1 /* Copyright 1992, 1993, 1994 Henry Spencer.  All rights reserved.
2    See file COPYRIGHT for details.
3 
4    This file was modified by Oracle on 2015-05-18 for 32-bit compatibility.
5 
6    Modifications Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights
7    reserved. */
8 
9 #include <my_global.h>
10 #include <m_string.h>
11 #include <m_ctype.h>
12 #ifdef _WIN32
13 #include  <limits.h>
14 #endif
15 
16 #include "my_regex.h"
17 #include "utils.h"
18 #include "regex2.h"
19 
20 #include "cclass.h"
21 #include "cname.h"
22 
23 /*
24  * parse structure, passed up and down to avoid global variables and
25  * other clumsinesses
26  */
27 struct parse {
28 	char *next;		/* next character in RE */
29 	char *end;		/* end of string (-> NUL normally) */
30 	int error;		/* has an error been seen? */
31 	sop *strip;		/* malloced strip */
32 	sopno ssize;		/* malloced strip size (allocated) */
33 	sopno slen;		/* malloced strip length (used) */
34 	int ncsalloc;		/* number of csets allocated */
35 	struct re_guts *g;
36 #	define	NPAREN	10	/* we need to remember () 1-9 for back refs */
37 	sopno pbegin[NPAREN];	/* -> ( ([0] unused) */
38 	sopno pend[NPAREN];	/* -> ) ([0] unused) */
39 	const CHARSET_INFO *charset; /* for ctype things  */
40 };
41 
42 /* Check if there is enough stack space for recursion. */
43 my_regex_stack_check_t my_regex_enough_mem_in_stack= NULL;
44 
45 #include "regcomp.ih"
46 
47 static char nuls[10];		/* place to point scanner in event of error */
48 
49 struct cclass cclasses[CCLASS_LAST+1]= {
50   { "alnum",	"","", _MY_U | _MY_L | _MY_NMR},
51   { "alpha",	"","", _MY_U | _MY_L },
52   { "blank",	"","", _MY_B },
53   { "cntrl",	"","", _MY_CTR },
54   { "digit",	"","", _MY_NMR },
55   { "graph",	"","", _MY_PNT | _MY_U | _MY_L | _MY_NMR},
56   { "lower",	"","", _MY_L },
57   { "print",	"","", _MY_PNT | _MY_U | _MY_L | _MY_NMR | _MY_B },
58   { "punct",	"","", _MY_PNT },
59   { "space",	"","", _MY_SPC },
60   { "upper",	"","", _MY_U },
61   { "xdigit",	"","", _MY_X },
62   { NULL,NULL,NULL, 0 }
63 };
64 
65 /*
66  * macros for use with parse structure
67  * BEWARE:  these know that the parse structure is named `p' !!!
68  */
69 #define	PEEK()	(*p->next)
70 #define	PEEK2()	(*(p->next+1))
71 #define	MORE()	(p->next < p->end)
72 #define	MORE2()	(p->next+1 < p->end)
73 #define	SEE(c)	(MORE() && PEEK() == (c))
74 #define	SEETWO(a, b)	(MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
75 #define	EAT(c)	((SEE(c)) ? (NEXT(), 1) : 0)
76 #define	EATTWO(a, b)	((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
77 #define	NEXT()	(p->next++)
78 #define	NEXT2()	(p->next += 2)
79 #define	NEXTn(n)	(p->next += (n))
80 #define	GETNEXT()	(*p->next++)
81 #define	SETERROR(e)	seterr(p, (e))
82 #define	REQUIRE(co, e)	((co) || SETERROR(e))
83 #define	MUSTSEE(c, e)	(REQUIRE(MORE() && PEEK() == (c), e))
84 #define	MUSTEAT(c, e)	(REQUIRE(MORE() && GETNEXT() == (c), e))
85 #define	MUSTNOTSEE(c, e)	(REQUIRE(!MORE() || PEEK() != (c), e))
86 #define	EMIT(op, sopnd)	doemit(p, (sop)(op), (size_t)(sopnd))
87 #define	INSERT(op, pos)	doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
88 #define	AHEAD(pos)		dofwd(p, pos, HERE()-(pos))
89 #define	ASTERN(sop, pos)	EMIT(sop, HERE()-pos)
90 #define	HERE()		(p->slen)
91 #define	THERE()		(p->slen - 1)
92 #define	THERETHERE()	(p->slen - 2)
93 #define	DROP(n)	(p->slen -= (n))
94 
95 #ifndef NDEBUG
96 static int never = 0;		/* for use in asserts; shuts lint up */
97 #else
98 #define	never	0		/* some <assert.h>s have bugs too */
99 #endif
100 
101 /*
102  - regcomp - interface for parser and compilation
103  = extern int regcomp(regex_t *, const char *, int);
104  = #define	MY_REG_BASIC	0000
105  = #define	MY_REG_EXTENDED	0001
106  = #define	MY_REG_ICASE	0002
107  = #define	MY_REG_NOSUB	0004
108  = #define	MY_REG_NEWLINE	0010
109  = #define	MY_REG_NOSPEC	0020
110  = #define	MY_REG_PEND	0040
111  = #define	MY_REG_DUMP	0200
112  */
113 int				/* 0 success, otherwise MY_REG_something */
my_regcomp(preg,pattern,cflags,charset)114 my_regcomp(preg, pattern, cflags, charset)
115 my_regex_t *preg;
116 const char *pattern;
117 int cflags;
118 const CHARSET_INFO *charset;
119 {
120 	struct parse pa;
121 	struct re_guts *g;
122 	struct parse *p = &pa;
123 	int i;
124 	size_t len;
125 #ifdef REDEBUG
126 #	define	GOODFLAGS(f)	(f)
127 #else
128 #	define	GOODFLAGS(f)	((f)&~MY_REG_DUMP)
129 #endif
130 
131 	my_regex_init(charset, NULL);	/* Init cclass if neaded */
132 	preg->charset=charset;
133 	cflags = GOODFLAGS(cflags);
134 	if ((cflags&MY_REG_EXTENDED) && (cflags&MY_REG_NOSPEC))
135 		return(MY_REG_INVARG);
136 
137 	if (cflags&MY_REG_PEND) {
138 		if (preg->re_endp < pattern)
139 			return(MY_REG_INVARG);
140 		len = preg->re_endp - pattern;
141 	} else
142 		len = strlen((char *)pattern);
143 
144 	/*
145 	 Find the maximum len we can safely process
146 	 without a rollover and a mis-malloc.
147 	 p->ssize is a sopno is a long (32+ bit signed);
148 	 size_t is 16+ bit unsigned.
