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[perl5.git] / regcomp.c
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 #ifndef PERL_IN_XSUB_RE
87 #  include "INTERN.h"
88 #endif
89
90 #define REG_COMP_C
91 #include "regcomp.h"
92
93 #ifdef op
94 #undef op
95 #endif /* op */
96
97 #ifdef MSDOS
98 # if defined(BUGGY_MSC6)
99  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
100  # pragma optimize("a",off)
101  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
102  # pragma optimize("w",on )
103 # endif /* BUGGY_MSC6 */
104 #endif /* MSDOS */
105
106 #ifndef STATIC
107 #define STATIC  static
108 #endif
109
110 typedef struct RExC_state_t {
111     U16         flags16;                /* are we folding, multilining? */
112     char        *precomp;               /* uncompiled string. */
113     regexp      *rx;
114     char        *start;                 /* Start of input for compile */
115     char        *end;                   /* End of input for compile */
116     char        *parse;                 /* Input-scan pointer. */
117     I32         whilem_seen;            /* number of WHILEM in this expr */
118     regnode     *emit_start;            /* Start of emitted-code area */
119     regnode     *emit;                  /* Code-emit pointer; &regdummy = don't = compiling */
120     I32         naughty;                /* How bad is this pattern? */
121     I32         sawback;                /* Did we see \1, ...? */
122     U32         seen;
123     I32         size;                   /* Code size. */
124     I32         npar;                   /* () count. */
125     I32         extralen;
126     I32         seen_zerolen;
127     I32         seen_evals;
128     I32         utf8;
129 #if ADD_TO_REGEXEC
130     char        *starttry;              /* -Dr: where regtry was called. */
131 #define RExC_starttry   (pRExC_state->starttry)
132 #endif
133 } RExC_state_t;
134
135 #define RExC_flags16    (pRExC_state->flags16)
136 #define RExC_precomp    (pRExC_state->precomp)
137 #define RExC_rx         (pRExC_state->rx)
138 #define RExC_start      (pRExC_state->start)
139 #define RExC_end        (pRExC_state->end)
140 #define RExC_parse      (pRExC_state->parse)
141 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
142 #define RExC_offsets    (pRExC_state->rx->offsets) /* I am not like the others */
143 #define RExC_emit       (pRExC_state->emit)
144 #define RExC_emit_start (pRExC_state->emit_start)
145 #define RExC_naughty    (pRExC_state->naughty)
146 #define RExC_sawback    (pRExC_state->sawback)
147 #define RExC_seen       (pRExC_state->seen)
148 #define RExC_size       (pRExC_state->size)
149 #define RExC_npar       (pRExC_state->npar)
150 #define RExC_extralen   (pRExC_state->extralen)
151 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
152 #define RExC_seen_evals (pRExC_state->seen_evals)
153 #define RExC_utf8       (pRExC_state->utf8)
154
155 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
156 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
157         ((*s) == '{' && regcurly(s)))
158
159 #ifdef SPSTART
160 #undef SPSTART          /* dratted cpp namespace... */
161 #endif
162 /*
163  * Flags to be passed up and down.
164  */
165 #define WORST           0       /* Worst case. */
166 #define HASWIDTH        0x1     /* Known to match non-null strings. */
167 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
168 #define SPSTART         0x4     /* Starts with * or +. */
169 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
170
171 /* Length of a variant. */
172
173 typedef struct scan_data_t {
174     I32 len_min;
175     I32 len_delta;
176     I32 pos_min;
177     I32 pos_delta;
178     SV *last_found;
179     I32 last_end;                       /* min value, <0 unless valid. */
180     I32 last_start_min;
181     I32 last_start_max;
182     SV **longest;                       /* Either &l_fixed, or &l_float. */
183     SV *longest_fixed;
184     I32 offset_fixed;
185     SV *longest_float;
186     I32 offset_float_min;
187     I32 offset_float_max;
188     I32 flags;
189     I32 whilem_c;
190     I32 *last_closep;
191     struct regnode_charclass_class *start_class;
192 } scan_data_t;
193
194 /*
195  * Forward declarations for pregcomp()'s friends.
196  */
197
198 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
199                                       0, 0, 0, 0, 0, 0};
200
201 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
202 #define SF_BEFORE_SEOL          0x1
203 #define SF_BEFORE_MEOL          0x2
204 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
205 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
206
207 #ifdef NO_UNARY_PLUS
208 #  define SF_FIX_SHIFT_EOL      (0+2)
209 #  define SF_FL_SHIFT_EOL               (0+4)
210 #else
211 #  define SF_FIX_SHIFT_EOL      (+2)
212 #  define SF_FL_SHIFT_EOL               (+4)
213 #endif
214
215 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
216 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
217
218 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
219 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
220 #define SF_IS_INF               0x40
221 #define SF_HAS_PAR              0x80
222 #define SF_IN_PAR               0x100
223 #define SF_HAS_EVAL             0x200
224 #define SCF_DO_SUBSTR           0x400
225 #define SCF_DO_STCLASS_AND      0x0800
226 #define SCF_DO_STCLASS_OR       0x1000
227 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
228 #define SCF_WHILEM_VISITED_POS  0x2000
229
230 #define UTF RExC_utf8
231 #define LOC (RExC_flags16 & PMf_LOCALE)
232 #define FOLD (RExC_flags16 & PMf_FOLD)
233
234 #define OOB_UNICODE             12345678
235 #define OOB_NAMEDCLASS          -1
236
237 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
238 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
239
240
241 /* length of regex to show in messages that don't mark a position within */
242 #define RegexLengthToShowInErrorMessages 127
243
244 /*
245  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
246  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
247  * op/pragma/warn/regcomp.
248  */
249 #define MARKER1 "<-- HERE"    /* marker as it appears in the description */
250 #define MARKER2 " <-- HERE "  /* marker as it appears within the regex */
251
252 #define REPORT_LOCATION " in regex; marked by " MARKER1 " in m/%.*s" MARKER2 "%s/"
253
254 /*
255  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
256  * arg. Show regex, up to a maximum length. If it's too long, chop and add
257  * "...".
258  */
259 #define FAIL(msg)                                                             \
260     STMT_START {                                                             \
261         char *ellipses = "";                                                 \
262         IV len = RExC_end - RExC_precomp;                                \
263                                                                              \
264         if (!SIZE_ONLY)                                                      \
265             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
266                                                                              \
267         if (len > RegexLengthToShowInErrorMessages) {                        \
268             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
269             len = RegexLengthToShowInErrorMessages - 10;                     \
270             ellipses = "...";                                                \
271         }                                                                    \
272         Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                            \
273                    msg, (int)len, RExC_precomp, ellipses);                  \
274     } STMT_END
275
276 /*
277  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
278  * args. Show regex, up to a maximum length. If it's too long, chop and add
279  * "...".
280  */
281 #define FAIL2(pat,msg)                                                        \
282     STMT_START {                                                             \
283         char *ellipses = "";                                                 \
284         IV len = RExC_end - RExC_precomp;                                \
285                                                                              \
286         if (!SIZE_ONLY)                                                      \
287             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
288                                                                              \
289         if (len > RegexLengthToShowInErrorMessages) {                        \
290             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
291             len = RegexLengthToShowInErrorMessages - 10;                     \
292             ellipses = "...";                                                \
293         }                                                                    \
294         S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                        \
295                     msg, (int)len, RExC_precomp, ellipses);                \
296     } STMT_END
297
298
299 /*
300  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
301  */
302 #define Simple_vFAIL(m)                                                      \
303     STMT_START {                                                             \
304       IV offset = RExC_parse - RExC_precomp; \
305                                                                              \
306       Perl_croak(aTHX_ "%s" REPORT_LOCATION,               \
307                  m, (int)offset, RExC_precomp, RExC_precomp + offset);     \
308     } STMT_END
309
310 /*
311  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
312  */
313 #define vFAIL(m)                                                             \
314     STMT_START {                                                             \
315       if (!SIZE_ONLY)                                                        \
316             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
317       Simple_vFAIL(m);                                                       \
318     } STMT_END
319
320 /*
321  * Like Simple_vFAIL(), but accepts two arguments.
322  */
323 #define Simple_vFAIL2(m,a1)                                                  \
324     STMT_START {                                                             \
325       IV offset = RExC_parse - RExC_precomp; \
326                                                                              \
327       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,       \
328                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
329     } STMT_END
330
331 /*
332  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
333  */
334 #define vFAIL2(m,a1)                                                         \
335     STMT_START {                                                             \
336       if (!SIZE_ONLY)                                                        \
337             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
338       Simple_vFAIL2(m, a1);                                                  \
339     } STMT_END
340
341
342 /*
343  * Like Simple_vFAIL(), but accepts three arguments.
344  */
345 #define Simple_vFAIL3(m, a1, a2)                                             \
346     STMT_START {                                                             \
347       IV offset = RExC_parse - RExC_precomp; \
348                                                                              \
349       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,   \
350                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
351     } STMT_END
352
353 /*
354  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
355  */
356 #define vFAIL3(m,a1,a2)                                                      \
357     STMT_START {                                                             \
358       if (!SIZE_ONLY)                                                        \
359             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
360       Simple_vFAIL3(m, a1, a2);                                              \
361     } STMT_END
362
363 /*
364  * Like Simple_vFAIL(), but accepts four arguments.
365  */
366 #define Simple_vFAIL4(m, a1, a2, a3)                                         \
367     STMT_START {                                                             \
368       IV offset = RExC_parse - RExC_precomp; \
369                                                                              \
370       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,\
371                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
372     } STMT_END
373
374 /*
375  * Like Simple_vFAIL(), but accepts five arguments.
376  */
377 #define Simple_vFAIL5(m, a1, a2, a3, a4)                                     \
378     STMT_START {                                                             \
379       IV offset = RExC_parse - RExC_precomp; \
380       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,\
381                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
382     } STMT_END
383
384
385 #define vWARN(loc,m)                                                         \
386     STMT_START {                                                             \
387         IV offset = loc - RExC_precomp;          \
388         Perl_warner(aTHX_ WARN_REGEXP, "%s" REPORT_LOCATION,\
389                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
390     } STMT_END                                                               \
391
392 #define vWARNdep(loc,m)                                                         \
393     STMT_START {                                                             \
394         IV offset = loc - RExC_precomp;          \
395         int warn_cat = ckWARN(WARN_REGEXP) ? WARN_REGEXP : WARN_DEPRECATED;  \
396         Perl_warner(aTHX_ warn_cat, "%s" REPORT_LOCATION,\
397                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
398     } STMT_END                                                               \
399
400
401 #define vWARN2(loc, m, a1)                                                   \
402     STMT_START {                                                             \
403         IV offset = loc - RExC_precomp;          \
404         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
405                  a1,                                                         \
406                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
407     } STMT_END
408
409 #define vWARN3(loc, m, a1, a2)                                               \
410     STMT_START {                                                             \
411       IV offset = loc - RExC_precomp;        \
412         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,                    \
413                  a1, a2,                                                     \
414                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
415     } STMT_END
416
417 #define vWARN4(loc, m, a1, a2, a3)                                           \
418     STMT_START {                                                             \
419       IV offset = loc - RExC_precomp;            \
420         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
421                  a1, a2, a3,                                                 \
422                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
423     } STMT_END
424
425 /* used for the parse_flags section for (?c) -- japhy */
426 #define vWARN5(loc, m, a1, a2, a3, a4)                                       \
427   STMT_START {                                                   \
428       IV offset = loc - RExC_precomp;   \
429         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,      \
430                  a1, a2, a3, a4,                                 \
431                  (int)offset, RExC_precomp, RExC_precomp + offset);  \
432     } STMT_END
433
434
435 /* Allow for side effects in s */
436 #define REGC(c,s) STMT_START { if (!SIZE_ONLY) *(s) = (c); else (void)(s);} STMT_END
437
438 /* Macros for recording node offsets.   20001227 mjd@plover.com 
439  * Nodes are numbered 1, 2, 3, 4.  Node #n's position is recorded in
440  * element 2*n-1 of the array.  Element #2n holds the byte length node #n.
441  * Element 0 holds the number n.
442  */
443
444 #define MJD_OFFSET_DEBUG(x)
445 /* #define MJD_OFFSET_DEBUG(x) fprintf x */
446
447
448 #  define Set_Node_Offset_To_R(node,byte)                           \
449    STMT_START {                                        \
450      if (! SIZE_ONLY) {                                  \
451        if((node) < 0) {                   \
452          Perl_croak(aTHX_ "value of node is %d in Offset macro", node); \
453        } else {                                                        \
454          RExC_offsets[2*(node)-1] = (byte);                               \
455        }                                                               \
456      }                                                                 \
457    } STMT_END
458
459 #  define Set_Node_Offset(node,byte) Set_Node_Offset_To_R((node)-RExC_emit_start, (byte)-RExC_start)
460 #  define Set_Cur_Node_Offset Set_Node_Offset(RExC_emit, RExC_parse)
461
462 #  define Set_Node_Length_To_R(node,len)                            \
463    STMT_START {                                        \
464      if (! SIZE_ONLY) {                                  \
465        MJD_OFFSET_DEBUG((stderr, "** (%d) size of node %d is %d.\n", __LINE__, (node), (len))); \
466        if((node) < 0) {                   \
467          Perl_croak(aTHX_ "value of node is %d in Length macro", node); \
468        } else {                                                        \
469          RExC_offsets[2*(node)] = (len);                               \
470        }                                                               \
471      }                                                                 \
472    } STMT_END
473
474 #  define Set_Node_Length(node,len) Set_Node_Length_To_R((node)-RExC_emit_start, len)
475 #  define Set_Cur_Node_Length(len)  Set_Node_Length(RExC_emit, len)
476 #  define Set_Node_Cur_Length(node)   Set_Node_Length(node, RExC_parse - parse_start)
477
478 /* Get offsets and lengths */
479 #define Node_Offset(n) (RExC_offsets[2*((n)-RExC_emit_start)-1])
480 #define Node_Length(n) (RExC_offsets[2*((n)-RExC_emit_start)])
481
482 static void clear_re(pTHX_ void *r);
483
484 /* Mark that we cannot extend a found fixed substring at this point.
485    Updata the longest found anchored substring and the longest found
486    floating substrings if needed. */
487
488 STATIC void
489 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
490 {
491     STRLEN l = CHR_SVLEN(data->last_found);
492     STRLEN old_l = CHR_SVLEN(*data->longest);
493
494     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
495         sv_setsv(*data->longest, data->last_found);
496         if (*data->longest == data->longest_fixed) {
497             data->offset_fixed = l ? data->last_start_min : data->pos_min;
498             if (data->flags & SF_BEFORE_EOL)
499                 data->flags
500                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
501             else
502                 data->flags &= ~SF_FIX_BEFORE_EOL;
503         }
504         else {
505             data->offset_float_min = l ? data->last_start_min : data->pos_min;
506             data->offset_float_max = (l
507                                       ? data->last_start_max
508                                       : data->pos_min + data->pos_delta);
509             if (data->flags & SF_BEFORE_EOL)
510                 data->flags
511                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
512             else
513                 data->flags &= ~SF_FL_BEFORE_EOL;
514         }
515     }
516     SvCUR_set(data->last_found, 0);
517     data->last_end = -1;
518     data->flags &= ~SF_BEFORE_EOL;
519 }
520
521 /* Can match anything (initialization) */
522 STATIC void
523 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
524 {
525     ANYOF_CLASS_ZERO(cl);
526     ANYOF_BITMAP_SETALL(cl);
527     cl->flags = ANYOF_EOS|ANYOF_UNICODE_ALL;
528     if (LOC)
529         cl->flags |= ANYOF_LOCALE;
530 }
531
532 /* Can match anything (initialization) */
533 STATIC int
534 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
535 {
536     int value;
537
538     for (value = 0; value <= ANYOF_MAX; value += 2)
539         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
540             return 1;
541     if (!(cl->flags & ANYOF_UNICODE_ALL))
542         return 0;
543     if (!ANYOF_BITMAP_TESTALLSET(cl))
544         return 0;
545     return 1;
546 }
547
548 /* Can match anything (initialization) */
549 STATIC void
550 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
551 {
552     Zero(cl, 1, struct regnode_charclass_class);
553     cl->type = ANYOF;
554     cl_anything(pRExC_state, cl);
555 }
556
557 STATIC void
558 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
559 {
560     Zero(cl, 1, struct regnode_charclass_class);
561     cl->type = ANYOF;
562     cl_anything(pRExC_state, cl);
563     if (LOC)
564         cl->flags |= ANYOF_LOCALE;
565 }
566
567 /* 'And' a given class with another one.  Can create false positives */
568 /* We assume that cl is not inverted */
569 STATIC void
570 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
571          struct regnode_charclass_class *and_with)
572 {
573     if (!(and_with->flags & ANYOF_CLASS)
574         && !(cl->flags & ANYOF_CLASS)
575         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
576         && !(and_with->flags & ANYOF_FOLD)
577         && !(cl->flags & ANYOF_FOLD)) {
578         int i;
579
580         if (and_with->flags & ANYOF_INVERT)
581             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
582                 cl->bitmap[i] &= ~and_with->bitmap[i];
583         else
584             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
585                 cl->bitmap[i] &= and_with->bitmap[i];
586     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
587     if (!(and_with->flags & ANYOF_EOS))
588         cl->flags &= ~ANYOF_EOS;
589
590     if (cl->flags & ANYOF_UNICODE_ALL && and_with->flags & ANYOF_UNICODE) {
591         cl->flags &= ~ANYOF_UNICODE_ALL;
592         cl->flags |= ANYOF_UNICODE;
593         ARG_SET(cl, ARG(and_with));
594     }
595     if (!(and_with->flags & ANYOF_UNICODE_ALL))
596         cl->flags &= ~ANYOF_UNICODE_ALL;
597     if (!(and_with->flags & (ANYOF_UNICODE|ANYOF_UNICODE_ALL)))
598         cl->flags &= ~ANYOF_UNICODE;
599 }
600
601 /* 'OR' a given class with another one.  Can create false positives */
602 /* We assume that cl is not inverted */
603 STATIC void
604 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
605 {
606     if (or_with->flags & ANYOF_INVERT) {
607         /* We do not use
608          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
609          *   <= (B1 | !B2) | (CL1 | !CL2)
610          * which is wasteful if CL2 is small, but we ignore CL2:
611          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
612          * XXXX Can we handle case-fold?  Unclear:
613          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
614          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
615          */
616         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
617              && !(or_with->flags & ANYOF_FOLD)
618              && !(cl->flags & ANYOF_FOLD) ) {
619             int i;
620
621             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
622                 cl->bitmap[i] |= ~or_with->bitmap[i];
623         } /* XXXX: logic is complicated otherwise */
624         else {
625             cl_anything(pRExC_state, cl);
626         }
627     } else {
628         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
629         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
630              && (!(or_with->flags & ANYOF_FOLD)
631                  || (cl->flags & ANYOF_FOLD)) ) {
632             int i;
633
634             /* OR char bitmap and class bitmap separately */
635             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
636                 cl->bitmap[i] |= or_with->bitmap[i];
637             if (or_with->flags & ANYOF_CLASS) {
638                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
639                     cl->classflags[i] |= or_with->classflags[i];
640                 cl->flags |= ANYOF_CLASS;
641             }
642         }
643         else { /* XXXX: logic is complicated, leave it along for a moment. */
644             cl_anything(pRExC_state, cl);
645         }
646     }
647     if (or_with->flags & ANYOF_EOS)
648         cl->flags |= ANYOF_EOS;
649
650     if (cl->flags & ANYOF_UNICODE && or_with->flags & ANYOF_UNICODE &&
651         ARG(cl) != ARG(or_with)) {
652         cl->flags |= ANYOF_UNICODE_ALL;
653         cl->flags &= ~ANYOF_UNICODE;
654     }
655     if (or_with->flags & ANYOF_UNICODE_ALL) {
656         cl->flags |= ANYOF_UNICODE_ALL;
657         cl->flags &= ~ANYOF_UNICODE;
658     }
659 }
660
661 /*
662  * There are strange code-generation bugs caused on sparc64 by gcc-2.95.2.
663  * These need to be revisited when a newer toolchain becomes available.
664  */
665 #if defined(__sparc64__) && defined(__GNUC__)
666 #   if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
667 #       undef  SPARC64_GCC_WORKAROUND
668 #       define SPARC64_GCC_WORKAROUND 1
669 #   endif
670 #endif
671
672 /* REx optimizer.  Converts nodes into quickier variants "in place".
673    Finds fixed substrings.  */
674
675 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
676    to the position after last scanned or to NULL. */
677
678 STATIC I32
679 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
680                         /* scanp: Start here (read-write). */
681                         /* deltap: Write maxlen-minlen here. */
682                         /* last: Stop before this one. */
683 {
684     I32 min = 0, pars = 0, code;
685     regnode *scan = *scanp, *next;
686     I32 delta = 0;
687     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
688     int is_inf_internal = 0;            /* The studied chunk is infinite */
689     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
690     scan_data_t data_fake;
691     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
692
693     while (scan && OP(scan) != END && scan < last) {
694         /* Peephole optimizer: */
695
696         if (PL_regkind[(U8)OP(scan)] == EXACT) {
697             /* Merge several consecutive EXACTish nodes into one. */
698             regnode *n = regnext(scan);
699             U32 stringok = 1;
700 #ifdef DEBUGGING
701             regnode *stop = scan;
702 #endif
703
704             next = scan + NODE_SZ_STR(scan);
705             /* Skip NOTHING, merge EXACT*. */
706             while (n &&
707                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
708                      (stringok && (OP(n) == OP(scan))))
709                    && NEXT_OFF(n)
710                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
711                 if (OP(n) == TAIL || n > next)
712                     stringok = 0;
713                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
714                     NEXT_OFF(scan) += NEXT_OFF(n);
715                     next = n + NODE_STEP_REGNODE;
716 #ifdef DEBUGGING
717                     if (stringok)
718                         stop = n;
719 #endif
720                     n = regnext(n);
721                 }
722                 else if (stringok) {
723                     int oldl = STR_LEN(scan);
724                     regnode *nnext = regnext(n);
725
726                     if (oldl + STR_LEN(n) > U8_MAX)
727                         break;
728                     NEXT_OFF(scan) += NEXT_OFF(n);
729                     STR_LEN(scan) += STR_LEN(n);
730                     next = n + NODE_SZ_STR(n);
731                     /* Now we can overwrite *n : */
732                     Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
733 #ifdef DEBUGGING
734                     stop = next - 1;
735 #endif
736                     n = nnext;
737                 }
738             }
739 #ifdef DEBUGGING
740             /* Allow dumping */
741             n = scan + NODE_SZ_STR(scan);
742             while (n <= stop) {
743                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
744                     OP(n) = OPTIMIZED;
745                     NEXT_OFF(n) = 0;
746                 }
747                 n++;
748             }
749 #endif
750         }
751         /* Follow the next-chain of the current node and optimize
752            away all the NOTHINGs from it.  */
753         if (OP(scan) != CURLYX) {
754             int max = (reg_off_by_arg[OP(scan)]
755                        ? I32_MAX
756                        /* I32 may be smaller than U16 on CRAYs! */
757                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
758             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
759             int noff;
760             regnode *n = scan;
761         
762             /* Skip NOTHING and LONGJMP. */
763             while ((n = regnext(n))
764                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
765                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
766                    && off + noff < max)
767                 off += noff;
768             if (reg_off_by_arg[OP(scan)])
769                 ARG(scan) = off;
770             else
771                 NEXT_OFF(scan) = off;
772         }
773         /* The principal pseudo-switch.  Cannot be a switch, since we
774            look into several different things.  */
775         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
776                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
777             next = regnext(scan);
778             code = OP(scan);
779         
780             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
781                 I32 max1 = 0, min1 = I32_MAX, num = 0;
782                 struct regnode_charclass_class accum;
783                 
784                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
785                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
786                 if (flags & SCF_DO_STCLASS)
787                     cl_init_zero(pRExC_state, &accum);
788                 while (OP(scan) == code) {
789                     I32 deltanext, minnext, f = 0, fake;
790                     struct regnode_charclass_class this_class;
791
792                     num++;
793                     data_fake.flags = 0;
794                     if (data) {         
795                         data_fake.whilem_c = data->whilem_c;
796                         data_fake.last_closep = data->last_closep;
797                     }
798                     else
799                         data_fake.last_closep = &fake;
800                     next = regnext(scan);
801                     scan = NEXTOPER(scan);
802                     if (code != BRANCH)
803                         scan = NEXTOPER(scan);
804                     if (flags & SCF_DO_STCLASS) {
805                         cl_init(pRExC_state, &this_class);
806                         data_fake.start_class = &this_class;
807                         f = SCF_DO_STCLASS_AND;
808                     }           
809                     if (flags & SCF_WHILEM_VISITED_POS)
810                         f |= SCF_WHILEM_VISITED_POS;
811                     /* we suppose the run is continuous, last=next...*/
812                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
813                                           next, &data_fake, f);
814                     if (min1 > minnext)
815                         min1 = minnext;
816                     if (max1 < minnext + deltanext)
817                         max1 = minnext + deltanext;
818                     if (deltanext == I32_MAX)
819                         is_inf = is_inf_internal = 1;
820                     scan = next;
821                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
822                         pars++;
823                     if (data && (data_fake.flags & SF_HAS_EVAL))
824                         data->flags |= SF_HAS_EVAL;
825                     if (data)
826                         data->whilem_c = data_fake.whilem_c;
827                     if (flags & SCF_DO_STCLASS)
828                         cl_or(pRExC_state, &accum, &this_class);
829                     if (code == SUSPEND)
830                         break;
831                 }
832                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
833                     min1 = 0;
834                 if (flags & SCF_DO_SUBSTR) {
835                     data->pos_min += min1;
836                     data->pos_delta += max1 - min1;
837                     if (max1 != min1 || is_inf)
838                         data->longest = &(data->longest_float);
839                 }
840                 min += min1;
841                 delta += max1 - min1;
842                 if (flags & SCF_DO_STCLASS_OR) {
843                     cl_or(pRExC_state, data->start_class, &accum);
844                     if (min1) {
845                         cl_and(data->start_class, &and_with);
846                         flags &= ~SCF_DO_STCLASS;
847                     }
848                 }
849                 else if (flags & SCF_DO_STCLASS_AND) {
850                     if (min1) {
851                         cl_and(data->start_class, &accum);
852                         flags &= ~SCF_DO_STCLASS;
853                     }
854                     else {
855                         /* Switch to OR mode: cache the old value of
856                          * data->start_class */
857                         StructCopy(data->start_class, &and_with,
858                                    struct regnode_charclass_class);
859                         flags &= ~SCF_DO_STCLASS_AND;
860                         StructCopy(&accum, data->start_class,
861                                    struct regnode_charclass_class);
862                         flags |= SCF_DO_STCLASS_OR;
863                         data->start_class->flags |= ANYOF_EOS;
864                     }
865                 }
866             }
867             else if (code == BRANCHJ)   /* single branch is optimized. */
868                 scan = NEXTOPER(NEXTOPER(scan));
869             else                        /* single branch is optimized. */
870                 scan = NEXTOPER(scan);
871             continue;
872         }
873         else if (OP(scan) == EXACT) {
874             I32 l = STR_LEN(scan);
875             UV uc = *((U8*)STRING(scan));
876             if (UTF) {
877                 U8 *s = (U8*)STRING(scan);
878                 l = utf8_length(s, s + l);
879                 uc = utf8_to_uvchr(s, NULL);
880             }
881             min += l;
882             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
883                 /* The code below prefers earlier match for fixed
884                    offset, later match for variable offset.  */
885                 if (data->last_end == -1) { /* Update the start info. */
886                     data->last_start_min = data->pos_min;
887                     data->last_start_max = is_inf
888                         ? I32_MAX : data->pos_min + data->pos_delta;
889                 }
890                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
891                 data->last_end = data->pos_min + l;
892                 data->pos_min += l; /* As in the first entry. */
893                 data->flags &= ~SF_BEFORE_EOL;
894             }
895             if (flags & SCF_DO_STCLASS_AND) {
896                 /* Check whether it is compatible with what we know already! */
897                 int compat = 1;
898
899                 if (uc >= 0x100 ||
900                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
901                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
902                     && (!(data->start_class->flags & ANYOF_FOLD)
903                         || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
904                     )
905                     compat = 0;
906                 ANYOF_CLASS_ZERO(data->start_class);
907                 ANYOF_BITMAP_ZERO(data->start_class);
908                 if (compat)
909                     ANYOF_BITMAP_SET(data->start_class, uc);
910                 data->start_class->flags &= ~ANYOF_EOS;
911                 if (uc < 0x100)
912                   data->start_class->flags &= ~ANYOF_UNICODE_ALL;
913             }
914             else if (flags & SCF_DO_STCLASS_OR) {
915                 /* false positive possible if the class is case-folded */
916                 if (uc < 0x100)
917                     ANYOF_BITMAP_SET(data->start_class, uc);
918                 else
919                     data->start_class->flags |= ANYOF_UNICODE_ALL;
920                 data->start_class->flags &= ~ANYOF_EOS;
921                 cl_and(data->start_class, &and_with);
922             }
923             flags &= ~SCF_DO_STCLASS;
924         }
925         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
926             I32 l = STR_LEN(scan);
927             UV uc = *((U8*)STRING(scan));
928
929             /* Search for fixed substrings supports EXACT only. */
930             if (flags & SCF_DO_SUBSTR)
931                 scan_commit(pRExC_state, data);
932             if (UTF) {
933                 U8 *s = (U8 *)STRING(scan);
934                 l = utf8_length(s, s + l);
935                 uc = utf8_to_uvchr(s, NULL);
936             }
937             min += l;
938             if (data && (flags & SCF_DO_SUBSTR))
939                 data->pos_min += l;
940             if (flags & SCF_DO_STCLASS_AND) {
941                 /* Check whether it is compatible with what we know already! */
942                 int compat = 1;
943
944                 if (uc >= 0x100 ||
945                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
946                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
947                      && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
948                     compat = 0;
949                 ANYOF_CLASS_ZERO(data->start_class);
950                 ANYOF_BITMAP_ZERO(data->start_class);
951                 if (compat) {
952                     ANYOF_BITMAP_SET(data->start_class, uc);
953                     data->start_class->flags &= ~ANYOF_EOS;
954                     data->start_class->flags |= ANYOF_FOLD;
955                     if (OP(scan) == EXACTFL)
956                         data->start_class->flags |= ANYOF_LOCALE;
957                 }
958             }
959             else if (flags & SCF_DO_STCLASS_OR) {
960                 if (data->start_class->flags & ANYOF_FOLD) {
961                     /* false positive possible if the class is case-folded.
962                        Assume that the locale settings are the same... */
963                     if (uc < 0x100)
964                         ANYOF_BITMAP_SET(data->start_class, uc);
965                     data->start_class->flags &= ~ANYOF_EOS;
966                 }
967                 cl_and(data->start_class, &and_with);
968             }
969             flags &= ~SCF_DO_STCLASS;
970         }
971         else if (strchr((char*)PL_varies,OP(scan))) {
972             I32 mincount, maxcount, minnext, deltanext, fl = 0;
973             I32 f = flags, pos_before = 0;
974             regnode *oscan = scan;
975             struct regnode_charclass_class this_class;
976             struct regnode_charclass_class *oclass = NULL;
977             I32 next_is_eval = 0;
978
979             switch (PL_regkind[(U8)OP(scan)]) {
980             case WHILEM:                /* End of (?:...)* . */
981                 scan = NEXTOPER(scan);
982                 goto finish;
983             case PLUS:
984                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
985                     next = NEXTOPER(scan);
986                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
987                         mincount = 1;
988                         maxcount = REG_INFTY;
989                         next = regnext(scan);
990                         scan = NEXTOPER(scan);
991                         goto do_curly;
992                     }
993                 }
994                 if (flags & SCF_DO_SUBSTR)
995                     data->pos_min++;
996                 min++;
997                 /* Fall through. */
998             case STAR:
999                 if (flags & SCF_DO_STCLASS) {
1000                     mincount = 0;
1001                     maxcount = REG_INFTY;
1002                     next = regnext(scan);
1003                     scan = NEXTOPER(scan);
1004                     goto do_curly;
1005                 }
1006                 is_inf = is_inf_internal = 1;
1007                 scan = regnext(scan);
1008                 if (flags & SCF_DO_SUBSTR) {
1009                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
1010                     data->longest = &(data->longest_float);
1011                 }
1012                 goto optimize_curly_tail;
1013             case CURLY:
1014                 mincount = ARG1(scan);
1015                 maxcount = ARG2(scan);
1016                 next = regnext(scan);
1017                 if (OP(scan) == CURLYX) {
1018                     I32 lp = (data ? *(data->last_closep) : 0);
1019
1020                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
1021                 }
1022                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
1023                 next_is_eval = (OP(scan) == EVAL);
1024               do_curly:
1025                 if (flags & SCF_DO_SUBSTR) {
1026                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
1027                     pos_before = data->pos_min;
1028                 }
1029                 if (data) {
1030                     fl = data->flags;
1031                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
1032                     if (is_inf)
1033                         data->flags |= SF_IS_INF;
1034                 }
1035                 if (flags & SCF_DO_STCLASS) {
1036                     cl_init(pRExC_state, &this_class);
1037                     oclass = data->start_class;
1038                     data->start_class = &this_class;
1039                     f |= SCF_DO_STCLASS_AND;
1040                     f &= ~SCF_DO_STCLASS_OR;
1041                 }
1042                 /* These are the cases when once a subexpression
1043                    fails at a particular position, it cannot succeed
1044                    even after backtracking at the enclosing scope.
1045                 
1046                    XXXX what if minimal match and we are at the
1047                         initial run of {n,m}? */
1048                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
1049                     f &= ~SCF_WHILEM_VISITED_POS;
1050
1051                 /* This will finish on WHILEM, setting scan, or on NULL: */
1052                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
1053                                       mincount == 0
1054                                         ? (f & ~SCF_DO_SUBSTR) : f);
1055
1056                 if (flags & SCF_DO_STCLASS)
1057                     data->start_class = oclass;
1058                 if (mincount == 0 || minnext == 0) {
1059                     if (flags & SCF_DO_STCLASS_OR) {
1060                         cl_or(pRExC_state, data->start_class, &this_class);
1061                     }
1062                     else if (flags & SCF_DO_STCLASS_AND) {
1063                         /* Switch to OR mode: cache the old value of
1064                          * data->start_class */
1065                         StructCopy(data->start_class, &and_with,
1066                                    struct regnode_charclass_class);
1067                         flags &= ~SCF_DO_STCLASS_AND;
1068                         StructCopy(&this_class, data->start_class,
1069                                    struct regnode_charclass_class);
1070                         flags |= SCF_DO_STCLASS_OR;
1071                         data->start_class->flags |= ANYOF_EOS;
1072                     }
1073                 } else {                /* Non-zero len */
1074                     if (flags & SCF_DO_STCLASS_OR) {
1075                         cl_or(pRExC_state, data->start_class, &this_class);
1076                         cl_and(data->start_class, &and_with);
1077                     }
1078                     else if (flags & SCF_DO_STCLASS_AND)
1079                         cl_and(data->start_class, &this_class);
1080                     flags &= ~SCF_DO_STCLASS;
1081                 }
1082                 if (!scan)              /* It was not CURLYX, but CURLY. */
1083                     scan = next;
1084                 if (ckWARN(WARN_REGEXP)
1085                        /* ? quantifier ok, except for (?{ ... }) */
1086                     && (next_is_eval || !(mincount == 0 && maxcount == 1))
1087                     && (minnext == 0) && (deltanext == 0)
1088                     && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1089                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1090                 {
1091                     vWARN(RExC_parse,
1092                           "Quantifier unexpected on zero-length expression");
1093                 }
1094
1095                 min += minnext * mincount;
1096                 is_inf_internal |= ((maxcount == REG_INFTY
1097                                      && (minnext + deltanext) > 0)
1098                                     || deltanext == I32_MAX);
1099                 is_inf |= is_inf_internal;
1100                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1101
1102                 /* Try powerful optimization CURLYX => CURLYN. */
1103                 if (  OP(oscan) == CURLYX && data
1104                       && data->flags & SF_IN_PAR
1105                       && !(data->flags & SF_HAS_EVAL)
1106                       && !deltanext && minnext == 1 ) {
1107                     /* Try to optimize to CURLYN.  */
1108                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1109                     regnode *nxt1 = nxt;
1110 #ifdef DEBUGGING
1111                     regnode *nxt2;
1112 #endif
1113
1114                     /* Skip open. */
1115                     nxt = regnext(nxt);
1116                     if (!strchr((char*)PL_simple,OP(nxt))
1117                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1118                              && STR_LEN(nxt) == 1))
1119                         goto nogo;
1120 #ifdef DEBUGGING
1121                     nxt2 = nxt;
1122 #endif
1123                     nxt = regnext(nxt);
1124                     if (OP(nxt) != CLOSE)
1125                         goto nogo;
1126                     /* Now we know that nxt2 is the only contents: */
1127                     oscan->flags = ARG(nxt);
1128                     OP(oscan) = CURLYN;
1129                     OP(nxt1) = NOTHING; /* was OPEN. */
1130 #ifdef DEBUGGING
1131                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1132                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1133                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1134                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1135                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1136                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1137 #endif
1138                 }
1139               nogo:
1140
1141                 /* Try optimization CURLYX => CURLYM. */
1142                 if (  OP(oscan) == CURLYX && data
1143                       && !(data->flags & SF_HAS_PAR)
1144                       && !(data->flags & SF_HAS_EVAL)
1145                       && !deltanext  ) {
1146                     /* XXXX How to optimize if data == 0? */
1147                     /* Optimize to a simpler form.  */
1148                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1149                     regnode *nxt2;
1150
1151                     OP(oscan) = CURLYM;
1152                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1153                             && (OP(nxt2) != WHILEM))
1154                         nxt = nxt2;
1155                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1156                     /* Need to optimize away parenths. */
1157                     if (data->flags & SF_IN_PAR) {
1158                         /* Set the parenth number.  */
1159                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1160
1161                         if (OP(nxt) != CLOSE)
1162                             FAIL("Panic opt close");
1163                         oscan->flags = ARG(nxt);
1164                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1165                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1166 #ifdef DEBUGGING
1167                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1168                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1169                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1170                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1171 #endif
1172 #if 0
1173                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1174                             regnode *nnxt = regnext(nxt1);
1175                         
1176                             if (nnxt == nxt) {
1177                                 if (reg_off_by_arg[OP(nxt1)])
1178                                     ARG_SET(nxt1, nxt2 - nxt1);
1179                                 else if (nxt2 - nxt1 < U16_MAX)
1180                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1181                                 else
1182                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1183                             }
1184                             nxt1 = nnxt;
1185                         }
1186 #endif
1187                         /* Optimize again: */
1188                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1189                                     NULL, 0);
1190                     }
1191                     else
1192                         oscan->flags = 0;
1193                 }
1194                 else if ((OP(oscan) == CURLYX)
1195                          && (flags & SCF_WHILEM_VISITED_POS)
1196                          /* See the comment on a similar expression above.
