Auto merge of #160863 - JonathanBrouwer:rollup-RAWntd8, r=<try>

Rollup of 9 pull requests


try-job: dist-various-1
try-job: test-various
try-job: x86_64-gnu-aux
try-job: x86_64-gnu-llvm-21-3
try-job: x86_64-msvc-1
try-job: aarch64-apple-1
try-job: aarch64-apple-2
try-job: x86_64-mingw-1
try-job: i686-msvc-1
try-job: i686-msvc-2

Author: bors

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -647,6 +647,25 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                 None
             }
         } else {
+            // We are not checking dereferenceability, but we still want to ensure that the pointer
+            // *could* be dereferenceable in *some* memory: we have to be able to compute the
+            // address at the end of this range without overflowing..
+            let scalar = Scalar::from_maybe_pointer(place.ptr(), self.ecx);
+            // Skip this if we don't know the absolute address (during CTFE).
+            if let Ok(addr) = scalar.try_to_scalar_int() {
+                // Try to compute the end address.
+                let addr = Size::from_bytes(addr.to_target_usize(*self.ecx.tcx));
+                if addr.checked_add(size, self.ecx).is_none() {
+                    throw_validation_failure!(
+                        self.path,
+                        format!(
+                            "encountered a {ptr_kind} that is too close to the end of the address space for a pointee of {} bytes",
+                            size.bytes(),
+                        )
+                    )
+                }
+            }
+
             // Pointer remains unchanged.
             None
         };
@@ -658,20 +677,6 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
             self.reset_pointer_provenance(value, &ptr)?;
         }
 
-        // Check alignment after dereferenceable (if both are violated, trigger the error above).
-        try_validation!(
-            self.ecx.check_ptr_align(
-                place.ptr(),
-                align,
-            ),
-            self.path,
-            Ub(AlignmentCheckFailed(Misalignment { required, has }, _msg)) => format!(
-                "encountered an unaligned {ptr_kind} (required {required_bytes} byte alignment but found {found_bytes})",
-                required_bytes = required.bytes(),
-                found_bytes = has.bytes()
-            ),
-        );
-
         // Make sure this is non-null. This is obviously needed when `may_dangle` is set,
         // but even if we did check dereferenceability above that would still allow null
         // pointers if `size` is zero.
@@ -686,6 +691,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                 )
             )
         }
+
         // Do not allow references to uninhabited types.
         if !place.layout.ty.is_opsem_inhabited(*self.ecx.tcx, self.ecx.typing_env) {
             let ty = place.layout.ty;
@@ -695,6 +701,20 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
             )
         }
 
+        // Check alignment after dereferenceable (if both are violated, trigger the error above).
+        try_validation!(
+            self.ecx.check_ptr_align(
+                place.ptr(),
+                align,
+            ),
+            self.path,
+            Ub(AlignmentCheckFailed(Misalignment { required, has }, _msg)) => format!(
+                "encountered an unaligned {ptr_kind} (required {required_bytes} byte alignment but found {found_bytes})",
+                required_bytes = required.bytes(),
+                found_bytes = has.bytes()
+            ),
+        );
+
         // Recursive checking (but not inside `MaybeDangling` of course).
         if let Some(ref_tracking) = self.ref_tracking.as_deref_mut()
             && !self.may_dangle

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -1192,6 +1192,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Type check the pattern. Override if necessary to avoid knock-on errors.
         self.check_pat_top(decl.pat, decl_ty, ty_span, origin_expr, Some(decl.origin));
         let pat_ty = self.node_ty(decl.pat.hir_id);
+        if decl.ty.is_none()
+            && decl.init.is_none()
+            && !matches!(decl.pat.kind, hir::PatKind::Binding(.., None) | hir::PatKind::Wild)
+        {
+            self.register_wf_obligation(
+                decl_ty.into(),
+                decl.pat.span,
+                ObligationCauseCode::WellFormed(None),
+            );
+        }
         self.overwrite_local_ty_if_err(decl.hir_id, decl.pat, pat_ty);
 
