xref: /openbsd-src/gnu/usr.bin/perl/regcomp.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*    regcomp.c
2  */
3 
4 /*
5  * "A fair jaw-cracker dwarf-language must be."  --Samwise Gamgee
6  */
7 
8 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
9  * confused with the original package (see point 3 below).  Thanks, Henry!
10  */
11 
12 /* Additional note: this code is very heavily munged from Henry's version
13  * in places.  In some spots I've traded clarity for efficiency, so don't
14  * blame Henry for some of the lack of readability.
15  */
16 
17 /* The names of the functions have been changed from regcomp and
18  * regexec to  pregcomp and pregexec in order to avoid conflicts
19  * with the POSIX routines of the same names.
20 */
21 
22 #ifdef PERL_EXT_RE_BUILD
23 /* need to replace pregcomp et al, so enable that */
24 #  ifndef PERL_IN_XSUB_RE
25 #    define PERL_IN_XSUB_RE
26 #  endif
27 /* need access to debugger hooks */
28 #  if defined(PERL_EXT_RE_DEBUG) && !defined(DEBUGGING)
29 #    define DEBUGGING
30 #  endif
31 #endif
32 
33 #ifdef PERL_IN_XSUB_RE
34 /* We *really* need to overwrite these symbols: */
35 #  define Perl_pregcomp my_regcomp
36 #  define Perl_regdump my_regdump
37 #  define Perl_regprop my_regprop
38 #  define Perl_pregfree my_regfree
39 #  define Perl_re_intuit_string my_re_intuit_string
40 /* *These* symbols are masked to allow static link. */
41 #  define Perl_regnext my_regnext
42 #  define Perl_save_re_context my_save_re_context
43 #  define Perl_reginitcolors my_reginitcolors
44 
45 #  define PERL_NO_GET_CONTEXT
46 #endif
47 
48 /*SUPPRESS 112*/
49 /*
50  * pregcomp and pregexec -- regsub and regerror are not used in perl
51  *
52  *	Copyright (c) 1986 by University of Toronto.
53  *	Written by Henry Spencer.  Not derived from licensed software.
54  *
55  *	Permission is granted to anyone to use this software for any
56  *	purpose on any computer system, and to redistribute it freely,
57  *	subject to the following restrictions:
58  *
59  *	1. The author is not responsible for the consequences of use of
60  *		this software, no matter how awful, even if they arise
61  *		from defects in it.
62  *
63  *	2. The origin of this software must not be misrepresented, either
64  *		by explicit claim or by omission.
65  *
66  *	3. Altered versions must be plainly marked as such, and must not
67  *		be misrepresented as being the original software.
68  *
69  *
70  ****    Alterations to Henry's code are...
71  ****
72  ****    Copyright (c) 1991-2001, Larry Wall
73  ****
74  ****    You may distribute under the terms of either the GNU General Public
75  ****    License or the Artistic License, as specified in the README file.
76 
77  *
78  * Beware that some of this code is subtly aware of the way operator
79  * precedence is structured in regular expressions.  Serious changes in
80  * regular-expression syntax might require a total rethink.
81  */
82 #include "EXTERN.h"
83 #define PERL_IN_REGCOMP_C
84 #include "perl.h"
85 
86 #ifdef PERL_IN_XSUB_RE
87 #  if defined(PERL_CAPI) || defined(PERL_OBJECT)
88 #    include "XSUB.h"
89 #  endif
90 #else
91 #  include "INTERN.h"
92 #endif
93 
94 #define REG_COMP_C
95 #include "regcomp.h"
96 
97 #ifdef op
98 #undef op
99 #endif /* op */
100 
101 #ifdef MSDOS
102 # if defined(BUGGY_MSC6)
103  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
104  # pragma optimize("a",off)
105  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
106  # pragma optimize("w",on )
107 # endif /* BUGGY_MSC6 */
108 #endif /* MSDOS */
109 
110 #ifndef STATIC
111 #define	STATIC	static
112 #endif
113 
114 #define	ISMULT1(c)	((c) == '*' || (c) == '+' || (c) == '?')
115 #define	ISMULT2(s)	((*s) == '*' || (*s) == '+' || (*s) == '?' || \
116 	((*s) == '{' && regcurly(s)))
117 
118 #ifdef SPSTART
119 #undef SPSTART		/* dratted cpp namespace... */
120 #endif
121 /*
122  * Flags to be passed up and down.
123  */
124 #define	WORST		0	/* Worst case. */
125 #define	HASWIDTH	0x1	/* Known to match non-null strings. */
126 #define	SIMPLE		0x2	/* Simple enough to be STAR/PLUS operand. */
127 #define	SPSTART		0x4	/* Starts with * or +. */
128 #define TRYAGAIN	0x8	/* Weeded out a declaration. */
129 
130 /* Length of a variant. */
131 
132 typedef struct scan_data_t {
133     I32 len_min;
134     I32 len_delta;
135     I32 pos_min;
136     I32 pos_delta;
137     SV *last_found;
138     I32 last_end;			/* min value, <0 unless valid. */
139     I32 last_start_min;
140     I32 last_start_max;
141     SV **longest;			/* Either &l_fixed, or &l_float. */
142     SV *longest_fixed;
143     I32 offset_fixed;
144     SV *longest_float;
145     I32 offset_float_min;
146     I32 offset_float_max;
147     I32 flags;
148     I32 whilem_c;
149     I32 *last_closep;
150     struct regnode_charclass_class *start_class;
151 } scan_data_t;
152 
153 /*
154  * Forward declarations for pregcomp()'s friends.
155  */
156 
157 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
158 				      0, 0, 0, 0, 0, 0};
159 
160 #define SF_BEFORE_EOL		(SF_BEFORE_SEOL|SF_BEFORE_MEOL)
161 #define SF_BEFORE_SEOL		0x1
162 #define SF_BEFORE_MEOL		0x2
163 #define SF_FIX_BEFORE_EOL	(SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
164 #define SF_FL_BEFORE_EOL	(SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
165 
166 #ifdef NO_UNARY_PLUS
167 #  define SF_FIX_SHIFT_EOL	(0+2)
168 #  define SF_FL_SHIFT_EOL		(0+4)
169 #else
170 #  define SF_FIX_SHIFT_EOL	(+2)
171 #  define SF_FL_SHIFT_EOL		(+4)
172 #endif
173 
174 #define SF_FIX_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
175 #define SF_FIX_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
176 
177 #define SF_FL_BEFORE_SEOL	(SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
178 #define SF_FL_BEFORE_MEOL	(SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
179 #define SF_IS_INF		0x40
180 #define SF_HAS_PAR		0x80
181 #define SF_IN_PAR		0x100
182 #define SF_HAS_EVAL		0x200
183 #define SCF_DO_SUBSTR		0x400
184 #define SCF_DO_STCLASS_AND	0x0800
185 #define SCF_DO_STCLASS_OR	0x1000
186 #define SCF_DO_STCLASS		(SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
187 #define SCF_WHILEM_VISITED_POS	0x2000
188 
189 #define RF_utf8		8
190 #define UTF (PL_reg_flags & RF_utf8)
191 #define LOC (PL_regflags & PMf_LOCALE)
192 #define FOLD (PL_regflags & PMf_FOLD)
193 
194 #define OOB_CHAR8		1234
195 #define OOB_UTF8		123456
196 #define OOB_NAMEDCLASS		-1
197 
198 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
199 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
200 
201 
202 /* length of regex to show in messages that don't mark a position within */
203 #define RegexLengthToShowInErrorMessages 127
204 
205 /*
206  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
207  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
208  * op/pragma/warn/regcomp.
209  */
210 #define MARKER1 "HERE"      /* marker as it appears in the description */
211 #define MARKER2 " << HERE "  /* marker as it appears within the regex */
212 
213 #define REPORT_LOCATION " before " MARKER1 " mark in regex m/%.*s" MARKER2 "%s/"
214 
215 /*
216  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
217  * arg. Show regex, up to a maximum length. If it's too long, chop and add
218  * "...".
219  */
220 #define	FAIL(msg)                                                             \
221     STMT_START {                                                             \
222         char *ellipses = "";                                                 \
223         unsigned len = strlen(PL_regprecomp);                                \
224                                                                              \
225 	if (!SIZE_ONLY)                                                      \
226 	    SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);                 \
227                                                                              \
228 	if (len > RegexLengthToShowInErrorMessages) {                        \
229             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
230 	    len = RegexLengthToShowInErrorMessages - 10;                     \
231 	    ellipses = "...";                                                \
232 	}                                                                    \
233 	Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                            \
234 		   msg, (int)len, PL_regprecomp, ellipses);                  \
235     } STMT_END
236 
237 /*
238  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
239  * args. Show regex, up to a maximum length. If it's too long, chop and add
240  * "...".
241  */
242 #define	FAIL2(pat,msg)                                                        \
243     STMT_START {                                                             \
244         char *ellipses = "";                                                 \
245         unsigned len = strlen(PL_regprecomp);                                \
246                                                                              \
247 	if (!SIZE_ONLY)                                                      \
248 	    SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);                 \
249                                                                              \
250 	if (len > RegexLengthToShowInErrorMessages) {                        \
251             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
252 	    len = RegexLengthToShowInErrorMessages - 10;                     \
253 	    ellipses = "...";                                                \
254 	}                                                                    \
255 	S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                        \
256 		    msg, (int)len, PL_regprecomp, ellipses);                \
257     } STMT_END
258 
259 
260 /*
261  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
262  */
263 #define	Simple_vFAIL(m)                                                      \
264     STMT_START {                                                             \
265       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-PL_regcomp_parse); \
266                                                                              \
267       Perl_croak(aTHX_ "%s" REPORT_LOCATION,               \
268 		 m, (int)offset, PL_regprecomp, PL_regprecomp + offset);     \
269     } STMT_END
270 
271 /*
272  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
273  */
274 #define	vFAIL(m)                                                             \
275     STMT_START {                                                             \
276       if (!SIZE_ONLY)                                                        \
277 	    SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);                 \
278       Simple_vFAIL(m);                                                       \
279     } STMT_END
280 
281 /*
282  * Like Simple_vFAIL(), but accepts two arguments.
283  */
284 #define	Simple_vFAIL2(m,a1)                                                  \
285     STMT_START {                                                             \
286       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-PL_regcomp_parse); \
287                                                                              \
288       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,       \
289 		  (int)offset, PL_regprecomp, PL_regprecomp + offset);       \
290     } STMT_END
291 
292 /*
293  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
294  */
295 #define	vFAIL2(m,a1)                                                         \
296     STMT_START {                                                             \
297       if (!SIZE_ONLY)                                                        \
298 	    SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);                 \
299       Simple_vFAIL2(m, a1);                                                  \
300     } STMT_END
301 
302 
303 /*
304  * Like Simple_vFAIL(), but accepts three arguments.
305  */
306 #define	Simple_vFAIL3(m, a1, a2)                                             \
307     STMT_START {                                                             \
308       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-PL_regcomp_parse); \
309                                                                              \
310       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,   \
311 		  (int)offset, PL_regprecomp, PL_regprecomp + offset);       \
312     } STMT_END
313 
314 /*
315  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
316  */
317 #define	vFAIL3(m,a1,a2)                                                      \
318     STMT_START {                                                             \
319       if (!SIZE_ONLY)                                                        \
320 	    SAVEDESTRUCTOR_X(clear_re,(void*)PL_regcomp_rx);                 \
321       Simple_vFAIL3(m, a1, a2);                                              \
322     } STMT_END
323 
324 /*
325  * Like Simple_vFAIL(), but accepts four arguments.
326  */
327 #define	Simple_vFAIL4(m, a1, a2, a3)                                         \
328     STMT_START {                                                             \
329       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-PL_regcomp_parse); \
330                                                                              \
331       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,\
332 		  (int)offset, PL_regprecomp, PL_regprecomp + offset);       \
333     } STMT_END
334 
335 /*
336  * Like Simple_vFAIL(), but accepts five arguments.
337  */
338 #define	Simple_vFAIL5(m, a1, a2, a3, a4)                                     \
339     STMT_START {                                                             \
340       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-PL_regcomp_parse); \
341       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,\
342 		  (int)offset, PL_regprecomp, PL_regprecomp + offset);       \
343     } STMT_END
344 
345 
346 #define	vWARN(loc,m)                                                         \
347     STMT_START {                                                             \
348         unsigned offset = strlen(PL_regprecomp)-(PL_regxend-(loc));          \
349 	Perl_warner(aTHX_ WARN_REGEXP, "%s" REPORT_LOCATION,\
350 		 m, (int)offset, PL_regprecomp, PL_regprecomp + offset);          \
351     } STMT_END                                                               \
352 
353 
354 #define	vWARN2(loc, m, a1)                                                   \
355     STMT_START {                                                             \
356         unsigned offset = strlen(PL_regprecomp)-(PL_regxend-(loc));          \
357 	Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
358                  a1,                                                         \
359 		 (int)offset, PL_regprecomp, PL_regprecomp + offset);        \
360     } STMT_END
361 
362 #define	vWARN3(loc, m, a1, a2)                                               \
363     STMT_START {                                                             \
364       unsigned offset = strlen(PL_regprecomp) - (PL_regxend - (loc));        \
365 	Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,                    \
366                  a1, a2,                                                     \
367 		 (int)offset, PL_regprecomp, PL_regprecomp + offset);        \
368     } STMT_END
369 
370 #define	vWARN4(loc, m, a1, a2, a3)                                           \
371     STMT_START {                                                             \
372       unsigned offset = strlen(PL_regprecomp)-(PL_regxend-(loc));            \
373 	Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
374                  a1, a2, a3,                                                 \
375 		 (int)offset, PL_regprecomp, PL_regprecomp + offset);        \
376     } STMT_END
377 
378 
379 
380 /* Allow for side effects in s */
381 #define REGC(c,s) STMT_START { if (!SIZE_ONLY) *(s) = (c); else (s);} STMT_END
382 
383 static void clear_re(pTHXo_ void *r);
384 
385 /* Mark that we cannot extend a found fixed substring at this point.
386    Updata the longest found anchored substring and the longest found
387    floating substrings if needed. */
388 
389 STATIC void
390 S_scan_commit(pTHX_ scan_data_t *data)
391 {
392     STRLEN l = CHR_SVLEN(data->last_found);
393     STRLEN old_l = CHR_SVLEN(*data->longest);
394 
395     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
396 	sv_setsv(*data->longest, data->last_found);
397 	if (*data->longest == data->longest_fixed) {
398 	    data->offset_fixed = l ? data->last_start_min : data->pos_min;
399 	    if (data->flags & SF_BEFORE_EOL)
400 		data->flags
401 		    |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
402 	    else
403 		data->flags &= ~SF_FIX_BEFORE_EOL;
404 	}
405 	else {
406 	    data->offset_float_min = l ? data->last_start_min : data->pos_min;
407 	    data->offset_float_max = (l
408 				      ? data->last_start_max
409 				      : data->pos_min + data->pos_delta);
410 	    if (data->flags & SF_BEFORE_EOL)
411 		data->flags
412 		    |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
413 	    else
414 		data->flags &= ~SF_FL_BEFORE_EOL;
415 	}
416     }
417     SvCUR_set(data->last_found, 0);
418     data->last_end = -1;
419     data->flags &= ~SF_BEFORE_EOL;
420 }
421 
422 /* Can match anything (initialization) */
423 STATIC void
424 S_cl_anything(pTHX_ struct regnode_charclass_class *cl)
425 {
426     int value;
427 
428     ANYOF_CLASS_ZERO(cl);
429     for (value = 0; value < 256; ++value)
430 	ANYOF_BITMAP_SET(cl, value);
431     cl->flags = ANYOF_EOS;
432     if (LOC)
433 	cl->flags |= ANYOF_LOCALE;
434 }
435 
436 /* Can match anything (initialization) */
437 STATIC int
438 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
439 {
440     int value;
441 
442     for (value = 0; value <= ANYOF_MAX; value += 2)
443 	if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
444 	    return 1;
445     for (value = 0; value < 256; ++value)
446 	if (!ANYOF_BITMAP_TEST(cl, value))
447 	    return 0;
448     return 1;
449 }
450 
451 /* Can match anything (initialization) */
452 STATIC void
453 S_cl_init(pTHX_ struct regnode_charclass_class *cl)
454 {
455     Zero(cl, 1, struct regnode_charclass_class);
456     cl->type = ANYOF;
457     cl_anything(cl);
458 }
459 
460 STATIC void
461 S_cl_init_zero(pTHX_ struct regnode_charclass_class *cl)
462 {
463     Zero(cl, 1, struct regnode_charclass_class);
464     cl->type = ANYOF;
465     cl_anything(cl);
466     if (LOC)
467 	cl->flags |= ANYOF_LOCALE;
468 }
469 
470 /* 'And' a given class with another one.  Can create false positives */
471 /* We assume that cl is not inverted */
472 STATIC void
473 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
474 	 struct regnode_charclass_class *and_with)
475 {
476     if (!(and_with->flags & ANYOF_CLASS)
477 	&& !(cl->flags & ANYOF_CLASS)
478 	&& (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
479 	&& !(and_with->flags & ANYOF_FOLD)
480 	&& !(cl->flags & ANYOF_FOLD)) {
481 	int i;
482 
483 	if (and_with->flags & ANYOF_INVERT)
484 	    for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
485 		cl->bitmap[i] &= ~and_with->bitmap[i];
486 	else
487 	    for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
488 		cl->bitmap[i] &= and_with->bitmap[i];
489     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
490     if (!(and_with->flags & ANYOF_EOS))
491 	cl->flags &= ~ANYOF_EOS;
492 }
493 
494 /* 'OR' a given class with another one.  Can create false positives */
495 /* We assume that cl is not inverted */
496 STATIC void
497 S_cl_or(pTHX_ struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
498 {
499     if (or_with->flags & ANYOF_INVERT) {
500 	/* We do not use
501 	 * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
502 	 *   <= (B1 | !B2) | (CL1 | !CL2)
503 	 * which is wasteful if CL2 is small, but we ignore CL2:
504 	 *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
505 	 * XXXX Can we handle case-fold?  Unclear:
506 	 *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
507 	 *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
508 	 */
509 	if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
510 	     && !(or_with->flags & ANYOF_FOLD)
511 	     && !(cl->flags & ANYOF_FOLD) ) {
512 	    int i;
513 
514 	    for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
515 		cl->bitmap[i] |= ~or_with->bitmap[i];
516 	} /* XXXX: logic is complicated otherwise */
517 	else {
518 	    cl_anything(cl);
519 	}
520     } else {
521 	/* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
522 	if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
523 	     && (!(or_with->flags & ANYOF_FOLD)
524 		 || (cl->flags & ANYOF_FOLD)) ) {
525 	    int i;
526 
527 	    /* OR char bitmap and class bitmap separately */
528 	    for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
529 		cl->bitmap[i] |= or_with->bitmap[i];
530 	    if (or_with->flags & ANYOF_CLASS) {
531 		for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
532 		    cl->classflags[i] |= or_with->classflags[i];
533 		cl->flags |= ANYOF_CLASS;
534 	    }
535 	}
536 	else { /* XXXX: logic is complicated, leave it along for a moment. */
537 	    cl_anything(cl);
538 	}
539     }
540     if (or_with->flags & ANYOF_EOS)
541 	cl->flags |= ANYOF_EOS;
542 }
543 
544 /* REx optimizer.  Converts nodes into quickier variants "in place".
