#if !defined(__clang__) || __clang_major__ < 3    #ifndef __bridge        #define __bridge    #endif    #ifndef __bridge_retain        #define __bridge_retain    #endif    #ifndef __bridge_retained        #define __bridge_retained    #endif    #ifndef __autoreleasing        #define __autoreleasing    #endif    #ifndef __strong        #define __strong    #endif    #ifndef __unsafe_unretained        #define __unsafe_unretained    #endif    #ifndef __weak        #define __weak    #endif#endif#if __has_feature(objc_arc)    #define SAFE_ARC_PROP_RETAIN strong    #define SAFE_ARC_RETAIN(x) (x)    #define SAFE_ARC_RELEASE(x)    #define SAFE_ARC_AUTORELEASE(x) (x)    #define SAFE_ARC_BLOCK_COPY(x) (x)    #define SAFE_ARC_BLOCK_RELEASE(x)    #define SAFE_ARC_SUPER_DEALLOC()    #define SAFE_ARC_AUTORELEASE_POOL_START() @autoreleasepool {    #define SAFE_ARC_AUTORELEASE_POOL_END() }#else    #define SAFE_ARC_PROP_RETAIN retain    #define SAFE_ARC_RETAIN(x) ([(x) retain])    #define SAFE_ARC_RELEASE(x) ([(x) release])    #define SAFE_ARC_AUTORELEASE(x) ([(x) autorelease])    #define SAFE_ARC_BLOCK_COPY(x) (Block_copy(x))    #define SAFE_ARC_BLOCK_RELEASE(x) (Block_release(x))    #define SAFE_ARC_SUPER_DEALLOC() ([super dealloc])    #define SAFE_ARC_AUTORELEASE_POOL_START() NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];    #define SAFE_ARC_AUTORELEASE_POOL_END() [pool release];#endif