Show names for the strong roots in heap snapshot.

src/profile-generator.h

Index: src/profile-generator.h
diff --git a/src/profile-generator.h b/src/profile-generator.h
index 961cc8d1fcb61f2c9e4a0cf103f82d131219ad9f..13f3f17d70ada856e9dd2f7ee23a6aea8a3613aa 100644
--- a/src/profile-generator.h
+++ b/src/profile-generator.h
@@ -853,6 +853,15 @@ class HeapEntriesMap {
 
   static HeapEntry* const kHeapEntryPlaceholder;
 
+  static uint32_t Hash(HeapThing thing) {
+    return ComputeIntegerHash(
+        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(thing)),
+        v8::internal::kZeroHashSeed);
+  }
+  static bool HeapThingsMatch(HeapThing key1, HeapThing key2) {
+    return key1 == key2;
+  }
+
  private:
   struct EntryInfo {
     EntryInfo(HeapEntry* entry, HeapEntriesAllocator* allocator)
@@ -869,15 +878,6 @@ class HeapEntriesMap {
 
   static inline void AllocateHeapEntryForMapEntry(HashMap::Entry* map_entry);
 
-  static uint32_t Hash(HeapThing thing) {
-    return ComputeIntegerHash(
-        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(thing)),
-        v8::internal::kZeroHashSeed);
-  }
-  static bool HeapThingsMatch(HeapThing key1, HeapThing key2) {
-    return key1 == key2;
-  }
-
   HashMap entries_;
   int entries_count_;
   int total_children_count_;
@@ -1025,6 +1025,7 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   void SetGcRootsReference(VisitorSynchronization::SyncTag tag);
   void SetGcSubrootReference(
       VisitorSynchronization::SyncTag tag, bool is_weak, Object* child);
+  const char* GetGcSubrootName(Object* object);

[mnaganov (inactive), 2012/04/19 13:52:29]

If it deals only with strong roots, perhaps call it 'GetStrongGcSubrootName'?

[alexeif, 2012/04/19 15:27:43]

Done.

   void SetObjectName(HeapObject* object);
   void TagObject(Object* obj, const char* tag);
 
@@ -1039,6 +1040,7 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   SnapshottingProgressReportingInterface* progress_;
   SnapshotFillerInterface* filler_;
   HeapObjectsSet objects_tags_;
+  HashMap gc_subroot_names_;

[mnaganov (inactive), 2012/04/19 13:52:29]

Why are you using a generic HashMap? HeapObjectsSet can associate heap objects
with tags.

[alexeif, 2012/04/19 15:27:43]

Done.

 
   static HeapObject* const kGcRootsObject;
   static HeapObject* const kFirstGcSubrootObject;