545    Finds fixed substrings.  */
546 
547 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
548    to the position after last scanned or to NULL. */
549 
550 STATIC I32
551 S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
552 			/* scanp: Start here (read-write). */
553 			/* deltap: Write maxlen-minlen here. */
554 			/* last: Stop before this one. */
555 {
556     I32 min = 0, pars = 0, code;
557     regnode *scan = *scanp, *next;
558     I32 delta = 0;
559     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
560     int is_inf_internal = 0;		/* The studied chunk is infinite */
561     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
562     scan_data_t data_fake;
563     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
564 
565     while (scan && OP(scan) != END && scan < last) {
566 	/* Peephole optimizer: */
567 
568 	if (PL_regkind[(U8)OP(scan)] == EXACT) {
569 	    /* Merge several consecutive EXACTish nodes into one. */
570 	    regnode *n = regnext(scan);
571 	    U32 stringok = 1;
572 #ifdef DEBUGGING
573 	    regnode *stop = scan;
574 #endif
575 
576 	    next = scan + NODE_SZ_STR(scan);
577 	    /* Skip NOTHING, merge EXACT*. */
578 	    while (n &&
579 		   ( PL_regkind[(U8)OP(n)] == NOTHING ||
580 		     (stringok && (OP(n) == OP(scan))))
581 		   && NEXT_OFF(n)
582 		   && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
583 		if (OP(n) == TAIL || n > next)
584 		    stringok = 0;
585 		if (PL_regkind[(U8)OP(n)] == NOTHING) {
586 		    NEXT_OFF(scan) += NEXT_OFF(n);
587 		    next = n + NODE_STEP_REGNODE;
588 #ifdef DEBUGGING
589 		    if (stringok)
590 			stop = n;
591 #endif
592 		    n = regnext(n);
593 		}
594 		else if (stringok) {
595 		    int oldl = STR_LEN(scan);
596 		    regnode *nnext = regnext(n);
597 
598 		    if (oldl + STR_LEN(n) > U8_MAX)
599 			break;
600 		    NEXT_OFF(scan) += NEXT_OFF(n);
601 		    STR_LEN(scan) += STR_LEN(n);
602 		    next = n + NODE_SZ_STR(n);
603 		    /* Now we can overwrite *n : */
604 		    Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
605 #ifdef DEBUGGING
606 		    stop = next - 1;
607 #endif
608 		    n = nnext;
609 		}
610 	    }
611 #ifdef DEBUGGING
612 	    /* Allow dumping */
613 	    n = scan + NODE_SZ_STR(scan);
614 	    while (n <= stop) {
615 		if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
616 		    OP(n) = OPTIMIZED;
617 		    NEXT_OFF(n) = 0;
618 		}
619 		n++;
620 	    }
621 #endif
622 	}
623 	/* Follow the next-chain of the current node and optimize
624 	   away all the NOTHINGs from it.  */
625 	if (OP(scan) != CURLYX) {
626 	    int max = (reg_off_by_arg[OP(scan)]
627 		       ? I32_MAX
628 		       /* I32 may be smaller than U16 on CRAYs! */
629 		       : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
630 	    int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
631 	    int noff;
632 	    regnode *n = scan;
633 
634 	    /* Skip NOTHING and LONGJMP. */
635 	    while ((n = regnext(n))
636 		   && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
637 		       || ((OP(n) == LONGJMP) && (noff = ARG(n))))
638 		   && off + noff < max)
639 		off += noff;
640 	    if (reg_off_by_arg[OP(scan)])
641 		ARG(scan) = off;
642 	    else
643 		NEXT_OFF(scan) = off;
644 	}
645 	/* The principal pseudo-switch.  Cannot be a switch, since we
646 	   look into several different things.  */
647 	if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
648 		   || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
649 	    next = regnext(scan);
650 	    code = OP(scan);
651 
652 	    if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
653 		I32 max1 = 0, min1 = I32_MAX, num = 0;
654 		struct regnode_charclass_class accum;
655 
656 		if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
657 		    scan_commit(data);	/* Cannot merge strings after this. */
658 		if (flags & SCF_DO_STCLASS)
659 		    cl_init_zero(&accum);
660 		while (OP(scan) == code) {
661 		    I32 deltanext, minnext, f = 0, fake = 0;
662 		    struct regnode_charclass_class this_class;
663 
664 		    num++;
665 		    data_fake.flags = 0;
666 		    if (data) {
667 			data_fake.whilem_c = data->whilem_c;
668 			data_fake.last_closep = data->last_closep;
669 		    }
670 		    else
671 			data_fake.last_closep = &fake;
672 		    next = regnext(scan);
673 		    scan = NEXTOPER(scan);
674 		    if (code != BRANCH)
675 			scan = NEXTOPER(scan);
676 		    if (flags & SCF_DO_STCLASS) {
677 			cl_init(&this_class);
678 			data_fake.start_class = &this_class;
679 			f = SCF_DO_STCLASS_AND;
680 		    }
681 		    if (flags & SCF_WHILEM_VISITED_POS)
682 			f |= SCF_WHILEM_VISITED_POS;
683 		    /* we suppose the run is continuous, last=next...*/
684 		    minnext = study_chunk(&scan, &deltanext, next,
685 					  &data_fake, f);
686 		    if (min1 > minnext)
687 			min1 = minnext;
688 		    if (max1 < minnext + deltanext)
689 			max1 = minnext + deltanext;
690 		    if (deltanext == I32_MAX)
691 			is_inf = is_inf_internal = 1;
692 		    scan = next;
693 		    if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
694 			pars++;
695 		    if (data && (data_fake.flags & SF_HAS_EVAL))
696 			data->flags |= SF_HAS_EVAL;
697 		    if (data)
698 			data->whilem_c = data_fake.whilem_c;
699 		    if (flags & SCF_DO_STCLASS)
700 			cl_or(&accum, &this_class);
701 		    if (code == SUSPEND)
702 			break;
703 		}
704 		if (code == IFTHEN && num < 2) /* Empty ELSE branch */
705 		    min1 = 0;
706 		if (flags & SCF_DO_SUBSTR) {
707 		    data->pos_min += min1;
708 		    data->pos_delta += max1 - min1;
709 		    if (max1 != min1 || is_inf)
710 			data->longest = &(data->longest_float);
711 		}
712 		min += min1;
713 		delta += max1 - min1;
714 		if (flags & SCF_DO_STCLASS_OR) {
715 		    cl_or(data->start_class, &accum);
716 		    if (min1) {
717 			cl_and(data->start_class, &and_with);
718 			flags &= ~SCF_DO_STCLASS;
719 		    }
720 		}
721 		else if (flags & SCF_DO_STCLASS_AND) {
722 		    if (min1) {
723 			cl_and(data->start_class, &accum);
724 			flags &= ~SCF_DO_STCLASS;
725 		    }
726 		    else {
727 			/* Switch to OR mode: cache the old value of
728 			 * data->start_class */
729 			StructCopy(data->start_class, &and_with,
730 				   struct regnode_charclass_class);
731 			flags &= ~SCF_DO_STCLASS_AND;
732 			StructCopy(&accum, data->start_class,
733 				   struct regnode_charclass_class);
734 			flags |= SCF_DO_STCLASS_OR;
735 			data->start_class->flags |= ANYOF_EOS;
736 		    }
737 		}
738 	    }
739 	    else if (code == BRANCHJ)	/* single branch is optimized. */
740 		scan = NEXTOPER(NEXTOPER(scan));
741 	    else			/* single branch is optimized. */
742 		scan = NEXTOPER(scan);
743 	    continue;
744 	}
745 	else if (OP(scan) == EXACT) {
746 	    I32 l = STR_LEN(scan);
747 	    if (UTF) {
748 		unsigned char *s = (unsigned char *)STRING(scan);
749 		unsigned char *e = s + l;
750 		I32 newl = 0;
751 		while (s < e) {
752 		    newl++;
753 		    s += UTF8SKIP(s);
754 		}
755 		l = newl;
756 	    }
757 	    min += l;
758 	    if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
759 		/* The code below prefers earlier match for fixed
760 		   offset, later match for variable offset.  */
761 		if (data->last_end == -1) { /* Update the start info. */
762 		    data->last_start_min = data->pos_min;
763  		    data->last_start_max = is_inf
764  			? I32_MAX : data->pos_min + data->pos_delta;
765 		}
766 		sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
767 		data->last_end = data->pos_min + l;
768 		data->pos_min += l; /* As in the first entry. */
769 		data->flags &= ~SF_BEFORE_EOL;
770 	    }
771 	    if (flags & SCF_DO_STCLASS_AND) {
772 		/* Check whether it is compatible with what we know already! */
773 		int compat = 1;
774 
775 		if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
776 		    && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
777 		    && (!(data->start_class->flags & ANYOF_FOLD)
778 			|| !ANYOF_BITMAP_TEST(data->start_class,
779 					      PL_fold[*(U8*)STRING(scan)])))
780 		    compat = 0;
781 		ANYOF_CLASS_ZERO(data->start_class);
782 		ANYOF_BITMAP_ZERO(data->start_class);
783 		if (compat)
784 		    ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
785 		data->start_class->flags &= ~ANYOF_EOS;
786 	    }
787 	    else if (flags & SCF_DO_STCLASS_OR) {
788 		/* false positive possible if the class is case-folded */
789 		ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
790 		data->start_class->flags &= ~ANYOF_EOS;
791 		cl_and(data->start_class, &and_with);
792 	    }
793 	    flags &= ~SCF_DO_STCLASS;
794 	}
795 	else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
796 	    I32 l = STR_LEN(scan);
797 
798 	    /* Search for fixed substrings supports EXACT only. */
799 	    if (flags & SCF_DO_SUBSTR)
800 		scan_commit(data);
801 	    if (UTF) {
802 		unsigned char *s = (unsigned char *)STRING(scan);
803 		unsigned char *e = s + l;
804 		I32 newl = 0;
805 		while (s < e) {
806 		    newl++;
807 		    s += UTF8SKIP(s);
808 		}
809 		l = newl;
810 	    }
811 	    min += l;
812 	    if (data && (flags & SCF_DO_SUBSTR))
813 		data->pos_min += l;
814 	    if (flags & SCF_DO_STCLASS_AND) {
815 		/* Check whether it is compatible with what we know already! */
816 		int compat = 1;
817 
818 		if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
819 		    && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
820 		    && !ANYOF_BITMAP_TEST(data->start_class,
821 					  PL_fold[*(U8*)STRING(scan)]))
822 		    compat = 0;
823 		ANYOF_CLASS_ZERO(data->start_class);
824 		ANYOF_BITMAP_ZERO(data->start_class);
825 		if (compat) {
826 		    ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
827 		    data->start_class->flags &= ~ANYOF_EOS;
828 		    data->start_class->flags |= ANYOF_FOLD;
829 		    if (OP(scan) == EXACTFL)
830 			data->start_class->flags |= ANYOF_LOCALE;
831 		}
832 	    }
833 	    else if (flags & SCF_DO_STCLASS_OR) {
834 		if (data->start_class->flags & ANYOF_FOLD) {
835 		    /* false positive possible if the class is case-folded.
836 		       Assume that the locale settings are the same... */
837 		    ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
838 		    data->start_class->flags &= ~ANYOF_EOS;
839 		}
840 		cl_and(data->start_class, &and_with);
841 	    }
842 	    flags &= ~SCF_DO_STCLASS;
843 	}
844 	else if (strchr((char*)PL_varies,OP(scan))) {
845 	    I32 mincount, maxcount, minnext, deltanext, fl;
846 	    I32 f = flags, pos_before = 0;
847 	    regnode *oscan = scan;
848 	    struct regnode_charclass_class this_class;
849 	    struct regnode_charclass_class *oclass = NULL;
850 
851 	    switch (PL_regkind[(U8)OP(scan)]) {
852 	    case WHILEM:		/* End of (?:...)* . */
853 		scan = NEXTOPER(scan);
854 		goto finish;
855 	    case PLUS:
856 		if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
857 		    next = NEXTOPER(scan);
858 		    if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
859 			mincount = 1;
860 			maxcount = REG_INFTY;
861 			next = regnext(scan);
862 			scan = NEXTOPER(scan);
863 			goto do_curly;
864 		    }
865 		}
866 		if (flags & SCF_DO_SUBSTR)
867 		    data->pos_min++;
868 		min++;
869 		/* Fall through. */
870 	    case STAR:
871 		if (flags & SCF_DO_STCLASS) {
872 		    mincount = 0;
873 		    maxcount = REG_INFTY;
874 		    next = regnext(scan);
875 		    scan = NEXTOPER(scan);
876 		    goto do_curly;
877 		}
878 		is_inf = is_inf_internal = 1;
879 		scan = regnext(scan);
880 		if (flags & SCF_DO_SUBSTR) {
881 		    scan_commit(data);	/* Cannot extend fixed substrings */
882 		    data->longest = &(data->longest_float);
883 		}
884 		goto optimize_curly_tail;
885 	    case CURLY:
886 		mincount = ARG1(scan);
887 		maxcount = ARG2(scan);
888 		next = regnext(scan);
889 		if (OP(scan) == CURLYX) {
890 		    I32 lp = (data ? *(data->last_closep) : 0);
891 
892 		    scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
893 		}
894 		scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
895 	      do_curly:
896 		if (flags & SCF_DO_SUBSTR) {
897 		    if (mincount == 0) scan_commit(data); /* Cannot extend fixed substrings */
898 		    pos_before = data->pos_min;
899 		}
900 		if (data) {
901 		    fl = data->flags;
902 		    data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
903 		    if (is_inf)
904 			data->flags |= SF_IS_INF;
905 		}
906 		if (flags & SCF_DO_STCLASS) {
907 		    cl_init(&this_class);
908 		    oclass = data->start_class;
909 		    data->start_class = &this_class;
910 		    f |= SCF_DO_STCLASS_AND;
911 		    f &= ~SCF_DO_STCLASS_OR;
912 		}
913 		/* These are the cases when once a subexpression
914 		   fails at a particular position, it cannot succeed
915 		   even after backtracking at the enclosing scope.
916 
917 		   XXXX what if minimal match and we are at the
918 		        initial run of {n,m}? */
919 		if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
920 		    f &= ~SCF_WHILEM_VISITED_POS;
921 
922 		/* This will finish on WHILEM, setting scan, or on NULL: */
923 		minnext = study_chunk(&scan, &deltanext, last, data,
924 				      mincount == 0
925 					? (f & ~SCF_DO_SUBSTR) : f);
926 
927 		if (flags & SCF_DO_STCLASS)
928 		    data->start_class = oclass;
929 		if (mincount == 0 || minnext == 0) {
930 		    if (flags & SCF_DO_STCLASS_OR) {
931 			cl_or(data->start_class, &this_class);
932 		    }
933 		    else if (flags & SCF_DO_STCLASS_AND) {
934 			/* Switch to OR mode: cache the old value of
935 			 * data->start_class */
936 			StructCopy(data->start_class, &and_with,
937 				   struct regnode_charclass_class);
938 			flags &= ~SCF_DO_STCLASS_AND;
939 			StructCopy(&this_class, data->start_class,
940 				   struct regnode_charclass_class);
941 			flags |= SCF_DO_STCLASS_OR;
942 			data->start_class->flags |= ANYOF_EOS;
943 		    }
944 		} else {		/* Non-zero len */
945 		    if (flags & SCF_DO_STCLASS_OR) {
946 			cl_or(data->start_class, &this_class);
947 			cl_and(data->start_class, &and_with);
948 		    }
949 		    else if (flags & SCF_DO_STCLASS_AND)
950 			cl_and(data->start_class, &this_class);
951 		    flags &= ~SCF_DO_STCLASS;
952 		}
953 		if (!scan) 		/* It was not CURLYX, but CURLY. */
954 		    scan = next;
955 		if (ckWARN(WARN_REGEXP) && (minnext + deltanext == 0)
956 		    && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
957 		    && maxcount <= REG_INFTY/3) /* Complement check for big count */
958 		{
959 		    vWARN(PL_regcomp_parse,
960 			  "Quantifier unexpected on zero-length expression");
961 		}
962 
963 		min += minnext * mincount;
964 		is_inf_internal |= ((maxcount == REG_INFTY
965 				     && (minnext + deltanext) > 0)
966 				    || deltanext == I32_MAX);
967 		is_inf |= is_inf_internal;
968 		delta += (minnext + deltanext) * maxcount - minnext * mincount;
969 
970 		/* Try powerful optimization CURLYX => CURLYN. */
971 		if (  OP(oscan) == CURLYX && data
972 		      && data->flags & SF_IN_PAR
973 		      && !(data->flags & SF_HAS_EVAL)
974 		      && !deltanext && minnext == 1 ) {
975 		    /* Try to optimize to CURLYN.  */
976 		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
977 		    regnode *nxt1 = nxt, *nxt2;
978 
979 		    /* Skip open. */
980 		    nxt = regnext(nxt);
981 		    if (!strchr((char*)PL_simple,OP(nxt))
982 			&& !(PL_regkind[(U8)OP(nxt)] == EXACT
983 			     && STR_LEN(nxt) == 1))
984 			goto nogo;
985 		    nxt2 = nxt;
986 		    nxt = regnext(nxt);
987 		    if (OP(nxt) != CLOSE)
988 			goto nogo;
989 		    /* Now we know that nxt2 is the only contents: */
990 		    oscan->flags = ARG(nxt);
991 		    OP(oscan) = CURLYN;
992 		    OP(nxt1) = NOTHING;	/* was OPEN. */
993 #ifdef DEBUGGING
994 		    OP(nxt1 + 1) = OPTIMIZED; /* was count. */
995 		    NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
996 		    NEXT_OFF(nxt2) = 0;	/* just for consistancy with CURLY. */
997 		    OP(nxt) = OPTIMIZED;	/* was CLOSE. */
998 		    OP(nxt + 1) = OPTIMIZED; /* was count. */
999 		    NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1000 #endif
1001 		}
1002 	      nogo:
1003 
1004 		/* Try optimization CURLYX => CURLYM. */
1005 		if (  OP(oscan) == CURLYX && data
1006 		      && !(data->flags & SF_HAS_PAR)
1007 		      && !(data->flags & SF_HAS_EVAL)
1008 		      && !deltanext  ) {
1009 		    /* XXXX How to optimize if data == 0? */
1010 		    /* Optimize to a simpler form.  */
1011 		    regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1012 		    regnode *nxt2;
1013 
1014 		    OP(oscan) = CURLYM;
1015 		    while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1016 			    && (OP(nxt2) != WHILEM))
1017 			nxt = nxt2;
1018 		    OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1019 		    /* Need to optimize away parenths. */
1020 		    if (data->flags & SF_IN_PAR) {
1021 			/* Set the parenth number.  */
1022 			regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1023 
1024 			if (OP(nxt) != CLOSE)
1025 			    FAIL("Panic opt close");
1026 			oscan->flags = ARG(nxt);
1027 			OP(nxt1) = OPTIMIZED;	/* was OPEN. */
1028 			OP(nxt) = OPTIMIZED;	/* was CLOSE. */
1029 #ifdef DEBUGGING
1030 			OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1031 			OP(nxt + 1) = OPTIMIZED; /* was count. */
1032 			NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1033 			NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1034 #endif
1035 #if 0
1036 			while ( nxt1 && (OP(nxt1) != WHILEM)) {
1037 			    regnode *nnxt = regnext(nxt1);
1038 
1039 			    if (nnxt == nxt) {
1040 				if (reg_off_by_arg[OP(nxt1)])
1041 				    ARG_SET(nxt1, nxt2 - nxt1);
1042 				else if (nxt2 - nxt1 < U16_MAX)
1043 				    NEXT_OFF(nxt1) = nxt2 - nxt1;
1044 				else
1045 				    OP(nxt) = NOTHING;	/* Cannot beautify */
1046 			    }
1047 			    nxt1 = nnxt;
1048 			}
1049 #endif
1050 			/* Optimize again: */
1051 			study_chunk(&nxt1, &deltanext, nxt, NULL, 0);
1052 		    }
1053 		    else
1054 			oscan->flags = 0;
1055 		}
1056 		else if ((OP(oscan) == CURLYX)
1057 			 && (flags & SCF_WHILEM_VISITED_POS)
1058 			 /* See the comment on a similar expression above.
