Support ES6 weak collections in heap profiler

BUG=chromium:376196
LOG=Y
R=alph@chromium.org, yangguo@chromium.org

Review URL: https://codereview.chromium.org/294163005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21460 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap-snapshot-generator.cc

@@ -1097,6 +1097,10 @@ bool V8HeapExplorer::ExtractReferencesPass1(int entry, HeapObject* obj) {
     ExtractJSGlobalProxyReferences(entry, JSGlobalProxy::cast(obj));
   } else if (obj->IsJSArrayBuffer()) {
     ExtractJSArrayBufferReferences(entry, JSArrayBuffer::cast(obj));
+  } else if (obj->IsJSWeakSet()) {
+    ExtractJSWeakCollectionReferences(entry, JSWeakSet::cast(obj));
+  } else if (obj->IsJSWeakMap()) {
+    ExtractJSWeakCollectionReferences(entry, JSWeakMap::cast(obj));
   } else if (obj->IsJSObject()) {
     ExtractJSObjectReferences(entry, JSObject::cast(obj));
   } else if (obj->IsString()) {
@@ -1256,6 +1260,15 @@ void V8HeapExplorer::ExtractSymbolReferences(int entry, Symbol* symbol) {
 }
 
 
+void V8HeapExplorer::ExtractJSWeakCollectionReferences(
+    int entry, JSWeakCollection* collection) {
+  MarkAsWeakContainer(collection->table());
+  SetInternalReference(collection, entry,
+                       "table", collection->table(),
+                       JSWeakCollection::kTableOffset);
+}
+
+
 void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
   if (context == context->declaration_context()) {
     ScopeInfo* scope_info = context->closure()->shared()->scope_info();

src/heap-snapshot-generator.h

@@ -370,6 +370,8 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   void ExtractJSObjectReferences(int entry, JSObject* js_obj);
   void ExtractStringReferences(int entry, String* obj);
   void ExtractSymbolReferences(int entry, Symbol* symbol);
+  void ExtractJSWeakCollectionReferences(int entry,
+                                         JSWeakCollection* collection);
   void ExtractContextReferences(int entry, Context* context);
   void ExtractMapReferences(int entry, Map* map);
   void ExtractSharedFunctionInfoReferences(int entry,

test/cctest/test-heap-profiler.cc

@@ -495,6 +495,70 @@ TEST(HeapSnapshotSymbol) {
 }
 
 
+TEST(HeapSnapshotWeakCollection) {
+  i::FLAG_harmony_collections = true;
+
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  v8::HeapProfiler* heap_profiler = env->GetIsolate()->GetHeapProfiler();
+
+  CompileRun("k = {}; v = {};\n"
+             "ws = new WeakSet(); ws.add(k); ws.add(v);\n"
+             "wm = new WeakMap(); wm.set(k, v);\n");
+  const v8::HeapSnapshot* snapshot =
+      heap_profiler->TakeHeapSnapshot(v8_str("WeakCollections"));
+  CHECK(ValidateSnapshot(snapshot));
+  const v8::HeapGraphNode* global = GetGlobalObject(snapshot);
+  const v8::HeapGraphNode* k =
+      GetProperty(global, v8::HeapGraphEdge::kProperty, "k");
+  CHECK_NE(NULL, k);
+  const v8::HeapGraphNode* v =
+      GetProperty(global, v8::HeapGraphEdge::kProperty, "v");
+  CHECK_NE(NULL, v);
+
+  const v8::HeapGraphNode* ws =
+      GetProperty(global, v8::HeapGraphEdge::kProperty, "ws");
+  CHECK_NE(NULL, ws);
+  CHECK_EQ(v8::HeapGraphNode::kObject, ws->GetType());
+  CHECK_EQ(v8_str("WeakSet"), ws->GetName());
+
+  const v8::HeapGraphNode* ws_table =
+      GetProperty(ws, v8::HeapGraphEdge::kInternal, "table");
+  CHECK_EQ(v8::HeapGraphNode::kArray, ws_table->GetType());
+  CHECK_GT(ws_table->GetChildrenCount(), 0);
+  int weak_entries = 0;
+  for (int i = 0, count = ws_table->GetChildrenCount(); i < count; ++i) {
+    const v8::HeapGraphEdge* prop = ws_table->GetChild(i);
+    if (prop->GetType() != v8::HeapGraphEdge::kWeak) continue;
+    if (k->GetId() == prop->GetToNode()->GetId()) {
+      ++weak_entries;
+    }
+  }
+  CHECK_EQ(1, weak_entries);
+
+  const v8::HeapGraphNode* wm =
+      GetProperty(global, v8::HeapGraphEdge::kProperty, "wm");
+  CHECK_NE(NULL, wm);
+  CHECK_EQ(v8::HeapGraphNode::kObject, wm->GetType());
+  CHECK_EQ(v8_str("WeakMap"), wm->GetName());
+
+  const v8::HeapGraphNode* wm_table =
+      GetProperty(wm, v8::HeapGraphEdge::kInternal, "table");
+  CHECK_EQ(v8::HeapGraphNode::kArray, wm_table->GetType());
+  CHECK_GT(wm_table->GetChildrenCount(), 0);
+  weak_entries = 0;
+  for (int i = 0, count = wm_table->GetChildrenCount(); i < count; ++i) {
+    const v8::HeapGraphEdge* prop = wm_table->GetChild(i);
+    if (prop->GetType() != v8::HeapGraphEdge::kWeak) continue;
+    const v8::SnapshotObjectId to_node_id = prop->GetToNode()->GetId();
+    if (to_node_id == k->GetId() || to_node_id == v->GetId()) {
+      ++weak_entries;
+    }
+  }
+  CHECK_EQ(2, weak_entries);
+}
+
+
 TEST(HeapSnapshotInternalReferences) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);