From the iPhoneDeveloperTips Google Group
In your MyApplication_Prefix.pch file add these lines:
// DO NOT FORGET to add setting GCC_PREPROCESSOR_DEFINITIONS withvalue DEBUG=1 to your target's debug configuration !!!!!// DLog is almost a drop-in replacement for NSLog// DLog();// DLog(@"here");// DLog(@"value: %d", x);// Unfortunately this doesn't work DLog(aStringVariable); you have todo this instead DLog(@"%@", aStringVariable);#ifdef DEBUG# define DLog(fmt, ...) NSLog((@"%s [Line %d] " fmt),__PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__);#else# define DLog(...)#endif// ALog always displays output regardless of the DEBUG setting#define ALog(fmt, ...) NSLog((@"%s [Line %d] " fmt),__PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__);