How do you add verbose logging code to functions without affecting performance?

Question

Performance is important for a certain class I'm writing.

I thought about calling a function like so:

debug('This is a debug message, only visible when debugging is on');

And the contents would be like

function debug(message) {
    if (DEBUG) console.log(message);
}

So I wonder: is this enough for V8 to flag this as "dead code" if the DEBUG variable never changes?

Edit: I'm more worried about the performance in Node than on the browser, so removing the code while minifying would be insufficient.

Edit2: I made a JSPerf benchmark out of the proposed solutions, and they are very surprising: http://jsperf.com/verbose-debug-loggin-conditionals-functions-and-no-ops/3

Answer 1

I use comments that when a file is minified get removed, such as:

function name(arg) {
    // <debug>
    if (!arg) {
        throw new Error("arg must be defined"); 
    }
    // </debug>
    ... code goes here
}

For example: https://github.com/PANmedia/raptor-editor/blob/master/src/raptor-widget.js#L29-L33

An my (custom) build script to do the aforementioned https://github.com/PANmedia/raptor-build/blob/master/build/raptor-builder.js#L305-L313