Added static assert to BitField to ensure the contents fit within the field

src/utils.h

 // 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.
 
 #ifndef V8_UTILS_H_
 #define V8_UTILS_H_
 
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 287 matching lines @@
 
   // Returns a type U with the bit field value updated.
   static U update(U previous, T value) {
     return (previous & ~kMask) | encode(value);
   }
 
   // Extracts the bit field from the value.
   static T decode(U value) {
     return static_cast<T>((value & kMask) >> shift);
   }
+
+  STATIC_ASSERT((kNext - 1) / 8 < sizeof(U));

[Jakob Kummerow, 2016/08/17 15:47:01]

How about:

STATIC_ASSERT(kNext / kBitsPerByte <= sizeof(U));

 };
 
-
 template <class T, int shift, int size>
 class BitField8 : public BitFieldBase<T, shift, size, uint8_t> {};
 
 
 template <class T, int shift, int size>
 class BitField16 : public BitFieldBase<T, shift, size, uint16_t> {};
 
 
 template<class T, int shift, int size>
 class BitField : public BitFieldBase<T, shift, size, uint32_t> { };
@@ skipping 1248 matching lines @@
   byte* dst = reinterpret_cast<byte*>(p);
   for (size_t i = 0; i < sizeof(V); i++) {
     dst[i] = src[sizeof(V) - i - 1];
   }
 #endif  // V8_TARGET_LITTLE_ENDIAN
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_UTILS_H_