1197                             However, this time it not a subexpression
1198                             we care about, but the expression itself. */
1199                          && (maxcount == REG_INFTY)
1200                          && data && ++data->whilem_c < 16) {
1201                     /* This stays as CURLYX, we can put the count/of pair. */
1202                     /* Find WHILEM (as in regexec.c) */
1203                     regnode *nxt = oscan + NEXT_OFF(oscan);
1204
1205                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1206                         nxt += ARG(nxt);
1207                     PREVOPER(nxt)->flags = data->whilem_c
1208                         | (RExC_whilem_seen << 4); /* On WHILEM */
1209                 }
1210                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1211                     pars++;
1212                 if (flags & SCF_DO_SUBSTR) {
1213                     SV *last_str = Nullsv;
1214                     int counted = mincount != 0;
1215
1216                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1217 #if defined(SPARC64_GCC_WORKAROUND)
1218                         I32 b = 0;
1219                         STRLEN l = 0;
1220                         char *s = NULL;
1221                         I32 old = 0;
1222
1223                         if (pos_before >= data->last_start_min)
1224                             b = pos_before;
1225                         else
1226                             b = data->last_start_min;
1227
1228                         l = 0;
1229                         s = SvPV(data->last_found, l);
1230                         old = b - data->last_start_min;
1231
1232 #else
1233                         I32 b = pos_before >= data->last_start_min
1234                             ? pos_before : data->last_start_min;
1235                         STRLEN l;
1236                         char *s = SvPV(data->last_found, l);
1237                         I32 old = b - data->last_start_min;
1238 #endif
1239
1240                         if (UTF)
1241                             old = utf8_hop((U8*)s, old) - (U8*)s;
1242                         
1243                         l -= old;
1244                         /* Get the added string: */
1245                         last_str = newSVpvn(s  + old, l);
1246                         if (deltanext == 0 && pos_before == b) {
1247                             /* What was added is a constant string */
1248                             if (mincount > 1) {
1249                                 SvGROW(last_str, (mincount * l) + 1);
1250                                 repeatcpy(SvPVX(last_str) + l,
1251                                           SvPVX(last_str), l, mincount - 1);
1252                                 SvCUR(last_str) *= mincount;
1253                                 /* Add additional parts. */
1254                                 SvCUR_set(data->last_found,
1255                                           SvCUR(data->last_found) - l);
1256                                 sv_catsv(data->last_found, last_str);
1257                                 data->last_end += l * (mincount - 1);
1258                             }
1259                         } else {
1260                             /* start offset must point into the last copy */
1261                             data->last_start_min += minnext * (mincount - 1);
1262                             data->last_start_max += is_inf ? 0 : (maxcount - 1)
1263                                 * (minnext + data->pos_delta);
1264                         }
1265                     }
1266                     /* It is counted once already... */
1267                     data->pos_min += minnext * (mincount - counted);
1268                     data->pos_delta += - counted * deltanext +
1269                         (minnext + deltanext) * maxcount - minnext * mincount;
1270                     if (mincount != maxcount) {
1271                          /* Cannot extend fixed substrings found inside
1272                             the group.  */
1273                         scan_commit(pRExC_state,data);
1274                         if (mincount && last_str) {
1275                             sv_setsv(data->last_found, last_str);
1276                             data->last_end = data->pos_min;
1277                             data->last_start_min =
1278                                 data->pos_min - CHR_SVLEN(last_str);
1279                             data->last_start_max = is_inf
1280                                 ? I32_MAX
1281                                 : data->pos_min + data->pos_delta
1282                                 - CHR_SVLEN(last_str);
1283                         }
1284                         data->longest = &(data->longest_float);
1285                     }
1286                     SvREFCNT_dec(last_str);
1287                 }
1288                 if (data && (fl & SF_HAS_EVAL))
1289                     data->flags |= SF_HAS_EVAL;
1290               optimize_curly_tail:
1291                 if (OP(oscan) != CURLYX) {
1292                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1293                            && NEXT_OFF(next))
1294                         NEXT_OFF(oscan) += NEXT_OFF(next);
1295                 }
1296                 continue;
1297             default:                    /* REF and CLUMP only? */
1298                 if (flags & SCF_DO_SUBSTR) {
1299                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1300                     data->longest = &(data->longest_float);
1301                 }
1302                 is_inf = is_inf_internal = 1;
1303                 if (flags & SCF_DO_STCLASS_OR)
1304                     cl_anything(pRExC_state, data->start_class);
1305                 flags &= ~SCF_DO_STCLASS;
1306                 break;
1307             }
1308         }
1309         else if (strchr((char*)PL_simple,OP(scan))) {
1310             int value = 0;
1311
1312             if (flags & SCF_DO_SUBSTR) {
1313                 scan_commit(pRExC_state,data);
1314                 data->pos_min++;
1315             }
1316             min++;
1317             if (flags & SCF_DO_STCLASS) {
1318                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1319
1320                 /* Some of the logic below assumes that switching
1321                    locale on will only add false positives. */
1322                 switch (PL_regkind[(U8)OP(scan)]) {
1323                 case SANY:
1324                 default:
1325                   do_default:
1326                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1327                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1328                         cl_anything(pRExC_state, data->start_class);
1329                     break;
1330                 case REG_ANY:
1331                     if (OP(scan) == SANY)
1332                         goto do_default;
1333                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1334                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1335                                  || (data->start_class->flags & ANYOF_CLASS));
1336                         cl_anything(pRExC_state, data->start_class);
1337                     }
1338                     if (flags & SCF_DO_STCLASS_AND || !value)
1339                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1340                     break;
1341                 case ANYOF:
1342                     if (flags & SCF_DO_STCLASS_AND)
1343                         cl_and(data->start_class,
1344                                (struct regnode_charclass_class*)scan);
1345                     else
1346                         cl_or(pRExC_state, data->start_class,
1347                               (struct regnode_charclass_class*)scan);
1348                     break;
1349                 case ALNUM:
1350                     if (flags & SCF_DO_STCLASS_AND) {
1351                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1352                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1353                             for (value = 0; value < 256; value++)
1354                                 if (!isALNUM(value))
1355                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1356                         }
1357                     }
1358                     else {
1359                         if (data->start_class->flags & ANYOF_LOCALE)
1360                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1361                         else {
1362                             for (value = 0; value < 256; value++)
1363                                 if (isALNUM(value))
1364                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1365                         }
1366                     }
1367                     break;
1368                 case ALNUML:
1369                     if (flags & SCF_DO_STCLASS_AND) {
1370                         if (data->start_class->flags & ANYOF_LOCALE)
1371                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1372                     }
1373                     else {
1374                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1375                         data->start_class->flags |= ANYOF_LOCALE;
1376                     }
1377                     break;
1378                 case NALNUM:
1379                     if (flags & SCF_DO_STCLASS_AND) {
1380                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1381                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1382                             for (value = 0; value < 256; value++)
1383                                 if (isALNUM(value))
1384                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1385                         }
1386                     }
1387                     else {
1388                         if (data->start_class->flags & ANYOF_LOCALE)
1389                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1390                         else {
1391                             for (value = 0; value < 256; value++)
1392                                 if (!isALNUM(value))
1393                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1394                         }
1395                     }
1396                     break;
1397                 case NALNUML:
1398                     if (flags & SCF_DO_STCLASS_AND) {
1399                         if (data->start_class->flags & ANYOF_LOCALE)
1400                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1401                     }
1402                     else {
1403                         data->start_class->flags |= ANYOF_LOCALE;
1404                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1405                     }
1406                     break;
1407                 case SPACE:
1408                     if (flags & SCF_DO_STCLASS_AND) {
1409                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1410                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1411                             for (value = 0; value < 256; value++)
1412                                 if (!isSPACE(value))
1413                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1414                         }
1415                     }
1416                     else {
1417                         if (data->start_class->flags & ANYOF_LOCALE)
1418                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1419                         else {
1420                             for (value = 0; value < 256; value++)
1421                                 if (isSPACE(value))
1422                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1423                         }
1424                     }
1425                     break;
1426                 case SPACEL:
1427                     if (flags & SCF_DO_STCLASS_AND) {
1428                         if (data->start_class->flags & ANYOF_LOCALE)
1429                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1430                     }
1431                     else {
1432                         data->start_class->flags |= ANYOF_LOCALE;
1433                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1434                     }
1435                     break;
1436                 case NSPACE:
1437                     if (flags & SCF_DO_STCLASS_AND) {
1438                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1439                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1440                             for (value = 0; value < 256; value++)
1441                                 if (isSPACE(value))
1442                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1443                         }
1444                     }
1445                     else {
1446                         if (data->start_class->flags & ANYOF_LOCALE)
1447                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1448                         else {
1449                             for (value = 0; value < 256; value++)
1450                                 if (!isSPACE(value))
1451                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1452                         }
1453                     }
1454                     break;
1455                 case NSPACEL:
1456                     if (flags & SCF_DO_STCLASS_AND) {
1457                         if (data->start_class->flags & ANYOF_LOCALE) {
1458                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1459                             for (value = 0; value < 256; value++)
1460                                 if (!isSPACE(value))
1461                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1462                         }
1463                     }
1464                     else {
1465                         data->start_class->flags |= ANYOF_LOCALE;
1466                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1467                     }
1468                     break;
1469                 case DIGIT:
1470                     if (flags & SCF_DO_STCLASS_AND) {
1471                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1472                         for (value = 0; value < 256; value++)
1473                             if (!isDIGIT(value))
1474                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1475                     }
1476                     else {
1477                         if (data->start_class->flags & ANYOF_LOCALE)
1478                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1479                         else {
1480                             for (value = 0; value < 256; value++)
1481                                 if (isDIGIT(value))
1482                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1483                         }
1484                     }
1485                     break;
1486                 case NDIGIT:
1487                     if (flags & SCF_DO_STCLASS_AND) {
1488                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1489                         for (value = 0; value < 256; value++)
1490                             if (isDIGIT(value))
1491                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1492                     }
1493                     else {
1494                         if (data->start_class->flags & ANYOF_LOCALE)
1495                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1496                         else {
1497                             for (value = 0; value < 256; value++)
1498                                 if (!isDIGIT(value))
1499                                     ANYOF_BITMAP_SET(data->start_class, value);                 
1500                         }
1501                     }
1502                     break;
1503                 }
1504                 if (flags & SCF_DO_STCLASS_OR)
1505                     cl_and(data->start_class, &and_with);
1506                 flags &= ~SCF_DO_STCLASS;
1507             }
1508         }
1509         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1510             data->flags |= (OP(scan) == MEOL
1511                             ? SF_BEFORE_MEOL
1512                             : SF_BEFORE_SEOL);
1513         }
1514         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1515                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1516                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1517                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1518             /* Lookahead/lookbehind */
1519             I32 deltanext, minnext, fake = 0;
1520             regnode *nscan;
1521             struct regnode_charclass_class intrnl;
1522             int f = 0;
1523
1524             data_fake.flags = 0;
1525             if (data) {         
1526                 data_fake.whilem_c = data->whilem_c;
1527                 data_fake.last_closep = data->last_closep;
1528             }
1529             else
1530                 data_fake.last_closep = &fake;
1531             if ( flags & SCF_DO_STCLASS && !scan->flags
1532                  && OP(scan) == IFMATCH ) { /* Lookahead */
1533                 cl_init(pRExC_state, &intrnl);
1534                 data_fake.start_class = &intrnl;
1535                 f |= SCF_DO_STCLASS_AND;
1536             }
1537             if (flags & SCF_WHILEM_VISITED_POS)
1538                 f |= SCF_WHILEM_VISITED_POS;
1539             next = regnext(scan);
1540             nscan = NEXTOPER(NEXTOPER(scan));
1541             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1542             if (scan->flags) {
1543                 if (deltanext) {
1544                     vFAIL("Variable length lookbehind not implemented");
1545                 }
1546                 else if (minnext > U8_MAX) {
1547                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1548                 }
1549                 scan->flags = minnext;
1550             }
1551             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1552                 pars++;
1553             if (data && (data_fake.flags & SF_HAS_EVAL))
1554                 data->flags |= SF_HAS_EVAL;
1555             if (data)
1556                 data->whilem_c = data_fake.whilem_c;
1557             if (f & SCF_DO_STCLASS_AND) {
1558                 int was = (data->start_class->flags & ANYOF_EOS);
1559
1560                 cl_and(data->start_class, &intrnl);
1561                 if (was)
1562                     data->start_class->flags |= ANYOF_EOS;
1563             }
1564         }
1565         else if (OP(scan) == OPEN) {
1566             pars++;
1567         }
1568         else if (OP(scan) == CLOSE) {
1569             if (ARG(scan) == is_par) {
1570                 next = regnext(scan);
1571
1572                 if ( next && (OP(next) != WHILEM) && next < last)
1573                     is_par = 0;         /* Disable optimization */
1574             }
1575             if (data)
1576                 *(data->last_closep) = ARG(scan);
1577         }
1578         else if (OP(scan) == EVAL) {
1579                 if (data)
1580                     data->flags |= SF_HAS_EVAL;
1581         }
1582         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1583                 if (flags & SCF_DO_SUBSTR) {
1584                     scan_commit(pRExC_state,data);
1585                     data->longest = &(data->longest_float);
1586                 }
1587                 is_inf = is_inf_internal = 1;
1588                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1589                     cl_anything(pRExC_state, data->start_class);
1590                 flags &= ~SCF_DO_STCLASS;
1591         }
1592         /* Else: zero-length, ignore. */
1593         scan = regnext(scan);
1594     }
1595
1596   finish:
1597     *scanp = scan;
1598     *deltap = is_inf_internal ? I32_MAX : delta;
1599     if (flags & SCF_DO_SUBSTR && is_inf)
1600         data->pos_delta = I32_MAX - data->pos_min;
1601     if (is_par > U8_MAX)
1602         is_par = 0;
1603     if (is_par && pars==1 && data) {
1604         data->flags |= SF_IN_PAR;
1605         data->flags &= ~SF_HAS_PAR;
1606     }
1607     else if (pars && data) {
1608         data->flags |= SF_HAS_PAR;
1609         data->flags &= ~SF_IN_PAR;
1610     }
1611     if (flags & SCF_DO_STCLASS_OR)
1612         cl_and(data->start_class, &and_with);
1613     return min;
1614 }
1615
1616 STATIC I32
1617 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1618 {
1619     if (RExC_rx->data) {
1620         Renewc(RExC_rx->data,
1621                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1622                char, struct reg_data);
1623         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1624         RExC_rx->data->count += n;
1625     }
1626     else {
1627         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1628              char, struct reg_data);
1629         New(1208, RExC_rx->data->what, n, U8);
1630         RExC_rx->data->count = n;
1631     }
1632     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1633     return RExC_rx->data->count - n;
1634 }
1635
1636 void
1637 Perl_reginitcolors(pTHX)
1638 {
1639     int i = 0;
1640     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1641         
1642     if (s) {
1643         PL_colors[0] = s = savepv(s);
1644         while (++i < 6) {
1645             s = strchr(s, '\t');
1646             if (s) {
1647                 *s = '\0';
1648                 PL_colors[i] = ++s;
1649             }
1650             else
1651                 PL_colors[i] = s = "";
1652         }
1653     } else {
1654         while (i < 6)
1655             PL_colors[i++] = "";
1656     }
1657     PL_colorset = 1;
1658 }
1659
1660
1661 /*
1662  - pregcomp - compile a regular expression into internal code
1663  *
1664  * We can't allocate space until we know how big the compiled form will be,
1665  * but we can't compile it (and thus know how big it is) until we've got a
1666  * place to put the code.  So we cheat:  we compile it twice, once with code
1667  * generation turned off and size counting turned on, and once "for real".
