Define V8_EXPORT to nothing for clients of v8.

include/v8.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 44 matching lines @@
 #ifdef BUILDING_V8_SHARED
 #define V8EXPORT __declspec(dllexport)
 #elif USING_V8_SHARED
 #define V8EXPORT __declspec(dllimport)
 #else
 #define V8EXPORT
 #endif  // BUILDING_V8_SHARED
 
 #else  // _WIN32
 
-// Setup for Linux shared library export. There is no need to distinguish
-// between building or using the V8 shared library, but we should not
-// export symbols when we are building a static library.
+// Setup for Linux shared library export.
 #if defined(__GNUC__) && (__GNUC__ >= 4) && defined(V8_SHARED)
+#ifdef BUILDING_V8_SHARED
 #define V8EXPORT __attribute__ ((visibility("default")))
+#else
+#define V8EXPORT
+#endif
 #else  // defined(__GNUC__) && (__GNUC__ >= 4)
 #define V8EXPORT
 #endif  // defined(__GNUC__) && (__GNUC__ >= 4)
 
 #endif  // _WIN32
 
 /**
  * The v8 JavaScript engine.
  */
 namespace v8 {
@@ skipping 4392 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_