After reading this blog entry, I took these ideas, along with some other typical logging ideas such as logging levels, and created a Logging.h header file. In the spirit of appreciation, I thought I’d contribute the code from that file back to this thread. The code below can be used as-is…just paste it into a central header file somewhere (as mentioned, we created a Logging.h file). There are a series of switches that can be set to customize formats, and turn specific logging levels on and off, or remove logging altogether.

I hope this proves useful to someone.

…Bill Hollings

/*
* There are three levels of logging: debug, info and error, and each can be enabled independently
* via the LOGGING_LEVEL_DEBUG, LOGGING_LEVEL_INFO, and LOGGING_LEVEL_ERROR switches below, respectively.
* In addition, ALL logging can be enabled or disabled via the LOGGING_ENABLED switch below.
*
* To perform logging, use any of the following function calls in your code:
*
* LogDebug(fmt, …) – will print if LOGGING_LEVEL_DEBUG is set on.
* LogInfo(fmt, …) – will print if LOGGING_LEVEL_INFO is set on.
* LogError(fmt, …) – will print if LOGGING_LEVEL_ERROR is set on.
*
* Each logging entry can optionally automatically include class, method and line information by
* enabling the LOGGING_INCLUDE_CODE_LOCATION switch.
*
* Logging functions are implemented here via macros, so disabling logging, either entirely,
* or at a specific level, removes the corresponding log invocations from the compiled code,
* thus completely eliminating both the memory and CPU overhead that the logging calls would add.
*/

// Set this switch to enable or disable ALL logging.
#define LOGGING_ENABLED 1

// Set any or all of these switches to enable or disable logging at specific levels.
#define LOGGING_LEVEL_DEBUG 1
#define LOGGING_LEVEL_INFO 1
#define LOGGING_LEVEL_ERROR 1

// Set this switch to set whether or not to include class, method and line information in the log entries.
#define LOGGING_INCLUDE_CODE_LOCATION 1

// ***************** END OF USER SETTINGS ***************

#if !(defined(LOGGING_ENABLED) && LOGGING_ENABLED)
#undef LOGGING_LEVEL_DEBUG
#undef LOGGING_LEVEL_INFO
#undef LOGGING_LEVEL_ERROR
#endif

// Logging format
#define LOG_FORMAT_NO_LOCATION(fmt, lvl, …) NSLog((@”[%@] ” fmt), lvl, ##__VA_ARGS__)
#define LOG_FORMAT_WITH_LOCATION(fmt, lvl, …) NSLog((@”%s [Line %d] [%@] ” fmt), __PRETTY_FUNCTION__, __LINE__, lvl, ##__VA_ARGS__)

#if defined(LOGGING_INCLUDE_CODE_LOCATION) && LOGGING_INCLUDE_CODE_LOCATION
#define LOG_FORMAT(fmt, lvl, …) LOG_FORMAT_WITH_LOCATION(fmt, lvl, ##__VA_ARGS__)
#else
#define LOG_FORMAT(fmt, lvl, …) LOG_FORMAT_NO_LOCATION(fmt, lvl, ##__VA_ARGS__)
#endif

// Debug level logging
#if defined(LOGGING_LEVEL_DEBUG) && LOGGING_LEVEL_DEBUG
#define LogDebug(fmt, …) LOG_FORMAT(fmt, @”debug”, ##__VA_ARGS__)
#else
#define LogDebug(…)
#endif

// Info level logging
#if defined(LOGGING_LEVEL_INFO) && LOGGING_LEVEL_INFO
#define LogInfo(fmt, …) LOG_FORMAT(fmt, @”info”, ##__VA_ARGS__)
#else
#define LogInfo(…)
#endif

// Error level logging
#if defined(LOGGING_LEVEL_ERROR) && LOGGING_LEVEL_ERROR
#define LogError(fmt, …) LOG_FORMAT(fmt, @”***ERROR***”, ##__VA_ARGS__)
#else
#define LogError(…)
#endif

(It’s usually a security issue, too, but I don’t think that matters for a macro that isn’t going to be in release builds.)

Just in case anyone has this same problem:

When I tried to add a User Defined GCC_PREPROCESSOR_DEFINITIONS I received the error that this was already defined, although I couldn’t find it anywhere.

Instead I had to go to Show: All Settings and find: Preprocessor Macros under the GCC 4.2 – Preprocessing section and add DEBUG=1 to that item.

It seems Preprocessor Macros and GCC_PREPROCESSOR_DEFINITIONS are the same thing?

I’m using the 3.0 sdk if that matters…

The error message: implicit declaration of function DLog had me confused for a while until I realised I had also changed the definitions in the pch file!

Doooh.

Thanks

That was it. Thanks!

If you are using OTHER_CFLAGS then set the value to -DDEBUG=1, if you are instead using GCC_PREPROCESSOR_DEFINITIONS then the value needs to be just DEBUG=1