<?php
/*
* This file is part of Psy Shell.
*
* (c) 2012-2020 Justin Hileman
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Psy\CodeCleaner;
use PhpParser\Node;
use PhpParser\Node\Expr\Array_;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\Isset_;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\StaticCall;
use PhpParser\Node\Stmt\Unset_;
use Psy\Exception\FatalErrorException;
/**
* Validate that the functions are used correctly.
*
* @author Martin HasoĊ <martin.hason@gmail.com>
*/
class FunctionReturnInWriteContextPass extends CodeCleanerPass
{
const ISSET_MESSAGE = 'Cannot use isset() on the result of an expression (you can use "null !== expression" instead)';
const EXCEPTION_MESSAGE = "Can't use function return value in write context";
/**
* Validate that the functions are used correctly.
*
* @throws FatalErrorException if a function is passed as an argument reference
* @throws FatalErrorException if a function is used as an argument in the isset
* @throws FatalErrorException if a value is assigned to a function
*
* @param Node $node
*/
public function enterNode(Node $node)
{
if ($node instanceof Array_ || $this->isCallNode($node)) {
$items = $node instanceof Array_ ? $node->items : $node->args;
foreach ($items as $item) {
if ($item && $item->byRef && $this->isCallNode($item->value)) {
throw new FatalErrorException(self::EXCEPTION_MESSAGE, 0, E_ERROR, null, $node->getLine());
}
}
} elseif ($node instanceof Isset_ || $node instanceof Unset_) {
foreach ($node->vars as $var) {
if (!$this->isCallNode($var)) {
continue;
}
$msg = $node instanceof Isset_ ? self::ISSET_MESSAGE : self::EXCEPTION_MESSAGE;
throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
}
} elseif ($node instanceof Assign && $this->isCallNode($node->var)) {
throw new FatalErrorException(self::EXCEPTION_MESSAGE, 0, E_ERROR, null, $node->getLine());
}
}
private function isCallNode(Node $node)
{
return $node instanceof FuncCall || $node instanceof MethodCall || $node instanceof StaticCall;
}
}