Unused parameter warning

Question

I am getting "unused parameter 'testString'" warning from following code. But I am using testString to log. So how come it is unused ?

- (void)getString:(NSString *)testString {
          ICELogInfo(@"%@", testString);
}

ICELogInfo is a macro for NSLog.

#define ICELogInfo(fmt, ...) LOG_FORMAT(fmt, @"INFO", ##__VA_ARGS__)
#define LOG_FORMAT(fmt, lvl, ...) LOG_FORMAT_NO_LOCATION(fmt, lvl, ##__VA_ARGS__)
#define LOG_FORMAT_NO_LOCATION(fmt, lvl, ...) NSLog((@"%@ " fmt), lvl, ##__VA_ARGS__)

What I am doing wrong ?

Answer 1

You aren't doing something wrong. This is a common problem when using macros.

As a workaround if you want to get rid of the warning, you can use this code:

- (void)getString:(NSSTring*) __unused testString {
          ICELogInfo(@"%@", testString);
}

Answer 2

I've run into the same "problem" before. Solved it by using the unused flag as e.g.

- (void)getString:(NSString *)testString {
    ICELogInfo(@"%@", testString);
    #pragma unused (testString)
}