[compiler] Skip scope infos on "new scripts"

verwaest · V8 LUCI CQ · commit 31550587d42a · 2024-07-16T15:34:46.000Z
They aren't reachable anyway. They might exist if we serialized the code cache after eval ran though. Change-Id: Icdfa71edad6ad8d8e9a040e4088c7ad4eb4291f3 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5713171 Auto-Submit: Toon Verwaest <verwaest@chromium.org> Commit-Queue: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Leszek Swirski <leszeks@chromium.org> Commit-Queue: Toon Verwaest <verwaest@chromium.org> Cr-Commit-Position: refs/heads/main@{#95060}
diff --git a/src/codegen/compiler.cc b/src/codegen/compiler.cc
@@ -2226,9 +2226,10 @@ void BackgroundMergeTask::BeginMergeInBackground(
     DisallowGarbageCollection no_gc;
     Tagged<MaybeObject> maybe_new_sfi = new_script->infos()->get(i);
     Tagged<MaybeObject> maybe_old_info = old_script->infos()->get(i);
-    if (maybe_new_sfi.IsWeak()) {
-      // Since we're just compiled the new script, we're certain that we can
-      // only see shared function infos here.
+    // We might have scope infos in the table if it's deserialized from a code
+    // cache.
+    if (maybe_new_sfi.IsWeak() &&
+        Is<SharedFunctionInfo>(maybe_new_sfi.GetHeapObjectAssumeWeak())) {
       Tagged<SharedFunctionInfo> new_sfi =
           Cast<SharedFunctionInfo>(maybe_new_sfi.GetHeapObjectAssumeWeak());
       if (maybe_old_info.IsWeak()) {
