Auto merge of #157828 - JonathanBrouwer:rollup-2tPqsx9, r=JonathanBrouwer

Rollup of 23 pull requests

Successful merges:

 - #144220 (Add powerpc64-unknown-linux-gnuelfv2 target)
 - #153238 (debuginfo: slices are DW_TAG_array_type's)
 - #157112 (Update aarch64-unknown-freebsd target description)
 - #157322 (test pre-stabilization items on CI)
 - #157348 (Don't track cwd for `-Zremap-cwd-prefix` in incremental compilation)
 - #157490 (Add field-wise CoerceShared reborrow tests)
 - #157655 (Make Share::share final and improve docs)
 - #157672 (Region inference: Simplify initialisation of region values)
 - #157680 (Require `#[pin_v2]` for explicit pin-projection patterns)
 - #157688 (Create experimental test job `aarch64-apple-macos-26` for evaluating `macos-26` runner images)
 - #157796 (rustdoc: Some more lazy formatting)
 - #157818 (miri subtree update)
 - #157069 (Test that you can't implement Unpin for a compiler-generated future using TAIT)
 - #157079 (Don't recover `&raw EXPR` as a missing comma)
 - #157202 (add #[rustc_no_writable] to slice::get_unchecked_mut)
 - #157622 (Disable retagging for variadic arguments in const-eval)
 - #157684 (-Zassumptions-on-binders: insert empty assumptions when entering binders in the solver)
 - #157695 (Extend capabilities of `TypeFoldable_Generic`)
 - #157766 (interpret: avoid computing layout of sized raw pointee)
 - #157785 (fuchsia: Support AddressSanitizer on riscv64gc-unknown-fuchsia)
 - #157795 (revert 157013)
 - #157798 (Prevent approving PRs that wait for Crater or formal decisions)
 - #157803 (Rename `errors.rs` file to `diagnostics.rs` (7/N))

Failed merges:

 - #157752 (Rename `errors.rs` file to `diagnostics.rs` (6/N))

Author: bors

Cargo.lock

@@ -4892,6 +4892,7 @@ dependencies = [
 name = "rustc_type_ir_macros"
 version = "0.0.0"
 dependencies = [
+ "indexmap",
  "proc-macro2",
  "quote",
  "syn",

compiler/rustc_borrowck/src/diagnostics/find_use.rs

@@ -35,7 +35,7 @@ impl<'a, 'tcx> UseFinder<'a, 'tcx> {
 
         queue.push_back(self.start_point);
         while let Some(p) = queue.pop_front() {
-            if !self.regioncx.region_contains(self.region_vid, p) {
+            if !self.regioncx.region_contains_point(self.region_vid, p) {
                 continue;
             }
 

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -30,7 +30,7 @@ use crate::diagnostics::{RegionErrorKind, RegionErrors, UniverseInfo};
 use crate::handle_placeholders::{LoweredConstraints, RegionTracker};
 use crate::polonius::LiveLoans;
 use crate::polonius::legacy::PoloniusOutput;
-use crate::region_infer::values::{LivenessValues, RegionElement, RegionValues, ToElementIndex};
+use crate::region_infer::values::{LivenessValues, RegionElement, RegionValues};
 use crate::type_check::Locations;
 use crate::type_check::free_region_relations::UniversalRegionRelations;
 use crate::universal_regions::UniversalRegions;
@@ -345,7 +345,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             outlives_constraints,
             scc_annotations,
             type_tests,
-            liveness_constraints,
+            mut liveness_constraints,
             universe_causes,
             placeholder_indices,
         } = lowered_constraints;
@@ -364,106 +364,54 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         let mut scc_values =
             RegionValues::new(location_map, universal_regions.len(), placeholder_indices);
 
-        for region in liveness_constraints.regions() {
+        // Initializes the region variables with their initial live points.
+        for (region, definition) in definitions.iter_enumerated() {
             let scc = constraint_sccs.scc(region);
-            scc_values.merge_liveness(scc, region, &liveness_constraints);
-        }
 
