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

src/heap/objects-visiting.h

Index: src/heap/objects-visiting.h
diff --git a/src/heap/objects-visiting.h b/src/heap/objects-visiting.h
index 95cc80753a9daef391ec8d36211a13e81d751240..5a60f7f8d63ef6868cb46f2b7c033b524a98bb45 100644
--- a/src/heap/objects-visiting.h
+++ b/src/heap/objects-visiting.h
@@ -251,22 +251,15 @@ class StaticNewSpaceVisitor : public StaticVisitorBase {
     for (Object** p = start; p < end; p++) StaticVisitor::VisitPointer(heap, p);
   }
 
- private:
-  INLINE(static int VisitJSFunction(Map* map, HeapObject* object)) {
-    Heap* heap = map->GetHeap();
-    VisitPointers(heap, object,
-                  HeapObject::RawField(object, JSFunction::kPropertiesOffset),
-                  HeapObject::RawField(object, JSFunction::kCodeEntryOffset));
-
-    // Don't visit code entry. We are using this visitor only during scavenges.
-
-    VisitPointers(
-        heap, object, HeapObject::RawField(
-                          object, JSFunction::kCodeEntryOffset + kPointerSize),
-        HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset));
-    return JSFunction::kSize;
+  // Although we are using the JSFunction body descriptor which does not
+  // visit the code entry, compiler wants it to be accessible, therefore public.

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

nit: Let's drop the "therefore public" part of the sentence. The weird thing is
not the method being public, it's that the method needs to exist in the first
place. The VisitCodeEntry is always public.

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

Done.

+  // See JSFunction::BodyDescriptorImpl.
+  INLINE(static void VisitCodeEntry(Heap* heap, HeapObject* object,
+                                    Address entry_address)) {
+    UNREACHABLE();
   }
 
+ private:
   INLINE(static int VisitByteArray(Map* map, HeapObject* object)) {
     return reinterpret_cast<ByteArray*>(object)->ByteArraySize();
   }
@@ -405,8 +398,6 @@ class StaticMarkingVisitor : public StaticVisitorBase {
   // references to code objects either strongly or weakly.
   static void VisitSharedFunctionInfoStrongCode(Heap* heap, HeapObject* object);
   static void VisitSharedFunctionInfoWeakCode(Heap* heap, HeapObject* object);
-  static void VisitJSFunctionStrongCode(Heap* heap, HeapObject* object);

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

Can we keep these two methods for readability and make them just dispatch to the
BodyDescriptor in question? Basically one-line delegate functions.

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

Done.

-  static void VisitJSFunctionWeakCode(Heap* heap, HeapObject* object);
 
   class DataObjectVisitor {
    public: