Print function log /stack trace for entire program using firebug

Question

Firebug has the ability to log calls to a particular function name. I'm looking for a bug that sometimes stops a page from rendering, but doesn't cause any errors or warnings. The bug only appears about half the time. So how do I get a list of all the function calls for the entire program, or some kind of stack trace for the execution of the entire program?

Answer 1

Firefox provides console.trace() which is very handy to print the call stack. It is also available in Chrome and IE 11.

Alternatively try something like this:

function print_call_stack() {
  var stack = new Error().stack;
  console.log("PRINTING CALL STACK");
  console.log( stack );
}

Answer 2

When i need a stack trace i do the following, maybe you can draw some inspiration from it:

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'));
    }
};

Moderator's note: The code in this answer seems to also appear in this post from Eric Wenderlin's blog. The author of this answer claims it as his own code, though, written prior to the blog post linked here. Just for purposes of good-faith, I've added the link to the post and this note.

Answer 3

I accomplished this without firebug. Tested in both chrome and firefox:

console.error("I'm debugging this code.");

Once your program prints that to the console, you can click the little arrow to it to expand the call stack.

Answer 4

Try stepping through your code one line or one function at a time to determine where it stops working correctly. Or make some reasonable guesses and scatter logging statements through your code.