objective c - How to print out the method name and line number and conditionally disable NSLog?

Question

I'm doing a presentation on debugging in Xcode and would like to get more information on using NSLog efficiently.

In particular, I have two questions:

• is there a way to easily NSLog the current method's name / line number?
• is there a way to "disable" all NSLogs easily before compiling for release code?

Answer 1

Here are some useful macros around NSLog I use a lot:

#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__)

The DLog macro is used to only output when the DEBUG variable is set (-DDEBUG in the projects's C flags for the debug confirguration).

ALog will always output text (like the regular NSLog).

The output (e.g. ALog(@"Hello world") ) will look like this:

-[LibraryController awakeFromNib] [Line 364] Hello world