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   1  <?php
   2  
   3  /*
   4   * This file is part of Twig.
   5   *
   6   * (c) Fabien Potencier
   7   *
   8   * For the full copyright and license information, please view the LICENSE
   9   * file that was distributed with this source code.
  10   */
  11  
  12  namespace Twig\NodeVisitor;
  13  
  14  use Twig\Environment;
  15  use Twig\Node\CheckSecurityCallNode;
  16  use Twig\Node\CheckSecurityNode;
  17  use Twig\Node\CheckToStringNode;
  18  use Twig\Node\Expression\Binary\ConcatBinary;
  19  use Twig\Node\Expression\Binary\RangeBinary;
  20  use Twig\Node\Expression\FilterExpression;
  21  use Twig\Node\Expression\FunctionExpression;
  22  use Twig\Node\Expression\GetAttrExpression;
  23  use Twig\Node\Expression\NameExpression;
  24  use Twig\Node\ModuleNode;
  25  use Twig\Node\Node;
  26  use Twig\Node\PrintNode;
  27  use Twig\Node\SetNode;
  28  
  29  /**
  30   * @author Fabien Potencier <fabien@symfony.com>
  31   */
  32  final class SandboxNodeVisitor extends AbstractNodeVisitor
  33  {
  34      private $inAModule = false;
  35      private $tags;
  36      private $filters;
  37      private $functions;
  38  
  39      private $needsToStringWrap = false;
  40  
  41      protected function doEnterNode(Node $node, Environment $env)
  42      {
  43          if ($node instanceof ModuleNode) {
  44              $this->inAModule = true;
  45              $this->tags = [];
  46              $this->filters = [];
  47              $this->functions = [];
  48  
  49              return $node;
  50          } elseif ($this->inAModule) {
  51              // look for tags
  52              if ($node->getNodeTag() && !isset($this->tags[$node->getNodeTag()])) {
  53                  $this->tags[$node->getNodeTag()] = $node;
  54              }
  55  
  56              // look for filters
  57              if ($node instanceof FilterExpression && !isset($this->filters[$node->getNode('filter')->getAttribute('value')])) {
  58                  $this->filters[$node->getNode('filter')->getAttribute('value')] = $node;
  59              }
  60  
  61              // look for functions
  62              if ($node instanceof FunctionExpression && !isset($this->functions[$node->getAttribute('name')])) {
  63                  $this->functions[$node->getAttribute('name')] = $node;
  64              }
  65  
  66              // the .. operator is equivalent to the range() function
  67              if ($node instanceof RangeBinary && !isset($this->functions['range'])) {
  68                  $this->functions['range'] = $node;
  69              }
  70  
  71              if ($node instanceof PrintNode) {
  72                  $this->needsToStringWrap = true;
  73                  $this->wrapNode($node, 'expr');
  74              }
  75  
  76              if ($node instanceof SetNode && !$node->getAttribute('capture')) {
  77                  $this->needsToStringWrap = true;
  78              }
  79  
  80              // wrap outer nodes that can implicitly call __toString()
  81              if ($this->needsToStringWrap) {
  82                  if ($node instanceof ConcatBinary) {
  83                      $this->wrapNode($node, 'left');
  84                      $this->wrapNode($node, 'right');
  85                  }
  86                  if ($node instanceof FilterExpression) {
  87                      $this->wrapNode($node, 'node');
  88                      $this->wrapArrayNode($node, 'arguments');
  89                  }
  90                  if ($node instanceof FunctionExpression) {
  91                      $this->wrapArrayNode($node, 'arguments');
  92                  }
  93              }
  94          }
  95  
  96          return $node;
  97      }
  98  
  99      protected function doLeaveNode(Node $node, Environment $env)
 100      {
 101          if ($node instanceof ModuleNode) {
 102              $this->inAModule = false;
 103  
 104              $node->setNode('constructor_end', new Node([new CheckSecurityCallNode(), $node->getNode('constructor_end')]));
 105              $node->setNode('class_end', new Node([new CheckSecurityNode($this->filters, $this->tags, $this->functions), $node->getNode('class_end')]));
 106          } elseif ($this->inAModule) {
 107              if ($node instanceof PrintNode || $node instanceof SetNode) {
 108                  $this->needsToStringWrap = false;
 109              }
 110          }
 111  
 112          return $node;
 113      }
 114  
 115      private function wrapNode(Node $node, string $name)
 116      {
 117          $expr = $node->getNode($name);
 118          if ($expr instanceof NameExpression || $expr instanceof GetAttrExpression) {
 119              $node->setNode($name, new CheckToStringNode($expr));
 120          }
 121      }
 122  
 123      private function wrapArrayNode(Node $node, string $name)
 124      {
 125          $args = $node->getNode($name);
 126          foreach ($args as $name => $_) {
 127              $this->wrapNode($args, $name);
 128          }
 129      }
 130  
 131      public function getPriority()
 132      {
 133          return 0;
 134      }
 135  }
 136  
 137  class_alias('Twig\NodeVisitor\SandboxNodeVisitor', 'Twig_NodeVisitor_Sandbox');