1059 			    However, this time it not a subexpression
1060 			    we care about, but the expression itself. */
1061 			 && (maxcount == REG_INFTY)
1062 			 && data && ++data->whilem_c < 16) {
1063 		    /* This stays as CURLYX, we can put the count/of pair. */
1064 		    /* Find WHILEM (as in regexec.c) */
1065 		    regnode *nxt = oscan + NEXT_OFF(oscan);
1066 
1067 		    if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1068 			nxt += ARG(nxt);
1069 		    PREVOPER(nxt)->flags = data->whilem_c
1070 			| (PL_reg_whilem_seen << 4); /* On WHILEM */
1071 		}
1072 		if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1073 		    pars++;
1074 		if (flags & SCF_DO_SUBSTR) {
1075 		    SV *last_str = Nullsv;
1076 		    int counted = mincount != 0;
1077 
1078 		    if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1079 			I32 b = pos_before >= data->last_start_min
1080 			    ? pos_before : data->last_start_min;
1081 			STRLEN l;
1082 			char *s = SvPV(data->last_found, l);
1083 			I32 old = b - data->last_start_min;
1084 
1085 			if (UTF)
1086 			    old = utf8_hop((U8*)s, old) - (U8*)s;
1087 
1088 			l -= old;
1089 			/* Get the added string: */
1090 			last_str = newSVpvn(s  + old, l);
1091 			if (deltanext == 0 && pos_before == b) {
1092 			    /* What was added is a constant string */
1093 			    if (mincount > 1) {
1094 				SvGROW(last_str, (mincount * l) + 1);
1095 				repeatcpy(SvPVX(last_str) + l,
1096 					  SvPVX(last_str), l, mincount - 1);
1097 				SvCUR(last_str) *= mincount;
1098 				/* Add additional parts. */
1099 				SvCUR_set(data->last_found,
1100 					  SvCUR(data->last_found) - l);
1101 				sv_catsv(data->last_found, last_str);
1102 				data->last_end += l * (mincount - 1);
1103 			    }
1104 			} else {
1105 			    /* start offset must point into the last copy */
1106 			    data->last_start_min += minnext * (mincount - 1);
1107 			    data->last_start_max += is_inf ? 0 : (maxcount - 1)
1108 				* (minnext + data->pos_delta);
1109 			}
1110 		    }
1111 		    /* It is counted once already... */
1112 		    data->pos_min += minnext * (mincount - counted);
1113 		    data->pos_delta += - counted * deltanext +
1114 			(minnext + deltanext) * maxcount - minnext * mincount;
1115 		    if (mincount != maxcount) {
1116 			 /* Cannot extend fixed substrings found inside
1117 			    the group.  */
1118 			scan_commit(data);
1119 			if (mincount && last_str) {
1120 			    sv_setsv(data->last_found, last_str);
1121 			    data->last_end = data->pos_min;
1122 			    data->last_start_min =
1123 				data->pos_min - CHR_SVLEN(last_str);
1124 			    data->last_start_max = is_inf
1125 				? I32_MAX
1126 				: data->pos_min + data->pos_delta
1127 				- CHR_SVLEN(last_str);
1128 			}
1129 			data->longest = &(data->longest_float);
1130 		    }
1131 		    SvREFCNT_dec(last_str);
1132 		}
1133 		if (data && (fl & SF_HAS_EVAL))
1134 		    data->flags |= SF_HAS_EVAL;
1135 	      optimize_curly_tail:
1136 		if (OP(oscan) != CURLYX) {
1137 		    while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1138 			   && NEXT_OFF(next))
1139 			NEXT_OFF(oscan) += NEXT_OFF(next);
1140 		}
1141 		continue;
1142 	    default:			/* REF and CLUMP only? */
1143 		if (flags & SCF_DO_SUBSTR) {
1144 		    scan_commit(data);	/* Cannot expect anything... */
1145 		    data->longest = &(data->longest_float);
1146 		}
1147 		is_inf = is_inf_internal = 1;
1148 		if (flags & SCF_DO_STCLASS_OR)
1149 		    cl_anything(data->start_class);
1150 		flags &= ~SCF_DO_STCLASS;
1151 		break;
1152 	    }
1153 	}
1154 	else if (strchr((char*)PL_simple,OP(scan)) || PL_regkind[(U8)OP(scan)] == ANYUTF8) {
1155 	    int value;
1156 
1157 	    if (flags & SCF_DO_SUBSTR) {
1158 		scan_commit(data);
1159 		data->pos_min++;
1160 	    }
1161 	    min++;
1162 	    if (flags & SCF_DO_STCLASS) {
1163 		data->start_class->flags &= ~ANYOF_EOS;	/* No match on empty */
1164 
1165 		/* Some of the logic below assumes that switching
1166 		   locale on will only add false positives. */
1167 		switch (PL_regkind[(U8)OP(scan)]) {
1168 		case ANYUTF8:
1169 		case SANY:
1170 		case SANYUTF8:
1171 		case ALNUMUTF8:
1172 		case ANYOFUTF8:
1173 		case ALNUMLUTF8:
1174 		case NALNUMUTF8:
1175 		case NALNUMLUTF8:
1176 		case SPACEUTF8:
1177 		case NSPACEUTF8:
1178 		case SPACELUTF8:
1179 		case NSPACELUTF8:
1180 		case DIGITUTF8:
1181 		case NDIGITUTF8:
1182 		default:
1183 		  do_default:
1184 		    /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1185 		    if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1186 			cl_anything(data->start_class);
1187 		    break;
1188 		case REG_ANY:
1189 		    if (OP(scan) == SANY)
1190 			goto do_default;
1191 		    if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1192 			value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1193 				 || (data->start_class->flags & ANYOF_CLASS));
1194 			cl_anything(data->start_class);
1195 		    }
1196 		    if (flags & SCF_DO_STCLASS_AND || !value)
1197 			ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1198 		    break;
1199 		case ANYOF:
1200 		    if (flags & SCF_DO_STCLASS_AND)
1201 			cl_and(data->start_class,
1202 			       (struct regnode_charclass_class*)scan);
1203 		    else
1204 			cl_or(data->start_class,
1205 			      (struct regnode_charclass_class*)scan);
1206 		    break;
1207 		case ALNUM:
1208 		    if (flags & SCF_DO_STCLASS_AND) {
1209 			if (!(data->start_class->flags & ANYOF_LOCALE)) {
1210 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1211 			    for (value = 0; value < 256; value++)
1212 				if (!isALNUM(value))
1213 				    ANYOF_BITMAP_CLEAR(data->start_class, value);
1214 			}
1215 		    }
1216 		    else {
1217 			if (data->start_class->flags & ANYOF_LOCALE)
1218 			    ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1219 			else {
1220 			    for (value = 0; value < 256; value++)
1221 				if (isALNUM(value))
1222 				    ANYOF_BITMAP_SET(data->start_class, value);
1223 			}
1224 		    }
1225 		    break;
1226 		case ALNUML:
1227 		    if (flags & SCF_DO_STCLASS_AND) {
1228 			if (data->start_class->flags & ANYOF_LOCALE)
1229 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1230 		    }
1231 		    else {
1232 			ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1233 			data->start_class->flags |= ANYOF_LOCALE;
1234 		    }
1235 		    break;
1236 		case NALNUM:
1237 		    if (flags & SCF_DO_STCLASS_AND) {
1238 			if (!(data->start_class->flags & ANYOF_LOCALE)) {
1239 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1240 			    for (value = 0; value < 256; value++)
1241 				if (isALNUM(value))
1242 				    ANYOF_BITMAP_CLEAR(data->start_class, value);
1243 			}
1244 		    }
1245 		    else {
1246 			if (data->start_class->flags & ANYOF_LOCALE)
1247 			    ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1248 			else {
1249 			    for (value = 0; value < 256; value++)
1250 				if (!isALNUM(value))
1251 				    ANYOF_BITMAP_SET(data->start_class, value);
1252 			}
1253 		    }
1254 		    break;
1255 		case NALNUML:
1256 		    if (flags & SCF_DO_STCLASS_AND) {
1257 			if (data->start_class->flags & ANYOF_LOCALE)
1258 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1259 		    }
1260 		    else {
1261 			data->start_class->flags |= ANYOF_LOCALE;
1262 			ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1263 		    }
1264 		    break;
1265 		case SPACE:
1266 		    if (flags & SCF_DO_STCLASS_AND) {
1267 			if (!(data->start_class->flags & ANYOF_LOCALE)) {
1268 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1269 			    for (value = 0; value < 256; value++)
1270 				if (!isSPACE(value))
1271 				    ANYOF_BITMAP_CLEAR(data->start_class, value);
1272 			}
1273 		    }
1274 		    else {
1275 			if (data->start_class->flags & ANYOF_LOCALE)
1276 			    ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1277 			else {
1278 			    for (value = 0; value < 256; value++)
1279 				if (isSPACE(value))
1280 				    ANYOF_BITMAP_SET(data->start_class, value);
1281 			}
1282 		    }
1283 		    break;
1284 		case SPACEL:
1285 		    if (flags & SCF_DO_STCLASS_AND) {
1286 			if (data->start_class->flags & ANYOF_LOCALE)
1287 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1288 		    }
1289 		    else {
1290 			data->start_class->flags |= ANYOF_LOCALE;
1291 			ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1292 		    }
1293 		    break;
1294 		case NSPACE:
1295 		    if (flags & SCF_DO_STCLASS_AND) {
1296 			if (!(data->start_class->flags & ANYOF_LOCALE)) {
1297 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1298 			    for (value = 0; value < 256; value++)
1299 				if (isSPACE(value))
1300 				    ANYOF_BITMAP_CLEAR(data->start_class, value);
1301 			}
1302 		    }
1303 		    else {
1304 			if (data->start_class->flags & ANYOF_LOCALE)
1305 			    ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1306 			else {
1307 			    for (value = 0; value < 256; value++)
1308 				if (!isSPACE(value))
1309 				    ANYOF_BITMAP_SET(data->start_class, value);
1310 			}
1311 		    }
1312 		    break;
1313 		case NSPACEL:
1314 		    if (flags & SCF_DO_STCLASS_AND) {
1315 			if (data->start_class->flags & ANYOF_LOCALE) {
1316 			    ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1317 			    for (value = 0; value < 256; value++)
1318 				if (!isSPACE(value))
1319 				    ANYOF_BITMAP_CLEAR(data->start_class, value);
1320 			}
1321 		    }
1322 		    else {
1323 			data->start_class->flags |= ANYOF_LOCALE;
1324 			ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1325 		    }
1326 		    break;
1327 		case DIGIT:
1328 		    if (flags & SCF_DO_STCLASS_AND) {
1329 			ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1330 			for (value = 0; value < 256; value++)
1331 			    if (!isDIGIT(value))
1332 				ANYOF_BITMAP_CLEAR(data->start_class, value);
1333 		    }
1334 		    else {
1335 			if (data->start_class->flags & ANYOF_LOCALE)
1336 			    ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1337 			else {
1338 			    for (value = 0; value < 256; value++)
1339 				if (isDIGIT(value))
1340 				    ANYOF_BITMAP_SET(data->start_class, value);
1341 			}
1342 		    }
1343 		    break;
1344 		case NDIGIT:
1345 		    if (flags & SCF_DO_STCLASS_AND) {
1346 			ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1347 			for (value = 0; value < 256; value++)
1348 			    if (isDIGIT(value))
1349 				ANYOF_BITMAP_CLEAR(data->start_class, value);
1350 		    }
1351 		    else {
1352 			if (data->start_class->flags & ANYOF_LOCALE)
1353 			    ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1354 			else {
1355 			    for (value = 0; value < 256; value++)
1356 				if (!isDIGIT(value))
1357 				    ANYOF_BITMAP_SET(data->start_class, value);
1358 			}
1359 		    }
1360 		    break;
1361 		}
1362 		if (flags & SCF_DO_STCLASS_OR)
1363 		    cl_and(data->start_class, &and_with);
1364 		flags &= ~SCF_DO_STCLASS;
1365 	    }
1366 	}
1367 	else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1368 	    data->flags |= (OP(scan) == MEOL
1369 			    ? SF_BEFORE_MEOL
1370 			    : SF_BEFORE_SEOL);
1371 	}
1372 	else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1373 		 /* Lookbehind, or need to calculate parens/evals/stclass: */
1374 		   && (scan->flags || data || (flags & SCF_DO_STCLASS))
1375 		   && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1376 	    /* Lookahead/lookbehind */
1377 	    I32 deltanext, minnext, fake = 0;
1378 	    regnode *nscan;
1379 	    struct regnode_charclass_class intrnl;
1380 	    int f = 0;
1381 
1382 	    data_fake.flags = 0;
1383 	    if (data) {
1384 		data_fake.whilem_c = data->whilem_c;
1385 		data_fake.last_closep = data->last_closep;
1386 	    }
1387 	    else
1388 		data_fake.last_closep = &fake;
1389 	    if ( flags & SCF_DO_STCLASS && !scan->flags
1390 		 && OP(scan) == IFMATCH ) { /* Lookahead */
1391 		cl_init(&intrnl);
1392 		data_fake.start_class = &intrnl;
1393 		f |= SCF_DO_STCLASS_AND;
1394 	    }
1395 	    if (flags & SCF_WHILEM_VISITED_POS)
1396 		f |= SCF_WHILEM_VISITED_POS;
1397 	    next = regnext(scan);
1398 	    nscan = NEXTOPER(NEXTOPER(scan));
1399 	    minnext = study_chunk(&nscan, &deltanext, last, &data_fake, f);
1400 	    if (scan->flags) {
1401 		if (deltanext) {
1402 		    vFAIL("Variable length lookbehind not implemented");
1403 		}
1404 		else if (minnext > U8_MAX) {
1405 		    vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1406 		}
1407 		scan->flags = minnext;
1408 	    }
1409 	    if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1410 		pars++;
1411 	    if (data && (data_fake.flags & SF_HAS_EVAL))
1412 		data->flags |= SF_HAS_EVAL;
1413 	    if (data)
1414 		data->whilem_c = data_fake.whilem_c;
1415 	    if (f & SCF_DO_STCLASS_AND) {
1416 		int was = (data->start_class->flags & ANYOF_EOS);
1417 
1418 		cl_and(data->start_class, &intrnl);
1419 		if (was)
1420 		    data->start_class->flags |= ANYOF_EOS;
1421 	    }
1422 	}
1423 	else if (OP(scan) == OPEN) {
1424 	    pars++;
1425 	}
1426 	else if (OP(scan) == CLOSE) {
1427 	    if (ARG(scan) == is_par) {
1428 		next = regnext(scan);
1429 
1430 		if ( next && (OP(next) != WHILEM) && next < last)
1431 		    is_par = 0;		/* Disable optimization */
1432 	    }
1433 	    if (data)
1434 		*(data->last_closep) = ARG(scan);
1435 	}
1436 	else if (OP(scan) == EVAL) {
1437 		if (data)
1438 		    data->flags |= SF_HAS_EVAL;
1439 	}
1440 	else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1441 		if (flags & SCF_DO_SUBSTR) {
1442 		    scan_commit(data);
1443 		    data->longest = &(data->longest_float);
1444 		}
1445 		is_inf = is_inf_internal = 1;
1446 		if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1447 		    cl_anything(data->start_class);
1448 		flags &= ~SCF_DO_STCLASS;
1449 	}
1450 	/* Else: zero-length, ignore. */
1451 	scan = regnext(scan);
1452     }
1453 
1454   finish:
1455     *scanp = scan;
1456     *deltap = is_inf_internal ? I32_MAX : delta;
1457     if (flags & SCF_DO_SUBSTR && is_inf)
1458 	data->pos_delta = I32_MAX - data->pos_min;
1459     if (is_par > U8_MAX)
1460 	is_par = 0;
1461     if (is_par && pars==1 && data) {
1462 	data->flags |= SF_IN_PAR;
1463 	data->flags &= ~SF_HAS_PAR;
1464     }
1465     else if (pars && data) {
1466 	data->flags |= SF_HAS_PAR;
1467 	data->flags &= ~SF_IN_PAR;
1468     }
1469     if (flags & SCF_DO_STCLASS_OR)
1470 	cl_and(data->start_class, &and_with);
1471     return min;
1472 }
1473 
1474 STATIC I32
1475 S_add_data(pTHX_ I32 n, char *s)
1476 {
1477     if (PL_regcomp_rx->data) {
1478 	Renewc(PL_regcomp_rx->data,
1479 	       sizeof(*PL_regcomp_rx->data) + sizeof(void*) * (PL_regcomp_rx->data->count + n - 1),
1480 	       char, struct reg_data);
1481 	Renew(PL_regcomp_rx->data->what, PL_regcomp_rx->data->count + n, U8);
1482 	PL_regcomp_rx->data->count += n;
1483     }
1484     else {
1485 	Newc(1207, PL_regcomp_rx->data, sizeof(*PL_regcomp_rx->data) + sizeof(void*) * (n - 1),
1486 	     char, struct reg_data);
1487 	New(1208, PL_regcomp_rx->data->what, n, U8);
1488 	PL_regcomp_rx->data->count = n;
1489     }
1490     Copy(s, PL_regcomp_rx->data->what + PL_regcomp_rx->data->count - n, n, U8);
1491     return PL_regcomp_rx->data->count - n;
1492 }
1493 
1494 void
1495 Perl_reginitcolors(pTHX)
1496 {
1497     int i = 0;
1498     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1499 
1500     if (s) {
1501 	PL_colors[0] = s = savepv(s);
1502 	while (++i < 6) {
1503 	    s = strchr(s, '\t');
1504 	    if (s) {
1505 		*s = '\0';
1506 		PL_colors[i] = ++s;
1507 	    }
1508 	    else
1509 		PL_colors[i] = s = "";
1510 	}
1511     } else {
1512 	while (i < 6)
1513 	    PL_colors[i++] = "";
1514     }
1515     PL_colorset = 1;
1516 }
1517 
1518 
1519 /*
1520  - pregcomp - compile a regular expression into internal code
1521  *
1522  * We can't allocate space until we know how big the compiled form will be,
1523  * but we can't compile it (and thus know how big it is) until we've got a
1524  * place to put the code.  So we cheat:  we compile it twice, once with code
1525  * generation turned off and size counting turned on, and once "for real".
1526  * This also means that we don't allocate space until we are sure that the
1527  * thing really will compile successfully, and we never have to move the
1528  * code and thus invalidate pointers into it.  (Note that it has to be in
1529  * one piece because free() must be able to free it all.) [NB: not true in perl]
1530  *
1531  * Beware that the optimization-preparation code in here knows about some
1532  * of the structure of the compiled regexp.  [I'll say.]
1533  */
1534 regexp *
1535 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1536 {
1537     register regexp *r;
1538     regnode *scan;
1539     regnode *first;
1540     I32 flags;
1541     I32 minlen = 0;
1542     I32 sawplus = 0;
1543     I32 sawopen = 0;
1544     scan_data_t data;
1545 
1546     if (exp == NULL)
1547 	FAIL("NULL regexp argument");
1548 
1549     if (pm->op_pmdynflags & PMdf_UTF8) {
1550 	PL_reg_flags |= RF_utf8;
1551     }
1552     else
1553 	PL_reg_flags = 0;
1554 
1555     PL_regprecomp = exp;
1556     DEBUG_r(if (!PL_colorset) reginitcolors());
1557     DEBUG_r(PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1558 		      PL_colors[4],PL_colors[5],PL_colors[0],
1559 		      (int)(xend - exp), PL_regprecomp, PL_colors[1]));
1560     PL_regflags = pm->op_pmflags;
1561     PL_regsawback = 0;
1562 
1563     PL_regseen = 0;
1564     PL_seen_zerolen = *exp == '^' ? -1 : 0;
1565     PL_seen_evals = 0;
1566     PL_extralen = 0;
1567 
1568     /* First pass: determine size, legality. */
1569     PL_regcomp_parse = exp;
1570     PL_regxend = xend;
1571     PL_regnaughty = 0;
1572     PL_regnpar = 1;
1573     PL_regsize = 0L;
1574     PL_regcode = &PL_regdummy;
1575     PL_reg_whilem_seen = 0;
1576 #if 0 /* REGC() is (currently) a NOP at the first pass.
1577        * Clever compilers notice this and complain. --jhi */
1578     REGC((U8)REG_MAGIC, (char*)PL_regcode);
1579 #endif
1580     if (reg(0, &flags) == NULL) {
1581 	PL_regprecomp = Nullch;
1582 	return(NULL);
1583     }
1584     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)PL_regsize));
1585 
1586     /* Small enough for pointer-storage convention?
1587        If extralen==0, this means that we will not need long jumps. */
1588     if (PL_regsize >= 0x10000L && PL_extralen)
1589         PL_regsize += PL_extralen;
1590     else
1591 	PL_extralen = 0;
1592     if (PL_reg_whilem_seen > 15)
1593 	PL_reg_whilem_seen = 15;
1594 
1595     /* Allocate space and initialize. */
1596     Newc(1001, r, sizeof(regexp) + (unsigned)PL_regsize * sizeof(regnode),
1597 	 char, regexp);
1598     if (r == NULL)
1599 	FAIL("Regexp out of space");
1600 
1601 #ifdef DEBUGGING
1602     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1603     Zero(r, sizeof(regexp) + (unsigned)PL_regsize * sizeof(regnode), char);
1604 #endif
1605     r->refcnt = 1;
1606     r->prelen = xend - exp;
1607     r->precomp = savepvn(PL_regprecomp, r->prelen);
1608     r->subbeg = NULL;
1609     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1610     r->nparens = PL_regnpar - 1;	/* set early to validate backrefs */
1611 
1612     r->substrs = 0;			/* Useful during FAIL. */
1613     r->startp = 0;			/* Useful during FAIL. */
1614     r->endp = 0;			/* Useful during FAIL. */
1615 
1616     PL_regcomp_rx = r;
1617 
1618     /* Second pass: emit code. */
1619     PL_regcomp_parse = exp;
1620     PL_regxend = xend;
1621     PL_regnaughty = 0;
1622     PL_regnpar = 1;
1623     PL_regcode = r->program;
1624     /* Store the count of eval-groups for security checks: */
1625     PL_regcode->next_off = ((PL_seen_evals > U16_MAX) ? U16_MAX : PL_seen_evals);
1626     REGC((U8)REG_MAGIC, (char*) PL_regcode++);
1627     r->data = 0;
1628     if (reg(0, &flags) == NULL)
1629 	return(NULL);
1630 
1631     /* Dig out information for optimizations. */
1632     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1633     pm->op_pmflags = PL_regflags;
1634     if (UTF)
1635 	r->reganch |= ROPT_UTF8;
1636     r->regstclass = NULL;
1637     if (PL_regnaughty >= 10)	/* Probably an expensive pattern. */
1638 	r->reganch |= ROPT_NAUGHTY;
1639     scan = r->program + 1;		/* First BRANCH. */
1640 
1641     /* XXXX To minimize changes to RE engine we always allocate
1642        3-units-long substrs field. */
1643     Newz(1004, r->substrs, 1, struct reg_substr_data);
1644 
1645     StructCopy(&zero_scan_data, &data, scan_data_t);
1646     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1647     if (OP(scan) != BRANCH) {	/* Only one top-level choice. */
1648 	I32 fake;
1649 	STRLEN longest_float_length, longest_fixed_length;
1650 	struct regnode_charclass_class ch_class;
1651 	int stclass_flag;
1652 	I32 last_close = 0;
1653 
1654 	first = scan;
1655 	/* Skip introductions and multiplicators >= 1. */
1656 	while ((OP(first) == OPEN && (sawopen = 1)) ||
1657 	       /* An OR of *one* alternative - should not happen now. */
1658 	    (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1659 	    (OP(first) == PLUS) ||
1660 	    (OP(first) == MINMOD) ||
1661 	       /* An {n,m} with n>0 */
1662 	    (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1663 		if (OP(first) == PLUS)
1664 		    sawplus = 1;
1665 		else
1666 		    first += regarglen[(U8)OP(first)];
1667 		first = NEXTOPER(first);
1668 	}
1669 
1670 	/* Starting-point info. */
1671       again:
1672 	if (PL_regkind[(U8)OP(first)] == EXACT) {
1673 	    if (OP(first) == EXACT);	/* Empty, get anchored substr later. */
1674 	    else if ((OP(first) == EXACTF || OP(first) == EXACTFL)
1675 		     && !UTF)
1676 		r->regstclass = first;
1677 	}
1678 	else if (strchr((char*)PL_simple,OP(first)))
1679 	    r->regstclass = first;
1680 	else if (PL_regkind[(U8)OP(first)] == BOUND ||
1681 		 PL_regkind[(U8)OP(first)] == NBOUND)
1682 	    r->regstclass = first;
1683 	else if (PL_regkind[(U8)OP(first)] == BOL) {
1684 	    r->reganch |= (OP(first) == MBOL
1685 			   ? ROPT_ANCH_MBOL
1686 			   : (OP(first) == SBOL
1687 			      ? ROPT_ANCH_SBOL
1688 			      : ROPT_ANCH_BOL));
1689 	    first = NEXTOPER(first);
1690 	    goto again;
1691 	}
1692 	else if (OP(first) == GPOS) {
1693 	    r->reganch |= ROPT_ANCH_GPOS;
1694 	    first = NEXTOPER(first);
1695 	    goto again;
1696 	}
1697 	else if ((OP(first) == STAR &&
1698 	    PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1699 	    !(r->reganch & ROPT_ANCH) )
1700 	{
1701 	    /* turn .* into ^.* with an implied $*=1 */
1702 	    int type = OP(NEXTOPER(first));
1703 
1704 	    if (type == REG_ANY || type == ANYUTF8)
1705 		type = ROPT_ANCH_MBOL;
1706 	    else
1707 		type = ROPT_ANCH_SBOL;
1708 
1709 	    r->reganch |= type | ROPT_IMPLICIT;
1710 	    first = NEXTOPER(first);
1711 	    goto again;
1712 	}
1713 	if (sawplus && (!sawopen || !PL_regsawback)
1714 	    && !(PL_regseen & REG_SEEN_EVAL)) /* May examine pos and $& */
1715 	    /* x+ must match at the 1st pos of run of x's */
1716 	    r->reganch |= ROPT_SKIP;
1717 
1718 	/* Scan is after the zeroth branch, first is atomic matcher. */
1719 	DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1720 			      (IV)(first - scan + 1)));
1721 	/*
1722 	* If there's something expensive in the r.e., find the
1723 	* longest literal string that must appear and make it the
1724 	* regmust.  Resolve ties in favor of later strings, since
1725 	* the regstart check works with the beginning of the r.e.
