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\Scalar\DNumber;
Chris@0: use PhpParser\Node\Scalar\LNumber;
Chris@0: use PhpParser\Node\Stmt\Break_;
Chris@0: use PhpParser\Node\Stmt\Continue_;
Chris@0: use PhpParser\Node\Stmt\Do_;
Chris@0: use PhpParser\Node\Stmt\For_;
Chris@0: use PhpParser\Node\Stmt\Foreach_;
Chris@0: use PhpParser\Node\Stmt\Switch_;
Chris@0: use PhpParser\Node\Stmt\While_;
Chris@0: use Psy\Exception\FatalErrorException;
Chris@0: 
Chris@0: /**
Chris@0:  * The loop context pass handles invalid `break` and `continue` statements.
Chris@0:  */
Chris@0: class LoopContextPass extends CodeCleanerPass
Chris@0: {
Chris@0:     private $isPHP54;
Chris@0:     private $loopDepth;
Chris@0: 
Chris@0:     public function __construct()
Chris@0:     {
Chris@0:         $this->isPHP54 = version_compare(PHP_VERSION, '5.4.0', '>=');
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * {@inheritdoc}
Chris@0:      */
Chris@0:     public function beforeTraverse(array $nodes)
Chris@0:     {
Chris@0:         $this->loopDepth = 0;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @throws FatalErrorException if the node is a break or continue in a non-loop or switch context
Chris@0:      * @throws FatalErrorException if the node is trying to break out of more nested structures than exist
Chris@0:      * @throws FatalErrorException if the node is a break or continue and has a non-numeric argument
Chris@0:      * @throws FatalErrorException if the node is a break or continue and has an argument less than 1
Chris@0:      *
Chris@0:      * @param Node $node
Chris@0:      */
Chris@0:     public function enterNode(Node $node)
Chris@0:     {
Chris@0:         switch (true) {
Chris@0:             case $node instanceof Do_:
Chris@0:             case $node instanceof For_:
Chris@0:             case $node instanceof Foreach_:
Chris@0:             case $node instanceof Switch_:
Chris@0:             case $node instanceof While_:
Chris@0:                 $this->loopDepth++;
Chris@0:                 break;
Chris@0: 
Chris@0:             case $node instanceof Break_:
Chris@0:             case $node instanceof Continue_:
Chris@0:                 $operator = $node instanceof Break_ ? 'break' : 'continue';
Chris@0: 
Chris@0:                 if ($this->loopDepth === 0) {
Chris@0:                     $msg = sprintf("'%s' not in the 'loop' or 'switch' context", $operator);
Chris@0:                     throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
Chris@0:                 }
Chris@0: 
Chris@0:                 if ($node->num instanceof LNumber || $node->num instanceof DNumber) {
Chris@0:                     $num = $node->num->value;
Chris@0:                     if ($this->isPHP54 && ($node->num instanceof DNumber || $num < 1)) {
Chris@0:                         $msg = sprintf("'%s' operator accepts only positive numbers", $operator);
Chris@0:                         throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
Chris@0:                     }
Chris@0: 
Chris@0:                     if ($num > $this->loopDepth) {
Chris@0:                         $msg = sprintf("Cannot '%s' %d levels", $operator, $num);
Chris@0:                         throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
Chris@0:                     }
Chris@0:                 } elseif ($node->num && $this->isPHP54) {
Chris@0:                     $msg = sprintf("'%s' operator with non-constant operand is no longer supported", $operator);
Chris@0:                     throw new FatalErrorException($msg, 0, E_ERROR, null, $node->getLine());
Chris@0:                 }
Chris@0:                 break;
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param Node $node
Chris@0:      */
Chris@0:     public function leaveNode(Node $node)
Chris@0:     {
Chris@0:         switch (true) {
Chris@0:             case $node instanceof Do_:
Chris@0:             case $node instanceof For_:
Chris@0:             case $node instanceof Foreach_:
Chris@0:             case $node instanceof Switch_:
Chris@0:             case $node instanceof While_:
Chris@0:                 $this->loopDepth--;
Chris@0:                 break;
Chris@0:         }
Chris@0:     }
Chris@0: }