[interpreter] do not serialize bytecode for snapshot.

src/snapshot/serialize.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/snapshot/serialize.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ skipping 1662 matching lines @@
                    "BackRefWithSkip");
         sink_->PutInt(skip, "BackRefSkipDistance");
       }
       PutBackReference(obj, back_reference);
     }
     return true;
   }
   return false;
 }
 
-
 StartupSerializer::StartupSerializer(Isolate* isolate, SnapshotByteSink* sink)
-    : Serializer(isolate, sink), root_index_wave_front_(0) {
+    : Serializer(isolate, sink),
+      root_index_wave_front_(0),
+      serializing_builtins_(false) {
   // Clear the cache of objects used by the partial snapshot.  After the
   // strong roots have been serialized we can create a partial snapshot
   // which will repopulate the cache with objects needed by that partial
   // snapshot.
   isolate->partial_snapshot_cache()->Clear();
   InitializeCodeAddressMap();
 }
 
 
 void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
                                         WhereToPoint where_to_point, int skip) {
   DCHECK(!obj->IsJSFunction());
 
+  if (obj->IsCode()) {
+    Code* code = Code::cast(obj);
+    // If the function code is compiled (either as native code or bytecode),
+    // replace it with lazy-compile builtin. Only exception is when we are
+    // serializing the canonical interpreter-entry-trampoline builtin.
+    if (code->kind() == Code::FUNCTION ||
+        (!serializing_builtins_ && code->is_interpreter_entry_trampoline())) {
+      obj = isolate()->builtins()->builtin(Builtins::kCompileLazy);
+    }
+  } else if (obj->IsBytecodeArray()) {
+    obj = isolate()->heap()->undefined_value();
+  }
+
   int root_index = root_index_map_.Lookup(obj);
   // We can only encode roots as such if it has already been serialized.
   // That applies to root indices below the wave front.
   if (root_index != RootIndexMap::kInvalidRootIndex &&
       root_index < root_index_wave_front_) {
     PutRoot(root_index, obj, how_to_code, where_to_point, skip);
     return;
   }
 
-  if (obj->IsCode() && Code::cast(obj)->kind() == Code::FUNCTION) {
-    obj = isolate()->builtins()->builtin(Builtins::kCompileLazy);
-  }
-
   if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
 
   FlushSkip(skip);
 
   // Object has not yet been serialized.  Serialize it here.
   ObjectSerializer object_serializer(this, obj, sink_, how_to_code,
                                      where_to_point);
   object_serializer.Serialize();
 }
 
 
 void StartupSerializer::SerializeWeakReferencesAndDeferred() {
   // This phase comes right after the serialization (of the snapshot).
   // After we have done the partial serialization the partial snapshot cache
   // will contain some references needed to decode the partial snapshot.  We
   // add one entry with 'undefined' which is the sentinel that the deserializer
   // uses to know it is done deserializing the array.
   Object* undefined = isolate()->heap()->undefined_value();
   VisitPointer(&undefined);
   isolate()->heap()->IterateWeakRoots(this, VISIT_ALL);
   SerializeDeferredObjects();
   Pad();
 }
 
+void StartupSerializer::Synchronize(VisitorSynchronization::SyncTag tag) {
+  // We expect the builtins tag after builtins have been serialized.
+  DCHECK(!serializing_builtins_ || tag == VisitorSynchronization::kBuiltins);
+  serializing_builtins_ = (tag == VisitorSynchronization::kHandleScope);
+}
 
 void Serializer::PutRoot(int root_index,
                          HeapObject* object,
                          SerializerDeserializer::HowToCode how_to_code,
                          SerializerDeserializer::WhereToPoint where_to_point,
                          int skip) {
   if (FLAG_trace_serializer) {
     PrintF(" Encoding root %d:", root_index);
     object->ShortPrint();
     PrintF("\n");
@@ skipping 1074 matching lines @@
   SerializedCodeData* scd = new SerializedCodeData(cached_data);
   SanityCheckResult r = scd->SanityCheck(isolate, source);
   if (r == CHECK_SUCCESS) return scd;
   cached_data->Reject();
   source->GetIsolate()->counters()->code_cache_reject_reason()->AddSample(r);
   delete scd;
   return NULL;
 }
 }  // namespace internal
 }  // namespace v8