1<?php
2
3/*
4 * This file is part of Twig.
5 *
6 * (c) Fabien Potencier
7 * (c) Armin Ronacher
8 *
9 * For the full copyright and license information, please view the LICENSE
10 * file that was distributed with this source code.
11 */
12
13namespace Twig;
14
15use Twig\Error\SyntaxError;
16use Twig\Node\Expression\AbstractExpression;
17use Twig\Node\Expression\ArrayExpression;
18use Twig\Node\Expression\ArrowFunctionExpression;
19use Twig\Node\Expression\AssignNameExpression;
20use Twig\Node\Expression\Binary\ConcatBinary;
21use Twig\Node\Expression\BlockReferenceExpression;
22use Twig\Node\Expression\ConditionalExpression;
23use Twig\Node\Expression\ConstantExpression;
24use Twig\Node\Expression\GetAttrExpression;
25use Twig\Node\Expression\MethodCallExpression;
26use Twig\Node\Expression\NameExpression;
27use Twig\Node\Expression\ParentExpression;
28use Twig\Node\Expression\TestExpression;
29use Twig\Node\Expression\Unary\NegUnary;
30use Twig\Node\Expression\Unary\NotUnary;
31use Twig\Node\Expression\Unary\PosUnary;
32use Twig\Node\Node;
33
34/**
35 * Parses expressions.
36 *
37 * This parser implements a "Precedence climbing" algorithm.
38 *
39 * @see https://www.engr.mun.ca/~theo/Misc/exp_parsing.htm
40 * @see https://en.wikipedia.org/wiki/Operator-precedence_parser
41 *
42 * @author Fabien Potencier <fabien@symfony.com>
43 *
44 * @internal
45 */
46class ExpressionParser
47{
48    public const OPERATOR_LEFT = 1;
49    public const OPERATOR_RIGHT = 2;
50
51    private $parser;
52    private $env;
53    private $unaryOperators;
54    private $binaryOperators;
55
56    public function __construct(Parser $parser, Environment $env)
57    {
58        $this->parser = $parser;
59        $this->env = $env;
60        $this->unaryOperators = $env->getUnaryOperators();
61        $this->binaryOperators = $env->getBinaryOperators();
62    }
63
64    public function parseExpression($precedence = 0, $allowArrow = false)
65    {
66        if ($allowArrow && $arrow = $this->parseArrow()) {
67            return $arrow;
68        }
69
70        $expr = $this->getPrimary();
71        $token = $this->parser->getCurrentToken();
72        while ($this->isBinary($token) && $this->binaryOperators[$token->getValue()]['precedence'] >= $precedence) {
73            $op = $this->binaryOperators[$token->getValue()];
74            $this->parser->getStream()->next();
75
76            if ('is not' === $token->getValue()) {
77                $expr = $this->parseNotTestExpression($expr);
78            } elseif ('is' === $token->getValue()) {
79                $expr = $this->parseTestExpression($expr);
80            } elseif (isset($op['callable'])) {
81                $expr = $op['callable']($this->parser, $expr);
82            } else {
83                $expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
84                $class = $op['class'];
85                $expr = new $class($expr, $expr1, $token->getLine());
86            }
87
88            $token = $this->parser->getCurrentToken();
89        }
90
91        if (0 === $precedence) {
92            return $this->parseConditionalExpression($expr);
93        }
94
95        return $expr;
96    }
97
98    /**
99     * @return ArrowFunctionExpression|null
100     */
101    private function parseArrow()
102    {
103        $stream = $this->parser->getStream();
104
105        // short array syntax (one argument, no parentheses)?
