升级系统和XCode后，在IOS8上编译之前的项目会报如下错误：

Undefined symbols for architecture x86_64:
  "_opendir$INODE64",referenced from:
      _OPENSSL_DIR_read in libcocos2dx iOS.a(o_dir.o)
  "_readdir$INODE64",referenced from:
      _OPENSSL_DIR_read in libcocos2dx iOS.a(o_dir.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command Failed with exit code 1 (use -v to see invocation)

在工程目录下cocos/platform/CCImage.cpp添加如下代码：（具体位置在extern “C”下里面）

#if defined (__unix) || (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
#ifndef __ENABLE_COMPATIBILITY_WITH_UNIX_2003__
#define __ENABLE_COMPATIBILITY_WITH_UNIX_2003__
#include <stdio.h>
#include <dirent.h>
    FILE *fopen$UNIX2003( const char *filename,const char *mode )
    {
        return fopen(filename,mode);
    }
    size_t fwrite$UNIX2003( const void *a,size_t b,size_t c,FILE *d )
    {
        return fwrite(a,b,c,d);
    }
    char *strerror$UNIX2003( int errnum )
    {
        
        return strerror(errnum);
    }
    
    DIR *opendir$INODE64(const char * a)
    {
        return opendir(a);
    }
    
    struct dirent *readdir$INODE64(DIR *dir)
    {
        return readdir(dir);
    }
    
#endif
#endif

https://github.com/cocos2d/cocos2d-x/pull/6986