Possible to write a marco to add debugging statements to an entire project?

Has anyone been tried to create a marcro (or any other techinque) to skip through all files in a project and add debugging statements after each function declaration?

I'm using 100% javascript, so source could look like:

Thingy.prototype.doStuff = function doStuff() {
    ...
}
function doMoreStuff() {
    ...
}

function doEvenMoreStuff()
{
    ...
}

Desired outcome:

Thingy.prototype.doStuff = function doStuff() {
    document.write('entering doStuff()');
    ...
}
function doMoreStuff() {
    document.write('entering doMoreStuff()');
    ...
}

function doEvenMoreStuff()
{
    document.write('entering doEvenMoreStuff()');
    ...
}

I haven't been able to figure out how to do this by simple recording. The closest thing I've ever seen is PDT's ability to disable trace statements globally.

Thanks!
Ben