106        if ($stream->look(1)->test(/* Token::ARROW_TYPE */ 12)) {
107            $line = $stream->getCurrent()->getLine();
108            $token = $stream->expect(/* Token::NAME_TYPE */ 5);
109            $names = [new AssignNameExpression($token->getValue(), $token->getLine())];
110            $stream->expect(/* Token::ARROW_TYPE */ 12);
111
112            return new ArrowFunctionExpression($this->parseExpression(0), new Node($names), $line);
113        }
114
115        // first, determine if we are parsing an arrow function by finding => (long form)
116        $i = 0;
117        if (!$stream->look($i)->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
118            return null;
119        }
120        ++$i;
121        while (true) {
122            // variable name
123            ++$i;
124            if (!$stream->look($i)->test(/* Token::PUNCTUATION_TYPE */ 9, ',')) {
125                break;
126            }
127            ++$i;
128        }
129        if (!$stream->look($i)->test(/* Token::PUNCTUATION_TYPE */ 9, ')')) {
130            return null;
131        }
132        ++$i;
133        if (!$stream->look($i)->test(/* Token::ARROW_TYPE */ 12)) {
134            return null;
135        }
136
137        // yes, let's parse it properly
138        $token = $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, '(');
139        $line = $token->getLine();
140
141        $names = [];
142        while (true) {
143            $token = $stream->expect(/* Token::NAME_TYPE */ 5);
144            $names[] = new AssignNameExpression($token->getValue(), $token->getLine());
145
146            if (!$stream->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ',')) {
147                break;
148            }
149        }
150        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ')');
151        $stream->expect(/* Token::ARROW_TYPE */ 12);
152
153        return new ArrowFunctionExpression($this->parseExpression(0), new Node($names), $line);
154    }
155
156    private function getPrimary(): AbstractExpression
157    {
158        $token = $this->parser->getCurrentToken();
159
160        if ($this->isUnary($token)) {
161            $operator = $this->unaryOperators[$token->getValue()];
162            $this->parser->getStream()->next();
163            $expr = $this->parseExpression($operator['precedence']);
164            $class = $operator['class'];
165
166            return $this->parsePostfixExpression(new $class($expr, $token->getLine()));
167        } elseif ($token->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
168            $this->parser->getStream()->next();
169            $expr = $this->parseExpression();
170            $this->parser->getStream()->expect(/* Token::PUNCTUATION_TYPE */ 9, ')', 'An opened parenthesis is not properly closed');
171
172            return $this->parsePostfixExpression($expr);
173        }
174
175        return $this->parsePrimaryExpression();
176    }
177
178    private function parseConditionalExpression($expr): AbstractExpression
179    {
180        while ($this->parser->getStream()->nextIf(/* Token::PUNCTUATION_TYPE */ 9, '?')) {
181            if (!$this->parser->getStream()->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ':')) {
182                $expr2 = $this->parseExpression();
183                if ($this->parser->getStream()->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ':')) {
184                    $expr3 = $this->parseExpression();
185                } else {
186                    $expr3 = new ConstantExpression('', $this->parser->getCurrentToken()->getLine());
187                }
188            } else {
189                $expr2 = $expr;
190                $expr3 = $this->parseExpression();
191            }
192
193            $expr = new ConditionalExpression($expr, $expr2, $expr3, $this->parser->getCurrentToken()->getLine());
194        }
195
196        return $expr;
197    }
198
199    private function isUnary(Token $token): bool
200    {
201        return $token->test(/* Token::OPERATOR_TYPE */ 8) && isset($this->unaryOperators[$token->getValue()]);
202    }
203
204    private function isBinary(Token $token): bool
205    {
206        return $token->test(/* Token::OPERATOR_TYPE */ 8) && isset($this->binaryOperators[$token->getValue()]);
207    }
208
209    public function parsePrimaryExpression()
210    {
211        $token = $this->parser->getCurrentToken();
212        switch ($token->getType()) {
213            case /* Token::NAME_TYPE */ 5:
214                $this->parser->getStream()->next();
215                switch ($token->getValue()) {
216                    case 'true':
217                    case 'TRUE':
218                        $node = new ConstantExpression(true, $token->getLine());
219                        break;
220
221                    case 'false':
222                    case 'FALSE':
223                        $node = new ConstantExpression(false, $token->getLine());
224                        break;
225
226                    case 'none':
227                    case 'NONE':
228                    case 'null':
229                    case 'NULL':
230                        $node = new ConstantExpression(null, $token->getLine());
231                        break;