1726 	* and avoiding duplication strengthens checking.  Not a
1727 	* strong reason, but sufficient in the absence of others.
1728 	* [Now we resolve ties in favor of the earlier string if
1729 	* it happens that c_offset_min has been invalidated, since the
1730 	* earlier string may buy us something the later one won't.]
1731 	*/
1732 	minlen = 0;
1733 
1734 	data.longest_fixed = newSVpvn("",0);
1735 	data.longest_float = newSVpvn("",0);
1736 	data.last_found = newSVpvn("",0);
1737 	data.longest = &(data.longest_fixed);
1738 	first = scan;
1739 	if (!r->regstclass) {
1740 	    cl_init(&ch_class);
1741 	    data.start_class = &ch_class;
1742 	    stclass_flag = SCF_DO_STCLASS_AND;
1743 	} else				/* XXXX Check for BOUND? */
1744 	    stclass_flag = 0;
1745 	data.last_closep = &last_close;
1746 
1747 	minlen = study_chunk(&first, &fake, scan + PL_regsize, /* Up to end */
1748 			     &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1749 	if ( PL_regnpar == 1 && data.longest == &(data.longest_fixed)
1750 	     && data.last_start_min == 0 && data.last_end > 0
1751 	     && !PL_seen_zerolen
1752 	     && (!(PL_regseen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1753 	    r->reganch |= ROPT_CHECK_ALL;
1754 	scan_commit(&data);
1755 	SvREFCNT_dec(data.last_found);
1756 
1757 	longest_float_length = CHR_SVLEN(data.longest_float);
1758 	if (longest_float_length
1759 	    || (data.flags & SF_FL_BEFORE_EOL
1760 		&& (!(data.flags & SF_FL_BEFORE_MEOL)
1761 		    || (PL_regflags & PMf_MULTILINE)))) {
1762 	    int t;
1763 
1764 	    if (SvCUR(data.longest_fixed) 			/* ok to leave SvCUR */
1765 		&& data.offset_fixed == data.offset_float_min
1766 		&& SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1767 		    goto remove_float;		/* As in (a)+. */
1768 
1769 	    r->float_substr = data.longest_float;
1770 	    r->float_min_offset = data.offset_float_min;
1771 	    r->float_max_offset = data.offset_float_max;
1772 	    t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1773 		       && (!(data.flags & SF_FL_BEFORE_MEOL)
1774 			   || (PL_regflags & PMf_MULTILINE)));
1775 	    fbm_compile(r->float_substr, t ? FBMcf_TAIL : 0);
1776 	}
1777 	else {
1778 	  remove_float:
1779 	    r->float_substr = Nullsv;
1780 	    SvREFCNT_dec(data.longest_float);
1781 	    longest_float_length = 0;
1782 	}
1783 
1784 	longest_fixed_length = CHR_SVLEN(data.longest_fixed);
1785 	if (longest_fixed_length
1786 	    || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
1787 		&& (!(data.flags & SF_FIX_BEFORE_MEOL)
1788 		    || (PL_regflags & PMf_MULTILINE)))) {
1789 	    int t;
1790 
1791 	    r->anchored_substr = data.longest_fixed;
1792 	    r->anchored_offset = data.offset_fixed;
1793 	    t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
1794 		 && (!(data.flags & SF_FIX_BEFORE_MEOL)
1795 		     || (PL_regflags & PMf_MULTILINE)));
1796 	    fbm_compile(r->anchored_substr, t ? FBMcf_TAIL : 0);
1797 	}
1798 	else {
1799 	    r->anchored_substr = Nullsv;
1800 	    SvREFCNT_dec(data.longest_fixed);
1801 	    longest_fixed_length = 0;
1802 	}
1803 	if (r->regstclass
1804 	    && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == ANYUTF8
1805 		|| OP(r->regstclass) == SANYUTF8 || OP(r->regstclass) == SANY))
1806 	    r->regstclass = NULL;
1807 	if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
1808 	    && !(data.start_class->flags & ANYOF_EOS)
1809 	    && !cl_is_anything(data.start_class)) {
1810 	    SV *sv;
1811 	    I32 n = add_data(1, "f");
1812 
1813 	    New(1006, PL_regcomp_rx->data->data[n], 1,
1814 		struct regnode_charclass_class);
1815 	    StructCopy(data.start_class,
1816 		       (struct regnode_charclass_class*)PL_regcomp_rx->data->data[n],
1817 		       struct regnode_charclass_class);
1818 	    r->regstclass = (regnode*)PL_regcomp_rx->data->data[n];
1819 	    r->reganch &= ~ROPT_SKIP;	/* Used in find_byclass(). */
1820 	    DEBUG_r((sv = sv_newmortal(),
1821 		     regprop(sv, (regnode*)data.start_class),
1822 		     PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1823 				   SvPVX(sv))));
1824 	}
1825 
1826 	/* A temporary algorithm prefers floated substr to fixed one to dig more info. */
1827 	if (longest_fixed_length > longest_float_length) {
1828 	    r->check_substr = r->anchored_substr;
1829 	    r->check_offset_min = r->check_offset_max = r->anchored_offset;
1830 	    if (r->reganch & ROPT_ANCH_SINGLE)
1831 		r->reganch |= ROPT_NOSCAN;
1832 	}
1833 	else {
1834 	    r->check_substr = r->float_substr;
1835 	    r->check_offset_min = data.offset_float_min;
1836 	    r->check_offset_max = data.offset_float_max;
1837 	}
1838 	/* XXXX Currently intuiting is not compatible with ANCH_GPOS.
1839 	   This should be changed ASAP!  */
1840 	if (r->check_substr && !(r->reganch & ROPT_ANCH_GPOS)) {
1841 	    r->reganch |= RE_USE_INTUIT;
1842 	    if (SvTAIL(r->check_substr))
1843 		r->reganch |= RE_INTUIT_TAIL;
1844 	}
1845     }
1846     else {
1847 	/* Several toplevels. Best we can is to set minlen. */
1848 	I32 fake;
1849 	struct regnode_charclass_class ch_class;
1850 	I32 last_close = 0;
1851 
1852 	DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
1853 	scan = r->program + 1;
1854 	cl_init(&ch_class);
1855 	data.start_class = &ch_class;
1856 	data.last_closep = &last_close;
1857 	minlen = study_chunk(&scan, &fake, scan + PL_regsize, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
1858 	r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
1859 	if (!(data.start_class->flags & ANYOF_EOS)
1860 	    && !cl_is_anything(data.start_class)) {
1861 	    SV *sv;
1862 	    I32 n = add_data(1, "f");
1863 
1864 	    New(1006, PL_regcomp_rx->data->data[n], 1,
1865 		struct regnode_charclass_class);
1866 	    StructCopy(data.start_class,
1867 		       (struct regnode_charclass_class*)PL_regcomp_rx->data->data[n],
1868 		       struct regnode_charclass_class);
1869 	    r->regstclass = (regnode*)PL_regcomp_rx->data->data[n];
1870 	    r->reganch &= ~ROPT_SKIP;	/* Used in find_byclass(). */
1871 	    DEBUG_r((sv = sv_newmortal(),
1872 		     regprop(sv, (regnode*)data.start_class),
1873 		     PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1874 				   SvPVX(sv))));
1875 	}
1876     }
1877 
1878     r->minlen = minlen;
1879     if (PL_regseen & REG_SEEN_GPOS)
1880 	r->reganch |= ROPT_GPOS_SEEN;
1881     if (PL_regseen & REG_SEEN_LOOKBEHIND)
1882 	r->reganch |= ROPT_LOOKBEHIND_SEEN;
1883     if (PL_regseen & REG_SEEN_EVAL)
1884 	r->reganch |= ROPT_EVAL_SEEN;
1885     Newz(1002, r->startp, PL_regnpar, I32);
1886     Newz(1002, r->endp, PL_regnpar, I32);
1887     PL_regdata = r->data; /* for regprop() ANYOFUTF8 */
1888     DEBUG_r(regdump(r));
1889     return(r);
1890 }
1891 
1892 /*
1893  - reg - regular expression, i.e. main body or parenthesized thing
1894  *
1895  * Caller must absorb opening parenthesis.
1896  *
1897  * Combining parenthesis handling with the base level of regular expression
1898  * is a trifle forced, but the need to tie the tails of the branches to what
1899  * follows makes it hard to avoid.
1900  */
1901 STATIC regnode *
1902 S_reg(pTHX_ I32 paren, I32 *flagp)
1903     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
1904 {
1905     register regnode *ret;		/* Will be the head of the group. */
1906     register regnode *br;
1907     register regnode *lastbr;
1908     register regnode *ender = 0;
1909     register I32 parno = 0;
1910     I32 flags, oregflags = PL_regflags, have_branch = 0, open = 0;
1911     char *oregcomp_parse = PL_regcomp_parse;
1912     char c;
1913 
1914     *flagp = 0;				/* Tentatively. */
1915 
1916     /* Make an OPEN node, if parenthesized. */
1917     if (paren) {
1918 	if (*PL_regcomp_parse == '?') {
1919 	    U16 posflags = 0, negflags = 0;
1920 	    U16 *flagsp = &posflags;
1921 	    int logical = 0;
1922 	    char *seqstart = PL_regcomp_parse;
1923 
1924 	    PL_regcomp_parse++;
1925 	    paren = *PL_regcomp_parse++;
1926 	    ret = NULL;			/* For look-ahead/behind. */
1927 	    switch (paren) {
1928 	    case '<':
1929 		PL_regseen |= REG_SEEN_LOOKBEHIND;
1930 		if (*PL_regcomp_parse == '!')
1931 		    paren = ',';
1932 		if (*PL_regcomp_parse != '=' && *PL_regcomp_parse != '!')
1933 		    goto unknown;
1934 		PL_regcomp_parse++;
1935 	    case '=':
1936 	    case '!':
1937 		PL_seen_zerolen++;
1938 	    case ':':
1939 	    case '>':
1940 		break;
1941 	    case '$':
1942 	    case '@':
1943 		vFAIL2("Sequence (?%c...) not implemented", (int)paren);
1944 		break;
1945 	    case '#':
1946 		while (*PL_regcomp_parse && *PL_regcomp_parse != ')')
1947 		    PL_regcomp_parse++;
1948 		if (*PL_regcomp_parse != ')')
1949 		    FAIL("Sequence (?#... not terminated");
1950 		nextchar();
1951 		*flagp = TRYAGAIN;
1952 		return NULL;
1953 	    case 'p':
1954 		if (SIZE_ONLY)
1955 		    vWARN(PL_regcomp_parse, "(?p{}) is deprecated - use (??{})");
1956 		/* FALL THROUGH*/
1957 	    case '?':
1958 		logical = 1;
1959 		paren = *PL_regcomp_parse++;
1960 		/* FALL THROUGH */
1961 	    case '{':
1962 	    {
1963 		I32 count = 1, n = 0;
1964 		char c;
1965 		char *s = PL_regcomp_parse;
1966 		SV *sv;
1967 		OP_4tree *sop, *rop;
1968 
1969 		PL_seen_zerolen++;
1970 		PL_regseen |= REG_SEEN_EVAL;
1971 		while (count && (c = *PL_regcomp_parse)) {
1972 		    if (c == '\\' && PL_regcomp_parse[1])
1973 			PL_regcomp_parse++;
1974 		    else if (c == '{')
1975 			count++;
1976 		    else if (c == '}')
1977 			count--;
1978 		    PL_regcomp_parse++;
1979 		}
1980 		if (*PL_regcomp_parse != ')')
1981 		{
1982 		    PL_regcomp_parse = s;
1983 		    vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
1984 		}
1985 		if (!SIZE_ONLY) {
1986 		    AV *av;
1987 
1988 		    if (PL_regcomp_parse - 1 - s)
1989 			sv = newSVpvn(s, PL_regcomp_parse - 1 - s);
1990 		    else
1991 			sv = newSVpvn("", 0);
1992 
1993 		    ENTER;
1994 		    Perl_save_re_context(aTHX);
1995 		    rop = sv_compile_2op(sv, &sop, "re", &av);
1996 		    LEAVE;
1997 
1998 		    n = add_data(3, "nop");
1999 		    PL_regcomp_rx->data->data[n] = (void*)rop;
2000 		    PL_regcomp_rx->data->data[n+1] = (void*)sop;
2001 		    PL_regcomp_rx->data->data[n+2] = (void*)av;
2002 		    SvREFCNT_dec(sv);
2003 		}
2004 		else {						/* First pass */
2005 		    if (PL_reginterp_cnt < ++PL_seen_evals
2006 			&& PL_curcop != &PL_compiling)
2007 			/* No compiled RE interpolated, has runtime
2008 			   components ===> unsafe.  */
2009 			FAIL("Eval-group not allowed at runtime, use re 'eval'");
2010 		    if (PL_tainted)
2011 			FAIL("Eval-group in insecure regular expression");
2012 		}
2013 
2014 		nextchar();
2015 		if (logical) {
2016 		    ret = reg_node(LOGICAL);
2017 		    if (!SIZE_ONLY)
2018 			ret->flags = 2;
2019 		    regtail(ret, reganode(EVAL, n));
2020 		    return ret;
2021 		}
2022 		return reganode(EVAL, n);
2023 	    }
2024 	    case '(':
2025 	    {
2026 		if (PL_regcomp_parse[0] == '?') {
2027 		    if (PL_regcomp_parse[1] == '=' || PL_regcomp_parse[1] == '!'
2028 			|| PL_regcomp_parse[1] == '<'
2029 			|| PL_regcomp_parse[1] == '{') { /* Lookahead or eval. */
2030 			I32 flag;
2031 
2032 			ret = reg_node(LOGICAL);
2033 			if (!SIZE_ONLY)
2034 			    ret->flags = 1;
2035 			regtail(ret, reg(1, &flag));
2036 			goto insert_if;
2037 		    }
2038 		}
2039 		else if (PL_regcomp_parse[0] >= '1' && PL_regcomp_parse[0] <= '9' ) {
2040 		    parno = atoi(PL_regcomp_parse++);
2041 
2042 		    while (isDIGIT(*PL_regcomp_parse))
2043 			PL_regcomp_parse++;
2044 		    ret = reganode(GROUPP, parno);
2045 		    if ((c = *nextchar()) != ')')
2046 			vFAIL("Switch condition not recognized");
2047 		  insert_if:
2048 		    regtail(ret, reganode(IFTHEN, 0));
2049 		    br = regbranch(&flags, 1);
2050 		    if (br == NULL)
2051 			br = reganode(LONGJMP, 0);
2052 		    else
2053 			regtail(br, reganode(LONGJMP, 0));
2054 		    c = *nextchar();
2055 		    if (flags&HASWIDTH)
2056 			*flagp |= HASWIDTH;
2057 		    if (c == '|') {
2058 			lastbr = reganode(IFTHEN, 0); /* Fake one for optimizer. */
2059 			regbranch(&flags, 1);
2060 			regtail(ret, lastbr);
2061 		 	if (flags&HASWIDTH)
2062 			    *flagp |= HASWIDTH;
2063 			c = *nextchar();
2064 		    }
2065 		    else
2066 			lastbr = NULL;
2067 		    if (c != ')')
2068 			vFAIL("Switch (?(condition)... contains too many branches");
2069 		    ender = reg_node(TAIL);
2070 		    regtail(br, ender);
2071 		    if (lastbr) {
2072 			regtail(lastbr, ender);
2073 			regtail(NEXTOPER(NEXTOPER(lastbr)), ender);
2074 		    }
2075 		    else
2076 			regtail(ret, ender);
2077 		    return ret;
2078 		}
2079 		else {
2080 		    vFAIL2("Unknown switch condition (?(%.2s", PL_regcomp_parse);
2081 		}
2082 	    }
2083             case 0:
2084 		PL_regcomp_parse--; /* for vFAIL to print correctly */
2085                 vFAIL("Sequence (? incomplete");
2086                 break;
2087 	    default:
2088 		--PL_regcomp_parse;
2089 	      parse_flags:
2090 		while (*PL_regcomp_parse && strchr("iogcmsx", *PL_regcomp_parse)) {
2091 		    if (*PL_regcomp_parse != 'o')
2092 			pmflag(flagsp, *PL_regcomp_parse);
2093 		    ++PL_regcomp_parse;
2094 		}
2095 		if (*PL_regcomp_parse == '-') {
2096 		    flagsp = &negflags;
2097 		    ++PL_regcomp_parse;
2098 		    goto parse_flags;
2099 		}
2100 		PL_regflags |= posflags;
2101 		PL_regflags &= ~negflags;
2102 		if (*PL_regcomp_parse == ':') {
2103 		    PL_regcomp_parse++;
2104 		    paren = ':';
2105 		    break;
2106 		}
2107 	      unknown:
2108 		if (*PL_regcomp_parse != ')') {
2109 		    PL_regcomp_parse++;
2110 		    vFAIL3("Sequence (%.*s...) not recognized", PL_regcomp_parse-seqstart, seqstart);
2111 		}
2112 		nextchar();
2113 		*flagp = TRYAGAIN;
2114 		return NULL;
2115 	    }
2116 	}
2117 	else {
2118 	    parno = PL_regnpar;
2119 	    PL_regnpar++;
2120 	    ret = reganode(OPEN, parno);
2121 	    open = 1;
2122 	}
2123     }
2124     else
2125 	ret = NULL;
2126 
2127     /* Pick up the branches, linking them together. */
2128     br = regbranch(&flags, 1);
2129     if (br == NULL)
2130 	return(NULL);
2131     if (*PL_regcomp_parse == '|') {
2132 	if (!SIZE_ONLY && PL_extralen) {
2133 	    reginsert(BRANCHJ, br);
2134 	}
2135 	else
2136 	    reginsert(BRANCH, br);
2137 	have_branch = 1;
2138 	if (SIZE_ONLY)
2139 	    PL_extralen += 1;		/* For BRANCHJ-BRANCH. */
2140     }
2141     else if (paren == ':') {
2142 	*flagp |= flags&SIMPLE;
2143     }
2144     if (open) {				/* Starts with OPEN. */
2145 	regtail(ret, br);		/* OPEN -> first. */
2146     }
2147     else if (paren != '?')		/* Not Conditional */
2148 	ret = br;
2149     if (flags&HASWIDTH)
2150 	*flagp |= HASWIDTH;
2151     *flagp |= flags&SPSTART;
2152     lastbr = br;
2153     while (*PL_regcomp_parse == '|') {
2154 	if (!SIZE_ONLY && PL_extralen) {
2155 	    ender = reganode(LONGJMP,0);
2156 	    regtail(NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2157 	}
2158 	if (SIZE_ONLY)
2159 	    PL_extralen += 2;		/* Account for LONGJMP. */
2160 	nextchar();
2161 	br = regbranch(&flags, 0);
2162 	if (br == NULL)
2163 	    return(NULL);
2164 	regtail(lastbr, br);		/* BRANCH -> BRANCH. */
2165 	lastbr = br;
2166 	if (flags&HASWIDTH)
2167 	    *flagp |= HASWIDTH;
2168 	*flagp |= flags&SPSTART;
2169     }
2170 
2171     if (have_branch || paren != ':') {
2172 	/* Make a closing node, and hook it on the end. */
2173 	switch (paren) {
2174 	case ':':
2175 	    ender = reg_node(TAIL);
2176 	    break;
2177 	case 1:
2178 	    ender = reganode(CLOSE, parno);
2179 	    break;
2180 	case '<':
2181 	case ',':
2182 	case '=':
2183 	case '!':
2184 	    *flagp &= ~HASWIDTH;
2185 	    /* FALL THROUGH */
2186 	case '>':
2187 	    ender = reg_node(SUCCEED);
2188 	    break;
2189 	case 0:
2190 	    ender = reg_node(END);
2191 	    break;
2192 	}
2193 	regtail(lastbr, ender);
2194 
2195 	if (have_branch) {
2196 	    /* Hook the tails of the branches to the closing node. */
2197 	    for (br = ret; br != NULL; br = regnext(br)) {
2198 		regoptail(br, ender);
2199 	    }
2200 	}
2201     }
2202 
2203     {
2204 	char *p;
2205 	static char parens[] = "=!<,>";
2206 
2207 	if (paren && (p = strchr(parens, paren))) {
2208 	    int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2209 	    int flag = (p - parens) > 1;
2210 
2211 	    if (paren == '>')
2212 		node = SUSPEND, flag = 0;
2213 	    reginsert(node,ret);
2214 	    ret->flags = flag;
2215 	    regtail(ret, reg_node(TAIL));
2216 	}
2217     }
2218 
2219     /* Check for proper termination. */
2220     if (paren) {
2221 	PL_regflags = oregflags;
2222 	if (PL_regcomp_parse >= PL_regxend || *nextchar() != ')') {
2223 	    PL_regcomp_parse = oregcomp_parse;
2224 	    vFAIL("Unmatched (");
2225 	}
2226     }
2227     else if (!paren && PL_regcomp_parse < PL_regxend) {
2228 	if (*PL_regcomp_parse == ')') {
2229 	    PL_regcomp_parse++;
2230 	    vFAIL("Unmatched )");
2231 	}
2232 	else
2233 	    FAIL("Junk on end of regexp");	/* "Can't happen". */
2234 	/* NOTREACHED */
2235     }
2236 
2237     return(ret);
2238 }
2239 
2240 /*
2241  - regbranch - one alternative of an | operator
2242  *
2243  * Implements the concatenation operator.