-        let mut result = Self {
-            definitions,
-            liveness_constraints,
-            constraints: outlives_constraints,
-            constraint_graph,
-            constraint_sccs,
-            scc_annotations,
-            universe_causes,
-            scc_values,
-            type_tests,
-            universal_region_relations,
-        };
-
-        result.init_free_and_bound_regions();
-
-        result
-    }
-
-    /// Initializes the region variables for each universally
-    /// quantified region (lifetime parameter). The first N variables
-    /// always correspond to the regions appearing in the function
-    /// signature (both named and anonymous) and where-clauses. This
-    /// function iterates over those regions and initializes them with
-    /// minimum values.
-    ///
-    /// For example:
-    /// ```ignore (illustrative)
-    /// fn foo<'a, 'b>( /* ... */ ) where 'a: 'b { /* ... */ }
-    /// ```
-    /// would initialize two variables like so:
-    /// ```ignore (illustrative)
-    /// R0 = { CFG, R0 } // 'a
-    /// R1 = { CFG, R0, R1 } // 'b
-    /// ```
-    /// Here, R0 represents `'a`, and it contains (a) the entire CFG
-    /// and (b) any universally quantified regions that it outlives,
-    /// which in this case is just itself. R1 (`'b`) in contrast also
-    /// outlives `'a` and hence contains R0 and R1.
-    ///
-    /// This bit of logic also handles invalid universe relations
-    /// for higher-kinded types.
-    ///
-    /// We Walk each SCC `A` and `B` such that `A: B`
-    /// and ensure that universe(A) can see universe(B).
-    ///
-    /// This serves to enforce the 'empty/placeholder' hierarchy
-    /// (described in more detail on `RegionKind`):
-    ///
-    /// ```ignore (illustrative)
-    /// static -----+
-    ///   |         |
-    /// empty(U0) placeholder(U1)
-    ///   |      /
-    /// empty(U1)
-    /// ```
-    ///
-    /// In particular, imagine we have variables R0 in U0 and R1
-    /// created in U1, and constraints like this;
-    ///
-    /// ```ignore (illustrative)
-    /// R1: !1 // R1 outlives the placeholder in U1
-    /// R1: R0 // R1 outlives R0
-    /// ```
-    ///
-    /// Here, we wish for R1 to be `'static`, because it
-    /// cannot outlive `placeholder(U1)` and `empty(U0)` any other way.
-    ///
-    /// Thanks to this loop, what happens is that the `R1: R0`
-    /// constraint has lowered the universe of `R1` to `U0`, which in turn
-    /// means that the `R1: !1` constraint here will cause
-    /// `R1` to become `'static`.
-    fn init_free_and_bound_regions(&mut self) {
-        for variable in self.definitions.indices() {
-            let scc = self.constraint_sccs.scc(variable);
-
-            match self.definitions[variable].origin {
+            // For each universally quantified region (lifetime parameter). The
+            // first N variables always correspond to the regions appearing in the
+            // function signature (both named and anonymous) and in where-clauses.
+            match definition.origin {
+                // For each free, universally quantified region X:
                 NllRegionVariableOrigin::FreeRegion => {
-                    // For each free, universally quantified region X:
-
                     // Add all nodes in the CFG to liveness constraints
-                    self.liveness_constraints.add_all_points(variable);
-                    self.scc_values.add_all_points(scc);
+                    liveness_constraints.add_all_points(region);
 
                     // Add `end(X)` into the set for X.
-                    self.scc_values.add_element(scc, variable);
+                    scc_values.add_free_region(scc, region);
                 }
 
                 NllRegionVariableOrigin::Placeholder(placeholder) => {
-                    self.scc_values.add_element(scc, placeholder);
+                    scc_values.add_placeholder(scc, placeholder);
                 }
 
                 NllRegionVariableOrigin::Existential { .. } => {
                     // For existential, regions, nothing to do.
                 }
             }
+
+            // Initially copy the liveness constraints of any region that
+            // has them, setting `scc_values[scc(region)] |= liveness_constraints[region]`.
+            //
+            // These values will later be propagated during [`Self::propagate_constraints()`].
+            // The values include any live-at-all-points constraints added above
+            // for free regions.
+            if let Some(liveness) = liveness_constraints.point_liveness(region) {
+                scc_values.merge_liveness(scc, liveness)
+            }
+        }
+
+        Self {
+            definitions,
+            liveness_constraints,
+            constraints: outlives_constraints,
+            constraint_graph,
+            constraint_sccs,
+            scc_annotations,
+            universe_causes,
+            scc_values,
+            type_tests,
+            universal_region_relations,
         }
     }
 
@@ -495,9 +443,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// Returns `true` if the region `r` contains the point `p`.
     ///
     /// Panics if called before `solve()` executes,
-    pub(crate) fn region_contains(&self, r: RegionVid, p: impl ToElementIndex<'tcx>) -> bool {
+    pub(crate) fn region_contains_point(&self, r: RegionVid, p: Location) -> bool {
         let scc = self.constraint_sccs.scc(r);
-        self.scc_values.contains(scc, p)
+        self.scc_values.contains_point(scc, p)
     }
 
