From bc4366b099e7a4d115650dcfec4aeeb62bfc3c54 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 12 Oct 2024 12:14:28 +0200
Subject: miri: avoid cloning AllocExtra

---
 src/tools/miri/src/diagnostics.rs |  4 ++--
 src/tools/miri/src/eval.rs        |  2 +-
 src/tools/miri/src/machine.rs     | 10 +++++++++-
 3 files changed, 12 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/tools/miri/src/diagnostics.rs b/src/tools/miri/src/diagnostics.rs
index 5b1bad28c07..475139a3b51 100644
--- a/src/tools/miri/src/diagnostics.rs
+++ b/src/tools/miri/src/diagnostics.rs
@@ -473,14 +473,14 @@ pub fn report_leaks<'tcx>(
     leaks: Vec<(AllocId, MemoryKind, Allocation<Provenance, AllocExtra<'tcx>, MiriAllocBytes>)>,
 ) {
     let mut any_pruned = false;
-    for (id, kind, mut alloc) in leaks {
+    for (id, kind, alloc) in leaks {
         let mut title = format!(
             "memory leaked: {id:?} ({}, size: {:?}, align: {:?})",
             kind,
             alloc.size().bytes(),
             alloc.align.bytes()
         );
-        let Some(backtrace) = alloc.extra.backtrace.take() else {
+        let Some(backtrace) = alloc.extra.backtrace else {
             ecx.tcx.dcx().err(title);
             continue;
         };
diff --git a/src/tools/miri/src/eval.rs b/src/tools/miri/src/eval.rs
index ece76e581f2..57b226de28c 100644
--- a/src/tools/miri/src/eval.rs
+++ b/src/tools/miri/src/eval.rs
@@ -476,7 +476,7 @@ pub fn eval_entry<'tcx>(
         }
         // Check for memory leaks.
         info!("Additional static roots: {:?}", ecx.machine.static_roots);
-        let leaks = ecx.find_leaked_allocations(&ecx.machine.static_roots);
+        let leaks = ecx.take_leaked_allocations(|ecx| &ecx.machine.static_roots);
         if !leaks.is_empty() {
             report_leaks(&ecx, leaks);
             tcx.dcx().note("set `MIRIFLAGS=-Zmiri-ignore-leaks` to disable this check");
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index b9cebcfe9cd..d346cd7b03e 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -321,7 +321,7 @@ impl ProvenanceExtra {
 }
 
 /// Extra per-allocation data
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub struct AllocExtra<'tcx> {
     /// Global state of the borrow tracker, if enabled.
     pub borrow_tracker: Option<borrow_tracker::AllocState>,
@@ -338,6 +338,14 @@ pub struct AllocExtra<'tcx> {
     pub backtrace: Option<Vec<FrameInfo<'tcx>>>,
 }
 
+// We need a `Clone` impl because the machine passes `Allocation` through `Cow`...
+// but that should never end up actually cloning our `AllocExtra`.
+impl<'tcx> Clone for AllocExtra<'tcx> {
+    fn clone(&self) -> Self {
+        panic!("our allocations should never be cloned");
+    }
+}
+
 impl VisitProvenance for AllocExtra<'_> {
     fn visit_provenance(&self, visit: &mut VisitWith<'_>) {
         let AllocExtra { borrow_tracker, data_race, weak_memory, backtrace: _ } = self;
-- 
cgit 1.4.1-3-g733a5