149 	*/
150 	{
151 	  size_t new_ssize = len / (size_t)2 * (size_t)3 + (size_t)1; /* ugh */
152 	  if ((new_ssize < len) ||	/* size_t rolled over */
153 	      ((SIZE_T_MAX / sizeof(sop)) < new_ssize) ||	/* malloc arg */
154 	      (new_ssize > LONG_MAX))	/* won't fit in ssize */
155 		return(MY_REG_ESPACE);	/* MY_REG_ESPACE or MY_REG_INVARG */
156 	  p->ssize = new_ssize;
157 	}
158 
159 	/* do the mallocs early so failure handling is easy */
160 	g = (struct re_guts *)malloc(sizeof(struct re_guts) +
161 							(NC-1)*sizeof(cat_t));
162 	if (g == NULL)
163 		return(MY_REG_ESPACE);
164 	p->strip = (sop *)malloc(p->ssize * sizeof(sop));
165 	p->slen = 0;
166 	if (p->strip == NULL) {
167 		free((char *)g);
168 		return(MY_REG_ESPACE);
169 	}
170 
171 	/* set things up */
172 	p->g = g;
173 	p->next = (char *)pattern;	/* convenience; we do not modify it */
174 	p->end = p->next + len;
175 	p->error = 0;
176 	p->ncsalloc = 0;
177 	p->charset = preg->charset;
178 	for (i = 0; i < NPAREN; i++) {
179 		p->pbegin[i] = 0;
180 		p->pend[i] = 0;
181 	}
182 	g->csetsize = NC;
183 	g->sets = NULL;
184 	g->setbits = NULL;
185 	g->ncsets = 0;
186 	g->cflags = cflags;
187 	g->iflags = 0;
188 	g->nbol = 0;
189 	g->neol = 0;
190 	g->must = NULL;
191 	g->mlen = 0;
192 	g->nsub = 0;
193 	g->ncategories = 1;	/* category 0 is "everything else" */
194 	g->categories = &g->catspace[-(CHAR_MIN)];
195 	(void) memset((char *)g->catspace, 0, NC*sizeof(cat_t));
196 	g->backrefs = 0;
197 
198 	/* do it */
199 	EMIT(OEND, 0);
200 	g->firststate = THERE();
201 	if (cflags&MY_REG_EXTENDED)
202 		p_ere(p, OUT);
203 	else if (cflags&MY_REG_NOSPEC)
204 		p_str(p);
205 	else
206 		p_bre(p, OUT, OUT);
207 	EMIT(OEND, 0);
208 	g->laststate = THERE();
209 
210 	/* tidy up loose ends and fill things in */
211 	categorize(p, g);
212 	stripsnug(p, g);
213 	findmust(p, g);
214 	g->nplus = pluscount(p, g);
215 	g->magic = MAGIC2;
216 	preg->re_nsub = g->nsub;
217 	preg->re_g = g;
218 	preg->re_magic = MAGIC1;
219 #ifndef REDEBUG
220 	/* not debugging, so can't rely on the assert() in regexec() */
221 	if (g->iflags&BAD)
222 		SETERROR(MY_REG_ASSERT);
223 #endif
224 
225 	/* win or lose, we're done */
226 	if (p->error != 0)	/* lose */
227 		my_regfree(preg);
228 	return(p->error);
229 }
230 
231 /*
232  - p_ere - ERE parser top level, concatenation and alternation
233  == static void p_ere(register struct parse *p, int stop);
234  */
235 static void
p_ere(p,stop)236 p_ere(p, stop)
237 struct parse *p;
238 int stop;			/* character this ERE should end at */
239 {
240 	char c;
241 	sopno prevback= 0;
242 	sopno prevfwd= 0;
243 	sopno conc;
244 	int first = 1;		/* is this the first alternative? */
245 
246 	for (;;) {
247 		/* do a bunch of concatenated expressions */
248 		conc = HERE();
249 		while (MORE() && (c = PEEK()) != '|' && c != stop)
250 		{
251 		  if (my_regex_enough_mem_in_stack &&
252 		      my_regex_enough_mem_in_stack(0))
253 		  {
254 		    SETERROR(MY_REG_ESPACE);
255 		    return;
256 		  }
257 		  p_ere_exp(p);
258 		}
259 		if(REQUIRE(HERE() != conc, MY_REG_EMPTY)) {}/* require nonempty */
260 
261 		if (!EAT('|'))
262 			break;		/* NOTE BREAK OUT */
263 
264 		if (first) {
265 			INSERT(OCH_, conc);	/* offset is wrong */
266 			prevfwd = conc;
267 			prevback = conc;
268 			first = 0;
269 		}
270 		ASTERN(OOR1, prevback);
271 		prevback = THERE();
272 		AHEAD(prevfwd);			/* fix previous offset */
273 		prevfwd = HERE();
274 		EMIT(OOR2, 0);			/* offset is very wrong */
275 	}
276 
277 	if (!first) {		/* tail-end fixups */
278 		AHEAD(prevfwd);
279 		ASTERN(O_CH, prevback);
280 	}
281 
282 	assert(!MORE() || SEE(stop));
283 }
284 
285 /*
286  - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
287  == static void p_ere_exp(register struct parse *p);
288  */
289 static void
p_ere_exp(p)290 p_ere_exp(p)
291 struct parse *p;
292 {
293 	char c;
294 	sopno pos;
295 	int count;
296 	int count2;
297 	sopno subno;
298 	int wascaret = 0;
299 
300 	assert(MORE());		/* caller should have ensured this */
301 	c = GETNEXT();
302 
303 	pos = HERE();
304 	switch (c) {
305 	case '(':
306 		if(REQUIRE(MORE(), MY_REG_EPAREN)) {}
307 		p->g->nsub++;
308 		subno = (sopno) p->g->nsub;
309 		if (subno < NPAREN)
310 		        p->pbegin[subno] = HERE();
311 		EMIT(OLPAREN, subno);
312 		if (!SEE(')'))
313 			p_ere(p, ')');
314 		if (subno < NPAREN) {
315 			p->pend[subno] = HERE();
316 			assert(p->pend[subno] != 0);
317 		}
318 		EMIT(ORPAREN, subno);
319 		if(MUSTEAT(')', MY_REG_EPAREN)) {}
320 		break;
321 	case '^':
322 		EMIT(OBOL, 0);
323 		p->g->iflags |= USEBOL;
324 		p->g->nbol++;
325 		wascaret = 1;
326 		break;
327 	case '$':
328 		EMIT(OEOL, 0);
329 		p->g->iflags |= USEEOL;
330 		p->g->neol++;
331 		break;
332 	case '|':
333 		SETERROR(MY_REG_EMPTY);
334 		break;
335 	case '*':
336 	case '+':
337 	case '?':
338 		SETERROR(MY_REG_BADRPT);
339 		break;
340 	case '.':
341 		if (p->g->cflags&MY_REG_NEWLINE)
342 			nonnewline(p);
343 		else
344 			EMIT(OANY, 0);
345 		break;
346 	case '[':
347 		p_bracket(p);
348 		break;
349 	case '\\':
350 		if(REQUIRE(MORE(), MY_REG_EESCAPE)) {}
351 		c = GETNEXT();
352 		ordinary(p, c);
353 		break;
354 	case '{':		/* okay as ordinary except if digit follows */
355 		if(REQUIRE(!MORE() || !my_isdigit(p->charset,PEEK()), MY_REG_BADRPT)) {}
356 		/* FALLTHROUGH */
357 	default:
358 		ordinary(p, c);
359 		break;
360 	}
361 
362 	if (!MORE())
363 		return;
364 	c = PEEK();
365 	/* we call { a repetition if followed by a digit */
366 	if (!( c == '*' || c == '+' || c == '?' ||
367 				(c == '{' && MORE2() &&
368 				 my_isdigit(p->charset,PEEK2())) ))
369 		return;		/* no repetition, we're done */
370 	NEXT();
371 
372 	if(REQUIRE(!wascaret, MY_REG_BADRPT)) {}
373 	switch (c) {
374 	case '*':	/* implemented as +? */
375 		/* this case does not require the (y|) trick, noKLUDGE */
376 		INSERT(OPLUS_, pos);
377 		ASTERN(O_PLUS, pos);
378 		INSERT(OQUEST_, pos);
379 		ASTERN(O_QUEST, pos);
380 		break;
381 	case '+':
382 		INSERT(OPLUS_, pos);
383 		ASTERN(O_PLUS, pos);
384 		break;
385 	case '?':
386 		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
387 		INSERT(OCH_, pos);		/* offset slightly wrong */
388 		ASTERN(OOR1, pos);		/* this one's right */
389 		AHEAD(pos);			/* fix the OCH_ */
390 		EMIT(OOR2, 0);			/* offset very wrong... */
391 		AHEAD(THERE());			/* ...so fix it */
392 		ASTERN(O_CH, THERETHERE());
393 		break;
394 	case '{':
395 		count = p_count(p);
396 		if (EAT(',')) {
397 			if (my_isdigit(p->charset,PEEK())) {
398 				count2 = p_count(p);
