RemoveCheckToStringNodeVisitor.php

<?php

declare (strict_types=1);
namespace Drupal\Core\Template;

use Twig\Environment;
use Twig\Node\CheckToStringNode;
use Twig\Node\Node;
use Twig\NodeVisitor\NodeVisitorInterface;

/**
 * Defines a TwigNodeVisitor that replaces CheckToStringNodes.
 *
 * Twig 3.14.1 resulted in a performance regression in Drupal due to checking if
 * __toString is an allowed method on objects. __toString is allowed on all
 * objects when Drupal's default SandboxPolicy is active. Therefore, Twig's
 * SandboxExtension checks are unnecessary.
 */
final class RemoveCheckToStringNodeVisitor implements NodeVisitorInterface {
    
    /**
     * {@inheritdoc}
     */
    public function enterNode(Node $node, Environment $env) : Node {
        if ($node instanceof CheckToStringNode) {
            // Replace CheckToStringNode with the faster equivalent, __toString is an
            // allowed method so any checking of __toString on a per-object basis is
            // performance overhead.
            $new = new TwigSimpleCheckToStringNode($node->getNode('expr'));
            // @todo https://www.drupal.org/project/drupal/issues/3488584 Update for
            //   Twig 4 as the spread attribute has been removed there.
            if ($node->hasAttribute('spread')) {
                $new->setAttribute('spread', $node->getAttribute('spread'));
            }
            return $new;
        }
        return $node;
    }
    
    /**
     * {@inheritdoc}
     */
    public function leaveNode(Node $node, Environment $env) : ?Node {
        return $node;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPriority() {
        // Runs after sandbox visitor.
        return 1;
    }

}