232
233                    default:
234                        if ('(' === $this->parser->getCurrentToken()->getValue()) {
235                            $node = $this->getFunctionNode($token->getValue(), $token->getLine());
236                        } else {
237                            $node = new NameExpression($token->getValue(), $token->getLine());
238                        }
239                }
240                break;
241
242            case /* Token::NUMBER_TYPE */ 6:
243                $this->parser->getStream()->next();
244                $node = new ConstantExpression($token->getValue(), $token->getLine());
245                break;
246
247            case /* Token::STRING_TYPE */ 7:
248            case /* Token::INTERPOLATION_START_TYPE */ 10:
249                $node = $this->parseStringExpression();
250                break;
251
252            case /* Token::OPERATOR_TYPE */ 8:
253                if (preg_match(Lexer::REGEX_NAME, $token->getValue(), $matches) && $matches[0] == $token->getValue()) {
254                    // in this context, string operators are variable names
255                    $this->parser->getStream()->next();
256                    $node = new NameExpression($token->getValue(), $token->getLine());
257                    break;
258                } elseif (isset($this->unaryOperators[$token->getValue()])) {
259                    $class = $this->unaryOperators[$token->getValue()]['class'];
260
261                    $ref = new \ReflectionClass($class);
262                    if (!(\in_array($ref->getName(), [NegUnary::class, PosUnary::class, 'Twig_Node_Expression_Unary_Neg', 'Twig_Node_Expression_Unary_Pos'])
263                        || $ref->isSubclassOf(NegUnary::class) || $ref->isSubclassOf(PosUnary::class)
264                        || $ref->isSubclassOf('Twig_Node_Expression_Unary_Neg') || $ref->isSubclassOf('Twig_Node_Expression_Unary_Pos'))
265                    ) {
266                        throw new SyntaxError(sprintf('Unexpected unary operator "%s".', $token->getValue()), $token->getLine(), $this->parser->getStream()->getSourceContext());
267                    }
268
269                    $this->parser->getStream()->next();
270                    $expr = $this->parsePrimaryExpression();
271
272                    $node = new $class($expr, $token->getLine());
273                    break;
274                }
275
276                // no break
277            default:
278                if ($token->test(/* Token::PUNCTUATION_TYPE */ 9, '[')) {
279                    $node = $this->parseArrayExpression();
280                } elseif ($token->test(/* Token::PUNCTUATION_TYPE */ 9, '{')) {
281                    $node = $this->parseHashExpression();
282                } elseif ($token->test(/* Token::OPERATOR_TYPE */ 8, '=') && ('==' === $this->parser->getStream()->look(-1)->getValue() || '!=' === $this->parser->getStream()->look(-1)->getValue())) {
283                    throw new SyntaxError(sprintf('Unexpected operator of value "%s". Did you try to use "===" or "!==" for strict comparison? Use "is same as(value)" instead.', $token->getValue()), $token->getLine(), $this->parser->getStream()->getSourceContext());
284                } else {
285                    throw new SyntaxError(sprintf('Unexpected token "%s" of value "%s".', Token::typeToEnglish($token->getType()), $token->getValue()), $token->getLine(), $this->parser->getStream()->getSourceContext());
286                }
287        }
288
289        return $this->parsePostfixExpression($node);
290    }
291
292    public function parseStringExpression()
293    {
294        $stream = $this->parser->getStream();
295
296        $nodes = [];
297        // a string cannot be followed by another string in a single expression
298        $nextCanBeString = true;
299        while (true) {
300            if ($nextCanBeString && $token = $stream->nextIf(/* Token::STRING_TYPE */ 7)) {
301                $nodes[] = new ConstantExpression($token->getValue(), $token->getLine());
302                $nextCanBeString = false;
303            } elseif ($stream->nextIf(/* Token::INTERPOLATION_START_TYPE */ 10)) {
304                $nodes[] = $this->parseExpression();
305                $stream->expect(/* Token::INTERPOLATION_END_TYPE */ 11);
306                $nextCanBeString = true;
307            } else {
308                break;
309            }
310        }
311
312        $expr = array_shift($nodes);
313        foreach ($nodes as $node) {
314            $expr = new ConcatBinary($expr, $node, $node->getTemplateLine());
315        }
316
317        return $expr;
318    }
319
320    public function parseArrayExpression()
321    {
322        $stream = $this->parser->getStream();
323        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, '[', 'An array element was expected');
324
325        $node = new ArrayExpression([], $stream->getCurrent()->getLine());
326        $first = true;
327        while (!$stream->test(/* Token::PUNCTUATION_TYPE */ 9, ']')) {
328            if (!$first) {
329                $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ',', 'An array element must be followed by a comma');
330
331                // trailing ,?