399 				if(REQUIRE(count <= count2, MY_REG_BADBR)) {}
400 			} else		/* single number with comma */
401 				count2 = RE_INFINITY;
402 		} else		/* just a single number */
403 			count2 = count;
404 		repeat(p, pos, count, count2);
405 		if (!EAT('}')) {	/* error heuristics */
406 			while (MORE() && PEEK() != '}')
407 				NEXT();
408 			if(REQUIRE(MORE(), MY_REG_EBRACE)) {}
409 			SETERROR(MY_REG_BADBR);
410 		}
411 		break;
412 	}
413 
414 	if (!MORE())
415 		return;
416 	c = PEEK();
417 	if (!( c == '*' || c == '+' || c == '?' ||
418 				(c == '{' && MORE2() &&
419 				 my_isdigit(p->charset,PEEK2())) ) )
420 		return;
421 	SETERROR(MY_REG_BADRPT);
422 }
423 
424 /*
425  - p_str - string (no metacharacters) "parser"
426  == static void p_str(register struct parse *p);
427  */
428 static void
p_str(p)429 p_str(p)
430 struct parse *p;
431 {
432 	if(REQUIRE(MORE(), MY_REG_EMPTY)) {}
433 	while (MORE())
434 		ordinary(p, GETNEXT());
435 }
436 
437 /*
438  - p_bre - BRE parser top level, anchoring and concatenation
439  == static void p_bre(register struct parse *p, register int end1, \
440  ==	register int end2);
441  * Giving end1 as OUT essentially eliminates the end1/end2 check.
442  *
443  * This implementation is a bit of a kludge, in that a trailing $ is first
444  * taken as an ordinary character and then revised to be an anchor.  The
445  * only undesirable side effect is that '$' gets included as a character
446  * category in such cases.  This is fairly harmless; not worth fixing.
447  * The amount of lookahead needed to avoid this kludge is excessive.
448  */
449 static void
p_bre(p,end1,end2)450 p_bre(p, end1, end2)
451 struct parse *p;
452 int end1;		/* first terminating character */
453 int end2;		/* second terminating character */
454 {
455 	sopno start = HERE();
456 	int first = 1;			/* first subexpression? */
457 	int wasdollar = 0;
458 
459 	if (EAT('^')) {
460 		EMIT(OBOL, 0);
461 		p->g->iflags |= USEBOL;
462 		p->g->nbol++;
463 	}
464 	while (MORE() && !SEETWO(end1, end2)) {
465 		wasdollar = p_simp_re(p, first);
466 		first = 0;
467 	}
468 	if (wasdollar) {	/* oops, that was a trailing anchor */
469 		DROP(1);
470 		EMIT(OEOL, 0);
471 		p->g->iflags |= USEEOL;
472 		p->g->neol++;
473 	}
474 
475 	if(REQUIRE(HERE() != start, MY_REG_EMPTY)) {}	/* require nonempty */
476 }
477 
478 /*
479  - p_simp_re - parse a simple RE, an atom possibly followed by a repetition
480  == static int p_simp_re(register struct parse *p, int starordinary);
481  */
482 static int			/* was the simple RE an unbackslashed $? */
p_simp_re(p,starordinary)483 p_simp_re(p, starordinary)
484 struct parse *p;
485 int starordinary;		/* is a leading * an ordinary character? */
486 {
487 	int c;
488 	int count;
489 	int count2;
490 	sopno pos;
491 	int i;
492 	sopno subno;
493 #	define	BACKSL	(1<<CHAR_BIT)
494 
495 	pos = HERE();		/* repetion op, if any, covers from here */
496 
497 	assert(MORE());		/* caller should have ensured this */
498 	c = GETNEXT();
499 	if (c == '\\') {
500 		if(REQUIRE(MORE(), MY_REG_EESCAPE)) {}
501 		c = BACKSL | (unsigned char)GETNEXT();
502 	}
503 	switch (c) {
504 	case '.':
505 		if (p->g->cflags&MY_REG_NEWLINE)
506 			nonnewline(p);
507 		else
508 			EMIT(OANY, 0);
509 		break;
510 	case '[':
511 		p_bracket(p);
512 		break;
513 	case BACKSL|'{':
514 		SETERROR(MY_REG_BADRPT);
515 		break;
516 	case BACKSL|'(':
517 		p->g->nsub++;
518 		subno = (sopno) p->g->nsub;
519 		if (subno < NPAREN)
520 			p->pbegin[subno] = HERE();
521 		EMIT(OLPAREN, subno);
522 		/* the MORE here is an error heuristic */
523 		if (MORE() && !SEETWO('\\', ')'))
524 			p_bre(p, '\\', ')');
525 		if (subno < NPAREN) {
526 			p->pend[subno] = HERE();
527 			assert(p->pend[subno] != 0);
528 		}
529 		EMIT(ORPAREN, subno);
530 		if(REQUIRE(EATTWO('\\', ')'), MY_REG_EPAREN)) {}
531 		break;
532 	case BACKSL|')':	/* should not get here -- must be user */
533 	case BACKSL|'}':
534 		SETERROR(MY_REG_EPAREN);
535 		break;
536 	case BACKSL|'1':
537 	case BACKSL|'2':
538 	case BACKSL|'3':
539 	case BACKSL|'4':
540 	case BACKSL|'5':
541 	case BACKSL|'6':
542 	case BACKSL|'7':
543 	case BACKSL|'8':
544 	case BACKSL|'9':
545 		i = (c&~BACKSL) - '0';
546 		assert(i < NPAREN);
547 		if (p->pend[i] != 0) {
548 			assert((uint) i <= p->g->nsub);
549 			EMIT(OBACK_, i);
550 			assert(p->pbegin[i] != 0);
551 			assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
552 			assert(OP(p->strip[p->pend[i]]) == ORPAREN);
553 			(void) dupl(p, p->pbegin[i]+1, p->pend[i]);
554                         if (p->error != 0)
555                           break;        /* purecov: inspected */
556 			EMIT(O_BACK, i);
557 		} else
558 			SETERROR(MY_REG_ESUBREG);
559 		p->g->backrefs = 1;
560 		break;
561 	case '*':
562 		if(REQUIRE(starordinary, MY_REG_BADRPT)) {}
563 		/* FALLTHROUGH */
564 	default:
565 		ordinary(p, c &~ BACKSL);
566 		break;
567 	}
568 
569 	if (EAT('*')) {		/* implemented as +? */
570 		/* this case does not require the (y|) trick, noKLUDGE */
571 		INSERT(OPLUS_, pos);
572 		ASTERN(O_PLUS, pos);
573 		INSERT(OQUEST_, pos);
574 		ASTERN(O_QUEST, pos);
575 	} else if (EATTWO('\\', '{')) {
576 		count = p_count(p);
577 		if (EAT(',')) {
578 			if (MORE() && my_isdigit(p->charset,PEEK())) {
579 				count2 = p_count(p);
580 				if(REQUIRE(count <= count2, MY_REG_BADBR)) {}
581 			} else		/* single number with comma */
582 				count2 = RE_INFINITY;
583 		} else		/* just a single number */
584 			count2 = count;
585 		repeat(p, pos, count, count2);
586 		if (!EATTWO('\\', '}')) {	/* error heuristics */
587 			while (MORE() && !SEETWO('\\', '}'))
588 				NEXT();
589 			if(REQUIRE(MORE(), MY_REG_EBRACE)) {}
590 			SETERROR(MY_REG_BADBR);
591 		}
592 	} else if (c == (unsigned char)'$')	/* $ (but not \$) ends it */
593 		return(1);
594 
595 	return(0);
596 }
597 
598 /*
599  - p_count - parse a repetition count
600  == static int p_count(register struct parse *p);
601  */
602 static int			/* the value */
p_count(p)603 p_count(p)
604 struct parse *p;
605 {
606 	int count = 0;
607 	int ndigits = 0;
608 
609 	while (MORE() && my_isdigit(p->charset,PEEK()) && count <= DUPMAX) {
610 		count = count*10 + (GETNEXT() - '0');
611 		ndigits++;
612 	}
613 
614 	if(REQUIRE(ndigits > 0 && count <= DUPMAX, MY_REG_BADBR)) {}
615 	return(count);
616 }
617 
618 /*
619  - p_bracket - parse a bracketed character list
620  == static void p_bracket(register struct parse *p);
621  *
622  * Note a significant property of this code:  if the allocset() did SETERROR,
623  * no set operations are done.
