[heap] Fix DCHECK in TransitionArrayNeedsCompaction

LeszekSwirski · Commit Bot · commit 9a6a22874c81 · 2021-01-12T14:10:49.000Z
The dead target check in TransitionArrayNeedsCompaction, confirming that Smi (uninitialized) targets imply that no other target is dead, has to additionally support Smi entries. Bug: v8:11305 Change-Id: I6f3fa9e7420b1bd0a64a25dae670f439e3f41162 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2622914 Commit-Queue: Leszek Swirski <leszeks@chromium.org> Commit-Queue: Ulan Degenbaev <ulan@chromium.org> Auto-Submit: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Ulan Degenbaev <ulan@chromium.org> Cr-Commit-Position: refs/heads/master@{#72040}
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
@@ -2290,7 +2290,9 @@ bool MarkCompactCollector::TransitionArrayNeedsCompaction(
 #ifdef DEBUG
       // Targets can only be dead iff this array is fully deserialized.
       for (int i = 0; i < num_transitions; ++i) {
-        DCHECK(!non_atomic_marking_state()->IsWhite(transitions.GetTarget(i)));
+        DCHECK_IMPLIES(
+            !transitions.GetRawTarget(i).IsSmi(),
+            !non_atomic_marking_state()->IsWhite(transitions.GetTarget(i)));
       }
 #endif
       return false;