332                if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, ']')) {
333                    break;
334                }
335            }
336            $first = false;
337
338            $node->addElement($this->parseExpression());
339        }
340        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ']', 'An opened array is not properly closed');
341
342        return $node;
343    }
344
345    public function parseHashExpression()
346    {
347        $stream = $this->parser->getStream();
348        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, '{', 'A hash element was expected');
349
350        $node = new ArrayExpression([], $stream->getCurrent()->getLine());
351        $first = true;
352        while (!$stream->test(/* Token::PUNCTUATION_TYPE */ 9, '}')) {
353            if (!$first) {
354                $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ',', 'A hash value must be followed by a comma');
355
356                // trailing ,?
357                if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, '}')) {
358                    break;
359                }
360            }
361            $first = false;
362
363            // a hash key can be:
364            //
365            //  * a number -- 12
366            //  * a string -- 'a'
367            //  * a name, which is equivalent to a string -- a
368            //  * an expression, which must be enclosed in parentheses -- (1 + 2)
369            if ($token = $stream->nextIf(/* Token::NAME_TYPE */ 5)) {
370                $key = new ConstantExpression($token->getValue(), $token->getLine());
371
372                // {a} is a shortcut for {a:a}
373                if ($stream->test(Token::PUNCTUATION_TYPE, [',', '}'])) {
374                    $value = new NameExpression($key->getAttribute('value'), $key->getTemplateLine());
375                    $node->addElement($value, $key);
376                    continue;
377                }
378            } elseif (($token = $stream->nextIf(/* Token::STRING_TYPE */ 7)) || $token = $stream->nextIf(/* Token::NUMBER_TYPE */ 6)) {
379                $key = new ConstantExpression($token->getValue(), $token->getLine());
380            } elseif ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
381                $key = $this->parseExpression();
382            } else {
383                $current = $stream->getCurrent();
384
385                throw new SyntaxError(sprintf('A hash key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s".', Token::typeToEnglish($current->getType()), $current->getValue()), $current->getLine(), $stream->getSourceContext());
386            }
387
388            $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ':', 'A hash key must be followed by a colon (:)');
389            $value = $this->parseExpression();
390
391            $node->addElement($value, $key);
392        }
393        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, '}', 'An opened hash is not properly closed');
394
395        return $node;
396    }
397
398    public function parsePostfixExpression($node)
399    {
400        while (true) {
401            $token = $this->parser->getCurrentToken();
402            if (/* Token::PUNCTUATION_TYPE */ 9 == $token->getType()) {
403                if ('.' == $token->getValue() || '[' == $token->getValue()) {
404                    $node = $this->parseSubscriptExpression($node);
405                } elseif ('|' == $token->getValue()) {
406                    $node = $this->parseFilterExpression($node);
407                } else {
408                    break;
409                }
410            } else {
411                break;
412            }
413        }
414
415        return $node;
416    }
417
418    public function getFunctionNode($name, $line)
419    {
420        switch ($name) {
421            case 'parent':
422                $this->parseArguments();
423                if (!\count($this->parser->getBlockStack())) {
424                    throw new SyntaxError('Calling "parent" outside a block is forbidden.', $line, $this->parser->getStream()->getSourceContext());
425                }