1668  * This also means that we don't allocate space until we are sure that the
1669  * thing really will compile successfully, and we never have to move the
1670  * code and thus invalidate pointers into it.  (Note that it has to be in
1671  * one piece because free() must be able to free it all.) [NB: not true in perl]
1672  *
1673  * Beware that the optimization-preparation code in here knows about some
1674  * of the structure of the compiled regexp.  [I'll say.]
1675  */
1676 regexp *
1677 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1678 {
1679     register regexp *r;
1680     regnode *scan;
1681     regnode *first;
1682     I32 flags;
1683     I32 minlen = 0;
1684     I32 sawplus = 0;
1685     I32 sawopen = 0;
1686     scan_data_t data;
1687     RExC_state_t RExC_state;
1688     RExC_state_t *pRExC_state = &RExC_state;
1689
1690     if (exp == NULL)
1691         FAIL("NULL regexp argument");
1692
1693     RExC_utf8 = pm->op_pmdynflags & PMdf_CMP_UTF8;
1694
1695     RExC_precomp = exp;
1696     DEBUG_r({
1697          if (!PL_colorset) reginitcolors();
1698          PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1699                        PL_colors[4],PL_colors[5],PL_colors[0],
1700                        (int)(xend - exp), RExC_precomp, PL_colors[1]);
1701     });
1702     RExC_flags16 = pm->op_pmflags;
1703     RExC_sawback = 0;
1704
1705     RExC_seen = 0;
1706     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1707     RExC_seen_evals = 0;
1708     RExC_extralen = 0;
1709
1710     /* First pass: determine size, legality. */
1711     RExC_parse = exp;
1712     RExC_start = exp;
1713     RExC_end = xend;
1714     RExC_naughty = 0;
1715     RExC_npar = 1;
1716     RExC_size = 0L;
1717     RExC_emit = &PL_regdummy;
1718     RExC_whilem_seen = 0;
1719 #if 0 /* REGC() is (currently) a NOP at the first pass.
1720        * Clever compilers notice this and complain. --jhi */
1721     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1722 #endif
1723     if (reg(pRExC_state, 0, &flags) == NULL) {
1724         RExC_precomp = Nullch;
1725         return(NULL);
1726     }
1727     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1728
1729     /* Small enough for pointer-storage convention?
1730        If extralen==0, this means that we will not need long jumps. */
1731     if (RExC_size >= 0x10000L && RExC_extralen)
1732         RExC_size += RExC_extralen;
1733     else
1734         RExC_extralen = 0;
1735     if (RExC_whilem_seen > 15)
1736         RExC_whilem_seen = 15;
1737
1738     /* Allocate space and initialize. */
1739     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1740          char, regexp);
1741     if (r == NULL)
1742         FAIL("Regexp out of space");
1743
1744 #ifdef DEBUGGING
1745     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1746     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1747 #endif
1748     r->refcnt = 1;
1749     r->prelen = xend - exp;
1750     r->precomp = savepvn(RExC_precomp, r->prelen);
1751     r->subbeg = NULL;
1752     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1753     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1754
1755     r->substrs = 0;                     /* Useful during FAIL. */
1756     r->startp = 0;                      /* Useful during FAIL. */
1757     r->endp = 0;                        /* Useful during FAIL. */
1758
1759     Newz(1304, r->offsets, 2*RExC_size+1, U32); /* MJD 20001228 */
1760     if (r->offsets) {
1761       r->offsets[0] = RExC_size; 
1762     }
1763     DEBUG_r(PerlIO_printf(Perl_debug_log, 
1764                           "%s %"UVuf" bytes for offset annotations.\n", 
1765                           r->offsets ? "Got" : "Couldn't get", 
1766                           (UV)((2*RExC_size+1) * sizeof(U32))));
1767
1768     RExC_rx = r;
1769
1770     /* Second pass: emit code. */
1771     RExC_flags16 = pm->op_pmflags;      /* don't let top level (?i) bleed */
1772     RExC_parse = exp;
1773     RExC_end = xend;
1774     RExC_naughty = 0;
1775     RExC_npar = 1;
1776     RExC_emit_start = r->program;
1777     RExC_emit = r->program;
1778     /* Store the count of eval-groups for security checks: */
1779     RExC_emit->next_off = ((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1780     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1781     r->data = 0;
1782     if (reg(pRExC_state, 0, &flags) == NULL)
1783         return(NULL);
1784
1785     /* Dig out information for optimizations. */
1786     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1787     pm->op_pmflags = RExC_flags16;
1788     if (UTF)
1789         r->reganch |= ROPT_UTF8;        /* Unicode in it? */
1790     r->regstclass = NULL;
1791     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1792         r->reganch |= ROPT_NAUGHTY;
1793     scan = r->program + 1;              /* First BRANCH. */
1794
1795     /* XXXX To minimize changes to RE engine we always allocate
1796        3-units-long substrs field. */
1797     Newz(1004, r->substrs, 1, struct reg_substr_data);
1798
1799     StructCopy(&zero_scan_data, &data, scan_data_t);
1800     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1801     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1802         I32 fake;
1803         STRLEN longest_float_length, longest_fixed_length;
1804         struct regnode_charclass_class ch_class;
1805         int stclass_flag;
1806         I32 last_close = 0;
1807
1808         first = scan;
1809         /* Skip introductions and multiplicators >= 1. */
1810         while ((OP(first) == OPEN && (sawopen = 1)) ||
1811                /* An OR of *one* alternative - should not happen now. */
1812             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1813             (OP(first) == PLUS) ||
1814             (OP(first) == MINMOD) ||
1815                /* An {n,m} with n>0 */
1816             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1817                 if (OP(first) == PLUS)
1818                     sawplus = 1;
1819                 else
1820                     first += regarglen[(U8)OP(first)];
1821                 first = NEXTOPER(first);
1822         }
1823
1824         /* Starting-point info. */
1825       again:
1826         if (PL_regkind[(U8)OP(first)] == EXACT) {
1827             if (OP(first) == EXACT)
1828                 ;       /* Empty, get anchored substr later. */
1829             else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
1830                 r->regstclass = first;
1831         }
1832         else if (strchr((char*)PL_simple,OP(first)))
1833             r->regstclass = first;
1834         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1835                  PL_regkind[(U8)OP(first)] == NBOUND)
1836             r->regstclass = first;
1837         else if (PL_regkind[(U8)OP(first)] == BOL) {
1838             r->reganch |= (OP(first) == MBOL
1839                            ? ROPT_ANCH_MBOL
1840                            : (OP(first) == SBOL
1841                               ? ROPT_ANCH_SBOL
1842                               : ROPT_ANCH_BOL));
1843             first = NEXTOPER(first);
1844             goto again;
1845         }
1846         else if (OP(first) == GPOS) {
1847             r->reganch |= ROPT_ANCH_GPOS;
1848             first = NEXTOPER(first);
1849             goto again;
1850         }
1851         else if ((OP(first) == STAR &&
1852             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1853             !(r->reganch & ROPT_ANCH) )
1854         {
1855             /* turn .* into ^.* with an implied $*=1 */
1856             int type = OP(NEXTOPER(first));
1857
1858             if (type == REG_ANY)
1859                 type = ROPT_ANCH_MBOL;
1860             else
1861                 type = ROPT_ANCH_SBOL;
1862
1863             r->reganch |= type | ROPT_IMPLICIT;
1864             first = NEXTOPER(first);
1865             goto again;
1866         }
1867         if (sawplus && (!sawopen || !RExC_sawback)
1868             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1869             /* x+ must match at the 1st pos of run of x's */
1870             r->reganch |= ROPT_SKIP;
1871
1872         /* Scan is after the zeroth branch, first is atomic matcher. */
1873         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1874                               (IV)(first - scan + 1)));
1875         /*
1876         * If there's something expensive in the r.e., find the
1877         * longest literal string that must appear and make it the
1878         * regmust.  Resolve ties in favor of later strings, since
1879         * the regstart check works with the beginning of the r.e.
1880         * and avoiding duplication strengthens checking.  Not a
1881         * strong reason, but sufficient in the absence of others.
1882         * [Now we resolve ties in favor of the earlier string if
1883         * it happens that c_offset_min has been invalidated, since the
1884         * earlier string may buy us something the later one won't.]
1885         */
1886         minlen = 0;
1887
1888         data.longest_fixed = newSVpvn("",0);
1889         data.longest_float = newSVpvn("",0);
1890         data.last_found = newSVpvn("",0);
1891         data.longest = &(data.longest_fixed);
1892         first = scan;
1893         if (!r->regstclass) {
1894             cl_init(pRExC_state, &ch_class);
1895             data.start_class = &ch_class;
1896             stclass_flag = SCF_DO_STCLASS_AND;
1897         } else                          /* XXXX Check for BOUND? */
1898             stclass_flag = 0;
1899         data.last_closep = &last_close;
1900
1901         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1902                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1903         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1904              && data.last_start_min == 0 && data.last_end > 0
1905              && !RExC_seen_zerolen
1906              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1907             r->reganch |= ROPT_CHECK_ALL;
1908         scan_commit(pRExC_state, &data);
1909         SvREFCNT_dec(data.last_found);
1910
1911         longest_float_length = CHR_SVLEN(data.longest_float);
1912         if (longest_float_length
1913             || (data.flags & SF_FL_BEFORE_EOL
1914                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1915                     || (RExC_flags16 & PMf_MULTILINE)))) {
1916             int t;
1917
1918             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1919                 && data.offset_fixed == data.offset_float_min
1920                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1921                     goto remove_float;          /* As in (a)+. */
1922
1923             r->float_substr = data.longest_float;
1924             r->float_min_offset = data.offset_float_min;
1925             r->float_max_offset = data.offset_float_max;
1926             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1927                        && (!(data.flags & SF_FL_BEFORE_MEOL)
1928                            || (RExC_flags16 & PMf_MULTILINE)));
1929             fbm_compile(r->float_substr, t ? FBMcf_TAIL : 0);
1930         }
1931         else {
1932           remove_float:
1933             r->float_substr = Nullsv;
1934             SvREFCNT_dec(data.longest_float);
1935             longest_float_length = 0;
1936         }
1937
1938         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
1939         if (longest_fixed_length
1940             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
1941                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
1942                     || (RExC_flags16 & PMf_MULTILINE)))) {
1943             int t;
1944
1945             r->anchored_substr = data.longest_fixed;
1946             r->anchored_offset = data.offset_fixed;
1947             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
1948                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
1949                      || (RExC_flags16 & PMf_MULTILINE)));
1950             fbm_compile(r->anchored_substr, t ? FBMcf_TAIL : 0);
1951         }
1952         else {
1953             r->anchored_substr = Nullsv;
1954             SvREFCNT_dec(data.longest_fixed);
1955             longest_fixed_length = 0;
1956         }
1957         if (r->regstclass
1958             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == SANY))
1959             r->regstclass = NULL;
1960         if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
1961             && !(data.start_class->flags & ANYOF_EOS)
1962             && !cl_is_anything(data.start_class)) {
1963             I32 n = add_data(pRExC_state, 1, "f");
1964
1965             New(1006, RExC_rx->data->data[n], 1,
1966                 struct regnode_charclass_class);
1967             StructCopy(data.start_class,
1968                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
1969                        struct regnode_charclass_class);
1970             r->regstclass = (regnode*)RExC_rx->data->data[n];
1971             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
1972             PL_regdata = r->data; /* for regprop() */
1973             DEBUG_r({ SV *sv = sv_newmortal();
1974                       regprop(sv, (regnode*)data.start_class);
1975                       PerlIO_printf(Perl_debug_log,
1976                                     "synthetic stclass `%s'.\n",
1977                                     SvPVX(sv));});
1978         }
1979
1980         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
1981         if (longest_fixed_length > longest_float_length) {
1982             r->check_substr = r->anchored_substr;
1983             r->check_offset_min = r->check_offset_max = r->anchored_offset;
1984             if (r->reganch & ROPT_ANCH_SINGLE)
1985                 r->reganch |= ROPT_NOSCAN;
1986         }
1987         else {
1988             r->check_substr = r->float_substr;
1989             r->check_offset_min = data.offset_float_min;
1990             r->check_offset_max = data.offset_float_max;
1991         }
1992         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
1993            This should be changed ASAP!  */
1994         if (r->check_substr && !(r->reganch & ROPT_ANCH_GPOS)) {
1995             r->reganch |= RE_USE_INTUIT;
1996             if (SvTAIL(r->check_substr))
1997                 r->reganch |= RE_INTUIT_TAIL;
1998         }
1999     }
2000     else {
2001         /* Several toplevels. Best we can is to set minlen. */
2002         I32 fake;
2003         struct regnode_charclass_class ch_class;
2004         I32 last_close = 0;
2005         
2006         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
2007         scan = r->program + 1;
2008         cl_init(pRExC_state, &ch_class);
2009         data.start_class = &ch_class;
2010         data.last_closep = &last_close;
2011         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
2012         r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
2013         if (!(data.start_class->flags & ANYOF_EOS)
2014             && !cl_is_anything(data.start_class)) {
2015             I32 n = add_data(pRExC_state, 1, "f");
2016
2017             New(1006, RExC_rx->data->data[n], 1,
2018                 struct regnode_charclass_class);
2019             StructCopy(data.start_class,
2020                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2021                        struct regnode_charclass_class);
2022             r->regstclass = (regnode*)RExC_rx->data->data[n];
2023             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2024             DEBUG_r({ SV* sv = sv_newmortal();
2025                       regprop(sv, (regnode*)data.start_class);
2026                       PerlIO_printf(Perl_debug_log,
2027                                     "synthetic stclass `%s'.\n",
2028                                     SvPVX(sv));});
2029         }
2030     }
2031
2032     r->minlen = minlen;
2033     if (RExC_seen & REG_SEEN_GPOS)
2034         r->reganch |= ROPT_GPOS_SEEN;
2035     if (RExC_seen & REG_SEEN_LOOKBEHIND)
2036         r->reganch |= ROPT_LOOKBEHIND_SEEN;
2037     if (RExC_seen & REG_SEEN_EVAL)
2038         r->reganch |= ROPT_EVAL_SEEN;
2039     if (RExC_seen & REG_SEEN_CANY)
2040         r->reganch |= ROPT_CANY_SEEN;
2041     Newz(1002, r->startp, RExC_npar, I32);
2042     Newz(1002, r->endp, RExC_npar, I32);
2043     PL_regdata = r->data; /* for regprop() */
2044     DEBUG_r(regdump(r));
2045     return(r);
2046 }
2047
2048 /*
2049  - reg - regular expression, i.e. main body or parenthesized thing
2050  *
2051  * Caller must absorb opening parenthesis.
