Make JSFunction::BodyDescriptor the only single place that knows how to iterate JSFunction's body.

src/heap/objects-visiting-inl.h

Index: src/heap/objects-visiting-inl.h
diff --git a/src/heap/objects-visiting-inl.h b/src/heap/objects-visiting-inl.h
index 86f6d01940a0c7b9126e439a8b1392ca71ae51da..61261742094eea16f303f3a733fa173d1771cfdd 100644
--- a/src/heap/objects-visiting-inl.h
+++ b/src/heap/objects-visiting-inl.h
@@ -63,7 +63,11 @@ void StaticNewSpaceVisitor<StaticVisitor>::Initialize() {
 
   table_.Register(kVisitSeqTwoByteString, &VisitSeqTwoByteString);
 
-  table_.Register(kVisitJSFunction, &VisitJSFunction);
+  // Don't visit code entry. We are using this visitor only during scavenges.
+  table_.Register(
+      kVisitJSFunction,
+      &FlexibleBodyVisitor<StaticVisitor, JSFunction::BodyDescriptorWeakCode,
+                           int>::Visit);
 
   table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer);
 
@@ -486,6 +490,13 @@ void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfo(
 template <typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitJSFunction(Map* map,
                                                           HeapObject* object) {
+  typedef FlexibleBodyVisitor<StaticVisitor,

[Michael Starzinger, 2015/11/10 10:40:32]

I would vote for keeping delegator methods as mentioned in the comment in the
header file.

[Igor Sheludko, 2015/11/10 10:58:11]

Done.

+                              JSFunction::BodyDescriptorStrongCode,
+                              void> JSFunctionStrongCodeBodyVisitor;
+
+  typedef FlexibleBodyVisitor<StaticVisitor, JSFunction::BodyDescriptorWeakCode,
+                              void> JSFunctionWeakCodeBodyVisitor;
+
   Heap* heap = map->GetHeap();
   JSFunction* function = JSFunction::cast(object);
   MarkCompactCollector* collector = heap->mark_compact_collector();
@@ -507,7 +518,7 @@ void StaticMarkingVisitor<StaticVisitor>::VisitJSFunction(Map* map,
         VisitSharedFunctionInfoWeakCode(heap, shared);
       }
       // Treat the reference to the code object weakly.
-      VisitJSFunctionWeakCode(heap, object);
+      JSFunctionWeakCodeBodyVisitor::Visit(map, object);
       return;
     } else {
       // Visit all unoptimized code objects to prevent flushing them.
@@ -517,7 +528,7 @@ void StaticMarkingVisitor<StaticVisitor>::VisitJSFunction(Map* map,
       }
     }
   }
-  VisitJSFunctionStrongCode(heap, object);
+  JSFunctionStrongCodeBodyVisitor::Visit(map, object);
 }
 
 
@@ -800,47 +811,6 @@ void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoWeakCode(
 }
 
 
-template <typename StaticVisitor>
-void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionStrongCode(
-    Heap* heap, HeapObject* object) {
-  Object** start_slot =
-      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
-  Object** end_slot =
-      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
-  StaticVisitor::VisitPointers(heap, object, start_slot, end_slot);
-
-  VisitCodeEntry(heap, object,
-                 object->address() + JSFunction::kCodeEntryOffset);
-  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
-                JSFunction::kPrototypeOrInitialMapOffset);
-
-  start_slot =
-      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
-  end_slot = HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
-  StaticVisitor::VisitPointers(heap, object, start_slot, end_slot);
-}
-
-
-template <typename StaticVisitor>
-void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionWeakCode(
-    Heap* heap, HeapObject* object) {
-  Object** start_slot =
-      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
-  Object** end_slot =
-      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
-  StaticVisitor::VisitPointers(heap, object, start_slot, end_slot);
-
-  // Skip visiting kCodeEntryOffset as it is treated weakly here.
-  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
-                JSFunction::kPrototypeOrInitialMapOffset);
-
-  start_slot =
-      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
-  end_slot = HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
-  StaticVisitor::VisitPointers(heap, object, start_slot, end_slot);
-}
-
-
 void Code::CodeIterateBody(ObjectVisitor* v) {
   int mode_mask = RelocInfo::kCodeTargetMask |
                   RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |