1<?php
2/**
3 * Statement utilities.
4 */
5
6declare(strict_types=1);
7
8namespace PhpMyAdmin\SqlParser\Utils;
9
10use PhpMyAdmin\SqlParser\Components\Expression;
11use PhpMyAdmin\SqlParser\Lexer;
12use PhpMyAdmin\SqlParser\Parser;
13use PhpMyAdmin\SqlParser\Statement;
14use PhpMyAdmin\SqlParser\Statements\AlterStatement;
15use PhpMyAdmin\SqlParser\Statements\AnalyzeStatement;
16use PhpMyAdmin\SqlParser\Statements\CallStatement;
17use PhpMyAdmin\SqlParser\Statements\CheckStatement;
18use PhpMyAdmin\SqlParser\Statements\ChecksumStatement;
19use PhpMyAdmin\SqlParser\Statements\CreateStatement;
20use PhpMyAdmin\SqlParser\Statements\DeleteStatement;
21use PhpMyAdmin\SqlParser\Statements\DropStatement;
22use PhpMyAdmin\SqlParser\Statements\ExplainStatement;
23use PhpMyAdmin\SqlParser\Statements\InsertStatement;
24use PhpMyAdmin\SqlParser\Statements\LoadStatement;
25use PhpMyAdmin\SqlParser\Statements\OptimizeStatement;
26use PhpMyAdmin\SqlParser\Statements\RenameStatement;
27use PhpMyAdmin\SqlParser\Statements\RepairStatement;
28use PhpMyAdmin\SqlParser\Statements\ReplaceStatement;
29use PhpMyAdmin\SqlParser\Statements\SelectStatement;
30use PhpMyAdmin\SqlParser\Statements\SetStatement;
31use PhpMyAdmin\SqlParser\Statements\ShowStatement;
32use PhpMyAdmin\SqlParser\Statements\TruncateStatement;
33use PhpMyAdmin\SqlParser\Statements\UpdateStatement;
34use PhpMyAdmin\SqlParser\Token;
35use PhpMyAdmin\SqlParser\TokensList;
36
37use function array_flip;
38use function array_keys;
39use function count;
40use function in_array;
41use function is_string;
42use function trim;
43
44/**
45 * Statement utilities.
46 */
47class Query
48{
49    /**
50     * Functions that set the flag `is_func`.
51     *
52     * @var string[]
53     */
54    public static $FUNCTIONS = [
55        'SUM',
56        'AVG',
57        'STD',
58        'STDDEV',
59        'MIN',
60        'MAX',
61        'BIT_OR',
62        'BIT_AND',
63    ];
64
65    /** @var array<string,false> */
66    public static $ALLFLAGS = [
67        /*
68         * select ... DISTINCT ...
69         */
70        'distinct' => false,
71
72        /*
73         * drop ... DATABASE ...
74         */
75        'drop_database' => false,
76
77        /*
78         * ... GROUP BY ...
79         */
80        'group' => false,
81
82        /*
83         * ... HAVING ...
84         */
85        'having' => false,
86
87        /*
88         * INSERT ...
89         * or
90         * REPLACE ...
91         * or
92         * DELETE ...
93         */
94        'is_affected' => false,
95
96        /*
97         * select ... PROCEDURE ANALYSE( ... ) ...
98         */
99        'is_analyse' => false,
100
101        /*
102         * select COUNT( ... ) ...
103         */
104        'is_count' => false,
105
106        /*
107         * DELETE ...
108         */
109        'is_delete' => false, // @deprecated; use `querytype`
110
111        /*
112         * EXPLAIN ...
113         */
114        'is_explain' => false, // @deprecated; use `querytype`
115
116        /*
117         * select ... INTO OUTFILE ...
118         */
119        'is_export' => false,
120
121        /*
122         * select FUNC( ... ) ...
123         */
124        'is_func' => false,
125
126        /*
127         * select ... GROUP BY ...
128         * or
129         * select ... HAVING ...
130         */
131        'is_group' => false,
132
133        /*
134         * INSERT ...
135         * or
136         * REPLACE ...
137         * or
138         * LOAD DATA ...
139         */
140        'is_insert' => false,
141
142        /*
143         * ANALYZE ...
144         * or
145         * CHECK ...
146         * or
147         * CHECKSUM ...
148         * or
149         * OPTIMIZE ...
150         * or
151         * REPAIR ...
152         */
153        'is_maint' => false,
154
155        /*
156         * CALL ...
157         */
158        'is_procedure' => false,
159
160        /*
161         * REPLACE ...
162         */
163        'is_replace' => false, // @deprecated; use `querytype`
164
165        /*
166         * SELECT ...
167         */
168        'is_select' => false, // @deprecated; use `querytype`
169
170        /*
171         * SHOW ...
172         */
173        'is_show' => false, // @deprecated; use `querytype`
174
175        /*
176         * Contains a subquery.
177         */
178        'is_subquery' => false,
179
180        /*
181         * ... JOIN ...
182         */
183        'join' => false,
184
185        /*
186         * ... LIMIT ...
187         */
188        'limit' => false,
189
190        /*
191         * TODO
192         */
193        'offset' => false,
194
195        /*
196         * ... ORDER ...
197         */
198        'order' => false,
199
200        /*
201         * The type of the query (which is usually the first keyword of
202         * the statement).
203         */
204        'querytype' => false,
205
206        /*
207         * Whether a page reload is required.
208         */
209        'reload' => false,
210
211        /*
212         * SELECT ... FROM ...
213         */
214        'select_from' => false,
215
216        /*
217         * ... UNION ...
218         */
219        'union' => false,
220    ];
221
222    /**
223     * Gets an array with flags select statement has.
224     *
225     * @param SelectStatement $statement the statement to be processed
226     * @param array           $flags     flags set so far
227     *
228     * @return array
229     */
230    private static function getFlagsSelect($statement, $flags)
231    {
232        $flags['querytype'] = 'SELECT';
233        $flags['is_select'] = true;
234
235        if (! empty($statement->from)) {
236            $flags['select_from'] = true;
237        }
238
239        if ($statement->options->has('DISTINCT')) {
240            $flags['distinct'] = true;
241        }
242
243        if (! empty($statement->group) || ! empty($statement->having)) {
244            $flags['is_group'] = true;
245        }
246
247        if (! empty($statement->into) && ($statement->into->type === 'OUTFILE')) {
248            $flags['is_export'] = true;
249        }
250
251        $expressions = $statement->expr;
252        if (! empty($statement->join)) {
253            foreach ($statement->join as $join) {
254                $expressions[] = $join->expr;
255            }
256        }
257
258        foreach ($expressions as $expr) {
259            if (! empty($expr->function)) {
260                if ($expr->function === 'COUNT') {
261                    $flags['is_count'] = true;
262                } elseif (in_array($expr->function, static::$FUNCTIONS)) {
263                    $flags['is_func'] = true;
264                }
265            }
266
267            if (empty($expr->subquery)) {
268                continue;
269            }
270
271            $flags['is_subquery'] = true;
272        }
273
274        if (! empty($statement->procedure) && ($statement->procedure->name === 'ANALYSE')) {
275            $flags['is_analyse'] = true;
276        }
277
278        if (! empty($statement->group)) {
279            $flags['group'] = true;
280        }
281
282        if (! empty($statement->having)) {
283            $flags['having'] = true;
284        }
285
286        if (! empty($statement->union)) {
287            $flags['union'] = true;
288        }
289
290        if (! empty($statement->join)) {
291            $flags['join'] = true;
292        }
293
294        return $flags;
295    }
296
297    /**
298     * Gets an array with flags this statement has.
299     *
300     * @param Statement|null $statement the statement to be processed
301     * @param bool           $all       if `false`, false values will not be included
302     *
303     * @return array
304     */
305    public static function getFlags($statement, $all = false)
306    {
307        $flags = ['querytype' => false];
308        if ($all) {
309            $flags = self::$ALLFLAGS;
310        }
311
312        if ($statement instanceof AlterStatement) {
313            $flags['querytype'] = 'ALTER';
314            $flags['reload'] = true;
315        } elseif ($statement instanceof CreateStatement) {
316            $flags['querytype'] = 'CREATE';
317            $flags['reload'] = true;
318        } elseif ($statement instanceof AnalyzeStatement) {
319            $flags['querytype'] = 'ANALYZE';
320            $flags['is_maint'] = true;
321        } elseif ($statement instanceof CheckStatement) {
322            $flags['querytype'] = 'CHECK';
323            $flags['is_maint'] = true;
324        } elseif ($statement instanceof ChecksumStatement) {
325            $flags['querytype'] = 'CHECKSUM';
326            $flags['is_maint'] = true;
327        } elseif ($statement instanceof OptimizeStatement) {
328            $flags['querytype'] = 'OPTIMIZE';
329            $flags['is_maint'] = true;
330        } elseif ($statement instanceof RepairStatement) {
331            $flags['querytype'] = 'REPAIR';
332            $flags['is_maint'] = true;
333        } elseif ($statement instanceof CallStatement) {
334            $flags['querytype'] = 'CALL';
335            $flags['is_procedure'] = true;
336        } elseif ($statement instanceof DeleteStatement) {
337            $flags['querytype'] = 'DELETE';
338            $flags['is_delete'] = true;
339            $flags['is_affected'] = true;
340        } elseif ($statement instanceof DropStatement) {
341            $flags['querytype'] = 'DROP';
342            $flags['reload'] = true;
343
344            if ($statement->options->has('DATABASE') || $statement->options->has('SCHEMA')) {
345                $flags['drop_database'] = true;
346            }
347        } elseif ($statement instanceof ExplainStatement) {
348            $flags['querytype'] = 'EXPLAIN';
349            $flags['is_explain'] = true;
350        } elseif ($statement instanceof InsertStatement) {
351            $flags['querytype'] = 'INSERT';
352            $flags['is_affected'] = true;
353            $flags['is_insert'] = true;
354        } elseif ($statement instanceof LoadStatement) {
355            $flags['querytype'] = 'LOAD';
356            $flags['is_affected'] = true;
357            $flags['is_insert'] = true;
358        } elseif ($statement instanceof ReplaceStatement) {
359            $flags['querytype'] = 'REPLACE';
360            $flags['is_affected'] = true;
361            $flags['is_replace'] = true;
362            $flags['is_insert'] = true;
363        } elseif ($statement instanceof SelectStatement) {
364            $flags = self::getFlagsSelect($statement, $flags);
365        } elseif ($statement instanceof ShowStatement) {
366            $flags['querytype'] = 'SHOW';
367            $flags['is_show'] = true;
368        } elseif ($statement instanceof UpdateStatement) {
369            $flags['querytype'] = 'UPDATE';
370            $flags['is_affected'] = true;
371        } elseif ($statement instanceof SetStatement) {
372            $flags['querytype'] = 'SET';
373        }
374
375        if (
376            ($statement instanceof SelectStatement)
377            || ($statement instanceof UpdateStatement)
378            || ($statement instanceof DeleteStatement)
379        ) {
380            if (! empty($statement->limit)) {
381                $flags['limit'] = true;
382            }
383
384            if (! empty($statement->order)) {
385                $flags['order'] = true;
386            }
387        }
388
389        return $flags;
390    }
391
392    /**
393     * Parses a query and gets all information about it.
394     *
395     * @param string $query the query to be parsed
396     *
397     * @return array The array returned is the one returned by
398     *               `static::getFlags()`, with the following keys added:
399     *               - parser - the parser used to analyze the query;
400     *               - statement - the first statement resulted from parsing;
401     *               - select_tables - the real name of the tables selected;
402     *               if there are no table names in the `SELECT`
403     *               expressions, the table names are fetched from the
404     *               `FROM` expressions
405     *               - select_expr - selected expressions
406     */
407    public static function getAll($query)
408    {
409        $parser = new Parser($query);
410
411        if (empty($parser->statements[0])) {
412            return static::getFlags(null, true);
413        }
414
415        $statement = $parser->statements[0];
416
417        $ret = static::getFlags($statement, true);
418
419        $ret['parser'] = $parser;
420        $ret['statement'] = $statement;
421
422        if ($statement instanceof SelectStatement) {
423            $ret['select_tables'] = [];
424            $ret['select_expr'] = [];
425
426            // Finding tables' aliases and their associated real names.
427            $tableAliases = [];
428            foreach ($statement->from as $expr) {
429                if (! isset($expr->table, $expr->alias) || ($expr->table === '') || ($expr->alias === '')) {
430                    continue;
431                }
432
433                $tableAliases[$expr->alias] = [
434                    $expr->table,
435                    $expr->database ?? null,
436                ];
437            }
438
439            // Trying to find selected tables only from the select expression.
440            // Sometimes, this is not possible because the tables aren't defined
441            // explicitly (e.g. SELECT * FROM film, SELECT film_id FROM film).
442            foreach ($statement->expr as $expr) {
443                if (isset($expr->table) && ($expr->table !== '')) {
444                    if (isset($tableAliases[$expr->table])) {
445                        $arr = $tableAliases[$expr->table];
446                    } else {
447                        $arr = [
448                            $expr->table,
449                            isset($expr->database) && ($expr->database !== '') ?
450                                $expr->database : null,
451                        ];
452                    }
453
454                    if (! in_array($arr, $ret['select_tables'])) {
455                        $ret['select_tables'][] = $arr;
456                    }
457                } else {
458                    $ret['select_expr'][] = $expr->expr;
459                }
460            }
461
462            // If no tables names were found in the SELECT clause or if there
463            // are expressions like * or COUNT(*), etc. tables names should be
464            // extracted from the FROM clause.
465            if (empty($ret['select_tables'])) {
466                foreach ($statement->from as $expr) {
467                    if (! isset($expr->table) || ($expr->table === '')) {
468                        continue;
469                    }
470
471                    $arr = [
472                        $expr->table,
473                        isset($expr->database) && ($expr->database !== '') ?
474                            $expr->database : null,
475                    ];
476                    if (in_array($arr, $ret['select_tables'])) {
477                        continue;
478                    }
479
480                    $ret['select_tables'][] = $arr;
481                }
482            }
483        }
484
485        return $ret;
486    }
487
488    /**
489     * Gets a list of all tables used in this statement.
490     *
491     * @param Statement $statement statement to be scanned
492     *
493     * @return array
494     */
495    public static function getTables($statement)
496    {
497        $expressions = [];
498
499        if (($statement instanceof InsertStatement) || ($statement instanceof ReplaceStatement)) {
500            $expressions = [$statement->into->dest];
501        } elseif ($statement instanceof UpdateStatement) {
502            $expressions = $statement->tables;
503        } elseif (($statement instanceof SelectStatement) || ($statement instanceof DeleteStatement)) {
504            $expressions = $statement->from;
505        } elseif (($statement instanceof AlterStatement) || ($statement instanceof TruncateStatement)) {
506            $expressions = [$statement->table];
507        } elseif ($statement instanceof DropStatement) {
508            if (! $statement->options->has('TABLE')) {
509                // No tables are dropped.
510                return [];
511            }
512
513            $expressions = $statement->fields;
514        } elseif ($statement instanceof RenameStatement) {
515            foreach ($statement->renames as $rename) {
516                $expressions[] = $rename->old;
517            }
518        }
519
520        $ret = [];
521        foreach ($expressions as $expr) {
522            if (empty($expr->table)) {
523                continue;
524            }
525
526            $expr->expr = null; // Force rebuild.
527            $expr->alias = null; // Aliases are not required.
528            $ret[] = Expression::build($expr);
529        }
530
531        return $ret;
532    }
533
534    /**
535     * Gets a specific clause.
536     *
537     * @param Statement  $statement the parsed query that has to be modified
538     * @param TokensList $list      the list of tokens
539     * @param string     $clause    the clause to be returned
540     * @param int|string $type      The type of the search.
541     *                              If int,
542     *                              -1 for everything that was before
543     *                              0 only for the clause
544     *                              1 for everything after
545     *                              If string, the name of the first clause that
546     *                              should not be included.
547     * @param bool       $skipFirst whether to skip the first keyword in clause
548     *
549     * @return string
550     */
551    public static function getClause($statement, $list, $clause, $type = 0, $skipFirst = true)
552    {
553        /**
554         * The index of the current clause.
555         *
556         * @var int
557         */
558        $currIdx = 0;
559
560        /**
561         * The count of brackets.
562         * We keep track of them so we won't insert the clause in a subquery.
563         *
564         * @var int
565         */
566        $brackets = 0;
567
568        /**
569         * The string to be returned.
570         *
571         * @var string
572         */
573        $ret = '';
574
575        /**
576         * The clauses of this type of statement and their index.
577         *
578         * @var array
579         */
580        $clauses = array_flip(array_keys($statement->getClauses()));
581
582        /**
583         * Lexer used for lexing the clause.
