Simplify ObjectVisitor for external references.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/36853003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17336 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -10327,7 +10327,7 @@ void ObjectVisitor::VisitEmbeddedPointer(RelocInfo* rinfo) {
 
 void ObjectVisitor::VisitExternalReference(RelocInfo* rinfo) {
   Address* p = rinfo->target_reference_address();
-  VisitExternalReferences(p, p + 1);
+  VisitExternalReference(p);
 }
 
 

src/objects.h

@@ -10340,6 +10340,9 @@ class ObjectVisitor BASE_EMBEDDED {
   // [start, end). Any or all of the values may be modified on return.
   virtual void VisitPointers(Object** start, Object** end) = 0;
 
+  // Handy shorthand for visiting a single pointer.
+  virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
+
   // To allow lazy clearing of inline caches the visitor has
   // a rich interface for iterating over Code objects..
 
@@ -10368,22 +10371,14 @@ class ObjectVisitor BASE_EMBEDDED {
   // about the code's age.
   virtual void VisitCodeAgeSequence(RelocInfo* rinfo);
 
-  // Handy shorthand for visiting a single pointer.
-  virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); }
-
   // Visit pointer embedded into a code object.
   virtual void VisitEmbeddedPointer(RelocInfo* rinfo);
 
-  // Visits a contiguous arrays of external references (references to the C++
-  // heap) in the half-open range [start, end). Any or all of the values
-  // may be modified on return.
-  virtual void VisitExternalReferences(Address* start, Address* end) {}
-
+  // Visits an external reference embedded into a code object.
   virtual void VisitExternalReference(RelocInfo* rinfo);
 
-  inline void VisitExternalReference(Address* p) {
-    VisitExternalReferences(p, p + 1);
-  }
+  // Visits an external reference. The value may be modified on return.
+  virtual void VisitExternalReference(Address* p) {}
 
   // Visits a handle that has an embedder-assigned class ID.
   virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {}

src/serialize.cc

@@ -1682,19 +1682,15 @@ void Serializer::ObjectSerializer::VisitEmbeddedPointer(RelocInfo* rinfo) {
 }
 
 
-void Serializer::ObjectSerializer::VisitExternalReferences(Address* start,
-                                                           Address* end) {
-  Address references_start = reinterpret_cast<Address>(start);
+void Serializer::ObjectSerializer::VisitExternalReference(Address* p) {
+  Address references_start = reinterpret_cast<Address>(p);
   int skip = OutputRawData(references_start, kCanReturnSkipInsteadOfSkipping);
 
-  for (Address* current = start; current < end; current++) {
   sink_->Put(kExternalReference + kPlain + kStartOfObject, "ExternalRef");
   sink_->PutInt(skip, "SkipB4ExternalRef");
-    skip = 0;
-    int reference_id = serializer_->EncodeExternalReference(*current);
+  int reference_id = serializer_->EncodeExternalReference(*p);
   sink_->PutInt(reference_id, "reference id");
-  }
-  bytes_processed_so_far_ += static_cast<int>((end - start) * kPointerSize);
+  bytes_processed_so_far_ += kPointerSize;
 }
 
 

src/serialize.h

@@ -339,10 +339,6 @@ class Deserializer: public SerializerDeserializer {
  private:
   virtual void VisitPointers(Object** start, Object** end);
 
-  virtual void VisitExternalReferences(Address* start, Address* end) {
-    UNREACHABLE();
-  }
-
   virtual void VisitRuntimeEntry(RelocInfo* rinfo) {
     UNREACHABLE();
   }
@@ -521,7 +517,7 @@ class Serializer : public SerializerDeserializer {
     void Serialize();
     void VisitPointers(Object** start, Object** end);
     void VisitEmbeddedPointer(RelocInfo* target);
-    void VisitExternalReferences(Address* start, Address* end);
+    void VisitExternalReference(Address* p);
     void VisitExternalReference(RelocInfo* rinfo);
     void VisitCodeTarget(RelocInfo* target);
     void VisitCodeEntry(Address entry_address);