How to get rid of the 'undeclared selector' warning

Solution 1:

Another option would be to disable the warning with:

#pragma GCC diagnostic ignored "-Wundeclared-selector"

You can place this line in the .m file where the warning occurs.

Update:

It works also with LLVM like this:

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"

... your code here ...

#pragma clang diagnostic pop

Solution 2:

Have a look at NSSelectorFromString.

 SEL selector = NSSelectorFromString(@"setError:");
 if ([self respondsToSelector:selector])

It will allow you to create a selector at runtime, instead of at compile time through the @selector keyword, and the compiler will have no chance to complain.

Solution 3:

I think this is because for some odd reason the selector isn't registered with the runtime.

Try registering the selector via sel_registerName():

SEL setErrorSelector = sel_registerName("setError:");

if([self respondsToSelector:setErrorSelector]) {
   [self performSelector:setErrorSelector withObject:[NSError errorWithDomain:@"SomeDomain" code:1 userInfo:nil]];
}

Solution 4:

I got that message to go away by #include'ing the file with the method. Nothing else was used from that file.

Solution 5:

I realise I'm a bit late to this thread but for completeness, you can globally turn off this warning using the target build settings.

In section, 'Apple LLVM warnings - Objective-C', change:

Undeclared Selector - NO