584         *
585         * @var Lexer
586         */
587        $lexer = new Lexer($clause);
588
589        /**
590         * The type of this clause.
591         *
592         * @var string
593         */
594        $clauseType = $lexer->list->getNextOfType(Token::TYPE_KEYWORD)->keyword;
595
596        /**
597         * The index of this clause.
598         *
599         * @var int
600         */
601        $clauseIdx = $clauses[$clauseType] ?? -1;
602
603        $firstClauseIdx = $clauseIdx;
604        $lastClauseIdx = $clauseIdx;
605
606        // Determining the behavior of this function.
607        if ($type === -1) {
608            $firstClauseIdx = -1; // Something small enough.
609            $lastClauseIdx = $clauseIdx - 1;
610        } elseif ($type === 1) {
611            $firstClauseIdx = $clauseIdx + 1;
612            $lastClauseIdx = 10000; // Something big enough.
613        } elseif (is_string($type) && isset($clauses[$type])) {
614            if ($clauses[$type] > $clauseIdx) {
615                $firstClauseIdx = $clauseIdx + 1;
616                $lastClauseIdx = $clauses[$type] - 1;
617            } else {
618                $firstClauseIdx = $clauses[$type] + 1;
619                $lastClauseIdx = $clauseIdx - 1;
620            }
621        }
622
623        // This option is unavailable for multiple clauses.
624        if ($type !== 0) {
625            $skipFirst = false;
626        }
627
628        for ($i = $statement->first; $i <= $statement->last; ++$i) {
629            $token = $list->tokens[$i];
630
631            if ($token->type === Token::TYPE_COMMENT) {
632                continue;
633            }
634
635            if ($token->type === Token::TYPE_OPERATOR) {
636                if ($token->value === '(') {
637                    ++$brackets;
638                } elseif ($token->value === ')') {
639                    --$brackets;
640                }
641            }
642
643            if ($brackets === 0) {
644                // Checking if the section was changed.
645                if (
646                    ($token->type === Token::TYPE_KEYWORD)
647                    && isset($clauses[$token->keyword])
648                    && ($clauses[$token->keyword] >= $currIdx)
649                ) {
650                    $currIdx = $clauses[$token->keyword];
651                    if ($skipFirst && ($currIdx === $clauseIdx)) {
652                        // This token is skipped (not added to the old
653                        // clause) because it will be replaced.
654                        continue;
655                    }
656                }
657            }
658
659            if (($firstClauseIdx > $currIdx) || ($currIdx > $lastClauseIdx)) {
660                continue;
661            }
662
663            $ret .= $token->token;
664        }
665
666        return trim($ret);
667    }
668
669    /**
670     * Builds a query by rebuilding the statement from the tokens list supplied
671     * and replaces a clause.
672     *
673     * It is a very basic version of a query builder.
674     *
675     * @param Statement  $statement the parsed query that has to be modified
676     * @param TokensList $list      the list of tokens
677     * @param string     $old       The type of the clause that should be
678     *                              replaced. This can be an entire clause.
679     * @param string     $new       The new clause. If this parameter is omitted
680     *                              it is considered to be equal with `$old`.
681     * @param bool       $onlyType  whether only the type of the clause should
682     *                              be replaced or the entire clause
683     *
684     * @return string
685     */
686    public static function replaceClause($statement, $list, $old, $new = null, $onlyType = false)
687    {
688        // TODO: Update the tokens list and the statement.
689
690        if ($new === null) {
691            $new = $old;
692        }
693
694        if ($onlyType) {
695            return static::getClause($statement, $list, $old, -1, false) . ' ' .
696                $new . ' ' . static::getClause($statement, $list, $old, 0) . ' ' .
697                static::getClause($statement, $list, $old, 1, false);
698        }
699
700        return static::getClause($statement, $list, $old, -1, false) . ' ' .
701            $new . ' ' . static::getClause($statement, $list, $old, 1, false);
702    }
703
704    /**
705     * Builds a query by rebuilding the statement from the tokens list supplied
706     * and replaces multiple clauses.
707     *
708     * @param Statement  $statement the parsed query that has to be modified
709     * @param TokensList $list      the list of tokens
710     * @param array      $ops       Clauses to be replaced. Contains multiple
711     *                              arrays having two values: [$old, $new].
712     *                              Clauses must be sorted.
