Viewing file:  SafeAnalysisNodeVisitor.php (4.82 KB) -rw-r--r--
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<?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.
*/
namespace Twig\NodeVisitor;
use Twig\Environment;
use Twig\Node\Expression\BlockReferenceExpression;
use Twig\Node\Expression\ConditionalExpression;
use Twig\Node\Expression\ConstantExpression;
use Twig\Node\Expression\FilterExpression;
use Twig\Node\Expression\FunctionExpression;
use Twig\Node\Expression\GetAttrExpression;
use Twig\Node\Expression\MethodCallExpression;
use Twig\Node\Expression\NameExpression;
use Twig\Node\Expression\ParentExpression;
use Twig\Node\Node;
/**
* @internal
*/
final class SafeAnalysisNodeVisitor implements NodeVisitorInterface
{
private $data = [];
private $safeVars = [];
public function setSafeVars(array $safeVars): void
{
$this->safeVars = $safeVars;
}
public function getSafe(Node $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'];
}
}
private function setSafe(Node $node, array $safe): void
{
$hash = spl_object_hash($node);
if (isset($this->data[$hash])) {
foreach ($this->data[$hash] as &$bucket) {
if ($bucket['key'] === $node) {
$bucket['value'] = $safe;
return;
}
}
}
$this->data[$hash][] = [
'key' => $node,
'value' => $safe,
];
}
public function enterNode(Node $node, Environment $env): Node
{
return $node;
}
public function leaveNode(Node $node, Environment $env): ?Node
{
if ($node instanceof ConstantExpression) {
// constants are marked safe for all
$this->setSafe($node, ['all']);
} elseif ($node instanceof BlockReferenceExpression) {
// blocks are safe by definition
$this->setSafe($node, ['all']);
} elseif ($node instanceof ParentExpression) {
// parent block is safe by definition
$this->setSafe($node, ['all']);
} elseif ($node instanceof ConditionalExpression) {
// 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 FilterExpression) {
// filter expression is safe when the filter is safe
$name = $node->getNode('filter')->getAttribute('value');
$args = $node->getNode('arguments');
if ($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, []);
}
} elseif ($node instanceof FunctionExpression) {
// function expression is safe when the function is safe
$name = $node->getAttribute('name');
$args = $node->getNode('arguments');
if ($function = $env->getFunction($name)) {
$this->setSafe($node, $function->getSafe($args));
} else {
$this->setSafe($node, []);
}
} elseif ($node instanceof MethodCallExpression) {
if ($node->getAttribute('safe')) {
$this->setSafe($node, ['all']);
} else {
$this->setSafe($node, []);
}
} elseif ($node instanceof GetAttrExpression && $node->getNode('node') instanceof NameExpression) {
$name = $node->getNode('node')->getAttribute('name');
if (\in_array($name, $this->safeVars)) {
$this->setSafe($node, ['all']);
} else {
$this->setSafe($node, []);
}
} else {
$this->setSafe($node, []);
}
return $node;
}
private function intersectSafe(array $a = null, array $b = null): array
{
if (null === $a || null === $b) {
return [];
}
if (\in_array('all', $a)) {
return $b;
}
if (\in_array('all', $b)) {
return $a;
}
return array_intersect($a, $b);
}
public function getPriority(): int
{
return 0;
}
}
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