Generalize virtually dispatched scavenger to virtually dispatched specialized visitors.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 4e20959a7a8c4b7bb6dae90feaba0e8e346865e0..61288d9de44514e8df5754c6728832663972a1cc 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -33,6 +33,7 @@
 #include "debug.h"
 #include "execution.h"
 #include "objects-inl.h"
+#include "objects-visiting.h"
 #include "macro-assembler.h"
 #include "scanner.h"
 #include "scopeinfo.h"
@@ -1042,7 +1043,7 @@ int HeapObject::SlowSizeFromMap(Map* map) {
 
   switch (instance_type) {
     case FIXED_ARRAY_TYPE:
-      return reinterpret_cast<FixedArray*>(this)->FixedArraySize();
+      return FixedArray::BodyDescriptor::SizeOf(map, this);
     case BYTE_ARRAY_TYPE:
       return reinterpret_cast<ByteArray*>(this)->ByteArraySize();
     case CODE_TYPE:
@@ -1073,7 +1074,7 @@ void HeapObject::IterateBody(InstanceType type, int object_size,
       case kSeqStringTag:
         break;
       case kConsStringTag:
-        reinterpret_cast<ConsString*>(this)->ConsStringIterateBody(v);
+        ConsString::BodyDescriptor::IterateBody(this, v);
         break;
       case kExternalStringTag:
         if ((type & kStringEncodingMask) == kAsciiStringTag) {
@@ -1090,7 +1091,7 @@ void HeapObject::IterateBody(InstanceType type, int object_size,
 
   switch (type) {
     case FIXED_ARRAY_TYPE:
-      reinterpret_cast<FixedArray*>(this)->FixedArrayIterateBody(v);
+      FixedArray::BodyDescriptor::IterateBody(this, object_size, v);
       break;
     case JS_OBJECT_TYPE:
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
@@ -1101,23 +1102,22 @@ void HeapObject::IterateBody(InstanceType type, int object_size,
     case JS_GLOBAL_PROXY_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case JS_BUILTINS_OBJECT_TYPE:
-      reinterpret_cast<JSObject*>(this)->JSObjectIterateBody(object_size, v);
+      JSObject::BodyDescriptor::IterateBody(this, object_size, v);
       break;
     case ODDBALL_TYPE:
-      reinterpret_cast<Oddball*>(this)->OddballIterateBody(v);
+      Oddball::BodyDescriptor::IterateBody(this, v);
       break;
     case PROXY_TYPE:
       reinterpret_cast<Proxy*>(this)->ProxyIterateBody(v);
       break;
     case MAP_TYPE:
-      reinterpret_cast<Map*>(this)->MapIterateBody(v);
+      Map::BodyDescriptor::IterateBody(this, v);
       break;
     case CODE_TYPE:
       reinterpret_cast<Code*>(this)->CodeIterateBody(v);
       break;
     case JS_GLOBAL_PROPERTY_CELL_TYPE:
-      reinterpret_cast<JSGlobalPropertyCell*>(this)
-          ->JSGlobalPropertyCellIterateBody(v);
+      JSGlobalPropertyCell::BodyDescriptor::IterateBody(this, v);
       break;
     case HEAP_NUMBER_TYPE:
     case FILLER_TYPE:
@@ -1131,16 +1131,15 @@ void HeapObject::IterateBody(InstanceType type, int object_size,
     case EXTERNAL_UNSIGNED_INT_ARRAY_TYPE:
     case EXTERNAL_FLOAT_ARRAY_TYPE:
       break;
-    case SHARED_FUNCTION_INFO_TYPE: {
-      SharedFunctionInfo* shared = reinterpret_cast<SharedFunctionInfo*>(this);
-      shared->SharedFunctionInfoIterateBody(v);
+    case SHARED_FUNCTION_INFO_TYPE:
+      SharedFunctionInfo::BodyDescriptor::IterateBody(this, v);
       break;
-    }
+
 #define MAKE_STRUCT_CASE(NAME, Name, name) \
         case NAME##_TYPE:
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
-      IterateStructBody(object_size, v);
+      StructBodyDescriptor::IterateBody(this, object_size, v);
       break;
     default:
       PrintF("Unknown type: %d\n", type);
@@ -1209,12 +1208,6 @@ String* JSObject::constructor_name() {
 }
 
 
-void JSObject::JSObjectIterateBody(int object_size, ObjectVisitor* v) {
-  // Iterate over all fields in the body. Assumes all are Object*.
-  IteratePointers(v, kPropertiesOffset, object_size);
-}
-
-
 Object* JSObject::AddFastPropertyUsingMap(Map* new_map,
                                           String* name,
                                           Object* value) {
@@ -2190,8 +2183,7 @@ Object* JSObject::NormalizeProperties(PropertyNormalizationMode mode,
     int new_instance_size = map()->instance_size() - instance_size_delta;
     new_map->set_inobject_properties(0);
     new_map->set_instance_size(new_instance_size);
-    new_map->set_scavenger(Heap::GetScavenger(new_map->instance_type(),
-                                              new_map->instance_size()));
+    new_map->set_visitor_id(StaticVisitorBase::GetVisitorId(new_map));
     Heap::CreateFillerObjectAt(this->address() + new_instance_size,
                                instance_size_delta);
   }
@@ -3407,11 +3399,6 @@ void CodeCacheHashTable::RemoveByIndex(int index) {
 }
 