         if let Some(blk) = decl.origin.try_get_else() {

compiler/rustc_infer/src/infer/context.rs

@@ -372,7 +372,8 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         use rustc_data_structures::undo_log::UndoLogs;
 
         use crate::infer::UndoLog;
-        inner.undo_log.push(UndoLog::PushSolverRegionConstraint);
+        let previous_was_and = inner.solver_region_constraint_storage.is_and();
+        inner.undo_log.push(UndoLog::PushSolverRegionConstraint { previous_was_and });
         inner.solver_region_constraint_storage.push(c);
     }
 

compiler/rustc_infer/src/infer/mod.rs

@@ -1895,12 +1895,21 @@ impl<'tcx> SolverRegionConstraintStorage<'tcx> {
         self.0.clone()
     }
 
-    fn pop(&mut self) -> Option<SolverRegionConstraint<'tcx>> {
+    fn is_and(&self) -> bool {
+        self.0.is_and()
+    }
+
+    fn pop(&mut self, previous_was_and: bool) -> Option<SolverRegionConstraint<'tcx>> {
         match &mut self.0 {
             SolverRegionConstraint::And(and) => {
                 let mut and = core::mem::take(and).into_iter().collect::<Vec<_>>();
                 let popped = and.pop()?;
-                self.0 = SolverRegionConstraint::And(and.into_boxed_slice());
+                if previous_was_and {
+                    self.0 = SolverRegionConstraint::And(and.into_boxed_slice());
+                } else {
+                    assert_eq!(and.len(), 1);
+                    self.0 = and.pop().unwrap();
+                }
                 Some(popped)
             }
             _ => unreachable!(),
@@ -1909,26 +1918,21 @@ impl<'tcx> SolverRegionConstraintStorage<'tcx> {
 
     #[instrument(level = "debug")]
     fn push(&mut self, constraint: SolverRegionConstraint<'tcx>) {
-        match &mut self.0 {
+        match core::mem::replace(&mut self.0, SolverRegionConstraint::new_true()) {
             SolverRegionConstraint::And(and) => {
-                let and = core::mem::take(and)
-                    .into_iter()
-                    .chain([constraint])
-                    .collect::<Vec<_>>()
-                    .into_boxed_slice();
+                let and =
+                    and.into_iter().chain([constraint]).collect::<Vec<_>>().into_boxed_slice();
                 self.0 = SolverRegionConstraint::And(and);
             }
-            _ => unreachable!(),
+            previous => {
+                self.0 = SolverRegionConstraint::And(Box::new([previous, constraint]));
+            }
         }
     }
 
     #[instrument(level = "debug", skip(self))]
     fn overwrite_solver_region_constraint(&mut self, constraint: SolverRegionConstraint<'tcx>) {
-        if !constraint.is_and() {
-            self.0 = SolverRegionConstraint::And(vec![constraint].into_boxed_slice())
-        } else {
-            self.0 = constraint;
-        }
+        self.0 = constraint;
     }
 }
 

compiler/rustc_infer/src/infer/snapshot/undo_log.rs

@@ -28,7 +28,7 @@ pub(crate) enum UndoLog<'tcx> {
     RegionUnificationTable(sv::UndoLog<ut::Delegate<RegionVidKey<'tcx>>>),
     ProjectionCache(traits::UndoLog<'tcx>),
     PushTypeOutlivesConstraint,
-    PushSolverRegionConstraint,
+    PushSolverRegionConstraint { previous_was_and: bool },
     OverwriteSolverRegionConstraint { old_constraint: SolverRegionConstraint<'tcx> },
     PushRegionAssumption,
     PushHirTypeckPotentiallyRegionDependentGoal,
@@ -79,8 +79,8 @@ impl<'tcx> Rollback<UndoLog<'tcx>> for InferCtxtInner<'tcx> {
                 self.region_constraint_storage.as_mut().unwrap().unification_table.reverse(undo)
             }
             UndoLog::ProjectionCache(undo) => self.projection_cache.reverse(undo),
-            UndoLog::PushSolverRegionConstraint => {
-                let popped = self.solver_region_constraint_storage.pop();
+            UndoLog::PushSolverRegionConstraint { previous_was_and } => {
+                let popped = self.solver_region_constraint_storage.pop(previous_was_and);
                 assert_matches!(
                     popped,
                     Some(_),