713     *
714     * @return string
715     */
716    public static function replaceClauses($statement, $list, array $ops)
717    {
718        $count = count($ops);
719
720        // Nothing to do.
721        if ($count === 0) {
722            return '';
723        }
724
725        /**
726         * Value to be returned.
727         *
728         * @var string
729         */
730        $ret = '';
731
732        // If there is only one clause, `replaceClause()` should be used.
733        if ($count === 1) {
734            return static::replaceClause($statement, $list, $ops[0][0], $ops[0][1]);
735        }
736
737        // Adding everything before first replacement.
738        $ret .= static::getClause($statement, $list, $ops[0][0], -1) . ' ';
739
740        // Doing replacements.
741        foreach ($ops as $i => $clause) {
742            $ret .= $clause[1] . ' ';
743
744            // Adding everything between this and next replacement.
745            if ($i + 1 === $count) {
746                continue;
747            }
748
749            $ret .= static::getClause($statement, $list, $clause[0], $ops[$i + 1][0]) . ' ';
750        }
751
752        // Adding everything after the last replacement.
753        return $ret . static::getClause($statement, $list, $ops[$count - 1][0], 1);
754    }
755
756    /**
757     * Gets the first full statement in the query.
758     *
759     * @param string $query     the query to be analyzed
760     * @param string $delimiter the delimiter to be used
761     *
762     * @return array array containing the first full query, the
763     *               remaining part of the query and the last
764     *               delimiter
765     */
766    public static function getFirstStatement($query, $delimiter = null)
767    {
768        $lexer = new Lexer($query, false, $delimiter);
769        $list = $lexer->list;
770
771        /**
772         * Whether a full statement was found.
773         *
774         * @var bool
775         */
776        $fullStatement = false;
777
778        /**
779         * The first full statement.
780         *
781         * @var string
782         */
783        $statement = '';
784
785        for ($list->idx = 0; $list->idx < $list->count; ++$list->idx) {
786            $token = $list->tokens[$list->idx];
787
788            if ($token->type === Token::TYPE_COMMENT) {
789                continue;
790            }
791
792            $statement .= $token->token;
793
794            if (($token->type === Token::TYPE_DELIMITER) && ! empty($token->token)) {
795                $delimiter = $token->token;
796                $fullStatement = true;
797                break;
798            }
799        }
800
801        // No statement was found so we return the entire query as being the
802        // remaining part.
803        if (! $fullStatement) {
804            return [
805                null,
806                $query,
807                $delimiter,
808            ];
809        }
810
811        // At least one query was found so we have to build the rest of the
812        // remaining query.
813        $query = '';
814        for (++$list->idx; $list->idx < $list->count; ++$list->idx) {
815            $query .= $list->tokens[$list->idx]->token;
816        }
817
818        return [
819            trim($statement),
820            $query,
821            $delimiter,
822        ];
823    }
824
825    /**
826     * Gets a starting offset of a specific clause.
827     *
828     * @param Statement  $statement the parsed query that has to be modified
829     * @param TokensList $list      the list of tokens
830     * @param string     $clause    the clause to be returned
831     *
832     * @return int
833     */
834    public static function getClauseStartOffset($statement, $list, $clause)
835    {
836        /**
837         * The count of brackets.
838         * We keep track of them so we won't insert the clause in a subquery.
839         *
840         * @var int
841         */
842        $brackets = 0;
843
844        /**
845         * The clauses of this type of statement and their index.
846         *
847         * @var array
848         */
849        $clauses = array_flip(array_keys($statement->getClauses()));
850
851        for ($i = $statement->first; $i <= $statement->last; ++$i) {
852            $token = $list->tokens[$i];
853
854            if ($token->type === Token::TYPE_COMMENT) {
855                continue;
856            }
857
858            if ($token->type === Token::TYPE_OPERATOR) {
859                if ($token->value === '(') {
860                    ++$brackets;
861                } elseif ($token->value === ')') {
862                    --$brackets;
863                }
864            }
865
866            if ($brackets !== 0) {
867                continue;
868            }
869
870            if (
871                ($token->type === Token::TYPE_KEYWORD)
872                && isset($clauses[$token->keyword])
873                && ($clause === $token->keyword)
874            ) {
875                return $i;
876            }
877
878            if ($token->keyword === 'UNION') {
879                return -1;
880            }
881        }
882
883        return -1;
884    }
885}
886