 
-void FixedArray::FixedArrayIterateBody(ObjectVisitor* v) {
-  IteratePointers(v, kHeaderSize, kHeaderSize + length() * kPointerSize);
-}
-
-
 static bool HasKey(FixedArray* array, Object* key) {
   int len0 = array->length();
   for (int i = 0; i < len0; i++) {
@@ -4501,16 +4488,6 @@ void ConsString::ConsStringReadBlockIntoBuffer(ReadBlockBuffer* rbb,
 }
 
 
-void ConsString::ConsStringIterateBody(ObjectVisitor* v) {
-  IteratePointers(v, kFirstOffset, kSecondOffset + kPointerSize);
-}
-
-
-void JSGlobalPropertyCell::JSGlobalPropertyCellIterateBody(ObjectVisitor* v) {
-  IteratePointers(v, kValueOffset, kValueOffset + kPointerSize);
-}
-
-
 uint16_t ConsString::ConsStringGet(int index) {
   ASSERT(index >= 0 && index < this->length());
 
@@ -4614,24 +4591,6 @@ void String::WriteToFlat(String* src,
 }
 
 
-#define FIELD_ADDR(p, offset) \
-  (reinterpret_cast<byte*>(p) + offset - kHeapObjectTag)
-
-void ExternalAsciiString::ExternalAsciiStringIterateBody(ObjectVisitor* v) {
-  typedef v8::String::ExternalAsciiStringResource Resource;
-  v->VisitExternalAsciiString(
-      reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)));
-}
-
-
-void ExternalTwoByteString::ExternalTwoByteStringIterateBody(ObjectVisitor* v) {
-  typedef v8::String::ExternalStringResource Resource;
-  v->VisitExternalTwoByteString(
-      reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)));
-}
-
-#undef FIELD_ADDR
-
 template <typename IteratorA, typename IteratorB>
 static inline bool CompareStringContents(IteratorA* ia, IteratorB* ib) {
   // General slow case check.  We know that the ia and ib iterators
@@ -5035,12 +4994,6 @@ void Map::ClearNonLiveTransitions(Object* real_prototype) {
 }
 
 
-void Map::MapIterateBody(ObjectVisitor* v) {
-  // Assumes all Object* members are contiguously allocated!
-  IteratePointers(v, kPointerFieldsBeginOffset, kPointerFieldsEndOffset);
-}
-
-
 Object* JSFunction::SetInstancePrototype(Object* value) {
   ASSERT(value->IsJSObject());
 
@@ -5104,12 +5057,6 @@ Context* JSFunction::GlobalContextFromLiterals(FixedArray* literals) {
 }
 
 
-void Oddball::OddballIterateBody(ObjectVisitor* v) {
-  // Assumes all Object* members are contiguously allocated!
-  IteratePointers(v, kToStringOffset, kToNumberOffset + kPointerSize);
-}
-
-
 Object* Oddball::Initialize(const char* to_string, Object* to_number) {
   Object* symbol = Heap::LookupAsciiSymbol(to_string);
   if (symbol->IsFailure()) return symbol;
@@ -5282,13 +5229,6 @@ void SharedFunctionInfo::SourceCodePrint(StringStream* accumulator,
 }
 
 
-void SharedFunctionInfo::SharedFunctionInfoIterateBody(ObjectVisitor* v) {
-  IteratePointers(v,
-                  kNameOffset,
-                  kThisPropertyAssignmentsOffset + kPointerSize);
-}
-
-
 void ObjectVisitor::VisitCodeTarget(RelocInfo* rinfo) {
   ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
   Object* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
@@ -5310,28 +5250,6 @@ void ObjectVisitor::VisitDebugTarget(RelocInfo* rinfo) {
 }
 
 
-void Code::CodeIterateBody(ObjectVisitor* v) {
-  int mode_mask = RelocInfo::kCodeTargetMask |
-                  RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
-                  RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
-                  RelocInfo::ModeMask(RelocInfo::JS_RETURN) |
-                  RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) |
-                  RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY);
-
-  // Use the relocation info pointer before it is visited by
-  // the heap compaction in the next statement.
-  RelocIterator it(this, mode_mask);
-
-  IteratePointers(v,
-                  kRelocationInfoOffset,
-                  kRelocationInfoOffset + kPointerSize);
-
-  for (; !it.done(); it.next()) {
-    it.rinfo()->Visit(v);
-  }
-}
-
-
 void Code::Relocate(intptr_t delta) {
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);