426
427                if (!$this->parser->getParent() && !$this->parser->hasTraits()) {
428                    throw new SyntaxError('Calling "parent" on a template that does not extend nor "use" another template is forbidden.', $line, $this->parser->getStream()->getSourceContext());
429                }
430
431                return new ParentExpression($this->parser->peekBlockStack(), $line);
432            case 'block':
433                $args = $this->parseArguments();
434                if (\count($args) < 1) {
435                    throw new SyntaxError('The "block" function takes one argument (the block name).', $line, $this->parser->getStream()->getSourceContext());
436                }
437
438                return new BlockReferenceExpression($args->getNode(0), \count($args) > 1 ? $args->getNode(1) : null, $line);
439            case 'attribute':
440                $args = $this->parseArguments();
441                if (\count($args) < 2) {
442                    throw new SyntaxError('The "attribute" function takes at least two arguments (the variable and the attributes).', $line, $this->parser->getStream()->getSourceContext());
443                }
444
445                return new GetAttrExpression($args->getNode(0), $args->getNode(1), \count($args) > 2 ? $args->getNode(2) : null, Template::ANY_CALL, $line);
446            default:
447                if (null !== $alias = $this->parser->getImportedSymbol('function', $name)) {
448                    $arguments = new ArrayExpression([], $line);
449                    foreach ($this->parseArguments() as $n) {
450                        $arguments->addElement($n);
451                    }
452
453                    $node = new MethodCallExpression($alias['node'], $alias['name'], $arguments, $line);
454                    $node->setAttribute('safe', true);
455
456                    return $node;
457                }
458
459                $args = $this->parseArguments(true);
460                $class = $this->getFunctionNodeClass($name, $line);
461
462                return new $class($name, $args, $line);
463        }
464    }
465
466    public function parseSubscriptExpression($node)
467    {
468        $stream = $this->parser->getStream();
469        $token = $stream->next();
470        $lineno = $token->getLine();
471        $arguments = new ArrayExpression([], $lineno);
472        $type = Template::ANY_CALL;
473        if ('.' == $token->getValue()) {
474            $token = $stream->next();
475            if (
476                /* Token::NAME_TYPE */ 5 == $token->getType()
477                ||
478                /* Token::NUMBER_TYPE */ 6 == $token->getType()
479                ||
480                (/* Token::OPERATOR_TYPE */ 8 == $token->getType() && preg_match(Lexer::REGEX_NAME, $token->getValue()))
481            ) {
482                $arg = new ConstantExpression($token->getValue(), $lineno);
483
484                if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
485                    $type = Template::METHOD_CALL;
486                    foreach ($this->parseArguments() as $n) {
487                        $arguments->addElement($n);
488                    }
489                }
490            } else {
491                throw new SyntaxError('Expected name or number.', $lineno, $stream->getSourceContext());
492            }
493
494            if ($node instanceof NameExpression && null !== $this->parser->getImportedSymbol('template', $node->getAttribute('name'))) {
495                if (!$arg instanceof ConstantExpression) {
496                    throw new SyntaxError(sprintf('Dynamic macro names are not supported (called on "%s").', $node->getAttribute('name')), $token->getLine(), $stream->getSourceContext());
497                }
498
499                $name = $arg->getAttribute('value');
500
501                $node = new MethodCallExpression($node, 'macro_'.$name, $arguments, $lineno);
502                $node->setAttribute('safe', true);
503
504                return $node;
505            }
506        } else {
507            $type = Template::ARRAY_CALL;
508
509            // slice?
