ScrambleVariable.php

<?php

class ScrambleVariable extends ScramblerVisitor
{
    use TrackingRenamerTrait;
    use ReportArraysTrait;

    /**
     * Constructor
     *
     * @param  StringScrambler $scrambler
     * @return void
     **/
    public function __construct(StringScrambler $scrambler)
    {
        parent::__construct($scrambler);
         $this->setIgnore(array("_ENV","PHPSESSID","PHP_SELF","GLOBALS","_COOKIE","_GET","_POST",
         "_SESSION","_FILES","_REQUEST","_SERVER","this"));
    }

    /**
     * Check all variable nodes
     *
     * @param  Node $node
     * @return void
     **/
    public function enterNode(Node $node)
    {
        // Function param or variable use
        if ($node instanceof Param || $node instanceof Variable) {

            if (!is_string($node->name)) {
                return;
            }

            if ($this->isRenamed($node->name)) {
                $node->name = $this->getNewName($node->name);
                return $node;
            }
        }

        // try {} catch () {}
        if ($node instanceof CatchStatement) {

            return $this->scramble($node, 'var');
        }

        // Function() use ($x, $y) {}
        if ($node instanceof ClosureUse) {
            return $this->scramble($node, 'var');
        }
    }

    public function leaveNode(Node $node) {
        if ($node instanceof Param || $node instanceof Variable) {

            $originalName = $node->name;

            if(!in_array($originalName, $this->getRenamed())){
                $this->scramble($node);

                $this->renamed($originalName, $node->name);
            }
        }
    }
}