Question

Please forgive me if this is an obvious question or if there are any errors. I am very new to Objective-C and have kind of been thrown in the deep end.

I am looking into Objective-C obfuscation. On simple method of this that I found here is to user the preprocessor to change method names to gibberish. My question is whether a decompiler can recognize preprocessor statements, such that it would be able to decompile the source back to the original method names. The example from the above referenced question is below:

#ifndef DEBUG
#define MyClass aqwe
#define myMethod oikl
#endif

@interface MyClass : NSObject {
}

- (void)myMethod;

Is it possible for, when not compiled for debugging, this code could be decompiled back to anything other than

@interface aqwe : NSObject {
}

- (void)oikl;

Answer 1

You could absolutely not un-obfuscate that. The preprocessor runs before the compiler gets its greasy paws on the code, so it’s just as if you had manually gone through and replaced all occurrences of MyClass with aqwe, etc.

Although, you should ask yourself why you want to do this. It’s just obfuscation remember, rather than actually securing anything about your code. People could still look and see the code that each method comprises. You’re just changing the name of symbols.