Compilation type and state allocate an unnecessary Smi on v8::Script.

src/objects.h

 // Copyright 2012 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 5831 matching lines @@
 
   // [context_data]: context data for the context this script was compiled in.
   DECL_ACCESSORS(context_data, Object)
 
   // [wrapper]: the wrapper cache.
   DECL_ACCESSORS(wrapper, Foreign)
 
   // [type]: the script type.
   DECL_ACCESSORS(type, Smi)
 
-  // [compilation]: how the the script was compiled.
-  DECL_ACCESSORS(compilation_type, Smi)
+  // [compilation_type]: how the the script was compiled.

[Michael Starzinger, 2013/07/29 14:43:58]

nit: Can we add a short sentence to the comment saying this is "encoded in the
flags field"? We might even consider moving it down to below the declaration of
the "flags" accessor.

[Mike West, 2013/07/29 14:52:12]

Makes sense. Upcoming patchset does both.

+  inline CompilationType compilation_type();
+  inline void set_compilation_type(CompilationType type);
 
-  // [is_compiled]: determines whether the script has already been compiled.
-  DECL_ACCESSORS(compilation_state, Smi)
+  // [compilation_state]: determines whether the script has already been
+  // compiled.

[Michael Starzinger, 2013/07/29 14:43:58]

Likewise.

[Mike West, 2013/07/29 14:52:12]

Done.

+  inline CompilationState compilation_state();
+  inline void set_compilation_state(CompilationState state);
 
   // [line_ends]: FixedArray of line ends positions.
   DECL_ACCESSORS(line_ends, Object)
 
   // [eval_from_shared]: for eval scripts the shared funcion info for the
   // function from which eval was called.
   DECL_ACCESSORS(eval_from_shared, Object)
 
   // [eval_from_instructions_offset]: the instruction offset in the code for the
   // function from which eval was called where eval was called.
   DECL_ACCESSORS(eval_from_instructions_offset, Smi)
 
+  // [flags]: Holds an exciting bitfield.
+  DECL_ACCESSORS(flags, Smi)
+
   static inline Script* cast(Object* obj);
 
   // If script source is an external string, check that the underlying
   // resource is accessible. Otherwise, always return true.
   inline bool HasValidSource();
 
   // Dispatched behavior.
   DECLARE_PRINTER(Script)
   DECLARE_VERIFIER(Script)
 
   static const int kSourceOffset = HeapObject::kHeaderSize;
   static const int kNameOffset = kSourceOffset + kPointerSize;
   static const int kLineOffsetOffset = kNameOffset + kPointerSize;
   static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
   static const int kDataOffset = kColumnOffsetOffset + kPointerSize;
   static const int kContextOffset = kDataOffset + kPointerSize;
   static const int kWrapperOffset = kContextOffset + kPointerSize;
   static const int kTypeOffset = kWrapperOffset + kPointerSize;
-  static const int kCompilationTypeOffset = kTypeOffset + kPointerSize;
-  static const int kCompilationStateOffset =
-      kCompilationTypeOffset + kPointerSize;
-  static const int kLineEndsOffset = kCompilationStateOffset + kPointerSize;
+  static const int kLineEndsOffset = kTypeOffset + kPointerSize;
   static const int kIdOffset = kLineEndsOffset + kPointerSize;
   static const int kEvalFromSharedOffset = kIdOffset + kPointerSize;
   static const int kEvalFrominstructionsOffsetOffset =
       kEvalFromSharedOffset + kPointerSize;
-  static const int kSize = kEvalFrominstructionsOffsetOffset + kPointerSize;
+  static const int kFlagsOffset =
+      kEvalFrominstructionsOffsetOffset + kPointerSize;
+  static const int kSize = kFlagsOffset + kPointerSize;
 
  private:
+  static const int kCompilationTypeBit = 0;

[Michael Starzinger, 2013/07/29 14:43:58]

nit: Lets add a one-liner comment "// Bit positions in the flags field." here.

[Mike West, 2013/07/29 14:52:12]

Done.

+  static const int kCompilationStateBit = 1;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(Script);
 };
 
 
 // List of builtin functions we want to identify to improve code
 // generation.
 //
 // Each entry has a name of a global object property holding an object
 // optionally followed by ".prototype", a name of a builtin function
 // on the object (the one the id is set for), and a label.
@@ skipping 3971 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_