gistfile1.m

// Use debugLog() or debugLogPretty() to log messages to the console when the "Debug" configuration 
// is used to build the project - these logging messages won't appear in a Release build.
//
// Use assertLog() for more serious conditions. On Debug builds, assertLog() will throw an assertion
// and on Release builds it will turn into a standard NSLog (in case it comes to digging through a user's
// device logs to fix something)
#ifdef DEBUG
  #define _D(...) __VA_ARGS__
  #define debugLog(fmt, ...)        NSLog(fmt, ##__VA_ARGS__)
  #define debugLogPretty(fmt, ...)  NSLog(@"%s (%@:%d)\n%@", \
                                    __PRETTY_FUNCTION__, \
                                    [[NSString stringWithUTF8String:__FILE__] lastPathComponent], \
                                    __LINE__, \
                                    [NSString stringWithFormat:(fmt), ##__VA_ARGS__])
  #define assertLog(fmt, ...) [[NSAssertionHandler currentHandler] handleFailureInFunction:[NSString stringWithCString:__PRETTY_FUNCTION__ encoding:NSUTF8StringEncoding] \
                                                                                      file:[NSString stringWithCString:__FILE__ encoding:NSUTF8StringEncoding] \
                                                                                lineNumber:__LINE__ \
                                                                               description:[NSString stringWithFormat:(fmt), ##__VA_ARGS__]]
#else
  #define _D(...)
  #define debugLog(fmt, ...)
  #define debugLogPretty(fmt, ...)
  #define assertLog(fmt, ...) NSLog(@"%s (%@:%d)\n%@", \
                             __PRETTY_FUNCTION__, \
                             [[NSString stringWithUTF8String:__FILE__] lastPathComponent], \
                             __LINE__, \
                             [NSString stringWithFormat:(fmt), ##__VA_ARGS__])
#endif

// Additionally, the verboseLog() or verboseLogPretty() macros can also be used to only log messages when
// the "Verbose" build configuration is selected.
#ifdef VERBOSE
  #define verboseLog(fmt, ...) debugLog(fmt, ##__VA_ARGS__)
  #define verboseLogPretty(fmt, ...) debugLogPretty(fmt, ##__VA_ARGS__)
#else
  #define verboseLog(fmt, ...)
  #define verboseLogPretty(fmt, ...)
#endif