Magic Class Invoker for procedural script

Question

I have inherited a project in bad conditions that contains the following class and I need your help to improve it, the truth is I don't know if it is correctly optimized or if it has security problems or if it can be simplified or refactored to mitigate some overload / overheating . I can't afford to scrap the entire project because of this class.

php v7.4

I proceed to explain what the class does, This class has 3 main objectives related to its sole responsibility:

responsibility: it is a bridge to the implementation of procedural and simple classes.

To achieve responsibility, 3 objectives are implemented:

1. Provide Access to prosedural functions by associating to a Generic class.
2. Extract from a directory the php files that correspond to the procedural libraries (where are the functions).
3. implement the magic method __call and call_user_func_array to facilitate the above common goals

Functional code example:

index.php

<?php
require_once 'function_wrapper.php';

class Main
{

    public static $funcObj = null;

    public function run()
    {

        $wrapper = new functionWrapper();
        $wrapper->proceduralFunctionLoader();

        echo '<pre>';
        echo var_dump(self::$funcObj['TEST']);
        echo '</pre>';
        echo '<br>';
        self::$funcObj['TEST']->testFoo();


    }

}


$main = new Main();
$main->run();

function_wrapper.php

<?php

class functionWrapper
{

    public function proceduralFunctionLoader()
    {
        $libpath      = $_SERVER["DOCUMENT_ROOT"].'lib/';
        $files        = array_diff(scandir($libpath, 1), ['..', '.']);
        $functionList = [];

        if (!empty($files)) {
            Main::$funcObj['TEST'] = [];
            foreach ($files as $key => $name) {
                if (strpos($name, 'lib.') !== false) {
                    $classDir = $libpath.$name;
                    require_once $classDir;
                    $functionList[$name] = $this->getFunctionsInFile($classDir);
                }
            }
            Main::$funcObj['TEST'] = $this;
        }
    }

    public function getFunctionsInFile($classDir)
    {
        $source           = file_get_contents($classDir);
        $tokens           = token_get_all($source);
        $functions        = [];
        $nextStringIsFunc = false;
        $inClass          = false;
        $bracesCount      = 0;
        foreach ($tokens as $token) {
            switch ($token[0]) {
                case T_CLASS:
                    $inClass = true;
                    break;
                case T_FUNCTION:
                    if (!$inClass) {
                        $nextStringIsFunc = true;
                    }
                    break;
                case T_STRING:
                    if ($nextStringIsFunc) {
                        $nextStringIsFunc = false;
                        $functions[]      = $token[1];
                    }
                    break;
                case '(':
                case ';':
                    $nextStringIsFunc = false;
                    break;
                case '{':
                    if ($inClass) {
                        ++$bracesCount;
                    }
                    break;
                case '}':
                    if ($inClass) {
                        --$bracesCount;
                        if (0 === $bracesCount) {
                            $inClass = false;
                        }
                    }
                    break;
            }
        }

        return $functions;
    }

    public function __call($functionName, $args)
    {
        try {
            $result = null;
            if (function_exists($functionName)) {
                $result = call_user_func_array($functionName, $args);
            }
            if (null === $result) {
                throw new Exception('A Function that does not exist has been Invoked in the System: '.$functionName.'. <br>');
            }

            return $result;
        } catch (Exception $e) {
            echo '<pre>';
            echo var_dump($e);
            echo '</pre>';
            exit();
        }
    }
}

/lib directory have 2 files inside:

lib.test.php

<?php
function testFoo2()
{
    echo '<h1>Hello World!!!</h1>';
}

lib.test2.php

<?php
function testFoo()
{
    Main::$funcObj['TEST']->testFoo2();

    return true;
}

I find one additional problems:

procedural script is forced to return true or any data; if it return nothing or false; trow error like call_user_func_array error documentation.

if i try implement a validator (expected to return true or false); how can i differentiate if the false return is equivalent to an error or the validation (function) returns false?