Rearrange the check for dead allocs in expose_ptr

src/intptrcast.rs

@@ -197,17 +197,20 @@ impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir,
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn expose_ptr(&mut self, alloc_id: AllocId, tag: BorTag) -> InterpResult<'tcx> {
         let ecx = self.eval_context_mut();
-        // Make sure we aren't trying to expose a dead allocation; this is part of justifying the
-        // way we treat the exposed set in VisitProvenance.
-        assert!(!matches!(ecx.get_alloc_info(alloc_id).2, AllocKind::Dead));
+        // Exposing a dead alloc is a no-op, because it's not possible to get a dead allocation
+        // via int2ptr.
+        if matches!(ecx.get_alloc_info(alloc_id).2, AllocKind::Dead) {
+            return Ok(());
+        }
         let global_state = ecx.machine.intptrcast.get_mut();
         // In strict mode, we don't need this, so we can save some cycles by not tracking it.
-        if global_state.provenance_mode != ProvenanceMode::Strict {
-            trace!("Exposing allocation id {alloc_id:?}");
-            global_state.exposed.insert(alloc_id);
-            if ecx.machine.borrow_tracker.is_some() {
-                ecx.expose_tag(alloc_id, tag)?;
-            }
+        if global_state.provenance_mode == ProvenanceMode::Strict {
+            return Ok(());
+        }
+        trace!("Exposing allocation id {alloc_id:?}");
+        global_state.exposed.insert(alloc_id);
+        if ecx.machine.borrow_tracker.is_some() {
+            ecx.expose_tag(alloc_id, tag)?;
         }
         Ok(())
     }