2244  */
2245 STATIC regnode *
2246 S_regbranch(pTHX_ I32 *flagp, I32 first)
2247 {
2248     register regnode *ret;
2249     register regnode *chain = NULL;
2250     register regnode *latest;
2251     I32 flags = 0, c = 0;
2252 
2253     if (first)
2254 	ret = NULL;
2255     else {
2256 	if (!SIZE_ONLY && PL_extralen)
2257 	    ret = reganode(BRANCHJ,0);
2258 	else
2259 	    ret = reg_node(BRANCH);
2260     }
2261 
2262     if (!first && SIZE_ONLY)
2263 	PL_extralen += 1;			/* BRANCHJ */
2264 
2265     *flagp = WORST;			/* Tentatively. */
2266 
2267     PL_regcomp_parse--;
2268     nextchar();
2269     while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != '|' && *PL_regcomp_parse != ')') {
2270 	flags &= ~TRYAGAIN;
2271 	latest = regpiece(&flags);
2272 	if (latest == NULL) {
2273 	    if (flags & TRYAGAIN)
2274 		continue;
2275 	    return(NULL);
2276 	}
2277 	else if (ret == NULL)
2278 	    ret = latest;
2279 	*flagp |= flags&HASWIDTH;
2280 	if (chain == NULL) 	/* First piece. */
2281 	    *flagp |= flags&SPSTART;
2282 	else {
2283 	    PL_regnaughty++;
2284 	    regtail(chain, latest);
2285 	}
2286 	chain = latest;
2287 	c++;
2288     }
2289     if (chain == NULL) {	/* Loop ran zero times. */
2290 	chain = reg_node(NOTHING);
2291 	if (ret == NULL)
2292 	    ret = chain;
2293     }
2294     if (c == 1) {
2295 	*flagp |= flags&SIMPLE;
2296     }
2297 
2298     return(ret);
2299 }
2300 
2301 /*
2302  - regpiece - something followed by possible [*+?]
2303  *
2304  * Note that the branching code sequences used for ? and the general cases
2305  * of * and + are somewhat optimized:  they use the same NOTHING node as
2306  * both the endmarker for their branch list and the body of the last branch.
2307  * It might seem that this node could be dispensed with entirely, but the
2308  * endmarker role is not redundant.
2309  */
2310 STATIC regnode *
2311 S_regpiece(pTHX_ I32 *flagp)
2312 {
2313     register regnode *ret;
2314     register char op;
2315     register char *next;
2316     I32 flags;
2317     char *origparse = PL_regcomp_parse;
2318     char *maxpos;
2319     I32 min;
2320     I32 max = REG_INFTY;
2321 
2322     ret = regatom(&flags);
2323     if (ret == NULL) {
2324 	if (flags & TRYAGAIN)
2325 	    *flagp |= TRYAGAIN;
2326 	return(NULL);
2327     }
2328 
2329     op = *PL_regcomp_parse;
2330 
2331     if (op == '{' && regcurly(PL_regcomp_parse)) {
2332 	next = PL_regcomp_parse + 1;
2333 	maxpos = Nullch;
2334 	while (isDIGIT(*next) || *next == ',') {
2335 	    if (*next == ',') {
2336 		if (maxpos)
2337 		    break;
2338 		else
2339 		    maxpos = next;
2340 	    }
2341 	    next++;
2342 	}
2343 	if (*next == '}') {		/* got one */
2344 	    if (!maxpos)
2345 		maxpos = next;
2346 	    PL_regcomp_parse++;
2347 	    min = atoi(PL_regcomp_parse);
2348 	    if (*maxpos == ',')
2349 		maxpos++;
2350 	    else
2351 		maxpos = PL_regcomp_parse;
2352 	    max = atoi(maxpos);
2353 	    if (!max && *maxpos != '0')
2354 		max = REG_INFTY;		/* meaning "infinity" */
2355 	    else if (max >= REG_INFTY)
2356 		vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2357 	    PL_regcomp_parse = next;
2358 	    nextchar();
2359 
2360 	do_curly:
2361 	    if ((flags&SIMPLE)) {
2362 		PL_regnaughty += 2 + PL_regnaughty / 2;
2363 		reginsert(CURLY, ret);
2364 	    }
2365 	    else {
2366 		regnode *w = reg_node(WHILEM);
2367 
2368 		w->flags = 0;
2369 		regtail(ret, w);
2370 		if (!SIZE_ONLY && PL_extralen) {
2371 		    reginsert(LONGJMP,ret);
2372 		    reginsert(NOTHING,ret);
2373 		    NEXT_OFF(ret) = 3;	/* Go over LONGJMP. */
2374 		}
2375 		reginsert(CURLYX,ret);
2376 		if (!SIZE_ONLY && PL_extralen)
2377 		    NEXT_OFF(ret) = 3;	/* Go over NOTHING to LONGJMP. */
2378 		regtail(ret, reg_node(NOTHING));
2379 		if (SIZE_ONLY)
2380 		    PL_reg_whilem_seen++, PL_extralen += 3;
2381 		PL_regnaughty += 4 + PL_regnaughty;	/* compound interest */
2382 	    }
2383 	    ret->flags = 0;
2384 
2385 	    if (min > 0)
2386 		*flagp = WORST;
2387 	    if (max > 0)
2388 		*flagp |= HASWIDTH;
2389 	    if (max && max < min)
2390 		vFAIL("Can't do {n,m} with n > m");
2391 	    if (!SIZE_ONLY) {
2392 		ARG1_SET(ret, min);
2393 		ARG2_SET(ret, max);
2394 	    }
2395 
2396 	    goto nest_check;
2397 	}
2398     }
2399 
2400     if (!ISMULT1(op)) {
2401 	*flagp = flags;
2402 	return(ret);
2403     }
2404 
2405 #if 0				/* Now runtime fix should be reliable. */
2406 
2407     /* if this is reinstated, don't forget to put this back into perldiag:
2408 
2409 	    =item Regexp *+ operand could be empty at {#} in regex m/%s/
2410 
2411 	   (F) The part of the regexp subject to either the * or + quantifier
2412            could match an empty string. The {#} shows in the regular
2413            expression about where the problem was discovered.
2414 
2415     */
2416 
2417     if (!(flags&HASWIDTH) && op != '?')
2418       vFAIL("Regexp *+ operand could be empty");
2419 #endif
2420 
2421     nextchar();
2422 
2423     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2424 
2425     if (op == '*' && (flags&SIMPLE)) {
2426 	reginsert(STAR, ret);
2427 	ret->flags = 0;
2428 	PL_regnaughty += 4;
2429     }
2430     else if (op == '*') {
2431 	min = 0;
2432 	goto do_curly;
2433     }
2434     else if (op == '+' && (flags&SIMPLE)) {
2435 	reginsert(PLUS, ret);
2436 	ret->flags = 0;
2437 	PL_regnaughty += 3;
2438     }
2439     else if (op == '+') {
2440 	min = 1;
2441 	goto do_curly;
2442     }
2443     else if (op == '?') {
2444 	min = 0; max = 1;
2445 	goto do_curly;
2446     }
2447   nest_check:
2448     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2449 	vWARN3(PL_regcomp_parse,
2450 	       "%.*s matches null string many times",
2451 	       PL_regcomp_parse - origparse,
2452 	       origparse);
2453     }
2454 
2455     if (*PL_regcomp_parse == '?') {
2456 	nextchar();
2457 	reginsert(MINMOD, ret);
2458 	regtail(ret, ret + NODE_STEP_REGNODE);
2459     }
2460     if (ISMULT2(PL_regcomp_parse)) {
2461 	PL_regcomp_parse++;
2462 	vFAIL("Nested quantifiers");
2463     }
2464 
2465     return(ret);
2466 }
2467 
2468 /*
2469  - regatom - the lowest level
2470  *
2471  * Optimization:  gobbles an entire sequence of ordinary characters so that
2472  * it can turn them into a single node, which is smaller to store and
2473  * faster to run.  Backslashed characters are exceptions, each becoming a
2474  * separate node; the code is simpler that way and it's not worth fixing.
2475  *
2476  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2477 STATIC regnode *
2478 S_regatom(pTHX_ I32 *flagp)
2479 {
2480     register regnode *ret = 0;
2481     I32 flags;
2482 
2483     *flagp = WORST;		/* Tentatively. */
2484 
2485 tryagain:
2486     switch (*PL_regcomp_parse) {
2487     case '^':
2488 	PL_seen_zerolen++;
2489 	nextchar();
2490 	if (PL_regflags & PMf_MULTILINE)
2491 	    ret = reg_node(MBOL);
2492 	else if (PL_regflags & PMf_SINGLELINE)
2493 	    ret = reg_node(SBOL);
2494 	else
2495 	    ret = reg_node(BOL);
2496 	break;
2497     case '$':
2498 	nextchar();
2499 	if (*PL_regcomp_parse)
2500 	    PL_seen_zerolen++;
2501 	if (PL_regflags & PMf_MULTILINE)
2502 	    ret = reg_node(MEOL);
2503 	else if (PL_regflags & PMf_SINGLELINE)
2504 	    ret = reg_node(SEOL);
2505 	else
2506 	    ret = reg_node(EOL);
2507 	break;
2508     case '.':
2509 	nextchar();
2510 	if (UTF) {
2511 	    if (PL_regflags & PMf_SINGLELINE)
2512 		ret = reg_node(SANYUTF8);
2513 	    else
2514 		ret = reg_node(ANYUTF8);
2515 	    *flagp |= HASWIDTH;
2516 	}
2517 	else {
2518 	    if (PL_regflags & PMf_SINGLELINE)
2519 		ret = reg_node(SANY);
2520 	    else
2521 		ret = reg_node(REG_ANY);
2522 	    *flagp |= HASWIDTH|SIMPLE;
2523 	}
2524 	PL_regnaughty++;
2525 	break;
2526     case '[':
2527     {
2528 	char *oregcomp_parse = ++PL_regcomp_parse;
2529 	ret = (UTF ? regclassutf8() : regclass());
2530 	if (*PL_regcomp_parse != ']') {
2531 	    PL_regcomp_parse = oregcomp_parse;
2532 	    vFAIL("Unmatched [");
2533 	}
2534 	nextchar();
2535 	*flagp |= HASWIDTH|SIMPLE;
2536 	break;
2537     }
2538     case '(':
2539 	nextchar();
2540 	ret = reg(1, &flags);
2541 	if (ret == NULL) {
2542 		if (flags & TRYAGAIN) {
2543 		    if (PL_regcomp_parse == PL_regxend) {
2544 			 /* Make parent create an empty node if needed. */
2545 			*flagp |= TRYAGAIN;
2546 			return(NULL);
2547 		    }
2548 		    goto tryagain;
2549 		}
2550 		return(NULL);
2551 	}
2552 	*flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2553 	break;
2554     case '|':
2555     case ')':
2556 	if (flags & TRYAGAIN) {
2557 	    *flagp |= TRYAGAIN;
2558 	    return NULL;
2559 	}
2560 	vFAIL("Internal urp");
2561 				/* Supposed to be caught earlier. */
2562 	break;
2563     case '{':
2564 	if (!regcurly(PL_regcomp_parse)) {
2565 	    PL_regcomp_parse++;
2566 	    goto defchar;
2567 	}
2568 	/* FALL THROUGH */
2569     case '?':
2570     case '+':
2571     case '*':
2572 	PL_regcomp_parse++;
2573 	vFAIL("Quantifier follows nothing");
2574 	break;
2575     case '\\':
2576 	switch (*++PL_regcomp_parse) {
2577 	case 'A':
2578 	    PL_seen_zerolen++;
2579 	    ret = reg_node(SBOL);
2580 	    *flagp |= SIMPLE;
2581 	    nextchar();
2582 	    break;
2583 	case 'G':
2584 	    ret = reg_node(GPOS);
2585 	    PL_regseen |= REG_SEEN_GPOS;
2586 	    *flagp |= SIMPLE;
2587 	    nextchar();
2588 	    break;
2589 	case 'Z':
2590 	    ret = reg_node(SEOL);
2591 	    *flagp |= SIMPLE;
2592 	    nextchar();
2593 	    break;
2594 	case 'z':
2595 	    ret = reg_node(EOS);
2596 	    *flagp |= SIMPLE;
2597 	    PL_seen_zerolen++;		/* Do not optimize RE away */
2598 	    nextchar();
2599 	    break;
2600 	case 'C':
2601 	    ret = reg_node(SANY);
2602 	    *flagp |= HASWIDTH|SIMPLE;
2603 	    nextchar();
2604 	    break;
2605 	case 'X':
2606 	    ret = reg_node(CLUMP);
2607 	    *flagp |= HASWIDTH;
2608 	    nextchar();
2609 	    if (UTF && !PL_utf8_mark)
2610 		is_utf8_mark((U8*)"~");		/* preload table */
2611 	    break;
2612 	case 'w':
2613 	    ret = reg_node(
2614 		UTF
2615 		    ? (LOC ? ALNUMLUTF8 : ALNUMUTF8)
2616 		    : (LOC ? ALNUML     : ALNUM));
2617 	    *flagp |= HASWIDTH|SIMPLE;
2618 	    nextchar();
2619 	    if (UTF && !PL_utf8_alnum)
2620 		is_utf8_alnum((U8*)"a");	/* preload table */
2621 	    break;
2622 	case 'W':
2623 	    ret = reg_node(
2624 		UTF
2625 		    ? (LOC ? NALNUMLUTF8 : NALNUMUTF8)
2626 		    : (LOC ? NALNUML     : NALNUM));
2627 	    *flagp |= HASWIDTH|SIMPLE;
2628 	    nextchar();
2629 	    if (UTF && !PL_utf8_alnum)
2630 		is_utf8_alnum((U8*)"a");	/* preload table */
2631 	    break;
2632 	case 'b':
2633 	    PL_seen_zerolen++;
2634 	    PL_regseen |= REG_SEEN_LOOKBEHIND;
2635 	    ret = reg_node(
2636 		UTF
2637 		    ? (LOC ? BOUNDLUTF8 : BOUNDUTF8)
2638 		    : (LOC ? BOUNDL     : BOUND));
2639 	    *flagp |= SIMPLE;
2640 	    nextchar();
2641 	    if (UTF && !PL_utf8_alnum)
2642 		is_utf8_alnum((U8*)"a");	/* preload table */
2643 	    break;
2644 	case 'B':
2645 	    PL_seen_zerolen++;
2646 	    PL_regseen |= REG_SEEN_LOOKBEHIND;
2647 	    ret = reg_node(
2648 		UTF
2649 		    ? (LOC ? NBOUNDLUTF8 : NBOUNDUTF8)
2650 		    : (LOC ? NBOUNDL     : NBOUND));
2651 	    *flagp |= SIMPLE;
2652 	    nextchar();
2653 	    if (UTF && !PL_utf8_alnum)
2654 		is_utf8_alnum((U8*)"a");	/* preload table */
2655 	    break;
2656 	case 's':
2657 	    ret = reg_node(
2658 		UTF
2659 		    ? (LOC ? SPACELUTF8 : SPACEUTF8)
2660 		    : (LOC ? SPACEL     : SPACE));
2661 	    *flagp |= HASWIDTH|SIMPLE;
2662 	    nextchar();
2663 	    if (UTF && !PL_utf8_space)
2664 		is_utf8_space((U8*)" ");	/* preload table */
2665 	    break;
2666 	case 'S':
2667 	    ret = reg_node(
2668 		UTF
2669 		    ? (LOC ? NSPACELUTF8 : NSPACEUTF8)
2670 		    : (LOC ? NSPACEL     : NSPACE));
2671 	    *flagp |= HASWIDTH|SIMPLE;
2672 	    nextchar();
2673 	    if (UTF && !PL_utf8_space)
2674 		is_utf8_space((U8*)" ");	/* preload table */
2675 	    break;
2676 	case 'd':
2677 	    ret = reg_node(UTF ? DIGITUTF8 : DIGIT);
2678 	    *flagp |= HASWIDTH|SIMPLE;
2679 	    nextchar();
2680 	    if (UTF && !PL_utf8_digit)
2681 		is_utf8_digit((U8*)"1");	/* preload table */
2682 	    break;
2683 	case 'D':
2684 	    ret = reg_node(UTF ? NDIGITUTF8 : NDIGIT);
2685 	    *flagp |= HASWIDTH|SIMPLE;
2686 	    nextchar();
2687 	    if (UTF && !PL_utf8_digit)
2688 		is_utf8_digit((U8*)"1");	/* preload table */
2689 	    break;
2690 	case 'p':
2691 	case 'P':
2692 	    {	/* a lovely hack--pretend we saw [\pX] instead */
2693 		char* oldregxend = PL_regxend;
2694 
2695 		if (PL_regcomp_parse[1] == '{') {
2696 		    PL_regxend = strchr(PL_regcomp_parse, '}');
2697 		    if (!PL_regxend) {
2698 			PL_regcomp_parse += 2;
2699 			PL_regxend = oldregxend;
2700 			vFAIL("Missing right brace on \\p{}");
2701 		    }
2702 		    PL_regxend++;
2703 		}
2704 		else
2705 		    PL_regxend = PL_regcomp_parse + 2;
2706 		PL_regcomp_parse--;
2707 
2708 		ret = regclassutf8();
2709 
2710 		PL_regxend = oldregxend;
2711 		PL_regcomp_parse--;
2712 		nextchar();
2713 		*flagp |= HASWIDTH|SIMPLE;
2714 	    }
2715 	    break;
2716 	case 'n':
2717 	case 'r':
2718 	case 't':
2719 	case 'f':
2720 	case 'e':
2721 	case 'a':
2722 	case 'x':
2723 	case 'c':
2724 	case '0':
2725 	    goto defchar;
2726 	case '1': case '2': case '3': case '4':
2727 	case '5': case '6': case '7': case '8': case '9':
2728 	    {
2729 		I32 num = atoi(PL_regcomp_parse);
2730 
2731 		if (num > 9 && num >= PL_regnpar)
2732 		    goto defchar;
2733 		else {
2734 		    while (isDIGIT(*PL_regcomp_parse))
2735 			PL_regcomp_parse++;
2736 
2737 		    if (!SIZE_ONLY && num > PL_regcomp_rx->nparens)
2738 			vFAIL("Reference to nonexistent group");
2739 		    PL_regsawback = 1;
2740 		    ret = reganode(FOLD
2741 				   ? (LOC ? REFFL : REFF)
2742 				   : REF, num);
2743 		    *flagp |= HASWIDTH;
2744 		    PL_regcomp_parse--;
2745 		    nextchar();
2746 		}
2747 	    }
2748 	    break;
2749 	case '\0':
2750 	    if (PL_regcomp_parse >= PL_regxend)
2751 		FAIL("Trailing \\");
2752 	    /* FALL THROUGH */
2753 	default:
2754 	    /* Do not generate `unrecognized' warnings here, we fall
2755 	       back into the quick-grab loop below */
2756 	    goto defchar;
2757 	}
2758 	break;
2759 
2760     case '#':
2761 	if (PL_regflags & PMf_EXTENDED) {
2762 	    while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != '\n') PL_regcomp_parse++;
2763 	    if (PL_regcomp_parse < PL_regxend)
2764 		goto tryagain;
2765 	}
2766 	/* FALL THROUGH */
2767 
2768     default: {
2769 	    register STRLEN len;
2770 	    register UV ender;
2771 	    register char *p;
2772 	    char *oldp, *s;
2773 	    STRLEN numlen;
2774 
2775 	    PL_regcomp_parse++;
2776 
2777 	defchar:
2778 	    ret = reg_node(FOLD
2779 			  ? (LOC ? EXACTFL : EXACTF)
2780 			  : EXACT);
2781 	    s = STRING(ret);
2782 	    for (len = 0, p = PL_regcomp_parse - 1;
2783 	      len < 127 && p < PL_regxend;
2784 	      len++)
2785 	    {
2786 		oldp = p;
2787 
2788 		if (PL_regflags & PMf_EXTENDED)
2789 		    p = regwhite(p, PL_regxend);
2790 		switch (*p) {
2791 		case '^':
2792 		case '$':
2793 		case '.':
2794 		case '[':
2795 		case '(':
2796 		case ')':
2797 		case '|':
2798 		    goto loopdone;
2799 		case '\\':
2800 		    switch (*++p) {
2801 		    case 'A':
2802 		    case 'G':
2803 		    case 'Z':
2804 		    case 'z':
2805 		    case 'w':
2806 		    case 'W':
2807 		    case 'b':
2808 		    case 'B':
2809 		    case 's':
2810 		    case 'S':
2811 		    case 'd':
2812 		    case 'D':
2813 		    case 'p':
2814 		    case 'P':
2815 			--p;
2816 			goto loopdone;
2817 		    case 'n':
2818 			ender = '\n';
2819 			p++;
2820 			break;
2821 		    case 'r':
2822 			ender = '\r';
2823 			p++;
2824 			break;
2825 		    case 't':
2826 			ender = '\t';
2827 			p++;
2828 			break;
2829 		    case 'f':
2830 			ender = '\f';
2831 			p++;
2832 			break;
2833 		    case 'e':
2834 #ifdef ASCIIish
2835 			  ender = '\033';
2836 #else
2837 			  ender = '\047';
2838 #endif
2839 			p++;
2840 			break;
2841 		    case 'a':
2842 #ifdef ASCIIish
2843 			  ender = '\007';
2844 #else
2845 			  ender = '\057';
2846 #endif
2847 			p++;
2848 			break;
2849 		    case 'x':
2850 			if (*++p == '{') {
2851 			    char* e = strchr(p, '}');
2852 
2853 			    if (!e) {
2854 				PL_regcomp_parse = p + 1;
2855 				vFAIL("Missing right brace on \\x{}");
2856 			    }
2857 			    else {
2858 				numlen = 1;	/* allow underscores */
2859 				ender = (UV)scan_hex(p + 1, e - p - 1, &numlen);
2860 				/* numlen is generous */
2861 				if (numlen + len >= 127) {
2862 				    p--;
2863 				    goto loopdone;
2864 				}
2865 				p = e + 1;
2866 			    }
2867 			}
2868 			else {
2869 			    numlen = 0;		/* disallow underscores */
2870 			    ender = (UV)scan_hex(p, 2, &numlen);
2871 			    p += numlen;
2872 			}
2873 			break;
2874 		    case 'c':
2875 			p++;
2876 			ender = UCHARAT(p++);
2877 			ender = toCTRL(ender);
2878 			break;
2879 		    case '0': case '1': case '2': case '3':case '4':
2880 		    case '5': case '6': case '7': case '8':case '9':
2881 			if (*p == '0' ||
2882 			  (isDIGIT(p[1]) && atoi(p) >= PL_regnpar) ) {
2883 			    numlen = 0;		/* disallow underscores */
2884 			    ender = (UV)scan_oct(p, 3, &numlen);
2885 			    p += numlen;
2886 			}
2887 			else {
2888 			    --p;
2889 			    goto loopdone;
2890 			}
2891 			break;
2892 		    case '\0':
2893 			if (p >= PL_regxend)
2894 			    FAIL("Trailing \\");
2895 			/* FALL THROUGH */
2896 		    default:
2897 			if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
2898 			    vWARN2(p +1, "Unrecognized escape \\%c passed through", *p);
2899 			goto normal_default;
2900 		    }
2901 		    break;
2902 		default:
2903 		  normal_default:
2904 		    if (UTF8_IS_START(*p) && UTF) {
2905 			ender = utf8_to_uv((U8*)p, PL_regxend - p,
2906 					   &numlen, 0);
2907 			p += numlen;
2908 		    }
2909 		    else
2910 			ender = *p++;
2911 		    break;
2912 		}
2913 		if (PL_regflags & PMf_EXTENDED)
2914 		    p = regwhite(p, PL_regxend);
2915 		if (UTF && FOLD) {
2916 		    if (LOC)
2917 			ender = toLOWER_LC_uni(ender);
2918 		    else
2919 			ender = toLOWER_uni(ender);
2920 		}
2921 		if (ISMULT2(p)) { /* Back off on ?+*. */
2922 		    if (len)
2923 			p = oldp;
2924 		    /* ender is a Unicode value so it can be > 0xff --
2925 		     * in other words, do not use UTF8_IS_CONTINUED(). */
2926 		    else if (ender >= 0x80 && UTF) {
2927 			reguni(ender, s, &numlen);
2928 			s += numlen;
2929 			len += numlen;
2930 		    }
2931 		    else {
2932 			len++;
2933 			REGC(ender, s++);
2934 		    }
2935 		    break;
2936 		}
2937 		/* ender is a Unicode value so it can be > 0xff --
2938 		 * in other words, do not use UTF8_IS_CONTINUED(). */
2939 		if (ender >= 0x80 && UTF) {
2940 		    reguni(ender, s, &numlen);
2941 		    s += numlen;
2942 		    len += numlen - 1;
2943 		}
2944 		else
2945 		    REGC(ender, s++);
2946 	    }
2947 	loopdone:
2948 	    PL_regcomp_parse = p - 1;
2949 	    nextchar();
2950 	    {
2951 		/* len is STRLEN which is unsigned, need to copy to signed */
2952 		IV iv = len;
2953 		if (iv < 0)
2954 		    vFAIL("Internal disaster");
2955 	    }
2956 	    if (len > 0)
2957 		*flagp |= HASWIDTH;
2958 	    if (len == 1)
2959 		*flagp |= SIMPLE;
2960 	    if (!SIZE_ONLY)
2961 		STR_LEN(ret) = len;
2962 	    if (SIZE_ONLY)
2963 		PL_regsize += STR_SZ(len);
2964 	    else
2965 		PL_regcode += STR_SZ(len);
2966 	}
2967 	break;
2968     }
2969 
2970     return(ret);
2971 }
2972 
2973 STATIC char *
2974 S_regwhite(pTHX_ char *p, char *e)
2975 {
2976     while (p < e) {
2977 	if (isSPACE(*p))
2978 	    ++p;
2979 	else if (*p == '#') {
2980 	    do {
2981 		p++;
2982 	    } while (p < e && *p != '\n');
2983 	}
2984 	else
2985 	    break;
2986     }
2987     return p;