510            $slice = false;
511            if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, ':')) {
512                $slice = true;
513                $arg = new ConstantExpression(0, $token->getLine());
514            } else {
515                $arg = $this->parseExpression();
516            }
517
518            if ($stream->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ':')) {
519                $slice = true;
520            }
521
522            if ($slice) {
523                if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, ']')) {
524                    $length = new ConstantExpression(null, $token->getLine());
525                } else {
526                    $length = $this->parseExpression();
527                }
528
529                $class = $this->getFilterNodeClass('slice', $token->getLine());
530                $arguments = new Node([$arg, $length]);
531                $filter = new $class($node, new ConstantExpression('slice', $token->getLine()), $arguments, $token->getLine());
532
533                $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ']');
534
535                return $filter;
536            }
537
538            $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ']');
539        }
540
541        return new GetAttrExpression($node, $arg, $arguments, $type, $lineno);
542    }
543
544    public function parseFilterExpression($node)
545    {
546        $this->parser->getStream()->next();
547
548        return $this->parseFilterExpressionRaw($node);
549    }
550
551    public function parseFilterExpressionRaw($node, $tag = null)
552    {
553        while (true) {
554            $token = $this->parser->getStream()->expect(/* Token::NAME_TYPE */ 5);
555
556            $name = new ConstantExpression($token->getValue(), $token->getLine());
557            if (!$this->parser->getStream()->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
558                $arguments = new Node();
559            } else {
560                $arguments = $this->parseArguments(true, false, true);
561            }
562
563            $class = $this->getFilterNodeClass($name->getAttribute('value'), $token->getLine());
564
565            $node = new $class($node, $name, $arguments, $token->getLine(), $tag);
566
567            if (!$this->parser->getStream()->test(/* Token::PUNCTUATION_TYPE */ 9, '|')) {
568                break;
569            }
570
571            $this->parser->getStream()->next();
572        }
573
574        return $node;
575    }
576
577    /**
578     * Parses arguments.
579     *
580     * @param bool $namedArguments Whether to allow named arguments or not
581     * @param bool $definition     Whether we are parsing arguments for a function definition
582     *
583     * @return Node
584     *
585     * @throws SyntaxError
586     */
587    public function parseArguments($namedArguments = false, $definition = false, $allowArrow = false)
588    {
589        $args = [];
590        $stream = $this->parser->getStream();
591
592        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, '(', 'A list of arguments must begin with an opening parenthesis');
593        while (!$stream->test(/* Token::PUNCTUATION_TYPE */ 9, ')')) {
594            if (!empty($args)) {
595                $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ',', 'Arguments must be separated by a comma');
596
597                // if the comma above was a trailing comma, early exit the argument parse loop
598                if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, ')')) {
599                    break;
600                }
601            }
602
603            if ($definition) {
604                $token = $stream->expect(/* Token::NAME_TYPE */ 5, null, 'An argument must be a name');
605                $value = new NameExpression($token->getValue(), $this->parser->getCurrentToken()->getLine());
606            } else {
607                $value = $this->parseExpression(0, $allowArrow);
608            }
609
610            $name = null;
611            if ($namedArguments && $token = $stream->nextIf(/* Token::OPERATOR_TYPE */ 8, '=')) {
612                if (!$value instanceof NameExpression) {
613                    throw new SyntaxError(sprintf('A parameter name must be a string, "%s" given.', \get_class($value)), $token->getLine(), $stream->getSourceContext());
614                }
615                $name = $value->getAttribute('name');
616
