Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of Psy Shell.
Chris@0:  *
Chris@0:  * (c) 2012-2018 Justin Hileman
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Psy\CodeCleaner;
Chris@0: 
Chris@0: use PhpParser\Node;
Chris@0: use PhpParser\Node\Expr\Yield_;
Chris@0: use PhpParser\Node\FunctionLike;
Chris@0: use Psy\Exception\FatalErrorException;
Chris@0: 
Chris@0: class FunctionContextPass extends CodeCleanerPass
Chris@0: {
Chris@0:     /** @var int */
Chris@0:     private $functionDepth;
Chris@0: 
Chris@0:     /**
Chris@0:      * @param array $nodes
Chris@0:      */
Chris@0:     public function beforeTraverse(array $nodes)
Chris@0:     {
Chris@0:         $this->functionDepth = 0;
Chris@0:     }
Chris@0: 
Chris@0:     public function enterNode(Node $node)
Chris@0:     {
Chris@0:         if ($node instanceof FunctionLike) {
Chris@0:             $this->functionDepth++;
Chris@0: 
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         // node is inside function context
Chris@0:         if ($this->functionDepth !== 0) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         // It causes fatal error.
Chris@0:         if ($node instanceof Yield_) {
Chris@0:             $msg = 'The "yield" expression can only be used inside a function';
Chris@0:             throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param \PhpParser\Node $node
Chris@0:      */
Chris@0:     public function leaveNode(Node $node)
Chris@0:     {
Chris@0:         if ($node instanceof FunctionLike) {
Chris@0:             $this->functionDepth--;
Chris@0:         }
Chris@0:     }
Chris@0: }