Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of Psy Shell.
Chris@0:  *
Chris@0:  * (c) 2012-2017 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\Empty_;
Chris@0: use PhpParser\Node\Expr\Variable;
Chris@0: use Psy\Exception\ParseErrorException;
Chris@0: 
Chris@0: /**
Chris@0:  * Validate that the user did not call the language construct `empty()` on a
Chris@0:  * statement in PHP < 5.5.
Chris@0:  */
Chris@0: class LegacyEmptyPass extends CodeCleanerPass
Chris@0: {
Chris@0:     /**
Chris@0:      * Validate use of empty in PHP < 5.5.
Chris@0:      *
Chris@0:      * @throws ParseErrorException if the user used empty with anything but a variable
Chris@0:      *
Chris@0:      * @param Node $node
Chris@0:      */
Chris@0:     public function enterNode(Node $node)
Chris@0:     {
Chris@0:         if (version_compare(PHP_VERSION, '5.5', '>=')) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         if (!$node instanceof Empty_) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         if (!$node->expr instanceof Variable) {
Chris@0:             $msg = sprintf('syntax error, unexpected %s', $this->getUnexpectedThing($node->expr));
Chris@0: 
Chris@0:             throw new ParseErrorException($msg, $node->expr->getLine());
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     private function getUnexpectedThing(Node $node)
Chris@0:     {
Chris@0:         switch ($node->getType()) {
Chris@0:             case 'Scalar_String':
Chris@0:             case 'Scalar_LNumber':
Chris@0:             case 'Scalar_DNumber':
Chris@0:                 return json_encode($node->value);
Chris@0: 
Chris@0:             case 'Expr_ConstFetch':
Chris@0:                 return (string) $node->name;
Chris@0: 
Chris@0:             default:
Chris@0:                 return $node->getType();
Chris@0:         }
Chris@0:     }
Chris@0: }