617                if ($definition) {
618                    $value = $this->parsePrimaryExpression();
619
620                    if (!$this->checkConstantExpression($value)) {
621                        throw new SyntaxError('A default value for an argument must be a constant (a boolean, a string, a number, or an array).', $token->getLine(), $stream->getSourceContext());
622                    }
623                } else {
624                    $value = $this->parseExpression(0, $allowArrow);
625                }
626            }
627
628            if ($definition) {
629                if (null === $name) {
630                    $name = $value->getAttribute('name');
631                    $value = new ConstantExpression(null, $this->parser->getCurrentToken()->getLine());
632                }
633                $args[$name] = $value;
634            } else {
635                if (null === $name) {
636                    $args[] = $value;
637                } else {
638                    $args[$name] = $value;
639                }
640            }
641        }
642        $stream->expect(/* Token::PUNCTUATION_TYPE */ 9, ')', 'A list of arguments must be closed by a parenthesis');
643
644        return new Node($args);
645    }
646
647    public function parseAssignmentExpression()
648    {
649        $stream = $this->parser->getStream();
650        $targets = [];
651        while (true) {
652            $token = $this->parser->getCurrentToken();
653            if ($stream->test(/* Token::OPERATOR_TYPE */ 8) && preg_match(Lexer::REGEX_NAME, $token->getValue())) {
654                // in this context, string operators are variable names
655                $this->parser->getStream()->next();
656            } else {
657                $stream->expect(/* Token::NAME_TYPE */ 5, null, 'Only variables can be assigned to');
658            }
659            $value = $token->getValue();
660            if (\in_array(strtr($value, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'abcdefghijklmnopqrstuvwxyz'), ['true', 'false', 'none', 'null'])) {
661                throw new SyntaxError(sprintf('You cannot assign a value to "%s".', $value), $token->getLine(), $stream->getSourceContext());
662            }
663            $targets[] = new AssignNameExpression($value, $token->getLine());
664
665            if (!$stream->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ',')) {
666                break;
667            }
668        }
669
670        return new Node($targets);
671    }
672
673    public function parseMultitargetExpression()
674    {
675        $targets = [];
676        while (true) {
677            $targets[] = $this->parseExpression();
678            if (!$this->parser->getStream()->nextIf(/* Token::PUNCTUATION_TYPE */ 9, ',')) {
679                break;
680            }
681        }
682
683        return new Node($targets);
684    }
685
686    private function parseNotTestExpression(Node $node): NotUnary
687    {
688        return new NotUnary($this->parseTestExpression($node), $this->parser->getCurrentToken()->getLine());
689    }
690
691    private function parseTestExpression(Node $node): TestExpression
692    {
693        $stream = $this->parser->getStream();
694        list($name, $test) = $this->getTest($node->getTemplateLine());
695
696        $class = $this->getTestNodeClass($test);
697        $arguments = null;
698        if ($stream->test(/* Token::PUNCTUATION_TYPE */ 9, '(')) {
699            $arguments = $this->parseArguments(true);
700        } elseif ($test->hasOneMandatoryArgument()) {
701            $arguments = new Node([0 => $this->parsePrimaryExpression()]);
702        }
703
704        if ('defined' === $name && $node instanceof NameExpression && null !== $alias = $this->parser->getImportedSymbol('function', $node->getAttribute('name'))) {
705            $node = new MethodCallExpression($alias['node'], $alias['name'], new ArrayExpression([], $node->getTemplateLine()), $node->getTemplateLine());
706            $node->setAttribute('safe', true);
707        }
708
709        return new $class($node, $name, $arguments, $this->parser->getCurrentToken()->getLine());
710    }
711
712    private function getTest(int $line): array
713    {
714        $stream = $this->parser->getStream();
715        $name = $stream->expect(/* Token::NAME_TYPE */ 5)->getValue();
716
717        if ($test = $this->env->getTest($name)) {
718            return [$name, $test];
719        }
720