624  */
625 static void
p_bracket(p)626 p_bracket(p)
627 struct parse *p;
628 {
629 	cset *cs = allocset(p);
630 	int invert = 0;
631 
632 	/* Dept of Truly Sickening Special-Case Kludges */
633 	if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
634 		EMIT(OBOW, 0);
635 		NEXTn(6);
636 		return;
637 	}
638 	if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
639 		EMIT(OEOW, 0);
640 		NEXTn(6);
641 		return;
642 	}
643 
644 	if (EAT('^'))
645 		invert++;	/* make note to invert set at end */
646 	if (EAT(']'))
647 		CHadd(cs, ']');
648 	else if (EAT('-'))
649 		CHadd(cs, '-');
650 	while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
651 		p_b_term(p, cs);
652 	if (EAT('-'))
653 		CHadd(cs, '-');
654 	if(MUSTEAT(']', MY_REG_EBRACK)) {}
655 
656 	if (p->error != 0)	/* don't mess things up further */
657 		return;
658 
659 	if (p->g->cflags&MY_REG_ICASE) {
660 		int i;
661 		int ci;
662 
663 		for (i = p->g->csetsize - 1; i >= 0; i--)
664 			if (CHIN(cs, i) && my_isalpha(p->charset,i)) {
665 				ci = othercase(p->charset,i);
666 				if (ci != i)
667 					CHadd(cs, ci);
668 			}
669 		if (cs->multis != NULL)
670 			mccase(p, cs);
671 	}
672 	if (invert) {
673 		int i;
674 
675 		for (i = p->g->csetsize - 1; i >= 0; i--)
676 			if (CHIN(cs, i))
677 				CHsub(cs, i);
678 			else
679 				CHadd(cs, i);
680 		if (p->g->cflags&MY_REG_NEWLINE)
681 			CHsub(cs, '\n');
682 		if (cs->multis != NULL)
683 			mcinvert(p, cs);
684 	}
685 
686 	assert(cs->multis == NULL);		/* xxx */
687 
688 	if (nch(p, cs) == 1) {		/* optimize singleton sets */
689 		ordinary(p, firstch(p, cs));
690 		freeset(p, cs);
691 	} else
692 		EMIT(OANYOF, freezeset(p, cs));
693 }
694 
695 /*
696  - p_b_term - parse one term of a bracketed character list
697  == static void p_b_term(register struct parse *p, register cset *cs);
698  */
699 static void
p_b_term(p,cs)700 p_b_term(p, cs)
701 struct parse *p;
702 cset *cs;
703 {
704 	char c;
705 	char start, finish;
706 	int i;
707 
708 	/* classify what we've got */
709 	switch ((MORE()) ? PEEK() : '\0') {
710 	case '[':
711 		c = (MORE2()) ? PEEK2() : '\0';
712 		break;
713 	case '-':
714 		SETERROR(MY_REG_ERANGE);
715 		return;			/* NOTE RETURN */
716 	default:
717 		c = '\0';
718 		break;
719 	}
720 
721 	switch (c) {
722 	case ':':		/* character class */
723 		NEXT2();
724 		if(REQUIRE(MORE(), MY_REG_EBRACK)) {}
725 		c = PEEK();
726 		if(REQUIRE(c != '-' && c != ']', MY_REG_ECTYPE)) {}
727 		p_b_cclass(p, cs);
728 		if(REQUIRE(MORE(), MY_REG_EBRACK)) {}
729 		if(REQUIRE(EATTWO(':', ']'), MY_REG_ECTYPE)) {}
730 		break;
731 	case '=':		/* equivalence class */
732 		NEXT2();
733 		if(REQUIRE(MORE(), MY_REG_EBRACK)) {}
734 		c = PEEK();
735 		if(REQUIRE(c != '-' && c != ']', MY_REG_ECOLLATE)) {}
736 		p_b_eclass(p, cs);
737 		if(REQUIRE(MORE(), MY_REG_EBRACK)) {}
738 		if(REQUIRE(EATTWO('=', ']'), MY_REG_ECOLLATE)) {}
739 		break;
740 	default:		/* symbol, ordinary character, or range */
741 /* xxx revision needed for multichar stuff */
742 		start = p_b_symbol(p);
743 		if (SEE('-') && MORE2() && PEEK2() != ']') {
744 			/* range */
745 			NEXT();
746 			if (EAT('-'))
747 				finish = '-';
748 			else
749 				finish = p_b_symbol(p);
750 		} else
751 			finish = start;
752 /* xxx what about signed chars here... */
753 		if(REQUIRE(start <= finish, MY_REG_ERANGE)) {}
754 		for (i = start; i <= finish; i++)
755 			CHadd(cs, i);
756 		break;
757 	}
758 }
759 
760 /*
761  - p_b_cclass - parse a character-class name and deal with it
762  == static void p_b_cclass(register struct parse *p, register cset *cs);
763  */
764 static void
p_b_cclass(p,cs)765 p_b_cclass(p, cs)
766 struct parse *p;
767 cset *cs;
768 {
769 	char *sp = p->next;
770 	struct cclass *cp;
771 	size_t len;
772 
773 	while (MORE() && my_isalpha(p->charset,PEEK()))
774 		NEXT();
775 	len = p->next - sp;
776 	for (cp = cclasses; cp->name != NULL; cp++)
777 		if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
778 			break;
779 	if (cp->name == NULL) {
780 		/* oops, didn't find it */
781 		SETERROR(MY_REG_ECTYPE);
782 		return;
783 	}
784 
785 #ifndef USE_ORIG_REGEX_CODE
786 	{
787 		size_t i;
788 		for (i=1 ; i<256 ; i++)
789 			if (p->charset->ctype[i+1] & cp->mask)
790 				CHadd(cs, i);
791 	}
792 #else
793 	{
794 		char *u = (char*) cp->chars;
795 		char c;
796 
797 		while ((c = *u++) != '\0')
798 			CHadd(cs, c);
799 
800 		for (u = (char*) cp->multis; *u != '\0'; u += strlen(u) + 1)
801 			MCadd(p, cs, u);
802 	}
803 #endif
804 
805 }
806 
807 /*
808  - p_b_eclass - parse an equivalence-class name and deal with it
809  == static void p_b_eclass(register struct parse *p, register cset *cs);
810  *
811  * This implementation is incomplete. xxx
812  */
813 static void
p_b_eclass(p,cs)814 p_b_eclass(p, cs)
815 struct parse *p;
816 cset *cs;
817 {
818 	char c;
819 
820 	c = p_b_coll_elem(p, '=');
821 	CHadd(cs, c);
822 }
823 
824 /*
825  - p_b_symbol - parse a character or [..]ed multicharacter collating symbol
826  == static char p_b_symbol(register struct parse *p);
827  */
828 static char			/* value of symbol */
p_b_symbol(p)829 p_b_symbol(p)
830 struct parse *p;
831 {
832 	char value;
833 
834 	if(REQUIRE(MORE(), MY_REG_EBRACK)) {}
835 	if (!EATTWO('[', '.'))