2052  *
2053  * Combining parenthesis handling with the base level of regular expression
2054  * is a trifle forced, but the need to tie the tails of the branches to what
2055  * follows makes it hard to avoid.
2056  */
2057 STATIC regnode *
2058 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
2059     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
2060 {
2061     register regnode *ret;              /* Will be the head of the group. */
2062     register regnode *br;
2063     register regnode *lastbr;
2064     register regnode *ender = 0;
2065     register I32 parno = 0;
2066     I32 flags, oregflags = RExC_flags16, have_branch = 0, open = 0;
2067
2068     /* for (?g), (?gc), and (?o) warnings; warning
2069        about (?c) will warn about (?g) -- japhy    */
2070
2071     I32 wastedflags = 0x00,
2072         wasted_o    = 0x01,
2073         wasted_g    = 0x02,
2074         wasted_gc   = 0x02 | 0x04,
2075         wasted_c    = 0x04;
2076
2077     char * parse_start = RExC_parse; /* MJD */
2078     char *oregcomp_parse = RExC_parse;
2079     char c;
2080
2081     *flagp = 0;                         /* Tentatively. */
2082
2083
2084     /* Make an OPEN node, if parenthesized. */
2085     if (paren) {
2086         if (*RExC_parse == '?') { /* (?...) */
2087             U16 posflags = 0, negflags = 0;
2088             U16 *flagsp = &posflags;
2089             int logical = 0;
2090             char *seqstart = RExC_parse;
2091
2092             RExC_parse++;
2093             paren = *RExC_parse++;
2094             ret = NULL;                 /* For look-ahead/behind. */
2095             switch (paren) {
2096             case '<':           /* (?<...) */
2097                 RExC_seen |= REG_SEEN_LOOKBEHIND;
2098                 if (*RExC_parse == '!')
2099                     paren = ',';
2100                 if (*RExC_parse != '=' && *RExC_parse != '!')
2101                     goto unknown;
2102                 RExC_parse++;
2103             case '=':           /* (?=...) */
2104             case '!':           /* (?!...) */
2105                 RExC_seen_zerolen++;
2106             case ':':           /* (?:...) */
2107             case '>':           /* (?>...) */
2108                 break;
2109             case '$':           /* (?$...) */
2110             case '@':           /* (?@...) */
2111                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
2112                 break;
2113             case '#':           /* (?#...) */
2114                 while (*RExC_parse && *RExC_parse != ')')
2115                     RExC_parse++;
2116                 if (*RExC_parse != ')')
2117                     FAIL("Sequence (?#... not terminated");
2118                 nextchar(pRExC_state);
2119                 *flagp = TRYAGAIN;
2120                 return NULL;
2121             case 'p':           /* (?p...) */
2122                 if (SIZE_ONLY && ckWARN2(WARN_DEPRECATED, WARN_REGEXP))
2123                     vWARNdep(RExC_parse, "(?p{}) is deprecated - use (??{})");
2124                 /* FALL THROUGH*/
2125             case '?':           /* (??...) */
2126                 logical = 1;
2127                 paren = *RExC_parse++;
2128                 /* FALL THROUGH */
2129             case '{':           /* (?{...}) */
2130             {
2131                 I32 count = 1, n = 0;
2132                 char c;
2133                 char *s = RExC_parse;
2134                 SV *sv;
2135                 OP_4tree *sop, *rop;
2136
2137                 RExC_seen_zerolen++;
2138                 RExC_seen |= REG_SEEN_EVAL;
2139                 while (count && (c = *RExC_parse)) {
2140                     if (c == '\\' && RExC_parse[1])
2141                         RExC_parse++;
2142                     else if (c == '{')
2143                         count++;
2144                     else if (c == '}')
2145                         count--;
2146                     RExC_parse++;
2147                 }
2148                 if (*RExC_parse != ')')
2149                 {
2150                     RExC_parse = s;             
2151                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2152                 }
2153                 if (!SIZE_ONLY) {
2154                     AV *av;
2155                 
2156                     if (RExC_parse - 1 - s)
2157                         sv = newSVpvn(s, RExC_parse - 1 - s);
2158                     else
2159                         sv = newSVpvn("", 0);
2160
2161                     ENTER;
2162                     Perl_save_re_context(aTHX);
2163                     rop = sv_compile_2op(sv, &sop, "re", &av);
2164                     sop->op_private |= OPpREFCOUNTED;
2165                     /* re_dup will OpREFCNT_inc */
2166                     OpREFCNT_set(sop, 1);
2167                     LEAVE;
2168
2169                     n = add_data(pRExC_state, 3, "nop");
2170                     RExC_rx->data->data[n] = (void*)rop;
2171                     RExC_rx->data->data[n+1] = (void*)sop;
2172                     RExC_rx->data->data[n+2] = (void*)av;
2173                     SvREFCNT_dec(sv);
2174                 }
2175                 else {                                          /* First pass */
2176                     if (PL_reginterp_cnt < ++RExC_seen_evals
2177                         && PL_curcop != &PL_compiling)
2178                         /* No compiled RE interpolated, has runtime
2179                            components ===> unsafe.  */
2180                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2181                     if (PL_tainting && PL_tainted)
2182                         FAIL("Eval-group in insecure regular expression");
2183                 }
2184                 
2185                 nextchar(pRExC_state);
2186                 if (logical) {
2187                     ret = reg_node(pRExC_state, LOGICAL);
2188                     if (!SIZE_ONLY)
2189                         ret->flags = 2;
2190                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2191                     /* deal with the length of this later - MJD */
2192                     return ret;
2193                 }
2194                 return reganode(pRExC_state, EVAL, n);
2195             }
2196             case '(':           /* (?(?{...})...) and (?(?=...)...) */
2197             {
2198                 if (RExC_parse[0] == '?') {        /* (?(?...)) */
2199                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2200                         || RExC_parse[1] == '<'
2201                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2202                         I32 flag;
2203                         
2204                         ret = reg_node(pRExC_state, LOGICAL);
2205                         if (!SIZE_ONLY)
2206                             ret->flags = 1;
2207                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2208                         goto insert_if;
2209                     }
2210                 }
2211                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2212                     /* (?(1)...) */
2213                     parno = atoi(RExC_parse++);
2214
2215                     while (isDIGIT(*RExC_parse))
2216                         RExC_parse++;
2217                     ret = reganode(pRExC_state, GROUPP, parno);
2218                     
2219                     if ((c = *nextchar(pRExC_state)) != ')')
2220                         vFAIL("Switch condition not recognized");
2221                   insert_if:
2222                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2223                     br = regbranch(pRExC_state, &flags, 1);
2224                     if (br == NULL)
2225                         br = reganode(pRExC_state, LONGJMP, 0);
2226                     else
2227                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2228                     c = *nextchar(pRExC_state);
2229                     if (flags&HASWIDTH)
2230                         *flagp |= HASWIDTH;
2231                     if (c == '|') {
2232                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2233                         regbranch(pRExC_state, &flags, 1);
2234                         regtail(pRExC_state, ret, lastbr);
2235                         if (flags&HASWIDTH)
2236                             *flagp |= HASWIDTH;
2237                         c = *nextchar(pRExC_state);
2238                     }
2239                     else
2240                         lastbr = NULL;
2241                     if (c != ')')
2242                         vFAIL("Switch (?(condition)... contains too many branches");
2243                     ender = reg_node(pRExC_state, TAIL);
2244                     regtail(pRExC_state, br, ender);
2245                     if (lastbr) {
2246                         regtail(pRExC_state, lastbr, ender);
2247                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2248                     }
2249                     else
2250                         regtail(pRExC_state, ret, ender);
2251                     return ret;
2252                 }
2253                 else {
2254                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2255                 }
2256             }
2257             case 0:
2258                 RExC_parse--; /* for vFAIL to print correctly */
2259                 vFAIL("Sequence (? incomplete");
2260                 break;
2261             default:
2262                 --RExC_parse;
2263               parse_flags:      /* (?i) */
2264                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2265                     /* (?g), (?gc) and (?o) are useless here
2266                        and must be globally applied -- japhy */
2267
2268                     if (*RExC_parse == 'o' || *RExC_parse == 'g') {
2269                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2270                             I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
2271                             if (! (wastedflags & wflagbit) ) {
2272                                 wastedflags |= wflagbit;
2273                                 vWARN5(
2274                                     RExC_parse + 1,
2275                                     "Useless (%s%c) - %suse /%c modifier",
2276                                     flagsp == &negflags ? "?-" : "?",
2277                                     *RExC_parse,
2278                                     flagsp == &negflags ? "don't " : "",
2279                                     *RExC_parse
2280                                 );
2281                             }
2282                         }
2283                     }
2284                     else if (*RExC_parse == 'c') {
2285                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2286                             if (! (wastedflags & wasted_c) ) {
2287                                 wastedflags |= wasted_gc;
2288                                 vWARN3(
2289                                     RExC_parse + 1,
2290                                     "Useless (%sc) - %suse /gc modifier",
2291                                     flagsp == &negflags ? "?-" : "?",
2292                                     flagsp == &negflags ? "don't " : ""
2293                                 );
2294                             }
2295                         }
2296                     }
2297                     else { pmflag(flagsp, *RExC_parse); }
2298
2299                     ++RExC_parse;
2300                 }
2301                 if (*RExC_parse == '-') {
2302                     flagsp = &negflags;
2303                     wastedflags = 0;  /* reset so (?g-c) warns twice */
2304                     ++RExC_parse;
2305                     goto parse_flags;
2306                 }
2307                 RExC_flags16 |= posflags;
2308                 RExC_flags16 &= ~negflags;
2309                 if (*RExC_parse == ':') {
2310                     RExC_parse++;
2311                     paren = ':';
2312                     break;
2313                 }               
2314               unknown:
2315                 if (*RExC_parse != ')') {
2316                     RExC_parse++;
2317                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2318                 }
2319                 nextchar(pRExC_state);
2320                 *flagp = TRYAGAIN;
2321                 return NULL;
2322             }
2323         }
2324         else {                  /* (...) */
2325             parno = RExC_npar;
2326             RExC_npar++;
2327             ret = reganode(pRExC_state, OPEN, parno);
2328             Set_Node_Length(ret, 1); /* MJD */
2329             Set_Node_Offset(ret, RExC_parse); /* MJD */
