Merge pull request #4162 from rust-lang/rustup-2025-01-29

Automatic Rustup

Author: RalfJung

rust-version

@@ -1 +1 @@
-2f348cb7ce4063fa4eb40038e6ada3c5214717bd
+122fb29eb639aae852b9dcba0fd7aefc691be118

src/borrow_tracker/stacked_borrows/mod.rs

@@ -865,7 +865,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let this = self.eval_context_mut();
         let new_perm = NewPermission::from_ref_ty(val.layout.ty, kind, this);
         let cause = match kind {
-            RetagKind::TwoPhase { .. } => RetagCause::TwoPhase,
+            RetagKind::TwoPhase => RetagCause::TwoPhase,
             RetagKind::FnEntry => unreachable!(),
             RetagKind::Raw | RetagKind::Default => RetagCause::Normal,
         };
@@ -880,7 +880,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let this = self.eval_context_mut();
         let retag_fields = this.machine.borrow_tracker.as_mut().unwrap().get_mut().retag_fields;
         let retag_cause = match kind {
-            RetagKind::TwoPhase { .. } => unreachable!(), // can only happen in `retag_ptr_value`
+            RetagKind::TwoPhase => unreachable!(), // can only happen in `retag_ptr_value`
             RetagKind::FnEntry => RetagCause::FnEntry,
             RetagKind::Default | RetagKind::Raw => RetagCause::Normal,
         };

src/eval.rs

@@ -558,15 +558,15 @@ where
 
                 match chars.next() {
                     Some('"') => {
-                        cmd.extend(iter::repeat('\\').take(nslashes * 2 + 1));
+                        cmd.extend(iter::repeat_n('\\', nslashes * 2 + 1));
                         cmd.push('"');
                     }
                     Some(c) => {
-                        cmd.extend(iter::repeat('\\').take(nslashes));
+                        cmd.extend(iter::repeat_n('\\', nslashes));
                         cmd.push(c);
                     }
                     None => {
-                        cmd.extend(iter::repeat('\\').take(nslashes * 2));
+                        cmd.extend(iter::repeat_n('\\', nslashes * 2));
                         break;
                     }
                 }

src/lib.rs

@@ -36,6 +36,9 @@
     clippy::needless_question_mark,
     clippy::needless_lifetimes,
     clippy::too_long_first_doc_paragraph,
+    // Temporarily disabled as fixing it would cause conflicts
+    clippy::manual_repeat_n,
+    // We don't use translatable diagnostics
     rustc::diagnostic_outside_of_impl,
     // We are not implementing queries here so it's fine
     rustc::potential_query_instability,

tests/pass/disjoint-array-accesses.rs

@@ -0,0 +1,35 @@
+// This is a regression test for issue #135671 where a MIR refactor about arrays and their lengths
+// unexpectedly caused borrowck errors for disjoint borrows of array elements, for which we had no
+// tests. This is a collection of a few code samples from that issue.
+
+//@revisions: stack tree
+//@[tree]compile-flags: -Zmiri-tree-borrows
+
+struct Test {
+    a: i32,
+    b: i32,
+}
+
+fn one() {
+    let inputs: &mut [_] = &mut [Test { a: 0, b: 0 }];
+    let a = &mut inputs[0].a;
+    let b = &mut inputs[0].b;
+
+    *a = 0;
+    *b = 1;
+}
+
+fn two() {
+    let slice = &mut [(0, 0)][..];
+    std::mem::swap(&mut slice[0].0, &mut slice[0].1);
+}
+
+fn three(a: &mut [(i32, i32)], i: usize, j: usize) -> (&mut i32, &mut i32) {
+    (&mut a[i].0, &mut a[j].1)
+}
+
+fn main() {
+    one();
+    two();
+    three(&mut [(1, 2), (3, 4)], 0, 1);
+}