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