2330             open = 1;
2331         }
2332     }
2333     else                        /* ! paren */
2334         ret = NULL;
2335
2336     /* Pick up the branches, linking them together. */
2337     parse_start = RExC_parse;   /* MJD */
2338     br = regbranch(pRExC_state, &flags, 1);
2339     /*     branch_len = (paren != 0); */
2340     
2341     if (br == NULL)
2342         return(NULL);
2343     if (*RExC_parse == '|') {
2344         if (!SIZE_ONLY && RExC_extralen) {
2345             reginsert(pRExC_state, BRANCHJ, br);
2346         }
2347         else {                  /* MJD */
2348             reginsert(pRExC_state, BRANCH, br);
2349             Set_Node_Length(br, paren != 0);
2350             Set_Node_Offset_To_R(br-RExC_emit_start, parse_start-RExC_start);
2351         }
2352         have_branch = 1;
2353         if (SIZE_ONLY)
2354             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2355     }
2356     else if (paren == ':') {
2357         *flagp |= flags&SIMPLE;
2358     }
2359     if (open) {                         /* Starts with OPEN. */
2360         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2361     }
2362     else if (paren != '?')              /* Not Conditional */
2363         ret = br;
2364     if (flags&HASWIDTH)
2365         *flagp |= HASWIDTH;
2366     *flagp |= flags&SPSTART;
2367     lastbr = br;
2368     while (*RExC_parse == '|') {
2369         if (!SIZE_ONLY && RExC_extralen) {
2370             ender = reganode(pRExC_state, LONGJMP,0);
2371             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2372         }
2373         if (SIZE_ONLY)
2374             RExC_extralen += 2;         /* Account for LONGJMP. */
2375         nextchar(pRExC_state);
2376         br = regbranch(pRExC_state, &flags, 0);
2377         
2378         if (br == NULL)
2379             return(NULL);
2380         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2381         lastbr = br;
2382         if (flags&HASWIDTH)
2383             *flagp |= HASWIDTH;
2384         *flagp |= flags&SPSTART;
2385     }
2386
2387     if (have_branch || paren != ':') {
2388         /* Make a closing node, and hook it on the end. */
2389         switch (paren) {
2390         case ':':
2391             ender = reg_node(pRExC_state, TAIL);
2392             break;
2393         case 1:
2394             ender = reganode(pRExC_state, CLOSE, parno);
2395             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
2396             Set_Node_Length(ender,1); /* MJD */
2397             break;
2398         case '<':
2399         case ',':
2400         case '=':
2401         case '!':
2402             *flagp &= ~HASWIDTH;
2403             /* FALL THROUGH */
2404         case '>':
2405             ender = reg_node(pRExC_state, SUCCEED);
2406             break;
2407         case 0:
2408             ender = reg_node(pRExC_state, END);
2409             break;
2410         }
2411         regtail(pRExC_state, lastbr, ender);
2412
2413         if (have_branch) {
2414             /* Hook the tails of the branches to the closing node. */
2415             for (br = ret; br != NULL; br = regnext(br)) {
2416                 regoptail(pRExC_state, br, ender);
2417             }
2418         }
2419     }
2420
2421     {
2422         char *p;
2423         static char parens[] = "=!<,>";
2424
2425         if (paren && (p = strchr(parens, paren))) {
2426             int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2427             int flag = (p - parens) > 1;
2428
2429             if (paren == '>')
2430                 node = SUSPEND, flag = 0;
2431             reginsert(pRExC_state, node,ret);
2432             ret->flags = flag;
2433             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2434         }
2435     }
2436
2437     /* Check for proper termination. */
2438     if (paren) {
2439         RExC_flags16 = oregflags;
2440         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2441             RExC_parse = oregcomp_parse;
2442             vFAIL("Unmatched (");
2443         }
2444     }
2445     else if (!paren && RExC_parse < RExC_end) {
2446         if (*RExC_parse == ')') {
2447             RExC_parse++;
2448             vFAIL("Unmatched )");
2449         }
2450         else
2451             FAIL("Junk on end of regexp");      /* "Can't happen". */
2452         /* NOTREACHED */
2453     }
2454
2455     return(ret);
2456 }
2457
2458 /*
2459  - regbranch - one alternative of an | operator
2460  *
2461  * Implements the concatenation operator.
2462  */
2463 STATIC regnode *
2464 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2465 {
2466     register regnode *ret;
2467     register regnode *chain = NULL;
2468     register regnode *latest;
2469     I32 flags = 0, c = 0;
2470
2471     if (first)
2472         ret = NULL;
2473     else {
2474         if (!SIZE_ONLY && RExC_extralen)
2475             ret = reganode(pRExC_state, BRANCHJ,0);
2476         else {
2477             ret = reg_node(pRExC_state, BRANCH);
2478             Set_Node_Length(ret, 1);
2479         }
2480     }
2481         
2482     if (!first && SIZE_ONLY)
2483         RExC_extralen += 1;                     /* BRANCHJ */
2484
2485     *flagp = WORST;                     /* Tentatively. */
2486
2487     RExC_parse--;
2488     nextchar(pRExC_state);
2489     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2490         flags &= ~TRYAGAIN;
2491         latest = regpiece(pRExC_state, &flags);
2492         if (latest == NULL) {
2493             if (flags & TRYAGAIN)
2494                 continue;
2495             return(NULL);
2496         }
2497         else if (ret == NULL)
2498             ret = latest;
2499         *flagp |= flags&HASWIDTH;
2500         if (chain == NULL)      /* First piece. */
2501             *flagp |= flags&SPSTART;
2502         else {
2503             RExC_naughty++;
2504             regtail(pRExC_state, chain, latest);
2505         }
2506         chain = latest;
2507         c++;
2508     }
2509     if (chain == NULL) {        /* Loop ran zero times. */
2510         chain = reg_node(pRExC_state, NOTHING);
2511         if (ret == NULL)
2512             ret = chain;
2513     }
2514     if (c == 1) {
2515         *flagp |= flags&SIMPLE;
2516     }
2517
2518     return(ret);
2519 }
2520
2521 /*
2522  - regpiece - something followed by possible [*+?]
2523  *
2524  * Note that the branching code sequences used for ? and the general cases
2525  * of * and + are somewhat optimized:  they use the same NOTHING node as
2526  * both the endmarker for their branch list and the body of the last branch.
2527  * It might seem that this node could be dispensed with entirely, but the
2528  * endmarker role is not redundant.
2529  */
2530 STATIC regnode *
2531 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2532 {
2533     register regnode *ret;
2534     register char op;
2535     register char *next;
2536     I32 flags;
2537     char *origparse = RExC_parse;
2538     char *maxpos;
2539     I32 min;
2540     I32 max = REG_INFTY;
2541     char *parse_start;
2542
2543     ret = regatom(pRExC_state, &flags);
2544     if (ret == NULL) {
2545         if (flags & TRYAGAIN)
2546             *flagp |= TRYAGAIN;
2547         return(NULL);
2548     }
2549
2550     op = *RExC_parse;
2551
2552     if (op == '{' && regcurly(RExC_parse)) {
2553         parse_start = RExC_parse; /* MJD */
2554         next = RExC_parse + 1;
2555         maxpos = Nullch;
2556         while (isDIGIT(*next) || *next == ',') {
2557             if (*next == ',') {
2558                 if (maxpos)
2559                     break;
2560                 else
2561                     maxpos = next;
2562             }
2563             next++;
2564         }
2565         if (*next == '}') {             /* got one */
2566             if (!maxpos)
2567                 maxpos = next;
2568             RExC_parse++;
2569             min = atoi(RExC_parse);
2570             if (*maxpos == ',')
2571                 maxpos++;
2572             else
2573                 maxpos = RExC_parse;
2574             max = atoi(maxpos);
2575             if (!max && *maxpos != '0')
2576                 max = REG_INFTY;                /* meaning "infinity" */
2577             else if (max >= REG_INFTY)
2578                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2579             RExC_parse = next;
2580             nextchar(pRExC_state);
2581
2582         do_curly:
2583             if ((flags&SIMPLE)) {
2584                 RExC_naughty += 2 + RExC_naughty / 2;
2585                 reginsert(pRExC_state, CURLY, ret);
2586                 Set_Node_Offset(ret, parse_start+1); /* MJD */
2587                 Set_Node_Cur_Length(ret);
2588             }
2589             else {
2590                 regnode *w = reg_node(pRExC_state, WHILEM);
2591
2592                 w->flags = 0;
2593                 regtail(pRExC_state, ret, w);
2594                 if (!SIZE_ONLY && RExC_extralen) {
2595                     reginsert(pRExC_state, LONGJMP,ret);
2596                     reginsert(pRExC_state, NOTHING,ret);
2597                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2598                 }
2599                 reginsert(pRExC_state, CURLYX,ret);
2600                                 /* MJD hk */
2601                 Set_Node_Offset(ret, parse_start+1);
2602                 Set_Node_Length(ret, 
2603                                 op == '{' ? (RExC_parse - parse_start) : 1);
2604                 
2605                 if (!SIZE_ONLY && RExC_extralen)
2606                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2607                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2608                 if (SIZE_ONLY)
2609                     RExC_whilem_seen++, RExC_extralen += 3;
2610                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2611             }
2612             ret->flags = 0;
2613
2614             if (min > 0)
2615                 *flagp = WORST;
2616             if (max > 0)
2617                 *flagp |= HASWIDTH;
2618             if (max && max < min)
2619                 vFAIL("Can't do {n,m} with n > m");
2620             if (!SIZE_ONLY) {
2621                 ARG1_SET(ret, min);
2622                 ARG2_SET(ret, max);
2623             }
2624
2625             goto nest_check;
2626         }
2627     }
2628
2629     if (!ISMULT1(op)) {
2630         *flagp = flags;
2631         return(ret);
2632     }
2633
2634 #if 0                           /* Now runtime fix should be reliable. */
2635
2636     /* if this is reinstated, don't forget to put this back into perldiag:
2637
2638             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2639
2640            (F) The part of the regexp subject to either the * or + quantifier
2641            could match an empty string. The {#} shows in the regular
2642            expression about where the problem was discovered.
2643
2644     */
2645
2646     if (!(flags&HASWIDTH) && op != '?')
2647       vFAIL("Regexp *+ operand could be empty");
2648 #endif
2649
2650     parse_start = RExC_parse;
2651     nextchar(pRExC_state);
2652
2653     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2654
2655     if (op == '*' && (flags&SIMPLE)) {
2656         reginsert(pRExC_state, STAR, ret);
2657         ret->flags = 0;
2658         RExC_naughty += 4;
2659     }
2660     else if (op == '*') {
2661         min = 0;
2662         goto do_curly;
2663     }
2664     else if (op == '+' && (flags&SIMPLE)) {
2665         reginsert(pRExC_state, PLUS, ret);
2666         ret->flags = 0;
2667         RExC_naughty += 3;
2668     }
2669     else if (op == '+') {
2670         min = 1;
2671         goto do_curly;
2672     }
2673     else if (op == '?') {
2674         min = 0; max = 1;
2675         goto do_curly;
2676     }
2677   nest_check:
2678     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2679         vWARN3(RExC_parse,
2680                "%.*s matches null string many times",
2681                RExC_parse - origparse,
2682                origparse);
2683     }
2684
2685     if (*RExC_parse == '?') {
2686         nextchar(pRExC_state);
2687         reginsert(pRExC_state, MINMOD, ret);
2688         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2689     }
2690     if (ISMULT2(RExC_parse)) {
2691         RExC_parse++;
2692         vFAIL("Nested quantifiers");
2693     }
2694
2695     return(ret);
2696 }
2697
2698 /*
2699  - regatom - the lowest level
2700  *
2701  * Optimization:  gobbles an entire sequence of ordinary characters so that
2702  * it can turn them into a single node, which is smaller to store and
2703  * faster to run.  Backslashed characters are exceptions, each becoming a
2704  * separate node; the code is simpler that way and it's not worth fixing.
