Enforce length/size limits for variable size heap object in order to

vm/os.h

 // 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.
 
 #ifndef VM_OS_H_
 #define VM_OS_H_
 
 #include "vm/globals.h"
 
 // Forward declarations.
@@ skipping 26 matching lines @@
   static int64_t GetCurrentTimeMillis();
 
   // Returns the current time in microseconds measured
   // from midnight January 1, 1970 UTC.
   static int64_t GetCurrentTimeMicros();
 
   // Returns the activation frame alignment constraint or zero if
   // the platform doesn't care. Guaranteed to be a power of two.
   static word ActivationFrameAlignment();
 
+  // This constant is guaranteed to be greater or equal to the
+  // preferred code alignment on all platforms.
+  static const int kMaxPreferredCodeAlignment = 32;
+
   // Returns the preferred code alignment or zero if
   // the platform doesn't care. Guaranteed to be a power of two.
   static word PreferredCodeAlignment();
 
   // Returns the stack size limit.
   static uword GetStackSizeLimit();
 
   // Returns number of available processor cores.
   static int NumberOfAvailableProcessors();
 
@@ skipping 40 matching lines @@
   static void Shutdown();
 
   static void Abort();
 
   static void Exit(int code);
 };
 
 }  // namespace dart
 
 #endif  // VM_OS_H_