cppgc: Add HoH::Trace utility method

Bug: chromium:1056170
Change-Id: I65a2b38c85a93ac2822cb7d2b7ac4bd66540348a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2468996
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70498}

src/heap/cppgc-js/cpp-heap.h

@@ -23,6 +23,9 @@ class V8_EXPORT_PRIVATE CppHeap final : public cppgc::internal::HeapBase,
           const std::vector<std::unique_ptr<cppgc::CustomSpaceBase>>&
               custom_spaces);
 
+  CppHeap(const CppHeap&) = delete;
+  CppHeap& operator=(const CppHeap&) = delete;
+
   HeapBase& AsBase() { return *this; }
   const HeapBase& AsBase() const { return *this; }
 

src/heap/cppgc/heap-object-header.cc

@@ -32,5 +32,10 @@ HeapObjectName HeapObjectHeader::GetName() const {
   return gc_info.name(Payload());
 }
 
+void HeapObjectHeader::Trace(Visitor* visitor) const {
+  const GCInfo& gc_info = GlobalGCInfoTable::GCInfoFromIndex(GetGCInfoIndex());
+  return gc_info.trace(visitor, Payload());
+}
+
 }  // namespace internal
 }  // namespace cppgc

src/heap/cppgc/heap-object-header.h

@@ -20,6 +20,9 @@
 #include "src/heap/cppgc/globals.h"
 
 namespace cppgc {
+
+class Visitor;
+
 namespace internal {
 
 // HeapObjectHeader contains meta data per object and is prepended to each
@@ -96,6 +99,8 @@ class HeapObjectHeader {
 
   V8_EXPORT_PRIVATE HeapObjectName GetName() const;
 
+  V8_EXPORT_PRIVATE void Trace(Visitor*) const;
+
  private:
   enum class EncodedHalf : uint8_t { kLow, kHigh };
 

src/heap/cppgc/marking-verifier.cc

@@ -70,8 +70,7 @@ bool MarkingVerifier::VisitHeapObjectHeader(HeapObjectHeader* header) {
   parent_ = header;
 
   if (!header->IsInConstruction()) {
-    GlobalGCInfoTable::GCInfoFromIndex(header->GetGCInfoIndex())
-        .trace(this, header->Payload());
+    header->Trace(this);
   } else {
     // Dispatches to conservative tracing implementation.
     TraceConservativelyIfNeeded(*header);