721        if ($stream->test(/* Token::NAME_TYPE */ 5)) {
722            // try 2-words tests
723            $name = $name.' '.$this->parser->getCurrentToken()->getValue();
724
725            if ($test = $this->env->getTest($name)) {
726                $stream->next();
727
728                return [$name, $test];
729            }
730        }
731
732        $e = new SyntaxError(sprintf('Unknown "%s" test.', $name), $line, $stream->getSourceContext());
733        $e->addSuggestions($name, array_keys($this->env->getTests()));
734
735        throw $e;
736    }
737
738    private function getTestNodeClass(TwigTest $test): string
739    {
740        if ($test->isDeprecated()) {
741            $stream = $this->parser->getStream();
742            $message = sprintf('Twig Test "%s" is deprecated', $test->getName());
743
744            if (!\is_bool($test->getDeprecatedVersion())) {
745                $message .= sprintf(' since version %s', $test->getDeprecatedVersion());
746            }
747            if ($test->getAlternative()) {
748                $message .= sprintf('. Use "%s" instead', $test->getAlternative());
749            }
750            $src = $stream->getSourceContext();
751            $message .= sprintf(' in %s at line %d.', $src->getPath() ?: $src->getName(), $stream->getCurrent()->getLine());
752
753            @trigger_error($message, \E_USER_DEPRECATED);
754        }
755
756        return $test->getNodeClass();
757    }
758
759    private function getFunctionNodeClass(string $name, int $line): string
760    {
761        if (false === $function = $this->env->getFunction($name)) {
762            $e = new SyntaxError(sprintf('Unknown "%s" function.', $name), $line, $this->parser->getStream()->getSourceContext());
763            $e->addSuggestions($name, array_keys($this->env->getFunctions()));
764
765            throw $e;
766        }
767
768        if ($function->isDeprecated()) {
769            $message = sprintf('Twig Function "%s" is deprecated', $function->getName());
770            if (!\is_bool($function->getDeprecatedVersion())) {
771                $message .= sprintf(' since version %s', $function->getDeprecatedVersion());
772            }
773            if ($function->getAlternative()) {
774                $message .= sprintf('. Use "%s" instead', $function->getAlternative());
775            }
776            $src = $this->parser->getStream()->getSourceContext();
777            $message .= sprintf(' in %s at line %d.', $src->getPath() ?: $src->getName(), $line);
778
779            @trigger_error($message, \E_USER_DEPRECATED);
780        }
781
782        return $function->getNodeClass();
783    }
784
785    private function getFilterNodeClass(string $name, int $line): string
786    {
787        if (false === $filter = $this->env->getFilter($name)) {
788            $e = new SyntaxError(sprintf('Unknown "%s" filter.', $name), $line, $this->parser->getStream()->getSourceContext());
789            $e->addSuggestions($name, array_keys($this->env->getFilters()));
790
791            throw $e;
792        }
793
794        if ($filter->isDeprecated()) {
795            $message = sprintf('Twig Filter "%s" is deprecated', $filter->getName());
796            if (!\is_bool($filter->getDeprecatedVersion())) {
797                $message .= sprintf(' since version %s', $filter->getDeprecatedVersion());
798            }
799            if ($filter->getAlternative()) {
800                $message .= sprintf('. Use "%s" instead', $filter->getAlternative());
801            }
802            $src = $this->parser->getStream()->getSourceContext();
803            $message .= sprintf(' in %s at line %d.', $src->getPath() ?: $src->getName(), $line);
804
805            @trigger_error($message, \E_USER_DEPRECATED);
806        }
807
808        return $filter->getNodeClass();
809    }
810
811    // checks that the node only contains "constant" elements
812    private function checkConstantExpression(Node $node): bool
813    {
814        if (!($node instanceof ConstantExpression || $node instanceof ArrayExpression
815            || $node instanceof NegUnary || $node instanceof PosUnary
816        )) {
817            return false;
818        }
819
820        foreach ($node as $n) {
821            if (!$this->checkConstantExpression($n)) {
822                return false;
823            }
824        }
825
826        return true;
827    }
828}
829
830class_alias('Twig\ExpressionParser', 'Twig_ExpressionParser');
831