Twig - display template names if debug mode is enabled

I'm using Twig lately and I was wondering if it is possible to output the template names which are loaded on the page. The best way I can think of is to display the name above the template itself as a html comment.

<!-- start @default/_components/_wrapper/form-wrapper.html.twig -->
    <form>
       ...
    </form>
<!-- end @default/_components/_wrapper/form-wrapper.html.twig -->

I know that I can get the template name by inserting {{ _self.templateName }} but I don't like to add it to every template or partial.

The solution should work for {% include %}, {% use %} etc and it would also be nice if it just happens when debug mode is enabled.

I tried to write an extension but no matter how I put it, I have to make some kind of call in each template.

The reason behind this is I'm trying to reduce the time searching for the templates somebody else implemented since the project is getting bigger and bigger.

Note: I'm NOT using Symfony.

Thanks in advance, any help is appreciated!

Solution

Thanks to @DarkBee I was pointed to the right direction and ended up using this: I created a debug-template.class.php with the following content:

<?php

abstract class DebugTemplate extends Twig_Template {

    public function display(array $context, array $blocks = array())
    {
        // workaround - only add the html comment when the partial is loaded with @
        if(substr($this->getTemplateName(),0,1) == '@') {
            echo '<!-- START: ' . $this->getTemplateName() . ' -->';
        }

        $this->displayWithErrorHandling($this->env->mergeGlobals($context), array_merge($this->blocks, $blocks));

        if(substr($this->getTemplateName(),0,1) == '@') {
            echo '<!-- END: ' . $this->getTemplateName() . ' -->';
        }

    }
}
?>

Then I took my index.php and added

require_once 'vendor/twig/twig/lib/Twig/TemplateInterface.php';
require_once 'vendor/twig/twig/lib/Twig/Template.php';

and added the DebugTemplate class

$twig = new Twig_Environment($loader, array(
    'cache' => false,
    'base_template_class' => 'DebugTemplate'
));

The result is just what I want and looks like this

<!-- START: @default/_components/panel.html.twig -->
        <div class="panel panel-default">
<!-- END: @default/_components/panel.html.twig -->