commit 09344cd5b4bbbe4befe92e727b06284ba5cd70a9
author Samuel Groß <saelo@chromium.org> Thu Aug 17 09:10:19 2023
committer V8 LUCI CQ <v8-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Aug 17 15:25:56 2023
tree ff8b6eb4540d77d702a0c6e8ebe90b5aceec97d0
parent 97c6f935aa8ec6b786f7ff7726f86785316f30d0

Merged: Squashed multiple commits.

Merged: [runtime] Recreate enum cache on map update
Revision: 1c623f9ff6e077be1c66f155485ea4005ddb6574

Merged: [runtime] Don't try to create empty enum cache.
Revision: 5516e06237c9f0013121f47319e8c253c896d52d

BUG=chromium:1470668,chromium:1472317
R=tebbi@chromium.org

Change-Id: I31d5491aba663661ba68bb55631747a195ed084e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4788990
Commit-Queue: Samuel Groß <saelo@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/branch-heads/11.6@{#32}
Cr-Branched-From: e29c028f391389a7a60ee37097e3ca9e396d6fa4-refs/heads/11.6.189@{#3}
Cr-Branched-From: 95cbef20e2aa556a1ea75431a48b36c4de6b9934-refs/heads/main@{#88340}

src/objects/map-updater.cc

diff --git a/src/objects/map-updater.cc b/src/objects/map-updater.cc
index 8b2e7f3..568df12 100644
--- a/src/objects/map-updater.cc
+++ b/src/objects/map-updater.cc
@@ -12,6 +12,7 @@
 #include "src/handles/handles.h"
 #include "src/heap/parked-scope-inl.h"
 #include "src/objects/field-type.h"
+#include "src/objects/keys.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/objects.h"
 #include "src/objects/property-details.h"
@@ -1037,6 +1038,13 @@
   // the new descriptors to maintain descriptors sharing invariant.
   split_map->ReplaceDescriptors(isolate_, *new_descriptors);
 
+  // If the old descriptors had an enum cache, make sure the new ones do too.
+  if (old_descriptors_->enum_cache().keys().length() > 0 &&
+      new_map->NumberOfEnumerableProperties() > 0) {
+    FastKeyAccumulator::InitializeFastPropertyEnumCache(
+        isolate_, new_map, new_map->NumberOfEnumerableProperties());
+  }
+
   if (has_integrity_level_transition_) {
     target_map_ = new_map;
     state_ = kAtIntegrityLevelSource;