Upgrade V8 to 5.1.281.57 DO NOT MERGE
FPIIM-449
Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/snapshot/partial-serializer.cc b/src/snapshot/partial-serializer.cc
new file mode 100644
index 0000000..0f1f133
--- /dev/null
+++ b/src/snapshot/partial-serializer.cc
@@ -0,0 +1,123 @@
+// Copyright 2016 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/partial-serializer.h"
+
+#include "src/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+
+PartialSerializer::PartialSerializer(Isolate* isolate,
+ Serializer* startup_snapshot_serializer,
+ SnapshotByteSink* sink)
+ : Serializer(isolate, sink),
+ startup_serializer_(startup_snapshot_serializer),
+ global_object_(NULL),
+ next_partial_cache_index_(0) {
+ InitializeCodeAddressMap();
+}
+
+PartialSerializer::~PartialSerializer() {
+ OutputStatistics("PartialSerializer");
+}
+
+void PartialSerializer::Serialize(Object** o) {
+ if ((*o)->IsContext()) {
+ Context* context = Context::cast(*o);
+ global_object_ = context->global_object();
+ back_reference_map()->AddGlobalProxy(context->global_proxy());
+ // The bootstrap snapshot has a code-stub context. When serializing the
+ // partial snapshot, it is chained into the weak context list on the isolate
+ // and it's next context pointer may point to the code-stub context. Clear
+ // it before serializing, it will get re-added to the context list
+ // explicitly when it's loaded.
+ if (context->IsNativeContext()) {
+ context->set(Context::NEXT_CONTEXT_LINK,
+ isolate_->heap()->undefined_value());
+ DCHECK(!context->global_object()->IsUndefined());
+ }
+ }
+ VisitPointer(o);
+ SerializeDeferredObjects();
+ Pad();
+}
+
+void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
+ WhereToPoint where_to_point, int skip) {
+ if (obj->IsMap()) {
+ // The code-caches link to context-specific code objects, which
+ // the startup and context serializes cannot currently handle.
+ DCHECK(Map::cast(obj)->code_cache() == obj->GetHeap()->empty_fixed_array());
+ }
+
+ // Replace typed arrays by undefined.
+ if (obj->IsJSTypedArray()) obj = isolate_->heap()->undefined_value();
+
+ int root_index = root_index_map_.Lookup(obj);
+ if (root_index != RootIndexMap::kInvalidRootIndex) {
+ PutRoot(root_index, obj, how_to_code, where_to_point, skip);
+ return;
+ }
+
+ if (ShouldBeInThePartialSnapshotCache(obj)) {
+ FlushSkip(skip);
+
+ int cache_index = PartialSnapshotCacheIndex(obj);
+ sink_->Put(kPartialSnapshotCache + how_to_code + where_to_point,
+ "PartialSnapshotCache");
+ sink_->PutInt(cache_index, "partial_snapshot_cache_index");
+ return;
+ }
+
+ // Pointers from the partial snapshot to the objects in the startup snapshot
+ // should go through the root array or through the partial snapshot cache.
+ // If this is not the case you may have to add something to the root array.
+ DCHECK(!startup_serializer_->back_reference_map()->Lookup(obj).is_valid());
+ // All the internalized strings that the partial snapshot needs should be
+ // either in the root table or in the partial snapshot cache.
+ DCHECK(!obj->IsInternalizedString());
+
+ if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
+
+ FlushSkip(skip);
+
+ // Clear literal boilerplates.
+ if (obj->IsJSFunction()) {
+ FixedArray* literals = JSFunction::cast(obj)->literals();
+ for (int i = 0; i < literals->length(); i++) literals->set_undefined(i);
+ }
+
+ // Object has not yet been serialized. Serialize it here.
+ ObjectSerializer serializer(this, obj, sink_, how_to_code, where_to_point);
+ serializer.Serialize();
+}
+
+int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) {
+ int index = partial_cache_index_map_.LookupOrInsert(
+ heap_object, next_partial_cache_index_);
+ if (index == PartialCacheIndexMap::kInvalidIndex) {
+ // This object is not part of the partial snapshot cache yet. Add it to the
+ // startup snapshot so we can refer to it via partial snapshot index from
+ // the partial snapshot.
+ startup_serializer_->VisitPointer(reinterpret_cast<Object**>(&heap_object));
+ return next_partial_cache_index_++;
+ }
+ return index;
+}
+
+bool PartialSerializer::ShouldBeInThePartialSnapshotCache(HeapObject* o) {
+ // Scripts should be referred only through shared function infos. We can't
+ // allow them to be part of the partial snapshot because they contain a
+ // unique ID, and deserializing several partial snapshots containing script
+ // would cause dupes.
+ DCHECK(!o->IsScript());
+ return o->IsName() || o->IsSharedFunctionInfo() || o->IsHeapNumber() ||
+ o->IsCode() || o->IsScopeInfo() || o->IsAccessorInfo() ||
+ o->map() ==
+ startup_serializer_->isolate()->heap()->fixed_cow_array_map();
+}
+
+} // namespace internal
+} // namespace v8