Call a macro every time any method is called - Obj

问题:

I wrote a debug macro that prints to the console the passed-in string whenever the global kDebug flag == YES.

I need to print out the name of a method and its class name whenever any method is called.

That works fine when I painstakingly go through every method and write the name of the class and the method in a string.

Is there any special handler that gets called when any method in Objective-C is called, and if so, is there a way that I can somehow override it to call my debug macro?

The entire purpose of this is so that I don't have to go through every method in my code and hand-code the method signature in the debug macro call.

回答1:

If you're looking for a method logging facility, rather than build your own, one is actually built into the Objective-C runtime.

You might want to read over the Objective-C section of Apple's Technote 2124: Technical Note TN2124: Mac OS X Debugging Magic

I would also recommend reading over Dave Dribin's blog posting about using the runtime's facility for tracing messages. You can find that here: Tracing Objective-C messages - Dave Dribin's Blog. Dave notes a logObjCMessageSend function that gets called, which you could use to customize your logging behavior. It's a little tricky to use, but Dave gives the info necessary to successfully use it.

回答2:

Take a look at Dtrace. Instruments provides a GUI interface. You can, say, provide a regex to match all the methods you want to log.

回答3:

sounds like you were looking for the __PRETTY_FUNCTION__ macro... but the accepted answer is probably a better way to go.

回答4:

I ended up with this code, after asking a similar question here How can I log names of each called class method in Objective-C?

- (BOOL)respondsToSelector:(SEL)aSelector {
    if(aSelector){
        NSLog(@"%@", NSStringFromSelector(aSelector));
    }
    return [super respondsToSelector:aSelector];
}