--- /dev/null
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * @final
+ */
+class Twig_NodeVisitor_SafeAnalysis extends Twig_BaseNodeVisitor
+{
+ protected $data = array();
+ protected $safeVars = array();
+
+ public function setSafeVars($safeVars)
+ {
+ $this->safeVars = $safeVars;
+ }
+
+ public function getSafe(Twig_NodeInterface $node)
+ {
+ $hash = spl_object_hash($node);
+ if (!isset($this->data[$hash])) {
+ return;
+ }
+
+ foreach ($this->data[$hash] as $bucket) {
+ if ($bucket['key'] !== $node) {
+ continue;
+ }
+
+ if (in_array('html_attr', $bucket['value'])) {
+ $bucket['value'][] = 'html';
+ }
+
+ return $bucket['value'];
+ }
+ }
+
+ protected function setSafe(Twig_NodeInterface $node, array $safe)
+ {
+ $hash = spl_object_hash($node);
+ if (isset($this->data[$hash])) {
+ foreach ($this->data[$hash] as &$bucket) {
+ if ($bucket['key'] === $node) {
+ $bucket['value'] = $safe;
+
+ return;
+ }
+ }
+ }
+ $this->data[$hash][] = array(
+ 'key' => $node,
+ 'value' => $safe,
+ );
+ }
+
+ protected function doEnterNode(Twig_Node $node, Twig_Environment $env)
+ {
+ return $node;
+ }
+
+ protected function doLeaveNode(Twig_Node $node, Twig_Environment $env)
+ {
+ if ($node instanceof Twig_Node_Expression_Constant) {
+ // constants are marked safe for all
+ $this->setSafe($node, array('all'));
+ } elseif ($node instanceof Twig_Node_Expression_BlockReference) {
+ // blocks are safe by definition
+ $this->setSafe($node, array('all'));
+ } elseif ($node instanceof Twig_Node_Expression_Parent) {
+ // parent block is safe by definition
+ $this->setSafe($node, array('all'));
+ } elseif ($node instanceof Twig_Node_Expression_Conditional) {
+ // intersect safeness of both operands
+ $safe = $this->intersectSafe($this->getSafe($node->getNode('expr2')), $this->getSafe($node->getNode('expr3')));
+ $this->setSafe($node, $safe);
+ } elseif ($node instanceof Twig_Node_Expression_Filter) {
+ // filter expression is safe when the filter is safe
+ $name = $node->getNode('filter')->getAttribute('value');
+ $args = $node->getNode('arguments');
+ if (false !== $filter = $env->getFilter($name)) {
+ $safe = $filter->getSafe($args);
+ if (null === $safe) {
+ $safe = $this->intersectSafe($this->getSafe($node->getNode('node')), $filter->getPreservesSafety());
+ }
+ $this->setSafe($node, $safe);
+ } else {
+ $this->setSafe($node, array());
+ }
+ } elseif ($node instanceof Twig_Node_Expression_Function) {
+ // function expression is safe when the function is safe
+ $name = $node->getAttribute('name');
+ $args = $node->getNode('arguments');
+ $function = $env->getFunction($name);
+ if (false !== $function) {
+ $this->setSafe($node, $function->getSafe($args));
+ } else {
+ $this->setSafe($node, array());
+ }
+ } elseif ($node instanceof Twig_Node_Expression_MethodCall) {
+ if ($node->getAttribute('safe')) {
+ $this->setSafe($node, array('all'));
+ } else {
+ $this->setSafe($node, array());
+ }
+ } elseif ($node instanceof Twig_Node_Expression_GetAttr && $node->getNode('node') instanceof Twig_Node_Expression_Name) {
+ $name = $node->getNode('node')->getAttribute('name');
+ // attributes on template instances are safe
+ if ('_self' == $name || in_array($name, $this->safeVars)) {
+ $this->setSafe($node, array('all'));
+ } else {
+ $this->setSafe($node, array());
+ }
+ } else {
+ $this->setSafe($node, array());
+ }
+
+ return $node;
+ }
+
+ protected function intersectSafe(array $a = null, array $b = null)
+ {
+ if (null === $a || null === $b) {
+ return array();
+ }
+
+ if (in_array('all', $a)) {
+ return $b;
+ }
+
+ if (in_array('all', $b)) {
+ return $a;
+ }
+
+ return array_intersect($a, $b);
+ }
+
+ public function getPriority()
+ {
+ return 0;
+ }
+}