836 		return(GETNEXT());
837 
838 	/* collating symbol */
839 	value = p_b_coll_elem(p, '.');
840 	if(REQUIRE(EATTWO('.', ']'), MY_REG_ECOLLATE)) {}
841 	return(value);
842 }
843 
844 /*
845  - p_b_coll_elem - parse a collating-element name and look it up
846  == static char p_b_coll_elem(register struct parse *p, int endc);
847  */
848 static char			/* value of collating element */
p_b_coll_elem(p,endc)849 p_b_coll_elem(p, endc)
850 struct parse *p;
851 int endc;			/* name ended by endc,']' */
852 {
853 	char *sp = p->next;
854 	struct cname *cp;
855 #ifdef _WIN64
856 	__int64 len;
857 #else
858 	int len;
859 #endif
860 	while (MORE() && !SEETWO(endc, ']'))
861 		NEXT();
862 	if (!MORE()) {
863 		SETERROR(MY_REG_EBRACK);
864 		return(0);
865 	}
866 	len = p->next - sp;
867 	for (cp = cnames; cp->name != NULL; cp++)
868 		if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
869 			return(cp->code);	/* known name */
870 	if (len == 1)
871 		return(*sp);	/* single character */
872 	SETERROR(MY_REG_ECOLLATE);			/* neither */
873 	return(0);
874 }
875 
876 /*
877  - othercase - return the case counterpart of an alphabetic
878  == static char othercase(int ch);
879  */
880 static char			/* if no counterpart, return ch */
othercase(charset,ch)881 othercase(charset,ch)
882 const CHARSET_INFO *charset;
883 int ch;
884 {
885 	/*
886 	  In MySQL some multi-byte character sets
887 	  have 'ctype' array but don't have 'to_lower'
888 	  and 'to_upper' arrays. In this case we handle
889 	  only basic latin letters a..z and A..Z.
890 
891 	  If 'to_lower' and 'to_upper' arrays are empty in a character set,
892 	  then my_isalpha(cs, ch) should never return TRUE for characters
893 	  other than basic latin letters. Otherwise it should be
894 	  considered as a mistake in character set definition.
895 	*/
896 	assert(my_isalpha(charset,ch));
897 	if (my_isupper(charset,ch))
898 	{
899 		return(charset->to_lower ? my_tolower(charset,ch) :
900 		                          ch - 'A' + 'a');
901 	}
902 	else if (my_islower(charset,ch))
903 	{
904 		return(charset->to_upper ? my_toupper(charset,ch) :
905 		                          ch - 'a' + 'A');
906 	}
907 	else			/* peculiar, but could happen */
908 		return(ch);
909 }
910 
911 /*
912  - bothcases - emit a dualcase version of a two-case character
913  == static void bothcases(register struct parse *p, int ch);
914  *
915  * Boy, is this implementation ever a kludge...
916  */
917 static void
bothcases(p,ch)918 bothcases(p, ch)
919 struct parse *p;
920 int ch;
921 {
922 	char *oldnext = p->next;
923 	char *oldend = p->end;
924 	char bracket[3];
925 
926 	assert(othercase(p->charset, ch) != ch); /* p_bracket() would recurse */
927 	p->next = bracket;
928 	p->end = bracket+2;
929 	bracket[0] = ch;
930 	bracket[1] = ']';
931 	bracket[2] = '\0';
932 	p_bracket(p);
933 	assert(p->next == bracket+2);
934 	p->next = oldnext;
935 	p->end = oldend;
936 }
937 
938 /*
939  - ordinary - emit an ordinary character
940  == static void ordinary(register struct parse *p, register int ch);
941  */
942 static void
ordinary(p,ch)943 ordinary(p, ch)
944 struct parse *p;
945 int ch;
946 {
947 	cat_t *cap = p->g->categories;
948 
949 	if ((p->g->cflags&MY_REG_ICASE) && my_isalpha(p->charset,ch) &&
950 	     othercase(p->charset,ch) != ch)
951 		bothcases(p, ch);
952 	else {
953 		EMIT(OCHAR, (unsigned char)ch);
954 		if (cap[ch] == 0)
955 			cap[ch] = p->g->ncategories++;
956 	}
957 }
958 
959 /*
960  - nonnewline - emit MY_REG_NEWLINE version of OANY
961  == static void nonnewline(register struct parse *p);
962  *
963  * Boy, is this implementation ever a kludge...
