Pass the pointer of owning object in GCPointer::set() part II (#1509)

Summary: Pull Request resolved: #1509

Differential Revision: D62227030

Author: lavenzg

include/hermes/VM/GCPointer-inline.h

@@ -71,6 +71,20 @@ GCPointerBase::set(PointerBase &base, CompressedPointer ptr, GC &gc) {
   setNoBarrier(ptr);
 }
 
+inline void GCPointerBase::set(
+    PointerBase &base,
+    CompressedPointer ptr,
+    GC &gc,
+    const GCCell *owningObj) {
+  assert(
+      (!ptr || gc.validPointer(ptr.get(base))) &&
+      "Cannot set a GCPointer to an invalid pointer");
+  // Write barrier must happen before the write.
+  (void)owningObj;
+  gc.writeBarrier(this, ptr.get(base));
+  setNoBarrier(ptr);
+}
+
 inline void GCPointerBase::setNull(GC &gc) {
   gc.snapshotWriteBarrier(this);
   setNoBarrier(CompressedPointer(nullptr));

include/hermes/VM/GCPointer.h

@@ -57,6 +57,11 @@ class GCPointerBase : public CompressedPointer {
   set(PointerBase &base, GCCell *ptr, GC &gc, const GCCell *owningObj) {
     setImpl<MaybeLargeObj::Yes, NonNull::No>(base, ptr, gc, owningObj);
   }
+  inline void set(
+      PointerBase &base,
+      CompressedPointer ptr,
+      GC &gc,
+      const GCCell *owningObj);
   inline void
   setNonNull(PointerBase &base, GCCell *ptr, GC &gc, const GCCell *owningObj) {
     setImpl<MaybeLargeObj::Yes, NonNull::Yes>(base, ptr, gc, owningObj);
@@ -140,10 +145,21 @@ class GCPointer : public GCPointerBase {
     GCPointerBase::setNonNull(base, ptr, gc, owningObj);
   }
 
-  /// Convenience overload of GCPointer::set for other GCPointers.
+  /// Convenience overload of GCPointer::set for other GCPointers. This must not
+  /// be used if it lives in an object that supports large allocation.
   void set(PointerBase &base, const GCPointer<T> &ptr, GC &gc) {
     GCPointerBase::set(base, ptr, gc);
   }
+
+  /// Convenience overload of GCPointer::set for other GCPointers. \p owningObj
+  /// is used by the writer barriers.
+  void set(
+      PointerBase &base,
+      const GCPointer<T> &ptr,
+      GC &gc,
+      const GCCell *owningObj) {
+    GCPointerBase::set(base, ptr, gc, owningObj);
+  }
 };
 
 } // namespace vm