Trace the method call stack

javascript_trace_method_call.js

/* source:
Martin Jespersen
http://stackoverflow.com/questions/4671031/print-function-log-stack-trace-for-entire-program-using-firebug
*/

function logStackTrace(levels) {
    var callstack = [];
    var isCallstackPopulated = false;
    try {
        i.dont.exist += 0; //doesn't exist- that's the point
    } catch (e) {
        if (e.stack) { //Firefox / chrome
            var lines = e.stack.split('\n');
            for (var i = 0, len = lines.length; i < len; i++) {
                    callstack.push(lines[i]);
            }
            //Remove call to logStackTrace()
            callstack.shift();
            isCallstackPopulated = true;
        }
        else if (window.opera && e.message) { //Opera
            var lines = e.message.split('\n');
            for (var i = 0, len = lines.length; i < len; i++) {
                if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
                    var entry = lines[i];
                    //Append next line also since it has the file info
                    if (lines[i + 1]) {
                        entry += " at " + lines[i + 1];
                        i++;
                    }
                    callstack.push(entry);
                }
            }
            //Remove call to logStackTrace()
            callstack.shift();
            isCallstackPopulated = true;
        }
    }
    if (!isCallstackPopulated) { //IE and Safari
        var currentFunction = arguments.callee.caller;
        while (currentFunction) {
            var fn = currentFunction.toString();
            var fname = fn.substring(fn.indexOf("function") + 8, fn.indexOf("(")) || "anonymous";
            callstack.push(fname);
            currentFunction = currentFunction.caller;
        }
    }
    if (levels) {
        console.log(callstack.slice(0, levels).join('\n'));
    }
    else {
        console.log(callstack.join('\n'));
    }
}