964  */
965 static void
nonnewline(p)966 nonnewline(p)
967 struct parse *p;
968 {
969 	char *oldnext = p->next;
970 	char *oldend = p->end;
971 	char bracket[4];
972 
973 	p->next = bracket;
974 	p->end = bracket+3;
975 	bracket[0] = '^';
976 	bracket[1] = '\n';
977 	bracket[2] = ']';
978 	bracket[3] = '\0';
979 	p_bracket(p);
980 	assert(p->next == bracket+3);
981 	p->next = oldnext;
982 	p->end = oldend;
983 }
984 
985 /*
986  - repeat - generate code for a bounded repetition, recursively if needed
987  == static void repeat(register struct parse *p, sopno start, int from, int to);
988  */
989 static void
repeat(p,start,from,to)990 repeat(p, start, from, to)
991 struct parse *p;
992 sopno start;			/* operand from here to end of strip */
993 int from;			/* repeated from this number */
994 int to;				/* to this number of times (maybe RE_INFINITY) */
995 {
996 	sopno finish = HERE();
997 #	define	N	2
998 #	define	INF	3
999 #	define	REP(f, t)	((f)*8 + (t))
1000 #	define	MAP(n)	(((n) <= 1) ? (n) : ((n) == RE_INFINITY) ? INF : N)
1001 	sopno copy;
1002 
1003 	if (p->error != 0)	/* head off possible runaway recursion */
1004 		return;
1005 
1006 	assert(from <= to);
1007 
1008 	switch (REP(MAP(from), MAP(to))) {
1009 	case REP(0, 0):			/* must be user doing this */
1010 		DROP(finish-start);	/* drop the operand */
1011 		break;
1012 	case REP(0, 1):			/* as x{1,1}? */
1013 	case REP(0, N):			/* as x{1,n}? */
1014 	case REP(0, INF):		/* as x{1,}? */
1015 		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
1016 		INSERT(OCH_, start);		/* offset is wrong... */
1017 		repeat(p, start+1, 1, to);
1018 		ASTERN(OOR1, start);
1019 		AHEAD(start);			/* ... fix it */
1020 		EMIT(OOR2, 0);
1021 		AHEAD(THERE());
1022 		ASTERN(O_CH, THERETHERE());
1023 		break;
1024 	case REP(1, 1):			/* trivial case */
1025 		/* done */
1026 		break;
1027 	case REP(1, N):			/* as x?x{1,n-1} */
1028 		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
1029 		INSERT(OCH_, start);
1030 		ASTERN(OOR1, start);
1031 		AHEAD(start);
1032 		EMIT(OOR2, 0);			/* offset very wrong... */
1033 		AHEAD(THERE());			/* ...so fix it */
1034 		ASTERN(O_CH, THERETHERE());
1035 		copy = dupl(p, start+1, finish+1);
1036                 if (p->error != 0)
1037                   return;        /* purecov: inspected */
1038 		assert(copy == finish+4);
1039 		repeat(p, copy, 1, to-1);
1040 		break;
1041 	case REP(1, INF):		/* as x+ */
1042 		INSERT(OPLUS_, start);
1043 		ASTERN(O_PLUS, start);
1044 		break;
1045 	case REP(N, N):			/* as xx{m-1,n-1} */
1046 		copy = dupl(p, start, finish);
1047                 if (p->error != 0)
1048                   return;
1049 		repeat(p, copy, from-1, to-1);
1050 		break;
1051 	case REP(N, INF):		/* as xx{n-1,INF} */
1052 		copy = dupl(p, start, finish);
1053                 if (p->error != 0)
1054                   return;        /* purecov: inspected */
1055 		repeat(p, copy, from-1, to);
1056 		break;
1057 	default:			/* "can't happen" */
1058 		SETERROR(MY_REG_ASSERT);	/* just in case */
1059 		break;
1060 	}
1061 }
1062 
1063 /*
1064  - seterr - set an error condition
1065  == static int seterr(register struct parse *p, int e);
1066  */
1067 static int			/* useless but makes type checking happy */
seterr(p,e)1068 seterr(p, e)
1069 struct parse *p;
1070 int e;
1071 {
1072 	if (p->error == 0)	/* keep earliest error condition */
1073 		p->error = e;
1074 	p->next = nuls;		/* try to bring things to a halt */
1075 	p->end = nuls;
1076 	return(0);		/* make the return value well-defined */
1077 }
1078 
1079 /*
1080  - allocset - allocate a set of characters for []
1081  == static cset *allocset(register struct parse *p);
1082  */
1083 static cset *
allocset(p)1084 allocset(p)
1085 struct parse *p;
1086 {
1087 	int no = p->g->ncsets++;
1088 	size_t nc;
1089 	size_t nbytes;
1090 	cset *cs;
1091 	size_t css = (size_t)p->g->csetsize;
1092 	int i;
1093 
1094 	if (no >= p->ncsalloc) {	/* need another column of space */
1095 		p->ncsalloc += CHAR_BIT;
1096 		nc = p->ncsalloc;
1097 		assert(nc % CHAR_BIT == 0);
1098 		nbytes = nc / CHAR_BIT * css;
1099 		if (p->g->sets == NULL)
1100 			p->g->sets = (cset *)malloc(nc * sizeof(cset));
1101 		else
1102 			p->g->sets = (cset *)realloc((char *)p->g->sets,
1103 							nc * sizeof(cset));
1104 		if (p->g->setbits == NULL)
1105 			p->g->setbits = (uch *)malloc(nbytes);
1106 		else {
1107 			p->g->setbits = (uch *)realloc((char *)p->g->setbits,
1108 								nbytes);
1109 			/* xxx this isn't right if setbits is now NULL */
1110 			for (i = 0; i < no; i++)
1111 				p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
1112 		}
1113 		if (p->g->sets != NULL && p->g->setbits != NULL)
1114 			(void) memset((char *)p->g->setbits + (nbytes - css),
1115 								0, css);
1116 		else {
1117 			no = 0;
1118 			SETERROR(MY_REG_ESPACE);
1119 			/* caller's responsibility not to do set ops */
1120 		}
1121 	}
1122 
1123 	assert(p->g->sets != NULL);	/* xxx */
1124 	cs = &p->g->sets[no];
1125 	cs->ptr = p->g->setbits + css*((no)/CHAR_BIT);
1126 	cs->mask = 1 << ((no) % CHAR_BIT);
1127 	cs->hash = 0;
1128 	cs->smultis = 0;
1129 	cs->multis = NULL;
1130 
1131 	return(cs);
1132 }
1133 
1134 /*
1135  - freeset - free a now-unused set
1136  == static void freeset(register struct parse *p, register cset *cs);
1137  */
1138 static void
freeset(p,cs)1139 freeset(p, cs)
1140 struct parse *p;
1141 cset *cs;
1142 {
1143 	size_t i;
1144 	cset *top = &p->g->sets[p->g->ncsets];
1145 	size_t css = (size_t)p->g->csetsize;
1146 
1147 	for (i = 0; i < css; i++)
1148 	  CHsub(cs, i);
1149 	if (cs == top-1)	/* recover only the easy case */
1150 	  p->g->ncsets--;
1151 }
1152 
1153 /*
1154  - freezeset - final processing on a set of characters
1155  == static int freezeset(register struct parse *p, register cset *cs);
1156  *
1157  * The main task here is merging identical sets.  This is usually a waste
1158  * of time (although the hash code minimizes the overhead), but can win
1159  * big if MY_REG_ICASE is being used.  MY_REG_ICASE, by the way, is why the hash
1160  * is done using addition rather than xor -- all ASCII [aA] sets xor to
1161  * the same value!
