,6 @@ impl f128 {
     ///
     /// ```rust
     /// #![feature(f128)]
-    /// #![feature(float_next_up_down)]
     /// # // FIXME(f16_f128): remove when `eqtf2` is available
     /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
@@ -570,13 +570,15 @@ impl f128 {
     /// # }
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextDown`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
+    #[doc(alias = "nextDown")]
     #[unstable(feature = "f128", issue = "116909")]
-    // #[unstable(feature = "float_next_up_down", issue = "91399")]
     pub const fn next_down(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here

library/core/src/num/f16.rs

@@ -497,7 +497,6 @@ impl f16 {
     ///
     /// ```rust
     /// #![feature(f16)]
-    /// #![feature(float_next_up_down)]
     /// # // FIXME(f16_f128): ABI issues on MSVC
     /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
@@ -509,13 +508,15 @@ impl f16 {
     /// # }
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextUp`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
+    #[doc(alias = "nextUp")]
     #[unstable(feature = "f16", issue = "116909")]
-    // #[unstable(feature = "float_next_up_down", issue = "91399")]
     pub const fn next_up(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here
@@ -551,7 +552,6 @@ impl f16 {
     ///
     /// ```rust
     /// #![feature(f16)]
-    /// #![feature(float_next_up_down)]
     /// # // FIXME(f16_f128): ABI issues on MSVC
     /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
@@ -563,13 +563,15 @@ impl f16 {
     /// # }
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextDown`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
+    #[doc(alias = "nextDown")]
     #[unstable(feature = "f16", issue = "116909")]
-    // #[unstable(feature = "float_next_up_down", issue = "91399")]
     pub const fn next_down(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here

library/core/src/num/f32.rs

@@ -726,20 +726,23 @@ impl f32 {
     /// is finite `x == x.next_up().next_down()` also holds.
     ///
     /// ```rust
-    /// #![feature(float_next_up_down)]
     /// // f32::EPSILON is the difference between 1.0 and the next number up.
     /// assert_eq!(1.0f32.next_up(), 1.0 + f32::EPSILON);
     /// // But not for most numbers.
     /// assert!(0.1f32.next_up() < 0.1 + f32::EPSILON);
     /// assert_eq!(16777216f32.next_up(), 16777218.0);
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextUp`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
-    #[unstable(feature = "float_next_up_down", issue = "91399")]
+    #[doc(alias = "nextUp")]
+    #[stable(feature = "float_next_up_down", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "float_next_up_down", since = "CURRENT_RUSTC_VERSION")]
     pub const fn next_up(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here
@@ -774,20 +777,23 @@ impl f32 {
     /// is finite `x == x.next_down().next_up()` also holds.
     ///
     /// ```rust
-    /// #![feature(float_next_up_down)]
     /// let x = 1.0f32;
     /// // Clamp value into range [0, 1).
     /// let clamped = x.clamp(0.0, 1.0f32.next_down());
     /// assert!(clamped < 1.0);
     /// assert_eq!(clamped.next_up(), 1.0);
     /// ```
     ///
+    /// This operation corresponds to IEEE-754 `nextDown`.
+    ///
     /// [`NEG_INFINITY`]: Self::NEG_INFINITY
     /// [`INFINITY`]: Self::INFINITY
     /// [`MIN`]: Self::MIN
     /// [`MAX`]: Self::MAX
     #[inline]
-    #[unstable(feature = "float_next_up_down", issue = "91399")]
+    #[doc(alias = "nextDown")]
+    #[stable(feature = "float_next_up_down", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "float_next_up_down", since = "CURRENT_RUSTC_VERSION")]
     pub const fn next_down(self) -> Self {
         // Some targets violate Rust's assumption of IEEE semantics, e.g. by flushing
         // denormals to zero. This is in general unsound and unsupported, but here