compiler/rustc_mir_transform/src/sroa.rs

@@ -69,7 +69,9 @@ fn escaping_locals<'tcx>(
             return true;
         }
         if let ty::Adt(def, _args) = ty.kind()
-            && (def.repr().simd() || tcx.is_lang_item(def.did(), LangItem::DynMetadata))
+            && (def.repr().simd()
+                || def.repr().scalable()
+                || tcx.is_lang_item(def.did(), LangItem::DynMetadata))
         {
             // Exclude #[repr(simd)] types so that they are not de-optimized into an array
             // (MCP#838 banned projections into SIMD types, but if the value is unused

compiler/rustc_mir_transform/src/validate.rs

@@ -707,7 +707,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             );
                         }
 
-                        if adt_def.repr().simd() {
+                        if adt_def.repr().simd() || adt_def.repr().scalable() {
                             self.fail(
                                 location,
                                 format!(

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

@@ -5,7 +5,7 @@ use std::ops::ControlFlow;
 use rustc_macros::StableHash;
 use rustc_type_ir::data_structures::HashSet;
 use rustc_type_ir::inherent::*;
-use rustc_type_ir::region_constraint::RegionConstraint;
+use rustc_type_ir::region_constraint::{RegionConstraint, evaluate_solver_constraint};
 use rustc_type_ir::relate::Relate;
 use rustc_type_ir::relate::solver_relating::RelateExt;
 use rustc_type_ir::search_graph::{CandidateHeadUsages, LowerAvailableDepth, PathKind};
@@ -1656,7 +1656,12 @@ where
         // `tests/ui/higher-ranked/leak-check/leak-check-in-selection-6-ambig-unify.rs`.
         let region_constraints = if self.cx().assumptions_on_binders() {
             ExternalRegionConstraints::NextGen(if let Certainty::Yes = certainty {
-                self.delegate.get_solver_region_constraint()
+                let constraint = self.delegate.get_solver_region_constraint();
+                debug_assert_eq!(
+                    constraint,
+                    evaluate_solver_constraint(&constraint.clone().canonical_form())
+                );
+                constraint
             } else {
                 RegionConstraint::new_true()
             })

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

@@ -9,6 +9,7 @@ use rustc_type_ir::outlives::{Component, push_outlives_components};
 use rustc_type_ir::region_constraint::TransitiveRelationBuilder;
 use rustc_type_ir::region_constraint::{
     Assumptions, RegionConstraint, eagerly_handle_placeholders_in_universe,
+    evaluate_solver_constraint,
 };
 use rustc_type_ir::{
     AliasTy, Binder, ClauseKind, InferCtxtLike, Interner, OutlivesClause, Region, TypeVisitable,
@@ -136,6 +137,7 @@ where
             .fold(constraint, |constraint, u| {
                 eagerly_handle_placeholders_in_universe(&**self.delegate, constraint, u)
             });
+        let constraint = evaluate_solver_constraint(&constraint.canonical_form());
 
         self.delegate.overwrite_solver_region_constraint(constraint.clone());
 

compiler/rustc_resolve/src/diagnostics/impls.rs

@@ -2973,7 +2973,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         };
         let scope = match &path[..failed_segment_idx] {
             [.., prev] => {
-                if prev.ident.name == kw::PathRoot {
+                if prev.ident.name == kw::PathRoot && self.tcx.sess.edition() > Edition::Edition2015
+                {
+                    format!("the list of imported crates")
+                } else if prev.ident.name == kw::PathRoot || prev.ident.name == kw::Crate {
                     format!("the crate root")
                 } else {
                     format!("`{}`", prev.ident)