[snapshot] Deserialize eagerly if serializer is active

When setting up an isolate for serialization, we need to disable lazy
deserialization to avoid replacing lazy builtins with DeserializeLazy.

Bug: v8:6624
Change-Id: I3e10e262f6dd856f92fd83e5e475127e8ca3f3bf
Reviewed-on: https://chromium-review.googlesource.com/655161Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47885}

src/snapshot/builtin-deserializer.cc

@@ -52,7 +52,7 @@ void BuiltinDeserializer::DeserializeEagerBuiltins() {
 
   Builtins* builtins = isolate()->builtins();
   for (int i = 0; i < Builtins::builtin_count; i++) {
-    if (FLAG_lazy_deserialization && Builtins::IsLazy(i)) {
+    if (IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
       // Do nothing. These builtins have been replaced by DeserializeLazy in
       // InitializeBuiltinsTable.
       DCHECK_EQ(builtins->builtin(Builtins::kDeserializeLazy),
@@ -148,7 +148,7 @@ Heap::Reservation BuiltinDeserializer::CreateReservationsForEagerBuiltins() {
 
     // Skip lazy builtins. These will be replaced by the DeserializeLazy code
     // object in InitializeBuiltinsTable and thus require no reserved space.
-    if (FLAG_lazy_deserialization && Builtins::IsLazy(i)) continue;
+    if (IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) continue;
 
     uint32_t builtin_size = ExtractBuiltinSize(i);
     DCHECK_LE(builtin_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
@@ -189,7 +189,7 @@ void BuiltinDeserializer::InitializeBuiltinsTable(
   for (int i = 0; i < Builtins::builtin_count; i++) {
     if (i == Builtins::kDeserializeLazy) continue;
 
-    if (FLAG_lazy_deserialization && Builtins::IsLazy(i)) {
+    if (IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
       builtins->set_builtin(i, deserialize_lazy);
     } else {
       InitializeBuiltinFromReservation(reservation[reservation_index], i);

src/snapshot/deserializer.cc

@@ -159,6 +159,10 @@ void Deserializer::SortMapDescriptors() {
   }
 }
 
+bool Deserializer::IsLazyDeserializationEnabled() const {
+  return FLAG_lazy_deserialization && !isolate()->serializer_enabled();
+}
+
 Deserializer::~Deserializer() {
 #ifdef DEBUG
   // Do not perform checks if we aborted deserialization.
@@ -332,7 +336,7 @@ HeapObject* Deserializer::PostProcessNewObject(HeapObject* obj, int space) {
 
 int Deserializer::MaybeReplaceWithDeserializeLazy(int builtin_id) {
   DCHECK(Builtins::IsBuiltinId(builtin_id));
-  return (FLAG_lazy_deserialization && Builtins::IsLazy(builtin_id) &&
+  return (IsLazyDeserializationEnabled() && Builtins::IsLazy(builtin_id) &&
           !deserializing_builtins_)
              ? Builtins::kDeserializeLazy
              : builtin_id;

src/snapshot/deserializer.h

@@ -105,6 +105,8 @@ class Deserializer : public SerializerDeserializer {
   bool deserializing_user_code() const { return deserializing_user_code_; }
   bool can_rehash() const { return can_rehash_; }
 
+  bool IsLazyDeserializationEnabled() const;
+
  private:
   void VisitRootPointers(Root root, Object** start, Object** end) override;