title: EXC_BAD_ACCESS upon accessing a static member?
body: <p>I've developed a game on Cocos2d-x v2 platform
  I started on Android, after completely finishing the coding on Eclipse I used the same code on Xcode to create and iOS version.
  After adding all the required libraries, I succeeded in compiling the code. However, the game hangs the moment it runs on an iOS device, although it runs without any problem on Android.
  I tried both the emulator and an iPod, but I always get an EXC_BAD_ACCESS when accessing a static member from a static method. The static member would always point to 0x0!!
  Here's an excerpt from the code:\</p>
  
  <p>AppDelegate.cpp</p>
  
  <pre><code>#include "AppDelegate.h"
  #include "NASEncData.h"
  AppDelegate::AppDelegate()
  {
      ep = NASEncData::sharedUserData();
  }
  </code></pre>
  
  <p>NASEncData.h</p>
  
  <pre><code>namespace CocosNas
  {
      class NASEncData : public CCObject
      {
  public:
          static NASEncData* sharedUserData();
  
  private:
          NASEncData();
  
          static void initXMLFilePath();
  
          static std::string m_sFilePath;
      }
  }
  </code></pre>
  
  <p>NASEncData.cpp</p>
  
  <pre><code>#include "NASEncData.h"
  
  
  NASEncData* NASEncData::sharedUserData()
  {
      initXMLFilePath();
  
      // only create xml file one time
      // the file exists after the programe exit
      if ((! isXMLFileExist()) &amp;&amp; (! createXMLFile()))
      {
          return NULL;
      }
  
      if (! m_spUserData)
      {
          m_spUserData = new NASEncData();
      }
  
      return m_spUserData;
  }
  
  void NASEncData::initXMLFilePath()
  {
      if (! m_sbIsFilePathInitialized)
      {
          m_sFilePath += CCFileUtils::sharedFileUtils()-&gt;getWriteablePath() + NASENCDATA_XML_FILE_NAME;                  &lt;----error happens here
          m_sbIsFilePathInitialized = true;
      }   
  }
  </code></pre>