Make objects embedded in optimized code weak.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 71 matching lines @@
       GenerateDeferredCode() &&
       GenerateJumpTable() &&
       GenerateSafepointTable();
 }
 
 
 void LCodeGen::FinishCode(Handle<Code> code) {
   ASSERT(is_done());
   code->set_stack_slots(GetStackSlotCount());
   code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
-  if (FLAG_weak_embedded_maps_in_optimized_code) {

[Hannes Payer (out of office), 2013/10/01 13:13:50]

Why did you remove that flag?

[ulan, 2013/10/01 14:50:29]

This check is moved inside the function in IsWeakEmbeddedObject() because we
handle both weak maps and weak objects in this 
RegisterDependentCodeForEmbeddedMaps now.

-    RegisterDependentCodeForEmbeddedMaps(code);
-  }
+  RegisterDependentCodeForEmbeddedMaps(code);
   PopulateDeoptimizationData(code);
   info()->CommitDependencies(code);
 }
 
 
 void LChunkBuilder::Abort(BailoutReason reason) {
   info()->set_bailout_reason(reason);
   status_ = ABORTED;
 }
 
@@ skipping 642 matching lines @@
                             LEnvironment* environment) {
   Deoptimizer::BailoutType bailout_type = info()->IsStub()
       ? Deoptimizer::LAZY
       : Deoptimizer::EAGER;
   DeoptimizeIf(cc, environment, bailout_type);
 }
 
 
 void LCodeGen::RegisterDependentCodeForEmbeddedMaps(Handle<Code> code) {
   ZoneList<Handle<Map> > maps(1, zone());
+  ZoneList<Handle<JSObject> > objects(1, zone());
   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
-    RelocInfo::Mode mode = it.rinfo()->rmode();
-    if (mode == RelocInfo::EMBEDDED_OBJECT &&
-        it.rinfo()->target_object()->IsMap()) {
-      Handle<Map> map(Map::cast(it.rinfo()->target_object()));
-      if (map->CanTransition()) {
+    if (Code::IsWeakEmbeddedObject(code->kind(), it.rinfo()->target_object())) {
+      if (it.rinfo()->target_object()->IsMap()) {
+        Handle<Map> map(Map::cast(it.rinfo()->target_object()));
         maps.Add(map, zone());
+      } else if (it.rinfo()->target_object()->IsJSObject()) {
+        Handle<JSObject> object(JSObject::cast(it.rinfo()->target_object()));
+        objects.Add(object, zone());
       }
     }
   }
 #ifdef VERIFY_HEAP
   // This disables verification of weak embedded maps after full GC.
   // AddDependentCode can cause a GC, which would observe the state where
   // this code is not yet in the depended code lists of the embedded maps.
   NoWeakEmbeddedMapsVerificationScope disable_verification_of_embedded_maps;
 #endif
   for (int i = 0; i < maps.length(); i++) {
     maps.at(i)->AddDependentCode(DependentCode::kWeaklyEmbeddedGroup, code);
   }
+  for (int i = 0; i < objects.length(); i++) {
+    AddWeakObjectToCodeDependency(isolate()->heap(), objects.at(i), code);
+  }
 }
 
 
 void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
   int length = deoptimizations_.length();
   if (length == 0) return;
   Handle<DeoptimizationInputData> data =
       factory()->NewDeoptimizationInputData(length, TENURED);
 
   Handle<ByteArray> translations =
@@ skipping 4732 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64