2988 }
2989 
2990 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
2991    Character classes ([:foo:]) can also be negated ([:^foo:]).
2992    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
2993    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
2994    but trigger warnings because they are currently unimplemented. */
2995 STATIC I32
2996 S_regpposixcc(pTHX_ I32 value)
2997 {
2998     char *posixcc = 0;
2999     I32 namedclass = OOB_NAMEDCLASS;
3000 
3001     if (value == '[' && PL_regcomp_parse + 1 < PL_regxend &&
3002 	/* I smell either [: or [= or [. -- POSIX has been here, right? */
3003 	(*PL_regcomp_parse == ':' ||
3004 	 *PL_regcomp_parse == '=' ||
3005 	 *PL_regcomp_parse == '.')) {
3006 	char  c = *PL_regcomp_parse;
3007 	char* s = PL_regcomp_parse++;
3008 
3009 	while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != c)
3010 	    PL_regcomp_parse++;
3011 	if (PL_regcomp_parse == PL_regxend)
3012 	    /* Grandfather lone [:, [=, [. */
3013 	    PL_regcomp_parse = s;
3014 	else {
3015 	    char* t = PL_regcomp_parse++; /* skip over the c */
3016 
3017   	    if (*PL_regcomp_parse == ']') {
3018   		PL_regcomp_parse++; /* skip over the ending ] */
3019   		posixcc = s + 1;
3020 		if (*s == ':') {
3021 		    I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3022 		    I32 skip = 5; /* the most common skip */
3023 
3024 		    switch (*posixcc) {
3025 		    case 'a':
3026 			if (strnEQ(posixcc, "alnum", 5))
3027 			    namedclass =
3028 				complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3029 			else if (strnEQ(posixcc, "alpha", 5))
3030 			    namedclass =
3031 				complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3032 			else if (strnEQ(posixcc, "ascii", 5))
3033 			    namedclass =
3034 				complement ? ANYOF_NASCII : ANYOF_ASCII;
3035 			break;
3036 		    case 'b':
3037 			if (strnEQ(posixcc, "blank", 5))
3038 			    namedclass =
3039 				complement ? ANYOF_NBLANK : ANYOF_BLANK;
3040 			break;
3041 		    case 'c':
3042 			if (strnEQ(posixcc, "cntrl", 5))
3043 			    namedclass =
3044 				complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3045 			break;
3046 		    case 'd':
3047 			if (strnEQ(posixcc, "digit", 5))
3048 			    namedclass =
3049 				complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3050 			break;
3051 		    case 'g':
3052 			if (strnEQ(posixcc, "graph", 5))
3053 			    namedclass =
3054 				complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3055 			break;
3056 		    case 'l':
3057 			if (strnEQ(posixcc, "lower", 5))
3058 			    namedclass =
3059 				complement ? ANYOF_NLOWER : ANYOF_LOWER;
3060 			break;
3061 		    case 'p':
3062 			if (strnEQ(posixcc, "print", 5))
3063 			    namedclass =
3064 				complement ? ANYOF_NPRINT : ANYOF_PRINT;
3065 			else if (strnEQ(posixcc, "punct", 5))
3066 			    namedclass =
3067 				complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3068 			break;
3069 		    case 's':
3070 			if (strnEQ(posixcc, "space", 5))
3071 			    namedclass =
3072 				complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3073 			break;
3074 		    case 'u':
3075 			if (strnEQ(posixcc, "upper", 5))
3076 			    namedclass =
3077 				complement ? ANYOF_NUPPER : ANYOF_UPPER;
3078  			break;
3079 		    case 'w': /* this is not POSIX, this is the Perl \w */
3080 			if (strnEQ(posixcc, "word", 4)) {
3081 			    namedclass =
3082 				complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3083 			    skip = 4;
3084 			}
3085 			break;
3086 		    case 'x':
3087 			if (strnEQ(posixcc, "xdigit", 6)) {
3088 			    namedclass =
3089 				complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3090 			    skip = 6;
3091 			}
3092 			break;
3093 		    }
3094 		    if (namedclass == OOB_NAMEDCLASS ||
3095 			posixcc[skip] != ':' ||
3096 			posixcc[skip+1] != ']')
3097 		    {
3098 			Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3099 				      t - s - 1, s + 1);
3100 		    }
3101 		} else if (!SIZE_ONLY) {
3102 		    /* [[=foo=]] and [[.foo.]] are still future. */
3103 
3104 		    /* adjust PL_regcomp_parse so the warning shows after
3105 		       the class closes */
3106 		    while (*PL_regcomp_parse && *PL_regcomp_parse != ']')
3107 			PL_regcomp_parse++;
3108 		    Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3109 		}
3110 	    } else {
3111 		/* Maternal grandfather:
3112 		 * "[:" ending in ":" but not in ":]" */
3113 		PL_regcomp_parse = s;
3114 	    }
3115 	}
3116     }
3117 
3118     return namedclass;
3119 }
3120 
3121 STATIC void
3122 S_checkposixcc(pTHX)
3123 {
3124     if (!SIZE_ONLY && ckWARN(WARN_REGEXP) &&
3125 	(*PL_regcomp_parse == ':' ||
3126 	 *PL_regcomp_parse == '=' ||
3127 	 *PL_regcomp_parse == '.')) {
3128 	char *s = PL_regcomp_parse;
3129  	char  c = *s++;
3130 
3131 	while(*s && isALNUM(*s))
3132 	    s++;
3133 	if (*s && c == *s && s[1] == ']') {
3134 	    vWARN3(s+2, "POSIX syntax [%c %c] belongs inside character classes", c, c);
3135 
3136 	    /* [[=foo=]] and [[.foo.]] are still future. */
3137 	    if (c == '=' || c == '.')
3138 	    {
3139 		/* adjust PL_regcomp_parse so the error shows after
3140 		   the class closes */
3141 		while (*PL_regcomp_parse && *PL_regcomp_parse++ != ']')
3142 		    ;
3143 		Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3144 	    }
3145 	}
3146     }
3147 }
3148 
3149 STATIC regnode *
3150 S_regclass(pTHX)
3151 {
3152     register U32 value;
3153     register I32 lastvalue = OOB_CHAR8;
3154     register I32 range = 0;
3155     register regnode *ret;
3156     STRLEN numlen;
3157     I32 namedclass;
3158     char *rangebegin;
3159     bool need_class = 0;
3160 
3161     ret = reg_node(ANYOF);
3162     if (SIZE_ONLY)
3163 	PL_regsize += ANYOF_SKIP;
3164     else {
3165 	ret->flags = 0;
3166 	ANYOF_BITMAP_ZERO(ret);
3167  	PL_regcode += ANYOF_SKIP;
3168 	if (FOLD)
3169 	    ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3170 	if (LOC)
3171 	    ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3172     }
3173     if (*PL_regcomp_parse == '^') {	/* Complement of range. */
3174 	PL_regnaughty++;
3175 	PL_regcomp_parse++;
3176 	if (!SIZE_ONLY)
3177 	    ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3178     }
3179 
3180     if (!SIZE_ONLY && ckWARN(WARN_REGEXP))
3181 	checkposixcc();
3182 
3183     if (*PL_regcomp_parse == ']' || *PL_regcomp_parse == '-')
3184 	goto skipcond;		/* allow 1st char to be ] or - */
3185     while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != ']') {
3186        skipcond:
3187 	namedclass = OOB_NAMEDCLASS;
3188 	if (!range)
3189 	    rangebegin = PL_regcomp_parse;
3190 	value = UCHARAT(PL_regcomp_parse++);
3191 	if (value == '[')
3192 	    namedclass = regpposixcc(value);
3193 	else if (value == '\\') {
3194 	    value = UCHARAT(PL_regcomp_parse++);
3195 	    /* Some compilers cannot handle switching on 64-bit integer
3196 	     * values, therefore the 'value' cannot be an UV. --jhi */
3197 	    switch (value) {
3198 	    case 'w':	namedclass = ANYOF_ALNUM;	break;
3199 	    case 'W':	namedclass = ANYOF_NALNUM;	break;
3200 	    case 's':	namedclass = ANYOF_SPACE;	break;
3201 	    case 'S':	namedclass = ANYOF_NSPACE;	break;
3202 	    case 'd':	namedclass = ANYOF_DIGIT;	break;
3203 	    case 'D':	namedclass = ANYOF_NDIGIT;	break;
3204 	    case 'n':	value = '\n';			break;
3205 	    case 'r':	value = '\r';			break;
3206 	    case 't':	value = '\t';			break;
3207 	    case 'f':	value = '\f';			break;
3208 	    case 'b':	value = '\b';			break;
3209 #ifdef ASCIIish
3210 	    case 'e':	value = '\033';			break;
3211 	    case 'a':	value = '\007';			break;
3212 #else
3213 	    case 'e':	value = '\047';			break;
3214 	    case 'a':	value = '\057';			break;
3215 #endif
3216 	    case 'x':
3217 		numlen = 0;		/* disallow underscores */
3218 		value = (UV)scan_hex(PL_regcomp_parse, 2, &numlen);
3219 		PL_regcomp_parse += numlen;
3220 		break;
3221 	    case 'c':
3222 		value = UCHARAT(PL_regcomp_parse++);
3223 		value = toCTRL(value);
3224 		break;
3225 	    case '0': case '1': case '2': case '3': case '4':
3226 	    case '5': case '6': case '7': case '8': case '9':
3227 		numlen = 0;		/* disallow underscores */
3228 		value = (UV)scan_oct(--PL_regcomp_parse, 3, &numlen);
3229 		PL_regcomp_parse += numlen;
3230 		break;
3231 	    default:
3232 		if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3233 
3234 		    vWARN2(PL_regcomp_parse, "Unrecognized escape \\%c in character class passed through", (int)value);
3235 		break;
3236 	    }
3237 	}
3238 	if (namedclass > OOB_NAMEDCLASS) {
3239 	    if (!need_class && !SIZE_ONLY)
3240 		ANYOF_CLASS_ZERO(ret);
3241 	    need_class = 1;
3242 	    if (range) { /* a-\d, a-[:digit:] */
3243 		if (!SIZE_ONLY) {
3244 		    if (ckWARN(WARN_REGEXP))
3245 			vWARN4(PL_regcomp_parse,
3246 			       "False [] range \"%*.*s\"",
3247 			       PL_regcomp_parse - rangebegin,
3248 			       PL_regcomp_parse - rangebegin,
3249 			       rangebegin);
3250 		    ANYOF_BITMAP_SET(ret, lastvalue);
3251 		    ANYOF_BITMAP_SET(ret, '-');
3252 		}
3253 		range = 0; /* this is not a true range */
3254 	    }
3255 	    if (!SIZE_ONLY) {
3256 		switch (namedclass) {
3257 		case ANYOF_ALNUM:
3258 		    if (LOC)
3259 			ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3260 		    else {
3261 			for (value = 0; value < 256; value++)
3262 			    if (isALNUM(value))
3263 				ANYOF_BITMAP_SET(ret, value);
3264 		    }
3265 		    break;
3266 		case ANYOF_NALNUM:
3267 		    if (LOC)
3268 			ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3269 		    else {
3270 			for (value = 0; value < 256; value++)
3271 			    if (!isALNUM(value))
3272 				ANYOF_BITMAP_SET(ret, value);
3273 		    }
3274 		    break;
3275 		case ANYOF_SPACE:
3276 		    if (LOC)
3277 			ANYOF_CLASS_SET(ret, ANYOF_SPACE);
3278 		    else {
3279 			for (value = 0; value < 256; value++)
3280 			    if (isSPACE(value))
3281 				ANYOF_BITMAP_SET(ret, value);
3282 		    }
3283 		    break;
3284 		case ANYOF_NSPACE:
3285 		    if (LOC)
3286 			ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
3287 		    else {
3288 			for (value = 0; value < 256; value++)
3289 			    if (!isSPACE(value))
3290 				ANYOF_BITMAP_SET(ret, value);
3291 		    }
3292 		    break;
3293 		case ANYOF_DIGIT:
3294 		    if (LOC)
3295 			ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3296 		    else {
3297 			for (value = '0'; value <= '9'; value++)
3298 			    ANYOF_BITMAP_SET(ret, value);
3299 		    }
3300 		    break;
3301 		case ANYOF_NDIGIT:
3302 		    if (LOC)
3303 			ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3304 		    else {
3305 			for (value = 0; value < '0'; value++)
3306 			    ANYOF_BITMAP_SET(ret, value);
3307 			for (value = '9' + 1; value < 256; value++)
3308 			    ANYOF_BITMAP_SET(ret, value);
3309 		    }
3310 		    break;
3311 		case ANYOF_NALNUMC:
3312 		    if (LOC)
3313 			ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3314 		    else {
3315 			for (value = 0; value < 256; value++)
3316 			    if (!isALNUMC(value))
3317 				ANYOF_BITMAP_SET(ret, value);
3318 		    }
3319 		    break;
3320 		case ANYOF_ALNUMC:
3321 		    if (LOC)
3322 			ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3323 		    else {
3324 			for (value = 0; value < 256; value++)
3325 			    if (isALNUMC(value))
3326 				ANYOF_BITMAP_SET(ret, value);
3327 		    }
3328 		    break;
3329 		case ANYOF_ALPHA:
3330 		    if (LOC)
3331 			ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3332 		    else {
3333 			for (value = 0; value < 256; value++)
3334 			    if (isALPHA(value))
3335 				ANYOF_BITMAP_SET(ret, value);
3336 		    }
3337 		    break;
3338 		case ANYOF_NALPHA:
3339 		    if (LOC)
3340 			ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3341 		    else {
3342 			for (value = 0; value < 256; value++)
3343 			    if (!isALPHA(value))
3344 				ANYOF_BITMAP_SET(ret, value);
3345 		    }
3346 		    break;
3347 		case ANYOF_ASCII:
3348 		    if (LOC)
3349 			ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3350 		    else {
3351 #ifdef ASCIIish
3352 			for (value = 0; value < 128; value++)
3353 			    ANYOF_BITMAP_SET(ret, value);
3354 #else  /* EBCDIC */
3355 			for (value = 0; value < 256; value++)
3356 			    if (isASCII(value))
3357 				ANYOF_BITMAP_SET(ret, value);
3358 #endif /* EBCDIC */
3359 		    }
3360 		    break;
3361 		case ANYOF_NASCII:
3362 		    if (LOC)
3363 			ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3364 		    else {
3365 #ifdef ASCIIish
3366 			for (value = 128; value < 256; value++)
3367 			    ANYOF_BITMAP_SET(ret, value);
3368 #else  /* EBCDIC */
3369 			for (value = 0; value < 256; value++)
3370 			    if (!isASCII(value))
3371 				ANYOF_BITMAP_SET(ret, value);
3372 #endif /* EBCDIC */
3373 		    }
3374 		    break;
3375 		case ANYOF_BLANK:
3376 		    if (LOC)
3377 			ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3378 		    else {
3379 			for (value = 0; value < 256; value++)
3380 			    if (isBLANK(value))
3381 				ANYOF_BITMAP_SET(ret, value);
3382 		    }
3383 		    break;
3384 		case ANYOF_NBLANK:
3385 		    if (LOC)
3386 			ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3387 		    else {
3388 			for (value = 0; value < 256; value++)
3389 			    if (!isBLANK(value))
3390 				ANYOF_BITMAP_SET(ret, value);
3391 		    }
3392 		    break;
3393 		case ANYOF_CNTRL:
3394 		    if (LOC)
3395 			ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3396 		    else {
3397 			for (value = 0; value < 256; value++)
3398 			    if (isCNTRL(value))
3399 				ANYOF_BITMAP_SET(ret, value);
3400 		    }
3401 		    lastvalue = OOB_CHAR8;
3402 		    break;
3403 		case ANYOF_NCNTRL:
3404 		    if (LOC)
3405 			ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3406 		    else {
3407 			for (value = 0; value < 256; value++)
3408 			    if (!isCNTRL(value))
3409 				ANYOF_BITMAP_SET(ret, value);
3410 		    }
3411 		    break;
3412 		case ANYOF_GRAPH:
3413 		    if (LOC)
3414 			ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3415 		    else {
3416 			for (value = 0; value < 256; value++)
3417 			    if (isGRAPH(value))
3418 				ANYOF_BITMAP_SET(ret, value);
3419 		    }
3420 		    break;
3421 		case ANYOF_NGRAPH:
3422 		    if (LOC)
3423 			ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3424 		    else {
3425 			for (value = 0; value < 256; value++)
3426 			    if (!isGRAPH(value))
3427 				ANYOF_BITMAP_SET(ret, value);
3428 		    }
3429 		    break;
3430 		case ANYOF_LOWER:
3431 		    if (LOC)
3432 			ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3433 		    else {
3434 			for (value = 0; value < 256; value++)
3435 			    if (isLOWER(value))
3436 				ANYOF_BITMAP_SET(ret, value);
3437 		    }
3438 		    break;
3439 		case ANYOF_NLOWER:
3440 		    if (LOC)
3441 			ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3442 		    else {
3443 			for (value = 0; value < 256; value++)
3444 			    if (!isLOWER(value))
3445 				ANYOF_BITMAP_SET(ret, value);
3446 		    }
3447 		    break;
3448 		case ANYOF_PRINT:
3449 		    if (LOC)
3450 			ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3451 		    else {
3452 			for (value = 0; value < 256; value++)
3453 			    if (isPRINT(value))
3454 				ANYOF_BITMAP_SET(ret, value);
3455 		    }
3456 		    break;
3457 		case ANYOF_NPRINT:
3458 		    if (LOC)
3459 			ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3460 		    else {
3461 			for (value = 0; value < 256; value++)
3462 			    if (!isPRINT(value))
3463 				ANYOF_BITMAP_SET(ret, value);
3464 		    }
3465 		    break;
3466 		case ANYOF_PSXSPC:
3467 		    if (LOC)
3468 			ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3469 		    else {
3470 			for (value = 0; value < 256; value++)
3471 			    if (isPSXSPC(value))
3472 				ANYOF_BITMAP_SET(ret, value);
3473 		    }
3474 		    break;
3475 		case ANYOF_NPSXSPC:
3476 		    if (LOC)
3477 			ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3478 		    else {
3479 			for (value = 0; value < 256; value++)
3480 			    if (!isPSXSPC(value))
3481 				ANYOF_BITMAP_SET(ret, value);
3482 		    }
3483 		    break;
3484 		case ANYOF_PUNCT:
3485 		    if (LOC)
3486 			ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3487 		    else {
3488 			for (value = 0; value < 256; value++)
3489 			    if (isPUNCT(value))
3490 				ANYOF_BITMAP_SET(ret, value);
3491 		    }
3492 		    break;
3493 		case ANYOF_NPUNCT:
3494 		    if (LOC)
3495 			ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3496 		    else {
3497 			for (value = 0; value < 256; value++)
