291 lines
10 KiB
PHP
291 lines
10 KiB
PHP
<?php declare(strict_types=1);
|
|
|
|
namespace PhpParser;
|
|
|
|
class NodeTraverser implements NodeTraverserInterface
|
|
{
|
|
/**
|
|
* If NodeVisitor::enterNode() returns DONT_TRAVERSE_CHILDREN, child nodes
|
|
* of the current node will not be traversed for any visitors.
|
|
*
|
|
* For subsequent visitors enterNode() will still be called on the current
|
|
* node and leaveNode() will also be invoked for the current node.
|
|
*/
|
|
const DONT_TRAVERSE_CHILDREN = 1;
|
|
|
|
/**
|
|
* If NodeVisitor::enterNode() or NodeVisitor::leaveNode() returns
|
|
* STOP_TRAVERSAL, traversal is aborted.
|
|
*
|
|
* The afterTraverse() method will still be invoked.
|
|
*/
|
|
const STOP_TRAVERSAL = 2;
|
|
|
|
/**
|
|
* If NodeVisitor::leaveNode() returns REMOVE_NODE for a node that occurs
|
|
* in an array, it will be removed from the array.
|
|
*
|
|
* For subsequent visitors leaveNode() will still be invoked for the
|
|
* removed node.
|
|
*/
|
|
const REMOVE_NODE = 3;
|
|
|
|
/**
|
|
* If NodeVisitor::enterNode() returns DONT_TRAVERSE_CURRENT_AND_CHILDREN, child nodes
|
|
* of the current node will not be traversed for any visitors.
|
|
*
|
|
* For subsequent visitors enterNode() will not be called as well.
|
|
* leaveNode() will be invoked for visitors that has enterNode() method invoked.
|
|
*/
|
|
const DONT_TRAVERSE_CURRENT_AND_CHILDREN = 4;
|
|
|
|
/** @var NodeVisitor[] Visitors */
|
|
protected $visitors = [];
|
|
|
|
/** @var bool Whether traversal should be stopped */
|
|
protected $stopTraversal;
|
|
|
|
public function __construct() {
|
|
// for BC
|
|
}
|
|
|
|
/**
|
|
* Adds a visitor.
|
|
*
|
|
* @param NodeVisitor $visitor Visitor to add
|
|
*/
|
|
public function addVisitor(NodeVisitor $visitor) {
|
|
$this->visitors[] = $visitor;
|
|
}
|
|
|
|
/**
|
|
* Removes an added visitor.
|
|
*
|
|
* @param NodeVisitor $visitor
|
|
*/
|
|
public function removeVisitor(NodeVisitor $visitor) {
|
|
foreach ($this->visitors as $index => $storedVisitor) {
|
|
if ($storedVisitor === $visitor) {
|
|
unset($this->visitors[$index]);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Traverses an array of nodes using the registered visitors.
|
|
*
|
|
* @param Node[] $nodes Array of nodes
|
|
*
|
|
* @return Node[] Traversed array of nodes
|
|
*/
|
|
public function traverse(array $nodes) : array {
|
|
$this->stopTraversal = false;
|
|
|
|
foreach ($this->visitors as $visitor) {
|
|
if (null !== $return = $visitor->beforeTraverse($nodes)) {
|
|
$nodes = $return;
|
|
}
|
|
}
|
|
|
|
$nodes = $this->traverseArray($nodes);
|
|
|
|
foreach ($this->visitors as $visitor) {
|
|
if (null !== $return = $visitor->afterTraverse($nodes)) {
|
|
$nodes = $return;
|
|
}
|
|
}
|
|
|
|
return $nodes;
|
|
}
|
|
|
|
/**
|
|
* Recursively traverse a node.
|
|
*
|
|
* @param Node $node Node to traverse.
|
|
*
|
|
* @return Node Result of traversal (may be original node or new one)
|
|
*/
|
|
protected function traverseNode(Node $node) : Node {
|
|
foreach ($node->getSubNodeNames() as $name) {
|
|
$subNode =& $node->$name;
|
|
|
|
if (\is_array($subNode)) {
|
|
$subNode = $this->traverseArray($subNode);
|
|
if ($this->stopTraversal) {
|
|
break;
|
|
}
|
|
} elseif ($subNode instanceof Node) {
|
|
$traverseChildren = true;
|
|
$breakVisitorIndex = null;
|
|
|
|
foreach ($this->visitors as $visitorIndex => $visitor) {
|
|
$return = $visitor->enterNode($subNode);
|
|
if (null !== $return) {
|
|
if ($return instanceof Node) {
|
|
$this->ensureReplacementReasonable($subNode, $return);
|
|
$subNode = $return;
|
|
} elseif (self::DONT_TRAVERSE_CHILDREN === $return) {
|
|
$traverseChildren = false;
|
|
} elseif (self::DONT_TRAVERSE_CURRENT_AND_CHILDREN === $return) {
|
|
$traverseChildren = false;
|
|
$breakVisitorIndex = $visitorIndex;
|
|
break;
|
|
} elseif (self::STOP_TRAVERSAL === $return) {
|
|
$this->stopTraversal = true;
|
|
break 2;
|
|
} else {
|
|
throw new \LogicException(
|
|
'enterNode() returned invalid value of type ' . gettype($return)
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
if ($traverseChildren) {
|
|
$subNode = $this->traverseNode($subNode);
|
|
if ($this->stopTraversal) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
foreach ($this->visitors as $visitorIndex => $visitor) {
|
|
$return = $visitor->leaveNode($subNode);
|
|
|
|
if (null !== $return) {
|
|
if ($return instanceof Node) {
|
|
$this->ensureReplacementReasonable($subNode, $return);
|
|
$subNode = $return;
|
|
} elseif (self::STOP_TRAVERSAL === $return) {
|
|
$this->stopTraversal = true;
|
|
break 2;
|
|
} elseif (\is_array($return)) {
|
|
throw new \LogicException(
|
|
'leaveNode() may only return an array ' .
|
|
'if the parent structure is an array'
|
|
);
|
|
} else {
|
|
throw new \LogicException(
|
|
'leaveNode() returned invalid value of type ' . gettype($return)
|
|
);
|
|
}
|
|
}
|
|
|
|
if ($breakVisitorIndex === $visitorIndex) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return $node;
|
|
}
|
|
|
|
/**
|
|
* Recursively traverse array (usually of nodes).
|
|
*
|
|
* @param array $nodes Array to traverse
|
|
*
|
|
* @return array Result of traversal (may be original array or changed one)
|
|
*/
|
|
protected function traverseArray(array $nodes) : array {
|
|
$doNodes = [];
|
|
|
|
foreach ($nodes as $i => &$node) {
|
|
if ($node instanceof Node) {
|
|
$traverseChildren = true;
|
|
$breakVisitorIndex = null;
|
|
|
|
foreach ($this->visitors as $visitorIndex => $visitor) {
|
|
$return = $visitor->enterNode($node);
|
|
if (null !== $return) {
|
|
if ($return instanceof Node) {
|
|
$this->ensureReplacementReasonable($node, $return);
|
|
$node = $return;
|
|
} elseif (self::DONT_TRAVERSE_CHILDREN === $return) {
|
|
$traverseChildren = false;
|
|
} elseif (self::DONT_TRAVERSE_CURRENT_AND_CHILDREN === $return) {
|
|
$traverseChildren = false;
|
|
$breakVisitorIndex = $visitorIndex;
|
|
break;
|
|
} elseif (self::STOP_TRAVERSAL === $return) {
|
|
$this->stopTraversal = true;
|
|
break 2;
|
|
} else {
|
|
throw new \LogicException(
|
|
'enterNode() returned invalid value of type ' . gettype($return)
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
if ($traverseChildren) {
|
|
$node = $this->traverseNode($node);
|
|
if ($this->stopTraversal) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
foreach ($this->visitors as $visitorIndex => $visitor) {
|
|
$return = $visitor->leaveNode($node);
|
|
|
|
if (null !== $return) {
|
|
if ($return instanceof Node) {
|
|
$this->ensureReplacementReasonable($node, $return);
|
|
$node = $return;
|
|
} elseif (\is_array($return)) {
|
|
$doNodes[] = [$i, $return];
|
|
break;
|
|
} elseif (self::REMOVE_NODE === $return) {
|
|
$doNodes[] = [$i, []];
|
|
break;
|
|
} elseif (self::STOP_TRAVERSAL === $return) {
|
|
$this->stopTraversal = true;
|
|
break 2;
|
|
} elseif (false === $return) {
|
|
throw new \LogicException(
|
|
'bool(false) return from leaveNode() no longer supported. ' .
|
|
'Return NodeTraverser::REMOVE_NODE instead'
|
|
);
|
|
} else {
|
|
throw new \LogicException(
|
|
'leaveNode() returned invalid value of type ' . gettype($return)
|
|
);
|
|
}
|
|
}
|
|
|
|
if ($breakVisitorIndex === $visitorIndex) {
|
|
break;
|
|
}
|
|
}
|
|
} elseif (\is_array($node)) {
|
|
throw new \LogicException('Invalid node structure: Contains nested arrays');
|
|
}
|
|
}
|
|
|
|
if (!empty($doNodes)) {
|
|
while (list($i, $replace) = array_pop($doNodes)) {
|
|
array_splice($nodes, $i, 1, $replace);
|
|
}
|
|
}
|
|
|
|
return $nodes;
|
|
}
|
|
|
|
private function ensureReplacementReasonable($old, $new) {
|
|
if ($old instanceof Node\Stmt && $new instanceof Node\Expr) {
|
|
throw new \LogicException(
|
|
"Trying to replace statement ({$old->getType()}) " .
|
|
"with expression ({$new->getType()}). Are you missing a " .
|
|
"Stmt_Expression wrapper?"
|
|
);
|
|
}
|
|
|
|
if ($old instanceof Node\Expr && $new instanceof Node\Stmt) {
|
|
throw new \LogicException(
|
|
"Trying to replace expression ({$old->getType()}) " .
|
|
"with statement ({$new->getType()})"
|
|
);
|
|
}
|
|
}
|
|
}
|