     /// Returns the lowest statement index in `start..=end` which is not contained by `r`.
@@ -608,7 +556,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         // To propagate constraints, we walk the DAG induced by the
         // SCC. For each SCC `A`, we visit its successors and compute
         // their values, then we union all those values to get our
-        // own.
+        // own. This one-shot approach works because iteration is in
+        // dependency order. I.e. a chain A: B: C will visit C, B, A.
         for scc_a in self.constraint_sccs.all_sccs() {
             // Walk each SCC `B` such that `A: B`...
             for &scc_b in self.constraint_sccs.successors(scc_a) {
@@ -1643,10 +1592,10 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         &self.definitions[r]
     }
 
-    /// Check if the SCC of `r` contains `upper`.
+    /// Check if the SCC of `r` contains `upper`, a free region.
     pub(crate) fn upper_bound_in_region_scc(&self, r: RegionVid, upper: RegionVid) -> bool {
         let r_scc = self.constraint_sccs.scc(r);
-        self.scc_values.contains(r_scc, upper)
+        self.scc_values.contains_free_region(r_scc, upper)
     }
 
     pub(crate) fn universal_regions(&self) -> &UniversalRegions<'tcx> {

compiler/rustc_borrowck/src/region_infer/opaque_types/region_ctxt.rs

@@ -78,11 +78,11 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> {
         let placeholder_indices = Default::default();
         let mut scc_values =
             RegionValues::new(location_map, universal_regions.len(), placeholder_indices);
-        for variable in definitions.indices() {
+        for (variable, definition) in definitions.iter_enumerated() {
             let scc = constraint_sccs.scc(variable);
-            match definitions[variable].origin {
+            match definition.origin {
                 NllRegionVariableOrigin::FreeRegion => {
-                    scc_values.add_element(scc, variable);
+                    scc_values.add_free_region(scc, variable);
                 }
                 _ => {}
             }

compiler/rustc_borrowck/src/region_infer/values.rs

@@ -95,9 +95,10 @@ impl LivenessValues {
         }
     }
 
-    /// Iterate through each region that has a value in this set.
-    pub(crate) fn regions(&self) -> impl Iterator<Item = RegionVid> {
-        self.points().rows()
+    /// Get the liveness status of a region `r`, if any.
+    /// Panics if liveness data is not tracked for any region.
+    pub(crate) fn point_liveness(&self, region: RegionVid) -> Option<&IntervalSet<PointIndex>> {
+        self.points().row(region)
     }
 
     /// Iterate through each region that has a value in this set.
@@ -166,13 +167,12 @@ impl LivenessValues {
     /// [`point`][rustc_mir_dataflow::points::PointIndex].
     #[inline]
     pub(crate) fn is_live_at_point(&self, region: RegionVid, point: PointIndex) -> bool {
-        self.points().row(region).is_some_and(|r| r.contains(point))
+        self.point_liveness(region).is_some_and(|r| r.contains(point))
     }
 
     /// Returns an iterator of all the points where `region` is live.
     fn live_points(&self, region: RegionVid) -> impl Iterator<Item = PointIndex> {
-        self.points()
-            .row(region)
+        self.point_liveness(region)
             .into_iter()
             .flat_map(|set| set.iter())
             .take_while(|&p| self.location_map.point_in_range(p))
@@ -296,18 +296,6 @@ impl<'tcx, N: Idx> RegionValues<'tcx, N> {
         }
     }
 
-    /// Adds the given element to the value for the given region. Returns whether
-    /// the element is newly added (i.e., was not already present).
-    pub(crate) fn add_element(&mut self, r: N, elem: impl ToElementIndex<'tcx>) -> bool {
-        debug!("add(r={:?}, elem={:?})", r, elem);
-        elem.add_to_row(self, r)
-    }
-
-    /// Adds all the control-flow points to the values for `r`.
-    pub(crate) fn add_all_points(&mut self, r: N) {
-        self.points.insert_all_into_row(r);
-    }
-
     /// Adds all elements in `r_from` to `r_to` (because e.g., `r_to:
     /// r_from`).
     pub(crate) fn add_region(&mut self, r_to: N, r_from: N) -> bool {
@@ -316,11 +304,6 @@ impl<'tcx, N: Idx> RegionValues<'tcx, N> {
             | self.placeholders.union_rows(r_from, r_to)
     }
 
-    /// Returns `true` if the region `r` contains the given element.
-    pub(crate) fn contains(&self, r: N, elem: impl ToElementIndex<'tcx>) -> bool {
-        elem.contained_in_row(self, r)
-    }
-
     /// Returns the lowest statement index in `start..=end` which is not contained by `r`.
     pub(crate) fn first_non_contained_inclusive(
         &self,
@@ -337,13 +320,9 @@ impl<'tcx, N: Idx> RegionValues<'tcx, N> {
         Some(first_unset.index() - block.index())
     }
 