3498 			    if (!isPUNCT(value))
3499 				ANYOF_BITMAP_SET(ret, value);
3500 		    }
3501 		    break;
3502 		case ANYOF_UPPER:
3503 		    if (LOC)
3504 			ANYOF_CLASS_SET(ret, ANYOF_UPPER);
3505 		    else {
3506 			for (value = 0; value < 256; value++)
3507 			    if (isUPPER(value))
3508 				ANYOF_BITMAP_SET(ret, value);
3509 		    }
3510 		    break;
3511 		case ANYOF_NUPPER:
3512 		    if (LOC)
3513 			ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
3514 		    else {
3515 			for (value = 0; value < 256; value++)
3516 			    if (!isUPPER(value))
3517 				ANYOF_BITMAP_SET(ret, value);
3518 		    }
3519 		    break;
3520 		case ANYOF_XDIGIT:
3521 		    if (LOC)
3522 			ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
3523 		    else {
3524 			for (value = 0; value < 256; value++)
3525 			    if (isXDIGIT(value))
3526 				ANYOF_BITMAP_SET(ret, value);
3527 		    }
3528 		    break;
3529 		case ANYOF_NXDIGIT:
3530 		    if (LOC)
3531 			ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
3532 		    else {
3533 			for (value = 0; value < 256; value++)
3534 			    if (!isXDIGIT(value))
3535 				ANYOF_BITMAP_SET(ret, value);
3536 		    }
3537 		    break;
3538 		default:
3539 		    vFAIL("Invalid [::] class");
3540 		    break;
3541 		}
3542 		if (LOC)
3543 		    ANYOF_FLAGS(ret) |= ANYOF_CLASS;
3544 		continue;
3545 	    }
3546 	}
3547 	if (range) {
3548 	    if (lastvalue > value) /* b-a */ {
3549 		Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3550 			      PL_regcomp_parse - rangebegin,
3551 			      PL_regcomp_parse - rangebegin,
3552 			      rangebegin);
3553 	    }
3554 	    range = 0;
3555 	}
3556 	else {
3557 	    lastvalue = value;
3558 	    if (*PL_regcomp_parse == '-' && PL_regcomp_parse+1 < PL_regxend &&
3559 		PL_regcomp_parse[1] != ']') {
3560 		PL_regcomp_parse++;
3561 		if (namedclass > OOB_NAMEDCLASS) { /* \w-, [:word:]- */
3562 		    if (ckWARN(WARN_REGEXP))
3563 			vWARN4(PL_regcomp_parse,
3564 			       "False [] range \"%*.*s\"",
3565 			       PL_regcomp_parse - rangebegin,
3566 			       PL_regcomp_parse - rangebegin,
3567 			       rangebegin);
3568 		    if (!SIZE_ONLY)
3569 			ANYOF_BITMAP_SET(ret, '-');
3570 		} else
3571 		    range = 1;
3572 		continue;	/* do it next time */
3573 	    }
3574 	}
3575 	/* now is the next time */
3576 	if (!SIZE_ONLY) {
3577 #ifndef ASCIIish /* EBCDIC, for example. */
3578 	    if ((isLOWER(lastvalue) && isLOWER(value)) ||
3579 		(isUPPER(lastvalue) && isUPPER(value)))
3580 	    {
3581 		I32 i;
3582  		if (isLOWER(lastvalue)) {
3583  		    for (i = lastvalue; i <= value; i++)
3584 			if (isLOWER(i))
3585 			    ANYOF_BITMAP_SET(ret, i);
3586  		} else {
3587  		    for (i = lastvalue; i <= value; i++)
3588 			if (isUPPER(i))
3589 			    ANYOF_BITMAP_SET(ret, i);
3590 		}
3591 	    }
3592 	    else
3593 #endif
3594 		for ( ; lastvalue <= value; lastvalue++)
3595 		    ANYOF_BITMAP_SET(ret, lastvalue);
3596         }
3597 	range = 0;
3598     }
3599     if (need_class) {
3600 	if (SIZE_ONLY)
3601 	    PL_regsize += ANYOF_CLASS_ADD_SKIP;
3602 	else
3603 	    PL_regcode += ANYOF_CLASS_ADD_SKIP;
3604     }
3605     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
3606     if (!SIZE_ONLY &&
3607 	(ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD) {
3608 	for (value = 0; value < 256; ++value) {
3609 	    if (ANYOF_BITMAP_TEST(ret, value)) {
3610 		I32 cf = PL_fold[value];
3611 		ANYOF_BITMAP_SET(ret, cf);
3612 	    }
3613 	}
3614 	ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
3615     }
3616     /* optimize inverted simple patterns (e.g. [^a-z]) */
3617     if (!SIZE_ONLY && (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
3618 	for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
3619 	    ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
3620 	ANYOF_FLAGS(ret) = 0;
3621     }
3622     return ret;
3623 }
3624 
3625 STATIC regnode *
3626 S_regclassutf8(pTHX)
3627 {
3628     register char *e;
3629     register U32 value;
3630     register U32 lastvalue = OOB_UTF8;
3631     register I32 range = 0;
3632     register regnode *ret;
3633     STRLEN numlen;
3634     I32 n;
3635     SV *listsv;
3636     U8 flags = 0;
3637     I32 namedclass;
3638     char *rangebegin;
3639 
3640     if (*PL_regcomp_parse == '^') {	/* Complement of range. */
3641 	PL_regnaughty++;
3642 	PL_regcomp_parse++;
3643 	if (!SIZE_ONLY)
3644 	    flags |= ANYOF_INVERT;
3645     }
3646     if (!SIZE_ONLY) {
3647 	if (FOLD)
3648 	    flags |= ANYOF_FOLD;
3649 	if (LOC)
3650 	    flags |= ANYOF_LOCALE;
3651 	listsv = newSVpvn("# comment\n", 10);
3652     }
3653 
3654     if (!SIZE_ONLY && ckWARN(WARN_REGEXP))
3655 	checkposixcc();
3656 
3657     if (*PL_regcomp_parse == ']' || *PL_regcomp_parse == '-')
3658 	goto skipcond;		/* allow 1st char to be ] or - */
3659 
3660     while (PL_regcomp_parse < PL_regxend && *PL_regcomp_parse != ']') {
3661        skipcond:
3662 	namedclass = OOB_NAMEDCLASS;
3663 	if (!range)
3664 	    rangebegin = PL_regcomp_parse;
3665 	value = utf8_to_uv((U8*)PL_regcomp_parse,
3666 			       PL_regxend - PL_regcomp_parse,
3667 			       &numlen, 0);
3668 	PL_regcomp_parse += numlen;
3669 	if (value == '[')
3670 	    namedclass = regpposixcc(value);
3671 	else if (value == '\\') {
3672 	    value = (U32)utf8_to_uv((U8*)PL_regcomp_parse,
3673 					PL_regxend - PL_regcomp_parse,
3674 					&numlen, 0);
3675 	    PL_regcomp_parse += numlen;
3676 	    /* Some compilers cannot handle switching on 64-bit integer
3677 	     * values, therefore value cannot be an UV.  Yes, this will
3678 	     * be a problem later if we want switch on Unicode.  --jhi */
3679 	    switch (value) {
3680 	    case 'w':		namedclass = ANYOF_ALNUM;		break;
3681 	    case 'W':		namedclass = ANYOF_NALNUM;		break;
3682 	    case 's':		namedclass = ANYOF_SPACE;		break;
3683 	    case 'S':		namedclass = ANYOF_NSPACE;		break;
3684 	    case 'd':		namedclass = ANYOF_DIGIT;		break;
3685 	    case 'D':		namedclass = ANYOF_NDIGIT;		break;
3686 	    case 'p':
3687 	    case 'P':
3688 		if (*PL_regcomp_parse == '{') {
3689 		    e = strchr(PL_regcomp_parse++, '}');
3690                     if (!e)
3691                         vFAIL("Missing right brace on \\p{}");
3692 		    n = e - PL_regcomp_parse;
3693 		}
3694 		else {
3695 		    e = PL_regcomp_parse;
3696 		    n = 1;
3697 		}
3698 		if (!SIZE_ONLY) {
3699 		    if (value == 'p')
3700 			Perl_sv_catpvf(aTHX_ listsv,
3701 				       "+utf8::%.*s\n", (int)n, PL_regcomp_parse);
3702 		    else
3703 			Perl_sv_catpvf(aTHX_ listsv,
3704 				       "!utf8::%.*s\n", (int)n, PL_regcomp_parse);
3705 		}
3706 		PL_regcomp_parse = e + 1;
3707 		lastvalue = OOB_UTF8;
3708 		continue;
3709 	    case 'n':		value = '\n';		break;
3710 	    case 'r':		value = '\r';		break;
3711 	    case 't':		value = '\t';		break;
3712 	    case 'f':		value = '\f';		break;
3713 	    case 'b':		value = '\b';		break;
3714 #ifdef ASCIIish
3715 	    case 'e':		value = '\033';		break;
3716 	    case 'a':		value = '\007';		break;
3717 #else
3718 	    case 'e':		value = '\047';		break;
3719 	    case 'a':		value = '\057';		break;
3720 #endif
3721 	    case 'x':
3722 		if (*PL_regcomp_parse == '{') {
3723 		    e = strchr(PL_regcomp_parse++, '}');
3724                     if (!e)
3725                         vFAIL("Missing right brace on \\x{}");
3726 		    numlen = 1;		/* allow underscores */
3727 		    value = (UV)scan_hex(PL_regcomp_parse,
3728 				     e - PL_regcomp_parse,
3729 				     &numlen);
3730 		    PL_regcomp_parse = e + 1;
3731 		}
3732 		else {
3733 		    numlen = 0;		/* disallow underscores */
3734 		    value = (UV)scan_hex(PL_regcomp_parse, 2, &numlen);
3735 		    PL_regcomp_parse += numlen;
3736 		}
3737 		break;
3738 	    case 'c':
3739 		value = UCHARAT(PL_regcomp_parse++);
3740 		value = toCTRL(value);
3741 		break;
3742 	    case '0': case '1': case '2': case '3': case '4':
3743 	    case '5': case '6': case '7': case '8': case '9':
3744 		numlen = 0;		/* disallow underscores */
3745 		value = (UV)scan_oct(--PL_regcomp_parse, 3, &numlen);
3746 		PL_regcomp_parse += numlen;
3747 		break;
3748 	    default:
3749 		if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3750 		    vWARN2(PL_regcomp_parse,
3751 			   "Unrecognized escape \\%c in character class passed through",
3752 			   (int)value);
3753 		break;
3754 	    }
3755 	}
3756 	if (namedclass > OOB_NAMEDCLASS) {
3757 	    if (range) { /* a-\d, a-[:digit:] */
3758 		if (!SIZE_ONLY) {
3759 		    if (ckWARN(WARN_REGEXP))
3760 			vWARN4(PL_regcomp_parse,
3761 			       "False [] range \"%*.*s\"",
3762 			       PL_regcomp_parse - rangebegin,
3763 			       PL_regcomp_parse - rangebegin,
3764 			       rangebegin);
3765 		    Perl_sv_catpvf(aTHX_ listsv,
3766 				   /* 0x002D is Unicode for '-' */
3767 				   "%04"UVxf"\n002D\n", (UV)lastvalue);
3768 		}
3769 		range = 0;
3770 	    }
3771 	    if (!SIZE_ONLY) {
3772 		switch (namedclass) {
3773 		case ANYOF_ALNUM:
3774 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");	break;
3775 		case ANYOF_NALNUM:
3776 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");	break;
3777 		case ANYOF_ALNUMC:
3778 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");	break;
3779 		case ANYOF_NALNUMC:
3780 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");	break;
3781 		case ANYOF_ALPHA:
3782 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");	break;
3783 		case ANYOF_NALPHA:
3784 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");	break;
3785 		case ANYOF_ASCII:
3786 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");	break;
3787 		case ANYOF_NASCII:
3788 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");	break;
3789 		case ANYOF_CNTRL:
3790 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");	break;
3791 		case ANYOF_NCNTRL:
3792 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");	break;
3793 		case ANYOF_GRAPH:
3794 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");	break;
3795 		case ANYOF_NGRAPH:
3796 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");	break;
3797 		case ANYOF_DIGIT:
3798 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");	break;
3799 		case ANYOF_NDIGIT:
3800 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");	break;
3801 		case ANYOF_LOWER:
3802 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");	break;
3803 		case ANYOF_NLOWER:
3804 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");	break;
3805 		case ANYOF_PRINT:
3806 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");	break;
3807 		case ANYOF_NPRINT:
3808 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");	break;
3809 		case ANYOF_PUNCT:
3810 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");	break;
3811 		case ANYOF_NPUNCT:
3812 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");	break;
3813 		case ANYOF_SPACE:
3814 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");break;
3815 		case ANYOF_NSPACE:
3816 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");break;
3817 		case ANYOF_BLANK:
3818 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");	break;
3819 		case ANYOF_NBLANK:
3820 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");	break;
3821 		case ANYOF_PSXSPC:
3822 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");	break;
3823 		case ANYOF_NPSXSPC:
3824 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");	break;
3825 		case ANYOF_UPPER:
3826 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");	break;
3827 		case ANYOF_NUPPER:
3828 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");	break;
3829 		case ANYOF_XDIGIT:
3830 		    Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");	break;
3831 		case ANYOF_NXDIGIT:
3832 		    Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");	break;
3833 		}
3834 		continue;
3835 	    }
3836 	}
3837         if (range) {
3838 	    if (lastvalue > value) { /* b-a */
3839 		Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3840 			      PL_regcomp_parse - rangebegin,
3841 			      PL_regcomp_parse - rangebegin,
3842 			      rangebegin);
3843 	    }
3844 	    range = 0;
3845 	}
3846 	else {
3847 	    lastvalue = value;
3848 	    if (*PL_regcomp_parse == '-' && PL_regcomp_parse+1 < PL_regxend &&
3849 		PL_regcomp_parse[1] != ']') {
3850 		PL_regcomp_parse++;
3851 		if (namedclass > OOB_NAMEDCLASS) { /* \w-, [:word:]- */
3852 		    if (ckWARN(WARN_REGEXP))
3853 			vWARN4(PL_regcomp_parse,
3854 			       "False [] range \"%*.*s\"",
3855 			       PL_regcomp_parse - rangebegin,
3856 			       PL_regcomp_parse - rangebegin,
3857 			       rangebegin);
3858 		    if (!SIZE_ONLY)
3859 			Perl_sv_catpvf(aTHX_ listsv,
3860 				       /* 0x002D is Unicode for '-' */
3861 				       "002D\n");
3862 		} else
3863 		    range = 1;
3864 		continue;	/* do it next time */
3865 	    }
3866 	}
3867 	/* now is the next time */
3868 	if (!SIZE_ONLY)
3869 	    Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
3870 			   (UV)lastvalue, (UV)value);
3871 	range = 0;
3872     }
3873 
3874     ret = reganode(ANYOFUTF8, 0);
3875 
3876     if (!SIZE_ONLY) {
3877 	SV *rv = swash_init("utf8", "", listsv, 1, 0);
3878 #ifdef DEBUGGING
3879 	AV *av = newAV();
3880 	av_push(av, rv);
3881 	av_push(av, listsv);
3882 	rv = newRV_noinc((SV*)av);
3883 #else
3884 	SvREFCNT_dec(listsv);
3885 #endif
3886 	n = add_data(1,"s");
3887 	PL_regcomp_rx->data->data[n] = (void*)rv;
3888 	ARG1_SET(ret, flags);
3889 	ARG2_SET(ret, n);
3890     }
3891 
3892     return ret;
3893 }
3894 
3895 STATIC char*
3896 S_nextchar(pTHX)
3897 {
3898     char* retval = PL_regcomp_parse++;
3899 
3900     for (;;) {
3901 	if (*PL_regcomp_parse == '(' && PL_regcomp_parse[1] == '?' &&
3902 		PL_regcomp_parse[2] == '#') {
3903 	    while (*PL_regcomp_parse && *PL_regcomp_parse != ')')
3904 		PL_regcomp_parse++;
3905 	    PL_regcomp_parse++;
3906 	    continue;
3907 	}
3908 	if (PL_regflags & PMf_EXTENDED) {
3909 	    if (isSPACE(*PL_regcomp_parse)) {
3910 		PL_regcomp_parse++;
3911 		continue;
3912 	    }
3913 	    else if (*PL_regcomp_parse == '#') {
3914 		while (*PL_regcomp_parse && *PL_regcomp_parse != '\n')
3915 		    PL_regcomp_parse++;
3916 		PL_regcomp_parse++;
3917 		continue;
3918 	    }
3919 	}
3920 	return retval;
3921     }
3922 }
3923 
3924 /*
3925 - reg_node - emit a node
3926 */
3927 STATIC regnode *			/* Location. */
3928 S_reg_node(pTHX_ U8 op)
3929 {
3930     register regnode *ret;
3931     register regnode *ptr;
3932 
3933     ret = PL_regcode;
3934     if (SIZE_ONLY) {
3935 	SIZE_ALIGN(PL_regsize);
3936 	PL_regsize += 1;
3937 	return(ret);
3938     }
3939 
3940     NODE_ALIGN_FILL(ret);
3941     ptr = ret;
3942     FILL_ADVANCE_NODE(ptr, op);
3943     PL_regcode = ptr;
3944 
3945     return(ret);
3946 }
3947 
3948 /*
3949 - reganode - emit a node with an argument
3950 */
3951 STATIC regnode *			/* Location. */
3952 S_reganode(pTHX_ U8 op, U32 arg)
3953 {
3954     register regnode *ret;
3955     register regnode *ptr;
3956 
3957     ret = PL_regcode;
3958     if (SIZE_ONLY) {
3959 	SIZE_ALIGN(PL_regsize);
3960 	PL_regsize += 2;
3961 	return(ret);
3962     }
3963 
3964     NODE_ALIGN_FILL(ret);
3965     ptr = ret;
3966     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
3967     PL_regcode = ptr;
3968 
3969     return(ret);
3970 }
3971 
3972 /*
3973 - reguni - emit (if appropriate) a Unicode character
3974 */
3975 STATIC void
3976 S_reguni(pTHX_ UV uv, char* s, STRLEN* lenp)
3977 {
3978     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uv_to_utf8((U8*)s, uv) - (U8*)s);
3979 }
3980 
3981 /*
3982 - reginsert - insert an operator in front of already-emitted operand
3983 *
3984 * Means relocating the operand.
3985 */
3986 STATIC void
3987 S_reginsert(pTHX_ U8 op, regnode *opnd)
3988 {
3989     register regnode *src;
3990     register regnode *dst;
3991     register regnode *place;
3992     register int offset = regarglen[(U8)op];
3993 
3994 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
3995 
3996     if (SIZE_ONLY) {
3997 	PL_regsize += NODE_STEP_REGNODE + offset;
3998 	return;
3999     }
4000 
4001     src = PL_regcode;
4002     PL_regcode += NODE_STEP_REGNODE + offset;
4003     dst = PL_regcode;
4004     while (src > opnd)
4005 	StructCopy(--src, --dst, regnode);
4006 
4007     place = opnd;		/* Op node, where operand used to be. */
4008     src = NEXTOPER(place);
4009     FILL_ADVANCE_NODE(place, op);
4010     Zero(src, offset, regnode);
4011 }
4012 
4013 /*
4014 - regtail - set the next-pointer at the end of a node chain of p to val.
4015 */
4016 STATIC void
4017 S_regtail(pTHX_ regnode *p, regnode *val)
4018 {
4019     register regnode *scan;
4020     register regnode *temp;
4021 
4022     if (SIZE_ONLY)
4023 	return;
4024 
4025     /* Find last node. */
4026     scan = p;
4027     for (;;) {
4028 	temp = regnext(scan);
4029 	if (temp == NULL)
4030 	    break;
4031 	scan = temp;
4032     }
4033 
4034     if (reg_off_by_arg[OP(scan)]) {
4035 	ARG_SET(scan, val - scan);
4036     }
4037     else {
4038 	NEXT_OFF(scan) = val - scan;
4039     }
4040 }
4041 
4042 /*
4043 - regoptail - regtail on operand of first argument; nop if operandless
4044 */
4045 STATIC void
4046 S_regoptail(pTHX_ regnode *p, regnode *val)
4047 {
4048     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4049     if (p == NULL || SIZE_ONLY)
4050 	return;
4051     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4052 	regtail(NEXTOPER(p), val);
4053     }
4054     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4055 	regtail(NEXTOPER(NEXTOPER(p)), val);
4056     }
4057     else
4058 	return;
4059 }
4060 
4061 /*
4062  - regcurly - a little FSA that accepts {\d+,?\d*}
4063  */
4064 STATIC I32
4065 S_regcurly(pTHX_ register char *s)
4066 {
4067     if (*s++ != '{')
4068 	return FALSE;
4069     if (!isDIGIT(*s))
4070 	return FALSE;
4071     while (isDIGIT(*s))
4072 	s++;
4073     if (*s == ',')
4074 	s++;
4075     while (isDIGIT(*s))
4076 	s++;
4077     if (*s != '}')
4078 	return FALSE;
4079     return TRUE;
4080 }
4081 
4082 
4083 STATIC regnode *
4084 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4085 {
4086 #ifdef DEBUGGING
4087     register U8 op = EXACT;	/* Arbitrary non-END op. */
4088     register regnode *next;
4089 
4090     while (op != END && (!last || node < last)) {
4091 	/* While that wasn't END last time... */
4092 
4093 	NODE_ALIGN(node);
4094 	op = OP(node);
4095 	if (op == CLOSE)
4096 	    l--;
4097 	next = regnext(node);
4098 	/* Where, what. */
4099 	if (OP(node) == OPTIMIZED)
4100 	    goto after_print;
4101 	regprop(sv, node);
4102 	PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4103 		      (int)(2*l + 1), "", SvPVX(sv));
4104 	if (next == NULL)		/* Next ptr. */
4105 	    PerlIO_printf(Perl_debug_log, "(0)");
4106 	else
4107 	    PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4108 	(void)PerlIO_putc(Perl_debug_log, '\n');
4109       after_print:
4110 	if (PL_regkind[(U8)op] == BRANCHJ) {
4111 	    register regnode *nnode = (OP(next) == LONGJMP
4112 				       ? regnext(next)
4113 				       : next);
4114 	    if (last && nnode > last)
4115 		nnode = last;
4116 	    node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4117 	}
4118 	else if (PL_regkind[(U8)op] == BRANCH) {
4119 	    node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4120 	}
4121 	else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4122 	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4123 			     NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4124 	}
4125 	else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4126 	    node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4127 			     next, sv, l + 1);
4128 	}
4129 	else if ( op == PLUS || op == STAR) {
4130 	    node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4131 	}
4132 	else if (op == ANYOF) {
4133 	    node = NEXTOPER(node);
4134 	    node += ANYOF_SKIP;
4135 	}
4136 	else if (PL_regkind[(U8)op] == EXACT) {
4137             /* Literal string, where present. */
4138 	    node += NODE_SZ_STR(node) - 1;
4139 	    node = NEXTOPER(node);
4140 	}
4141 	else {
4142 	    node = NEXTOPER(node);
4143 	    node += regarglen[(U8)op];
4144 	}
4145 	if (op == CURLYX || op == OPEN)
4146 	    l++;
4147 	else if (op == WHILEM)
4148 	    l--;
4149     }
4150 #endif	/* DEBUGGING */
4151     return node;
4152 }
4153 
4154 /*
4155  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4156  */
4157 void
4158 Perl_regdump(pTHX_ regexp *r)
4159 {
4160 #ifdef DEBUGGING
4161     SV *sv = sv_newmortal();
4162 
4163     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4164 
4165     /* Header fields of interest. */
4166     if (r->anchored_substr)
4167 	PerlIO_printf(Perl_debug_log,
4168 		      "anchored `%s%.*s%s'%s at %"IVdf" ",
4169 		      PL_colors[0],
4170 		      (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4171 		      SvPVX(r->anchored_substr),
4172 		      PL_colors[1],
4173 		      SvTAIL(r->anchored_substr) ? "$" : "",
4174 		      (IV)r->anchored_offset);
4175     if (r->float_substr)
4176 	PerlIO_printf(Perl_debug_log,
4177 		      "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4178 		      PL_colors[0],
4179 		      (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4180 		      SvPVX(r->float_substr),
4181 		      PL_colors[1],
4182 		      SvTAIL(r->float_substr) ? "$" : "",
4183 		      (IV)r->float_min_offset, (UV)r->float_max_offset);
4184     if (r->check_substr)
4185 	PerlIO_printf(Perl_debug_log,
4186 		      r->check_substr == r->float_substr
4187 		      ? "(checking floating" : "(checking anchored");
4188     if (r->reganch & ROPT_NOSCAN)
4189 	PerlIO_printf(Perl_debug_log, " noscan");
4190     if (r->reganch & ROPT_CHECK_ALL)
4191 	PerlIO_printf(Perl_debug_log, " isall");
4192     if (r->check_substr)
4193 	PerlIO_printf(Perl_debug_log, ") ");
4194 
4195     if (r->regstclass) {
4196 	regprop(sv, r->regstclass);
4197 	PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4198     }
4199     if (r->reganch & ROPT_ANCH) {
4200 	PerlIO_printf(Perl_debug_log, "anchored");
4201 	if (r->reganch & ROPT_ANCH_BOL)
4202 	    PerlIO_printf(Perl_debug_log, "(BOL)");
4203 	if (r->reganch & ROPT_ANCH_MBOL)
4204 	    PerlIO_printf(Perl_debug_log, "(MBOL)");
4205 	if (r->reganch & ROPT_ANCH_SBOL)
4206 	    PerlIO_printf(Perl_debug_log, "(SBOL)");
4207 	if (r->reganch & ROPT_ANCH_GPOS)
4208 	    PerlIO_printf(Perl_debug_log, "(GPOS)");
4209 	PerlIO_putc(Perl_debug_log, ' ');
4210     }
4211     if (r->reganch & ROPT_GPOS_SEEN)
4212 	PerlIO_printf(Perl_debug_log, "GPOS ");
4213     if (r->reganch & ROPT_SKIP)
4214 	PerlIO_printf(Perl_debug_log, "plus ");
4215     if (r->reganch & ROPT_IMPLICIT)
4216 	PerlIO_printf(Perl_debug_log, "implicit ");
4217     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4218     if (r->reganch & ROPT_EVAL_SEEN)
4219 	PerlIO_printf(Perl_debug_log, "with eval ");
4220     PerlIO_printf(Perl_debug_log, "\n");
4221 #endif	/* DEBUGGING */
4222 }
4223 
4224 STATIC void
4225 S_put_byte(pTHX_ SV *sv, int c)
4226 {
4227     if (isCNTRL(c) || c == 127 || c == 255)
4228 	Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4229     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4230 	Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4231     else
4232 	Perl_sv_catpvf(aTHX_ sv, "%c", c);
4233 }
4234 
4235 /*
4236 - regprop - printable representation of opcode
4237 */
4238 void
4239 Perl_regprop(pTHX_ SV *sv, regnode *o)
4240 {
4241 #ifdef DEBUGGING
4242     register int k;
4243 
4244     sv_setpvn(sv, "", 0);
4245     if (OP(o) >= reg_num)		/* regnode.type is unsigned */
4246 	FAIL("Corrupted regexp opcode");
4247     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4248 
4249     k = PL_regkind[(U8)OP(o)];
4250 
4251     if (k == EXACT)
4252 	Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>", PL_colors[0],
4253 		       STR_LEN(o), STRING(o), PL_colors[1]);
4254     else if (k == CURLY) {
4255 	if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4256 	    Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4257 	Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4258     }
4259     else if (k == WHILEM && o->flags)			/* Ordinal/of */
4260 	Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4261     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4262 	Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));	/* Parenth number */
4263     else if (k == LOGICAL)
4264 	Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);	/* 2: embedded, otherwise 1 */
4265     else if (k == ANYOF) {
4266 	int i, rangestart = -1;
4267 	bool anyofutf8 = OP(o) == ANYOFUTF8;
4268 	U8 flags = anyofutf8 ? ARG1(o) : o->flags;
4269 	const char * const anyofs[] = {	/* Should be syncronized with
4270 					 * ANYOF_ #xdefines in regcomp.h */
4271 	    "\\w",
4272 	    "\\W",
4273 	    "\\s",
4274 	    "\\S",
4275 	    "\\d",
4276 	    "\\D",
4277 	    "[:alnum:]",
4278 	    "[:^alnum:]",
4279 	    "[:alpha:]",
4280 	    "[:^alpha:]",
4281 	    "[:ascii:]",
4282 	    "[:^ascii:]",
4283 	    "[:ctrl:]",
4284 	    "[:^ctrl:]",
4285 	    "[:graph:]",
4286 	    "[:^graph:]",
4287 	    "[:lower:]",
4288 	    "[:^lower:]",
4289 	    "[:print:]",
4290 	    "[:^print:]",
4291 	    "[:punct:]",
4292 	    "[:^punct:]",
4293 	    "[:upper:]",
4294 	    "[:^upper:]",
4295 	    "[:xdigit:]",
4296 	    "[:^xdigit:]",
4297 	    "[:space:]",
4298 	    "[:^space:]",
4299 	    "[:blank:]",
4300 	    "[:^blank:]"
4301 	};
4302 
4303 	if (flags & ANYOF_LOCALE)
4304 	    sv_catpv(sv, "{loc}");
4305 	if (flags & ANYOF_FOLD)
4306 	    sv_catpv(sv, "{i}");
4307 	Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4308 	if (flags & ANYOF_INVERT)
4309 	    sv_catpv(sv, "^");
4310 	if (OP(o) == ANYOF) {
4311 	    for (i = 0; i <= 256; i++) {
4312 		if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4313 		    if (rangestart == -1)
4314 			rangestart = i;
4315 		} else if (rangestart != -1) {
4316 		    if (i <= rangestart + 3)
4317 			for (; rangestart < i; rangestart++)
4318 			    put_byte(sv, rangestart);
4319 		    else {
4320 			put_byte(sv, rangestart);
4321 			sv_catpv(sv, "-");
4322 			put_byte(sv, i - 1);
4323 		    }
4324 		    rangestart = -1;
4325 		}
4326 	    }
4327 	    if (o->flags & ANYOF_CLASS)
4328 		for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4329 		    if (ANYOF_CLASS_TEST(o,i))
4330 			sv_catpv(sv, anyofs[i]);
4331 	}
4332 	else {
4333 	    SV *rv = (SV*)PL_regdata->data[ARG2(o)];
4334 	    AV *av = (AV*)SvRV((SV*)rv);
4335 	    SV *sw = *av_fetch(av, 0, FALSE);
4336 	    SV *lv = *av_fetch(av, 1, FALSE);
4337 	    UV i;
4338 	    U8 s[UTF8_MAXLEN+1];
4339 	    for (i = 0; i <= 256; i++) { /* just the first 256 */
4340 		U8 *e = uv_to_utf8(s, i);
4341 		if (i < 256 && swash_fetch(sw, s)) {
4342 		    if (rangestart == -1)
4343 			rangestart = i;
4344 		} else if (rangestart != -1) {
4345 		    U8 *p;
4346 
4347 		    if (i <= rangestart + 3)
4348 			for (; rangestart < i; rangestart++) {
4349 			    for(e = uv_to_utf8(s, rangestart), p = s; p < e; p++)
4350 				put_byte(sv, *p);
4351 			}
4352 		    else {
4353 			for (e = uv_to_utf8(s, rangestart), p = s; p < e; p++)
4354 			    put_byte(sv, *p);
4355 			sv_catpv(sv, "-");
4356 			for (e = uv_to_utf8(s, i - 1), p = s; p < e; p++)
4357 			    put_byte(sv, *p);
4358 		    }
4359 		    rangestart = -1;
4360 		}
4361 	    }
4362 	    sv_catpv(sv, "...");
4363 	    {
4364 		char *s = savepv(SvPVX(lv));
4365 
4366 		while(*s && *s != '\n') s++;
4367 		if (*s == '\n') {
4368 		    char *t = ++s;
4369 
4370 		    while (*s) {
4371 			if (*s == '\n')
4372 			    *s = ' ';
4373 			s++;
4374 		    }
4375 		    if (s[-1] == ' ')
4376 			s[-1] = 0;
4377 
4378 		    sv_catpv(sv, t);
4379 		}
4380 	    }
4381 	}
4382 	Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4383     }
4384     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4385 	Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4386 #endif	/* DEBUGGING */
4387 }
4388 
4389 SV *
4390 Perl_re_intuit_string(pTHX_ regexp *prog)
4391 {				/* Assume that RE_INTUIT is set */
4392     DEBUG_r(
4393 	{   STRLEN n_a;
4394 	    char *s = SvPV(prog->check_substr,n_a);
4395 
4396 	    if (!PL_colorset) reginitcolors();
4397 	    PerlIO_printf(Perl_debug_log,
4398 		      "%sUsing REx substr:%s `%s%.60s%s%s'\n",
4399 		      PL_colors[4],PL_colors[5],PL_colors[0],
4400 		      s,
4401 		      PL_colors[1],
4402 		      (strlen(s) > 60 ? "..." : ""));
4403 	} );
4404 
4405     return prog->check_substr;
4406 }
4407 
4408 void
4409 Perl_pregfree(pTHX_ struct regexp *r)
4410 {
4411     DEBUG_r(if (!PL_colorset) reginitcolors());
4412 
4413     if (!r || (--r->refcnt > 0))
4414 	return;
4415     DEBUG_r(PerlIO_printf(Perl_debug_log,
4416 		      "%sFreeing REx:%s `%s%.60s%s%s'\n",
4417 		      PL_colors[4],PL_colors[5],PL_colors[0],
4418 		      r->precomp,
4419 		      PL_colors[1],
4420 		      (strlen(r->precomp) > 60 ? "..." : "")));
4421 
4422     if (r->precomp)
4423 	Safefree(r->precomp);
4424     if (RX_MATCH_COPIED(r))
4425 	Safefree(r->subbeg);
4426     if (r->substrs) {
4427 	if (r->anchored_substr)
4428 	    SvREFCNT_dec(r->anchored_substr);
4429 	if (r->float_substr)
4430 	    SvREFCNT_dec(r->float_substr);
4431 	Safefree(r->substrs);
4432     }
4433     if (r->data) {
4434 	int n = r->data->count;
4435 	AV* new_comppad = NULL;
4436 	AV* old_comppad;
4437 	SV** old_curpad;
4438 
4439 	while (--n >= 0) {
4440 	    switch (r->data->what[n]) {
4441 	    case 's':
4442 		SvREFCNT_dec((SV*)r->data->data[n]);
4443 		break;
4444 	    case 'f':
4445 		Safefree(r->data->data[n]);
4446 		break;
4447 	    case 'p':
4448 		new_comppad = (AV*)r->data->data[n];
4449 		break;
4450 	    case 'o':
4451 		if (new_comppad == NULL)
4452 		    Perl_croak(aTHX_ "panic: pregfree comppad");
4453 		old_comppad = PL_comppad;
4454 		old_curpad = PL_curpad;
4455 		/* Watch out for global destruction's random ordering. */
4456 		if (SvTYPE(new_comppad) == SVt_PVAV) {
4457 		    PL_comppad = new_comppad;
4458 		    PL_curpad = AvARRAY(new_comppad);
4459 		}
4460 		else
4461 		    PL_curpad = NULL;
4462 		op_free((OP_4tree*)r->data->data[n]);
4463 		PL_comppad = old_comppad;
4464 		PL_curpad = old_curpad;
4465 		SvREFCNT_dec((SV*)new_comppad);
4466 		new_comppad = NULL;
4467 		break;
4468 	    case 'n':
4469 		break;
4470 	    default:
4471 		FAIL2("panic: regfree data code '%c'", r->data->what[n]);
4472 	    }
4473 	}
4474 	Safefree(r->data->what);
4475 	Safefree(r->data);
4476     }
4477     Safefree(r->startp);
4478     Safefree(r->endp);
4479     Safefree(r);
4480 }
4481 
4482 /*
4483  - regnext - dig the "next" pointer out of a node
4484  *
4485  * [Note, when REGALIGN is defined there are two places in regmatch()
4486  * that bypass this code for speed.]
4487  */
4488 regnode *
4489 Perl_regnext(pTHX_ register regnode *p)
4490 {
4491     register I32 offset;
4492 
4493     if (p == &PL_regdummy)
4494 	return(NULL);
4495 
4496     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
4497     if (offset == 0)
4498 	return(NULL);
4499 
4500     return(p+offset);
4501 }
4502 
4503 STATIC void
4504 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
4505 {
4506     va_list args;
4507     STRLEN l1 = strlen(pat1);
4508     STRLEN l2 = strlen(pat2);
4509     char buf[512];
4510     SV *msv;
4511     char *message;
4512 
4513     if (l1 > 510)
4514 	l1 = 510;
4515     if (l1 + l2 > 510)
4516 	l2 = 510 - l1;
4517     Copy(pat1, buf, l1 , char);
4518     Copy(pat2, buf + l1, l2 , char);
4519     buf[l1 + l2] = '\n';
4520     buf[l1 + l2 + 1] = '\0';
4521 #ifdef I_STDARG
4522     /* ANSI variant takes additional second argument */
4523     va_start(args, pat2);
4524 #else
4525     va_start(args);
4526 #endif
4527     msv = vmess(buf, &args);
4528     va_end(args);
4529     message = SvPV(msv,l1);
4530     if (l1 > 512)
4531 	l1 = 512;
4532     Copy(message, buf, l1 , char);
4533     buf[l1] = '\0';			/* Overwrite \n */
4534     Perl_croak(aTHX_ "%s", buf);
4535 }
4536 
4537 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
4538 
4539 void
4540 Perl_save_re_context(pTHX)
4541 {
4542     SAVEPPTR(PL_bostr);
4543     SAVEPPTR(PL_regprecomp);		/* uncompiled string. */
4544     SAVEI32(PL_regnpar);		/* () count. */
4545     SAVEI32(PL_regsize);		/* Code size. */
4546     SAVEI16(PL_regflags);		/* are we folding, multilining? */
4547     SAVEPPTR(PL_reginput);		/* String-input pointer. */
4548     SAVEPPTR(PL_regbol);		/* Beginning of input, for ^ check. */
4549     SAVEPPTR(PL_regeol);		/* End of input, for $ check. */
4550     SAVEVPTR(PL_regstartp);		/* Pointer to startp array. */
4551     SAVEVPTR(PL_regendp);		/* Ditto for endp. */
4552     SAVEVPTR(PL_reglastparen);		/* Similarly for lastparen. */
4553     SAVEPPTR(PL_regtill);		/* How far we are required to go. */
4554     SAVEI8(PL_regprev);			/* char before regbol, \n if none */
4555     SAVEGENERICPV(PL_reg_start_tmp);	/* from regexec.c */
4556     PL_reg_start_tmp = 0;
4557     SAVEI32(PL_reg_start_tmpl);		/* from regexec.c */
4558     PL_reg_start_tmpl = 0;
4559     SAVEVPTR(PL_regdata);
4560     SAVEI32(PL_reg_flags);		/* from regexec.c */
4561     SAVEI32(PL_reg_eval_set);		/* from regexec.c */
4562     SAVEI32(PL_regnarrate);		/* from regexec.c */
4563     SAVEVPTR(PL_regprogram);		/* from regexec.c */
4564     SAVEINT(PL_regindent);		/* from regexec.c */
4565     SAVEVPTR(PL_regcc);			/* from regexec.c */
4566     SAVEVPTR(PL_curcop);
4567     SAVEVPTR(PL_regcomp_rx);		/* from regcomp.c */
4568     SAVEI32(PL_regseen);		/* from regcomp.c */
4569     SAVEI32(PL_regsawback);		/* Did we see \1, ...? */
4570     SAVEI32(PL_regnaughty);		/* How bad is this pattern? */
4571     SAVEVPTR(PL_regcode);		/* Code-emit pointer; &regdummy = don't */
4572     SAVEPPTR(PL_regxend);		/* End of input for compile */
4573     SAVEPPTR(PL_regcomp_parse);		/* Input-scan pointer. */
4574     SAVEVPTR(PL_reg_call_cc);		/* from regexec.c */
4575     SAVEVPTR(PL_reg_re);		/* from regexec.c */
4576     SAVEPPTR(PL_reg_ganch);		/* from regexec.c */
4577     SAVESPTR(PL_reg_sv);		/* from regexec.c */
4578     SAVEVPTR(PL_reg_magic);		/* from regexec.c */
4579     SAVEI32(PL_reg_oldpos);			/* from regexec.c */
4580     SAVEVPTR(PL_reg_oldcurpm);		/* from regexec.c */
4581     SAVEVPTR(PL_reg_curpm);		/* from regexec.c */
4582     SAVEI32(PL_regnpar);		/* () count. */
4583 #ifdef DEBUGGING
4584     SAVEPPTR(PL_reg_starttry);		/* from regexec.c */
4585 #endif
4586 }
4587 
4588 #ifdef PERL_OBJECT
4589 #include "XSUB.h"
4590 #undef this
4591 #define this pPerl
4592 #endif
4593 
4594 static void
4595 clear_re(pTHXo_ void *r)
4596 {
4597     ReREFCNT_dec((regexp *)r);
4598 }
4599 
4600