Write barrier audit: Verify previous value in generated code.

runtime/vm/scavenger.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scavenger.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
@@ skipping 349 matching lines @@
   } else {
     intptr_t size_in_bytes = size_in_words << kWordSizeLog2;
     VirtualMemory* reserved = VerifiedMemory::Reserve(size_in_bytes);
     if ((reserved == NULL) || !reserved->Commit(false)) {  // Not executable.
       // TODO(koda): If cache_ is not empty, we could try to delete it.
       delete reserved;
       return NULL;
     }
 #if defined(DEBUG)
     memset(reserved->address(), kZapValue, size_in_bytes);
+    VerifiedMemory::Accept(reserved->start(), size_in_bytes);
 #endif  // defined(DEBUG)
     return new SemiSpace(reserved);
   }
 }
 
 
 void SemiSpace::Delete() {
 #ifdef DEBUG
   if (reserved_ != NULL) {
     memset(reserved_->address(), kZapValue, size_in_words() << kWordSizeLog2);
@@ skipping 513 matching lines @@
 }
 
 
 void Scavenger::FreeExternal(intptr_t size) {
   ASSERT(size >= 0);
   external_size_ -= size;
   ASSERT(external_size_ >= 0);
 }
 
 }  // namespace dart