-    /// `self[to] |= values[from]`, essentially: that is, take all the
-    /// elements for the region `from` from `values` and add them to
-    /// the region `to` in `self`.
-    pub(crate) fn merge_liveness(&mut self, to: N, from: RegionVid, values: &LivenessValues) {
-        if let Some(set) = values.points().row(from) {
-            self.points.union_row(to, set);
-        }
+    /// Merge a row of liveness into our points.
+    pub(crate) fn merge_liveness(&mut self, to: N, liveness: &IntervalSet<PointIndex>) {
+        self.points.union_row(to, liveness);
     }
 
     /// Returns `true` if `sup_region` contains all the CFG points that
@@ -405,47 +384,26 @@ impl<'tcx, N: Idx> RegionValues<'tcx, N> {
     pub(crate) fn region_value_str(&self, r: N) -> String {
         pretty_print_region_elements(self.elements_contained_in(r))
     }
-}
-
-pub(crate) trait ToElementIndex<'tcx>: Debug + Copy {
-    fn add_to_row<N: Idx>(self, values: &mut RegionValues<'tcx, N>, row: N) -> bool;
-
-    fn contained_in_row<N: Idx>(self, values: &RegionValues<'tcx, N>, row: N) -> bool;
-}
-
-impl ToElementIndex<'_> for Location {
-    fn add_to_row<N: Idx>(self, values: &mut RegionValues<'_, N>, row: N) -> bool {
-        let index = values.location_map.point_from_location(self);
-        values.points.insert(row, index)
-    }
 
-    fn contained_in_row<N: Idx>(self, values: &RegionValues<'_, N>, row: N) -> bool {
-        let index = values.location_map.point_from_location(self);
-        values.points.contains(row, index)
-    }
-}
-
-impl ToElementIndex<'_> for RegionVid {
-    fn add_to_row<N: Idx>(self, values: &mut RegionValues<'_, N>, row: N) -> bool {
-        values.free_regions.insert(row, self)
+    /// Add a the free region with rvid `region` to SCC `scc`
+    pub(crate) fn add_free_region(&mut self, scc: N, region: RegionVid) {
+        self.free_regions.insert(scc, region);
     }
 
-    fn contained_in_row<N: Idx>(self, values: &RegionValues<'_, N>, row: N) -> bool {
-        values.free_regions.contains(row, self)
+    pub(crate) fn add_placeholder(&mut self, scc: N, placeholder: ty::PlaceholderRegion<'tcx>) {
+        let index = self.placeholder_indices.lookup_index(placeholder);
+        self.placeholders.insert(scc, index);
     }
-}
 
-impl<'tcx> ToElementIndex<'tcx> for ty::PlaceholderRegion<'tcx> {
-    fn add_to_row<N: Idx>(self, values: &mut RegionValues<'tcx, N>, row: N) -> bool {
-        let placeholder: ty::PlaceholderRegion<'tcx> = self.into();
-        let index = values.placeholder_indices.lookup_index(placeholder);
-        values.placeholders.insert(row, index)
+    /// Determine if `scc` contains the CFG point `p`.
+    pub(crate) fn contains_point(&self, scc: N, p: Location) -> bool {
+        let index = self.location_map.point_from_location(p);
+        self.points.contains(scc, index)
     }
 
-    fn contained_in_row<N: Idx>(self, values: &RegionValues<'tcx, N>, row: N) -> bool {
-        let placeholder: ty::PlaceholderRegion<'tcx> = self.into();
-        let index = values.placeholder_indices.lookup_index(placeholder);
-        values.placeholders.contains(row, index)
+    /// Determine if `scc` contains the free region `free_region`.
+    pub(crate) fn contains_free_region(&self, scc: N, free_region: RegionVid) -> bool {
+        self.free_regions.contains(scc, free_region)
     }
 }
 

compiler/rustc_codegen_llvm/src/context.rs

@@ -201,6 +201,14 @@ pub(crate) unsafe fn create_module<'ll>(
         if sess.target.arch == Arch::PowerPC64 {
             // LLVM 22 updated the ABI alignment for double on AIX: https://github.com/llvm/llvm-project/pull/144673
             target_data_layout = target_data_layout.replace("-f64:32:64", "");
+
+            // LLVM 22 fixed the data layout calculation for targets that default to ELFv1
+            // when the ABI is set to ELFv2. With LLVM 21, the ELFv1 datalayout must be used,
+            // which will overalign function entries.
+            // https://github.com/llvm/llvm-project/pull/149725
+            if sess.target.llvm_target == "powerpc64-unknown-linux-gnu" {
+                target_data_layout = target_data_layout.replace("-Fn32", "-Fi64");
+            }
         }
         if sess.target.arch == Arch::AmdGpu {
             // LLVM 22 specified ELF mangling in the amdgpu data layout: