wpide / vendor / nikic / php-parser / lib / PhpParser / NodeTraverser.php

NodeTraverser.php in WPIDE – File Manager & Code Editor 3.5.9, at vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php

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1	<?php declare(strict_types=1);
2
3	namespace PhpParser;
4
5	class NodeTraverser implements NodeTraverserInterface
6	{
7	/**
8	* If NodeVisitor::enterNode() returns DONT_TRAVERSE_CHILDREN, child nodes
9	* of the current node will not be traversed for any visitors.
10	*
11	* For subsequent visitors enterNode() will still be called on the current
12	* node and leaveNode() will also be invoked for the current node.
13	*/
14	const DONT_TRAVERSE_CHILDREN = 1;
15
16	/**
17	* If NodeVisitor::enterNode() or NodeVisitor::leaveNode() returns
18	* STOP_TRAVERSAL, traversal is aborted.
19	*
20	* The afterTraverse() method will still be invoked.
21	*/
22	const STOP_TRAVERSAL = 2;
23
24	/**
25	* If NodeVisitor::leaveNode() returns REMOVE_NODE for a node that occurs
26	* in an array, it will be removed from the array.
27	*
28	* For subsequent visitors leaveNode() will still be invoked for the
29	* removed node.
30	*/
31	const REMOVE_NODE = 3;
32
33	/**
34	* If NodeVisitor::enterNode() returns DONT_TRAVERSE_CURRENT_AND_CHILDREN, child nodes
35	* of the current node will not be traversed for any visitors.
36	*
37	* For subsequent visitors enterNode() will not be called as well.
38	* leaveNode() will be invoked for visitors that has enterNode() method invoked.
39	*/
40	const DONT_TRAVERSE_CURRENT_AND_CHILDREN = 4;
41
42	/** @var NodeVisitor[] Visitors */
43	protected $visitors = [];
44
45	/** @var bool Whether traversal should be stopped */
46	protected $stopTraversal;
47
48	public function __construct() {
49	// for BC
50	}
51
52	/**
53	* Adds a visitor.
54	*
55	* @param NodeVisitor $visitor Visitor to add
56	*/
57	public function addVisitor(NodeVisitor $visitor) {
58	$this->visitors[] = $visitor;
59	}
60
61	/**
62	* Removes an added visitor.
63	*
64	* @param NodeVisitor $visitor
65	*/
66	public function removeVisitor(NodeVisitor $visitor) {
67	foreach ($this->visitors as $index => $storedVisitor) {
68	if ($storedVisitor === $visitor) {
69	unset($this->visitors[$index]);
70	break;
71	}
72	}
73	}
74
75	/**
76	* Traverses an array of nodes using the registered visitors.
77	*
78	* @param Node[] $nodes Array of nodes
79	*
80	* @return Node[] Traversed array of nodes
81	*/
82	public function traverse(array $nodes) : array {
83	$this->stopTraversal = false;
84
85	foreach ($this->visitors as $visitor) {
86	if (null !== $return = $visitor->beforeTraverse($nodes)) {
87	$nodes = $return;
88	}
89	}
90
91	$nodes = $this->traverseArray($nodes);
92
93	foreach ($this->visitors as $visitor) {
94	if (null !== $return = $visitor->afterTraverse($nodes)) {
95	$nodes = $return;
96	}
97	}
98
99	return $nodes;
100	}
101
102	/**
103	* Recursively traverse a node.
104	*
105	* @param Node $node Node to traverse.
106	*
107	* @return Node Result of traversal (may be original node or new one)
108	*/
109	protected function traverseNode(Node $node) : Node {
110	foreach ($node->getSubNodeNames() as $name) {
111	$subNode =& $node->$name;
112
113	if (\is_array($subNode)) {
114	$subNode = $this->traverseArray($subNode);
115	if ($this->stopTraversal) {
116	break;
117	}
118	} elseif ($subNode instanceof Node) {
119	$traverseChildren = true;
120	$breakVisitorIndex = null;
121
122	foreach ($this->visitors as $visitorIndex => $visitor) {
123	$return = $visitor->enterNode($subNode);
124	if (null !== $return) {
125	if ($return instanceof Node) {
126	$this->ensureReplacementReasonable($subNode, $return);
127	$subNode = $return;
128	} elseif (self::DONT_TRAVERSE_CHILDREN === $return) {
129	$traverseChildren = false;
130	} elseif (self::DONT_TRAVERSE_CURRENT_AND_CHILDREN === $return) {
131	$traverseChildren = false;
132	$breakVisitorIndex = $visitorIndex;
133	break;
134	} elseif (self::STOP_TRAVERSAL === $return) {
135	$this->stopTraversal = true;
136	break 2;
137	} else {
138	throw new \LogicException(
139	'enterNode() returned invalid value of type ' . gettype($return)
140	);
141	}
142	}
143	}
144
145	if ($traverseChildren) {
146	$subNode = $this->traverseNode($subNode);
147	if ($this->stopTraversal) {
148	break;
149	}
150	}
151
152	foreach ($this->visitors as $visitorIndex => $visitor) {
153	$return = $visitor->leaveNode($subNode);
154
155	if (null !== $return) {
156	if ($return instanceof Node) {
157	$this->ensureReplacementReasonable($subNode, $return);
158	$subNode = $return;
159	} elseif (self::STOP_TRAVERSAL === $return) {
160	$this->stopTraversal = true;
161	break 2;
162	} elseif (\is_array($return)) {
163	throw new \LogicException(
164	'leaveNode() may only return an array ' .
165	'if the parent structure is an array'
166	);
167	} else {
168	throw new \LogicException(
169	'leaveNode() returned invalid value of type ' . gettype($return)
170	);
171	}
172	}
173
174	if ($breakVisitorIndex === $visitorIndex) {
175	break;
176	}
177	}
178	}
179	}
180
181	return $node;
182	}
183
184	/**
185	* Recursively traverse array (usually of nodes).
186	*
187	* @param array $nodes Array to traverse
188	*
189	* @return array Result of traversal (may be original array or changed one)
190	*/
191	protected function traverseArray(array $nodes) : array {
192	$doNodes = [];
193
194	foreach ($nodes as $i => &$node) {
195	if ($node instanceof Node) {
196	$traverseChildren = true;
197	$breakVisitorIndex = null;
198
199	foreach ($this->visitors as $visitorIndex => $visitor) {
200	$return = $visitor->enterNode($node);
201	if (null !== $return) {
202	if ($return instanceof Node) {
203	$this->ensureReplacementReasonable($node, $return);
204	$node = $return;
205	} elseif (self::DONT_TRAVERSE_CHILDREN === $return) {
206	$traverseChildren = false;
207	} elseif (self::DONT_TRAVERSE_CURRENT_AND_CHILDREN === $return) {
208	$traverseChildren = false;
209	$breakVisitorIndex = $visitorIndex;
210	break;
211	} elseif (self::STOP_TRAVERSAL === $return) {
212	$this->stopTraversal = true;
213	break 2;
214	} else {
215	throw new \LogicException(
216	'enterNode() returned invalid value of type ' . gettype($return)
217	);
218	}
219	}
220	}
221
222	if ($traverseChildren) {
223	$node = $this->traverseNode($node);
224	if ($this->stopTraversal) {
225	break;
226	}
227	}
228
229	foreach ($this->visitors as $visitorIndex => $visitor) {
230	$return = $visitor->leaveNode($node);
231
232	if (null !== $return) {
233	if ($return instanceof Node) {
234	$this->ensureReplacementReasonable($node, $return);
235	$node = $return;
236	} elseif (\is_array($return)) {
237	$doNodes[] = [$i, $return];
238	break;
239	} elseif (self::REMOVE_NODE === $return) {
240	$doNodes[] = [$i, []];
241	break;
242	} elseif (self::STOP_TRAVERSAL === $return) {
243	$this->stopTraversal = true;
244	break 2;
245	} elseif (false === $return) {
246	throw new \LogicException(
247	'bool(false) return from leaveNode() no longer supported. ' .
248	'Return NodeTraverser::REMOVE_NODE instead'
249	);
250	} else {
251	throw new \LogicException(
252	'leaveNode() returned invalid value of type ' . gettype($return)
253	);
254	}
255	}
256
257	if ($breakVisitorIndex === $visitorIndex) {
258	break;
259	}
260	}
261	} elseif (\is_array($node)) {
262	throw new \LogicException('Invalid node structure: Contains nested arrays');
263	}
264	}
265
266	if (!empty($doNodes)) {
267	while (list($i, $replace) = array_pop($doNodes)) {
268	array_splice($nodes, $i, 1, $replace);
269	}
270	}
271
272	return $nodes;
273	}
274
275	private function ensureReplacementReasonable($old, $new) {
276	if ($old instanceof Node\Stmt && $new instanceof Node\Expr) {
277	throw new \LogicException(
278	"Trying to replace statement ({$old->getType()}) " .
279	"with expression ({$new->getType()}). Are you missing a " .
280	"Stmt_Expression wrapper?"
281	);
282	}
283
284	if ($old instanceof Node\Expr && $new instanceof Node\Stmt) {
285	throw new \LogicException(
286	"Trying to replace expression ({$old->getType()}) " .
287	"with statement ({$new->getType()})"
288	);
289	}
290	}
291	}
292