1162  */
1163 static int			/* set number */
freezeset(p,cs)1164 freezeset(p, cs)
1165 struct parse *p;
1166 cset *cs;
1167 {
1168 	uch h = cs->hash;
1169 	size_t i;
1170 	cset *top = &p->g->sets[p->g->ncsets];
1171 	cset *cs2;
1172 	size_t css = (size_t)p->g->csetsize;
1173 
1174 	/* look for an earlier one which is the same */
1175 	for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
1176 		if (cs2->hash == h && cs2 != cs) {
1177 			/* maybe */
1178 			for (i = 0; i < css; i++)
1179 				if (!!CHIN(cs2, i) != !!CHIN(cs, i))
1180 					break;		/* no */
1181 			if (i == css)
1182 				break;			/* yes */
1183 		}
1184 
1185 	if (cs2 < top) {	/* found one */
1186 		freeset(p, cs);
1187 		cs = cs2;
1188 	}
1189 
1190 	return((int)(cs - p->g->sets));
1191 }
1192 
1193 /*
1194  - firstch - return first character in a set (which must have at least one)
1195  == static int firstch(register struct parse *p, register cset *cs);
1196  */
1197 static int			/* character; there is no "none" value */
firstch(p,cs)1198 firstch(p, cs)
1199 struct parse *p;
1200 cset *cs;
1201 {
1202 	size_t i;
1203 	size_t css = (size_t)p->g->csetsize;
1204 
1205 	for (i = 0; i < css; i++)
1206 		if (CHIN(cs, i))
1207 			return((char)i);
1208 	assert(never);
1209 	return(0);		/* arbitrary */
1210 }
1211 
1212 /*
1213  - nch - number of characters in a set
1214  == static int nch(register struct parse *p, register cset *cs);
1215  */
1216 static int
nch(p,cs)1217 nch(p, cs)
1218 struct parse *p;
1219 cset *cs;
1220 {
1221 	size_t i;
1222 	size_t css = (size_t)p->g->csetsize;
1223 	int n = 0;
1224 
1225 	for (i = 0; i < css; i++)
1226 		if (CHIN(cs, i))
1227 			n++;
1228 	return(n);
1229 }
1230 
1231 #ifdef USE_ORIG_REGEX_CODE
1232 /*
1233  - mcadd - add a collating element to a cset
1234  == static void mcadd(register struct parse *p, register cset *cs, \
1235  ==	register char *cp);
1236  */
1237 static void
mcadd(p,cs,cp)1238 mcadd(p, cs, cp)
1239 struct parse *p;
1240 cset *cs;
1241 char *cp;
1242 {
1243 	size_t oldend = cs->smultis;
1244 
1245 	cs->smultis += strlen(cp) + 1;
1246 	if (cs->multis == NULL)
1247 		cs->multis = malloc(cs->smultis);
1248 	else
1249 		cs->multis = realloc(cs->multis, cs->smultis);
1250 	if (cs->multis == NULL) {
1251 		SETERROR(MY_REG_ESPACE);
1252 		return;
1253 	}
1254 
1255 	(void) strcpy(cs->multis + oldend - 1, cp);
1256 	cs->multis[cs->smultis - 1] = '\0';
1257 }
1258 #endif
1259 
1260 /*
1261  - mcinvert - invert the list of collating elements in a cset
1262  == static void mcinvert(register struct parse *p, register cset *cs);
1263  *
1264  * This would have to know the set of possibilities.  Implementation
1265  * is deferred.
1266  */
1267 static void
1268 mcinvert(p, cs)
1269   struct parse *p MY_ATTRIBUTE((unused));
1270   cset *cs MY_ATTRIBUTE((unused));
1271 {
1272 	assert(cs->multis == NULL);	/* xxx */
1273 }
1274 
1275 /*
1276  - mccase - add case counterparts of the list of collating elements in a cset
1277  == static void mccase(register struct parse *p, register cset *cs);
1278  *
1279  * This would have to know the set of possibilities.  Implementation
1280  * is deferred.
1281  */
1282 static void
1283 mccase(p, cs)
1284 struct parse *p MY_ATTRIBUTE((unused));
1285 cset *cs MY_ATTRIBUTE((unused));
1286 {
1287 	assert(cs->multis == NULL);	/* xxx */
1288 }
1289 
1290 /*
1291  - isinsets - is this character in any sets?
1292  == static int isinsets(register struct re_guts *g, int c);
1293  */
1294 static int			/* predicate */
isinsets(g,c)1295 isinsets(g, c)
1296 struct re_guts *g;
1297 int c;
1298 {
1299 	uch *col;
1300 	int i;
1301 	int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1302 	unsigned uc = (unsigned char)c;
1303 
1304 	for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1305 		if (col[uc] != 0)
1306 			return(1);
1307 	return(0);
1308 }
1309 
1310 /*
1311  - samesets - are these two characters in exactly the same sets?
1312  == static int samesets(register struct re_guts *g, int c1, int c2);
1313  */
1314 static int			/* predicate */
samesets(g,c1,c2)1315 samesets(g, c1, c2)
1316 struct re_guts *g;
1317 int c1;
1318 int c2;
1319 {
1320 	uch *col;
1321 	int i;
1322 	int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1323 	unsigned uc1 = (unsigned char)c1;
1324 	unsigned uc2 = (unsigned char)c2;
1325 
1326 	for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1327 		if (col[uc1] != col[uc2])
1328 			return(0);
1329 	return(1);
1330 }
1331 
1332 /*
1333  - categorize - sort out character categories
1334  == static void categorize(struct parse *p, register struct re_guts *g);
1335  */
1336 static void
categorize(p,g)1337 categorize(p, g)
1338 struct parse *p;
1339 struct re_guts *g;
1340 {
1341 	cat_t *cats = g->categories;
1342 	int c;
1343 	int c2;
1344 	cat_t cat;
1345 
1346 	/* avoid making error situations worse */
1347 	if (p->error != 0)
1348 		return;
1349 
1350 	for (c = CHAR_MIN; c <= CHAR_MAX; c++)
1351 		if (cats[c] == 0 && isinsets(g, c)) {
1352 			cat = g->ncategories++;
1353 			cats[c] = cat;
1354 			for (c2 = c+1; c2 <= CHAR_MAX; c2++)
1355 				if (cats[c2] == 0 && samesets(g, c, c2))
1356 					cats[c2] = cat;
1357 		}
1358 }
1359 
1360 /*
1361  - dupl - emit a duplicate of a bunch of sops
1362  == static sopno dupl(register struct parse *p, sopno start, sopno finish);
1363  */
1364 static sopno			/* start of duplicate */
dupl(p,start,finish)1365 dupl(p, start, finish)
1366 struct parse *p;
1367 sopno start;			/* from here */
1368 sopno finish;			/* to this less one */
1369 {
1370 	sopno ret = HERE();
1371 	sopno len = finish - start;
1372 
1373 	assert(finish >= start);
1374 	if (len == 0)
1375 		return(ret);
1376 	enlarge(p, p->ssize + len);	/* this many unexpected additions */
1377         if (p->error != 0)
1378           return(p->error);
1379 
1380 	assert(p->ssize >= p->slen + len);
1381 	(void) memcpy((char *)(p->strip + p->slen),
1382 		(char *)(p->strip + start), (size_t)len*sizeof(sop));
1383 	p->slen += len;
1384 	return(ret);
1385 }
1386 
1387 /*
1388  - doemit - emit a strip operator
1389  == static void doemit(register struct parse *p, sop op, size_t opnd);
1390  *
1391  * It might seem better to implement this as a macro with a function as
1392  * hard-case backup, but it's just too big and messy unless there are
1393  * some changes to the data structures.  Maybe later.
