[heap] Avoid the use of cells to point from code to new-space objects.

src/compiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler.h"
 
 #include <algorithm>
 
 #include "src/ast/ast-numbering.h"
 #include "src/ast/prettyprinter.h"
@@ skipping 268 matching lines @@
   return SetLastStatus(GenerateCodeImpl());
 }
 
 
 namespace {
 
 void AddWeakObjectToCodeDependency(Isolate* isolate, Handle<HeapObject> object,
                                    Handle<Code> code) {
   Handle<WeakCell> cell = Code::WeakCellFor(code);
   Heap* heap = isolate->heap();
-  Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
-  dep = DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
-  heap->AddWeakObjectToCodeDependency(object, dep);
+  if (heap->InNewSpace(*object)) {
+    heap->RecordWeakCodeToNewSpaceReference(object, cell);

[ulan, 2016/06/08 14:37:00]

Could you rename it to AddWeakNewSpaceObjectToCodeDependency(object, cell) ?

To be consistent with the other function.

[ahaas, 2016/06/09 10:34:32]

Done. I named it differently because no DependentCode is created in this case.

+  } else {
+    Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
+    dep =
+        DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
+    heap->AddWeakObjectToCodeDependency(object, dep);
+  }
 }
 
 }  // namespace
 
 void CompilationJob::RegisterWeakObjectsInOptimizedCode(Handle<Code> code) {
   // TODO(turbofan): Move this to pipeline.cc once Crankshaft dies.
   Isolate* const isolate = code->GetIsolate();
   DCHECK(code->is_optimized_code());
   std::vector<Handle<Map>> maps;
   std::vector<Handle<HeapObject>> objects;
@@ skipping 1503 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8