1394  */
1395 static void
doemit(p,op,opnd)1396 doemit(p, op, opnd)
1397 struct parse *p;
1398 sop op;
1399 size_t opnd;
1400 {
1401 	/* avoid making error situations worse */
1402 	if (p->error != 0)
1403 		return;
1404 
1405 	/* deal with oversize operands ("can't happen", more or less) */
1406 	assert(opnd < 1<<OPSHIFT);
1407 
1408 	/* deal with undersized strip */
1409 	if (p->slen >= p->ssize)
1410 		enlarge(p, (p->ssize+1) / 2 * 3);	/* +50% */
1411 	assert(p->slen < p->ssize);
1412 
1413 	/* finally, it's all reduced to the easy case */
1414 	p->strip[p->slen++] = SOP(op, opnd);
1415 }
1416 
1417 /*
1418  - doinsert - insert a sop into the strip
1419  == static void doinsert(register struct parse *p, sop op, size_t opnd, sopno pos);
1420  */
1421 static void
doinsert(p,op,opnd,pos)1422 doinsert(p, op, opnd, pos)
1423 struct parse *p;
1424 sop op;
1425 size_t opnd;
1426 sopno pos;
1427 {
1428 	sopno sn;
1429 	sop s;
1430 	int i;
1431 
1432 	/* avoid making error situations worse */
1433 	if (p->error != 0)
1434 		return;
1435 
1436 	sn = HERE();
1437 	EMIT(op, opnd);		/* do checks, ensure space */
1438 	assert(HERE() == sn+1);
1439 	s = p->strip[sn];
1440 
1441 	/* adjust paren pointers */
1442 	assert(pos > 0);
1443 	for (i = 1; i < NPAREN; i++) {
1444 		if (p->pbegin[i] >= pos) {
1445 			p->pbegin[i]++;
1446 		}
1447 		if (p->pend[i] >= pos) {
1448 			p->pend[i]++;
1449 		}
1450 	}
1451 	{
1452           size_t length=(HERE()-pos-1)*sizeof(sop);
1453           memmove((uchar *) &p->strip[pos+1],
1454                   (uchar *) &p->strip[pos],
1455                   length);
1456         }
1457 	p->strip[pos] = s;
1458 }
1459 
1460 /*
1461  - dofwd - complete a forward reference
1462  == static void dofwd(register struct parse *p, sopno pos, sop value);
1463  */
1464 static void
dofwd(p,pos,value)1465 dofwd(p, pos, value)
1466 struct parse *p;
1467 sopno pos;
1468 sop value;
1469 {
1470 	/* avoid making error situations worse */
1471 	if (p->error != 0)
1472 		return;
1473 
1474 	assert(value < 1<<OPSHIFT);
1475 	p->strip[pos] = OP(p->strip[pos]) | value;
1476 }
1477 
1478 /*
1479  - enlarge - enlarge the strip
1480  == static void enlarge(register struct parse *p, sopno size);
1481  */
1482 static void
enlarge(p,size)1483 enlarge(p, size)
1484 struct parse *p;
1485 sopno size;
1486 {
1487 	sop *sp;
1488 
1489 	if (p->ssize >= size)
1490 		return;
1491 
1492         DBUG_EXECUTE_IF("bug24449090_simulate_oom",
1493                         {
1494                           free(p->strip);
1495                           p->strip= NULL;
1496                           p->ssize= 0;
1497                           SETERROR(MY_REG_ESPACE);
1498                           return;
1499                         });
1500 
1501 	sp = (sop *)realloc(p->strip, size*sizeof(sop));
1502 	if (sp == NULL) {
1503 		SETERROR(MY_REG_ESPACE);
1504 		return;
1505 	}
1506 	p->strip = sp;
1507 	p->ssize = size;
1508 }
1509 
1510 /*
1511  - stripsnug - compact the strip
1512  == static void stripsnug(register struct parse *p, register struct re_guts *g);
1513  */
1514 static void
stripsnug(p,g)1515 stripsnug(p, g)
1516 struct parse *p;
1517 struct re_guts *g;
1518 {
1519 	g->nstates = p->slen;
1520 	g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop));
1521 	if (g->strip == NULL) {
1522 		SETERROR(MY_REG_ESPACE);
1523 		g->strip = p->strip;
1524 	}
1525 }
1526 
1527 /*
1528  - findmust - fill in must and mlen with longest mandatory literal string
1529  == static void findmust(register struct parse *p, register struct re_guts *g);
1530  *
1531  * This algorithm could do fancy things like analyzing the operands of |
1532  * for common subsequences.  Someday.  This code is simple and finds most
1533  * of the interesting cases.
1534  *
1535  * Note that must and mlen got initialized during setup.
1536  */
1537 static void
findmust(p,g)1538 findmust(p, g)
1539 struct parse *p;
1540 struct re_guts *g;
1541 {
1542 	sop *scan;
1543 	sop *start= NULL;
1544 	sop *newstart= NULL;
1545 	sopno newlen;
1546 	sop s;
1547 	char *cp;
1548 	sopno i;
1549 
1550 	/* avoid making error situations worse */
1551 	if (p->error != 0)
1552 		return;
1553 
1554 	/* find the longest OCHAR sequence in strip */
1555 	newlen = 0;
1556 	scan = g->strip + 1;
1557 	do {
1558 		s = *scan++;
1559 		switch (OP(s)) {
1560 		case OCHAR:		/* sequence member */
1561 			if (newlen == 0)		/* new sequence */
1562 				newstart = scan - 1;
1563 			newlen++;
1564 			break;
1565 		case OPLUS_:		/* things that don't break one */
1566 		case OLPAREN:
1567 		case ORPAREN:
1568 			break;
1569 		case OQUEST_:		/* things that must be skipped */
1570 		case OCH_:
1571 			scan--;
1572 			do {
1573 				scan += OPND(s);
1574 				s = *scan;
1575 				/* assert() interferes w debug printouts */
1576 				if (OP(s) != O_QUEST && OP(s) != O_CH &&
1577 							OP(s) != OOR2) {
1578 					g->iflags |= BAD;
1579 					return;
1580 				}
1581 			} while (OP(s) != O_QUEST && OP(s) != O_CH);
1582 			/* fallthrough */
1583 		default:		/* things that break a sequence */
1584 			if (newlen > g->mlen) {		/* ends one */
1585 				start = newstart;
1586 				g->mlen = newlen;
1587 			}
1588 			newlen = 0;
1589 			break;
1590 		}
1591 	} while (OP(s) != OEND);
1592 
1593 	if (g->mlen == 0)		/* there isn't one */
1594 		return;
1595 
1596 	/* turn it into a character string */
1597 	g->must = malloc((size_t)g->mlen + 1);
1598 	if (g->must == NULL) {		/* argh; just forget it */
1599 		g->mlen = 0;
1600 		return;
1601 	}
1602 	cp = g->must;
1603 	scan = start;
1604 	for (i = g->mlen; i > 0; i--) {
1605 		while (OP(s = *scan++) != OCHAR)
1606 			continue;
1607 		assert(cp < g->must + g->mlen);
1608 		*cp++ = (char)OPND(s);
1609 	}
1610 	assert(cp == g->must + g->mlen);
1611 	*cp++ = '\0';		/* just on general principles */
1612 }
1613 
1614 /*
1615  - pluscount - count + nesting
1616  == static sopno pluscount(register struct parse *p, register struct re_guts *g);
1617  */
1618 static sopno			/* nesting depth */
pluscount(p,g)1619 pluscount(p, g)
1620 struct parse *p;
1621 struct re_guts *g;
1622 {
1623 	sop *scan;
1624 	sop s;
1625 	sopno plusnest = 0;
1626 	sopno maxnest = 0;
1627 
1628 	if (p->error != 0)
1629 		return(0);	/* there may not be an OEND */
1630 
1631 	scan = g->strip + 1;
1632 	do {
1633 		s = *scan++;
1634 		switch (OP(s)) {
1635 		case OPLUS_:
1636 			plusnest++;
1637 			break;
1638 		case O_PLUS:
1639 			if (plusnest > maxnest)
1640 				maxnest = plusnest;
1641 			plusnest--;
1642 			break;
1643 		}
1644 	} while (OP(s) != OEND);
1645 	if (plusnest != 0)
1646 		g->iflags |= BAD;
1647 	return(maxnest);
1648 }
1649