2705  *
2706  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2707 STATIC regnode *
2708 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2709 {
2710     register regnode *ret = 0;
2711     I32 flags;
2712     char *parse_start = 0;
2713
2714     *flagp = WORST;             /* Tentatively. */
2715
2716 tryagain:
2717     switch (*RExC_parse) {
2718     case '^':
2719         RExC_seen_zerolen++;
2720         nextchar(pRExC_state);
2721         if (RExC_flags16 & PMf_MULTILINE)
2722             ret = reg_node(pRExC_state, MBOL);
2723         else if (RExC_flags16 & PMf_SINGLELINE)
2724             ret = reg_node(pRExC_state, SBOL);
2725         else
2726             ret = reg_node(pRExC_state, BOL);
2727         Set_Node_Length(ret, 1); /* MJD */
2728         break;
2729     case '$':
2730         nextchar(pRExC_state);
2731         if (*RExC_parse)
2732             RExC_seen_zerolen++;
2733         if (RExC_flags16 & PMf_MULTILINE)
2734             ret = reg_node(pRExC_state, MEOL);
2735         else if (RExC_flags16 & PMf_SINGLELINE)
2736             ret = reg_node(pRExC_state, SEOL);
2737         else
2738             ret = reg_node(pRExC_state, EOL);
2739         Set_Node_Length(ret, 1); /* MJD */
2740         break;
2741     case '.':
2742         nextchar(pRExC_state);
2743         if (RExC_flags16 & PMf_SINGLELINE)
2744             ret = reg_node(pRExC_state, SANY);
2745         else
2746             ret = reg_node(pRExC_state, REG_ANY);
2747         *flagp |= HASWIDTH|SIMPLE;
2748         RExC_naughty++;
2749         Set_Node_Length(ret, 1); /* MJD */
2750         break;
2751     case '[':
2752     {
2753         char *oregcomp_parse = ++RExC_parse;
2754         ret = regclass(pRExC_state);
2755         if (*RExC_parse != ']') {
2756             RExC_parse = oregcomp_parse;
2757             vFAIL("Unmatched [");
2758         }
2759         nextchar(pRExC_state);
2760         *flagp |= HASWIDTH|SIMPLE;
2761         Set_Node_Length(ret, RExC_parse - oregcomp_parse + 1); /* MJD */
2762         break;
2763     }
2764     case '(':
2765         nextchar(pRExC_state);
2766         ret = reg(pRExC_state, 1, &flags);
2767         if (ret == NULL) {
2768                 if (flags & TRYAGAIN) {
2769                     if (RExC_parse == RExC_end) {
2770                          /* Make parent create an empty node if needed. */
2771                         *flagp |= TRYAGAIN;
2772                         return(NULL);
2773                     }
2774                     goto tryagain;
2775                 }
2776                 return(NULL);
2777         }
2778         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2779         break;
2780     case '|':
2781     case ')':
2782         if (flags & TRYAGAIN) {
2783             *flagp |= TRYAGAIN;
2784             return NULL;
2785         }
2786         vFAIL("Internal urp");
2787                                 /* Supposed to be caught earlier. */
2788         break;
2789     case '{':
2790         if (!regcurly(RExC_parse)) {
2791             RExC_parse++;
2792             goto defchar;
2793         }
2794         /* FALL THROUGH */
2795     case '?':
2796     case '+':
2797     case '*':
2798         RExC_parse++;
2799         vFAIL("Quantifier follows nothing");
2800         break;
2801     case '\\':
2802         switch (*++RExC_parse) {
2803         case 'A':
2804             RExC_seen_zerolen++;
2805             ret = reg_node(pRExC_state, SBOL);
2806             *flagp |= SIMPLE;
2807             nextchar(pRExC_state);
2808             Set_Node_Length(ret, 2); /* MJD */
2809             break;
2810         case 'G':
2811             ret = reg_node(pRExC_state, GPOS);
2812             RExC_seen |= REG_SEEN_GPOS;
2813             *flagp |= SIMPLE;
2814             nextchar(pRExC_state);
2815             Set_Node_Length(ret, 2); /* MJD */
2816             break;
2817         case 'Z':
2818             ret = reg_node(pRExC_state, SEOL);
2819             *flagp |= SIMPLE;
2820             RExC_seen_zerolen++;                /* Do not optimize RE away */
2821             nextchar(pRExC_state);
2822             break;
2823         case 'z':
2824             ret = reg_node(pRExC_state, EOS);
2825             *flagp |= SIMPLE;
2826             RExC_seen_zerolen++;                /* Do not optimize RE away */
2827             nextchar(pRExC_state);
2828             Set_Node_Length(ret, 2); /* MJD */
2829             break;
2830         case 'C':
2831             ret = reg_node(pRExC_state, CANY);
2832             RExC_seen |= REG_SEEN_CANY;
2833             *flagp |= HASWIDTH|SIMPLE;
2834             nextchar(pRExC_state);
2835             Set_Node_Length(ret, 2); /* MJD */
2836             break;
2837         case 'X':
2838             ret = reg_node(pRExC_state, CLUMP);
2839             *flagp |= HASWIDTH;
2840             nextchar(pRExC_state);
2841             Set_Node_Length(ret, 2); /* MJD */
2842             break;
2843         case 'w':
2844             ret = reg_node(pRExC_state, LOC ? ALNUML     : ALNUM);
2845             *flagp |= HASWIDTH|SIMPLE;
2846             nextchar(pRExC_state);
2847             Set_Node_Length(ret, 2); /* MJD */
2848             break;
2849         case 'W':
2850             ret = reg_node(pRExC_state, LOC ? NALNUML     : NALNUM);
2851             *flagp |= HASWIDTH|SIMPLE;
2852             nextchar(pRExC_state);
2853             Set_Node_Length(ret, 2); /* MJD */
2854             break;
2855         case 'b':
2856             RExC_seen_zerolen++;
2857             RExC_seen |= REG_SEEN_LOOKBEHIND;
2858             ret = reg_node(pRExC_state, LOC ? BOUNDL     : BOUND);
2859             *flagp |= SIMPLE;
2860             nextchar(pRExC_state);
2861             Set_Node_Length(ret, 2); /* MJD */
2862             break;
2863         case 'B':
2864             RExC_seen_zerolen++;
2865             RExC_seen |= REG_SEEN_LOOKBEHIND;
2866             ret = reg_node(pRExC_state, LOC ? NBOUNDL     : NBOUND);
2867             *flagp |= SIMPLE;
2868             nextchar(pRExC_state);
2869             Set_Node_Length(ret, 2); /* MJD */
2870             break;
2871         case 's':
2872             ret = reg_node(pRExC_state, LOC ? SPACEL     : SPACE);
2873             *flagp |= HASWIDTH|SIMPLE;
2874             nextchar(pRExC_state);
2875             Set_Node_Length(ret, 2); /* MJD */
2876             break;
2877         case 'S':
2878             ret = reg_node(pRExC_state, LOC ? NSPACEL     : NSPACE);
2879             *flagp |= HASWIDTH|SIMPLE;
2880             nextchar(pRExC_state);
2881             Set_Node_Length(ret, 2); /* MJD */
2882             break;
2883         case 'd':
2884             ret = reg_node(pRExC_state, DIGIT);
2885             *flagp |= HASWIDTH|SIMPLE;
2886             nextchar(pRExC_state);
2887             Set_Node_Length(ret, 2); /* MJD */
2888             break;
2889         case 'D':
2890             ret = reg_node(pRExC_state, NDIGIT);
2891             *flagp |= HASWIDTH|SIMPLE;
2892             nextchar(pRExC_state);
2893             Set_Node_Length(ret, 2); /* MJD */
2894             break;
2895         case 'p':
2896         case 'P':
2897             {   
2898                 char* oldregxend = RExC_end;
2899                 char* parse_start = RExC_parse;
2900
2901                 if (RExC_parse[1] == '{') {
2902                   /* a lovely hack--pretend we saw [\pX] instead */
2903                     RExC_end = strchr(RExC_parse, '}');
2904                     if (!RExC_end) {
2905                         U8 c = (U8)*RExC_parse;
2906                         RExC_parse += 2;
2907                         RExC_end = oldregxend;
2908                         vFAIL2("Missing right brace on \\%c{}", c);
2909                     }
2910                     RExC_end++;
2911                 }
2912                 else
2913                     RExC_end = RExC_parse + 2;
2914                 RExC_parse--;
2915
2916                 ret = regclass(pRExC_state);
2917
2918                 RExC_end = oldregxend;
2919                 RExC_parse--;
2920                 Set_Node_Cur_Length(ret); /* MJD */
2921                 nextchar(pRExC_state);
2922                 *flagp |= HASWIDTH|SIMPLE;
2923             }
2924             break;
2925         case 'n':
2926         case 'r':
2927         case 't':
2928         case 'f':
2929         case 'e':
2930         case 'a':
2931         case 'x':
2932         case 'c':
2933         case '0':
2934             goto defchar;
2935         case '1': case '2': case '3': case '4':
2936         case '5': case '6': case '7': case '8': case '9':
2937             {
2938                 I32 num = atoi(RExC_parse);
2939
2940                 if (num > 9 && num >= RExC_npar)
2941                     goto defchar;
2942                 else {
2943                     char * parse_start = RExC_parse - 1; /* MJD */
2944                     while (isDIGIT(*RExC_parse))
2945                         RExC_parse++;
2946
2947                     if (!SIZE_ONLY && num > RExC_rx->nparens)
2948                         vFAIL("Reference to nonexistent group");
2949                     RExC_sawback = 1;
2950                     ret = reganode(pRExC_state, FOLD
2951                                    ? (LOC ? REFFL : REFF)
2952                                    : REF, num);
2953                     *flagp |= HASWIDTH;
2954                     
2955                     /* override incorrect value set in reganode MJD */
2956                     Set_Node_Offset(ret, parse_start+1); 
2957                     Set_Node_Cur_Length(ret); /* MJD */
2958                     RExC_parse--;
2959                     nextchar(pRExC_state);
2960                 }
2961             }
2962             break;
2963         case '\0':
2964             if (RExC_parse >= RExC_end)
2965                 FAIL("Trailing \\");
2966             /* FALL THROUGH */
2967         default:
2968             /* Do not generate `unrecognized' warnings here, we fall
2969                back into the quick-grab loop below */
2970             goto defchar;
2971         }
2972         break;
2973
2974     case '#':
2975         if (RExC_flags16 & PMf_EXTENDED) {
2976             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
2977             if (RExC_parse < RExC_end)
2978                 goto tryagain;
2979         }
2980         /* FALL THROUGH */
2981
2982     default: {
2983             register STRLEN len;
2984             register UV ender;
2985             register char *p;
2986             char *oldp, *s;
2987             STRLEN numlen;
2988             STRLEN ulen;
2989             U8 tmpbuf[UTF8_MAXLEN_UCLC+1];
2990
2991             parse_start = RExC_parse - 1;
2992
2993             RExC_parse++;
2994
2995         defchar:
2996             ret = reg_node(pRExC_state, FOLD
2997                           ? (LOC ? EXACTFL : EXACTF)
2998                           : EXACT);
2999             s = STRING(ret);
3000             for (len = 0, p = RExC_parse - 1;
3001               len < 127 && p < RExC_end;
3002               len++)
3003             {
3004                 oldp = p;
3005
3006                 if (RExC_flags16 & PMf_EXTENDED)
3007                     p = regwhite(p, RExC_end);
3008                 switch (*p) {
3009                 case '^':
3010                 case '$':
3011                 case '.':
3012                 case '[':
3013                 case '(':
3014                 case ')':
3015                 case '|':
3016                     goto loopdone;
3017                 case '\\':
3018                     switch (*++p) {
3019                     case 'A':
3020                     case 'C':
3021                     case 'X':
3022                     case 'G':
3023                     case 'Z':
3024                     case 'z':
3025                     case 'w':
3026                     case 'W':
3027                     case 'b':
3028                     case 'B':
3029                     case 's':
3030                     case 'S':
3031                     case 'd':
3032                     case 'D':
3033                     case 'p':
3034                     case 'P':
3035                         --p;
3036                         goto loopdone;
3037                     case 'n':
3038                         ender = '\n';
3039                         p++;
3040                         break;
3041                     case 'r':
3042                         ender = '\r';
3043                         p++;
3044                         break;
3045                     case 't':
3046                         ender = '\t';
3047                         p++;
3048                         break;
3049                     case 'f':
3050                         ender = '\f';
3051                         p++;
3052                         break;
3053                     case 'e':
3054                           ender = ASCII_TO_NATIVE('\033');
3055                         p++;
3056                         break;
3057                     case 'a':
3058                           ender = ASCII_TO_NATIVE('\007');
3059                         p++;
3060                         break;
3061                     case 'x':
3062                         if (*++p == '{') {
3063                             char* e = strchr(p, '}');
3064         
3065                             if (!e) {
3066                                 RExC_parse = p + 1;
3067                                 vFAIL("Missing right brace on \\x{}");
3068                             }
3069                             else {
3070                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3071                                     | PERL_SCAN_DISALLOW_PREFIX;
3072                                 numlen = e - p - 1;
3073                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3074                                 if (ender > 0xff)
3075                                     RExC_utf8 = 1;
3076                                 /* numlen is generous */
3077                                 if (numlen + len >= 127) {
3078                                     p--;
3079                                     goto loopdone;
3080                                 }
3081                                 p = e + 1;
3082                             }
3083                         }
3084                         else {
3085                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3086                             numlen = 2;
3087                             ender = grok_hex(p, &numlen, &flags, NULL);
3088                             p += numlen;
3089                         }
3090                         break;
3091                     case 'c':
3092                         p++;
3093                         ender = UCHARAT(p++);
3094                         ender = toCTRL(ender);
3095                         break;
3096                     case '0': case '1': case '2': case '3':case '4':
3097                     case '5': case '6': case '7': case '8':case '9':
3098                         if (*p == '0' ||
3099                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3100                             I32 flags = 0;
3101                             numlen = 3;
3102                             ender = grok_oct(p, &numlen, &flags, NULL);
3103                             p += numlen;
3104                         }
3105                         else {
3106                             --p;
3107                             goto loopdone;
3108                         }
3109                         break;
3110                     case '\0':
3111                         if (p >= RExC_end)
3112                             FAIL("Trailing \\");
3113                         /* FALL THROUGH */
3114                     default:
3115                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3116                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3117                         goto normal_default;
3118                     }
3119                     break;
3120                 default:
3121                   normal_default:
3122                     if (UTF8_IS_START(*p) && UTF) {
3123                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3124                                                &numlen, 0);
3125                         p += numlen;
3126                     }
3127                     else
3128                         ender = *p++;
3129                     break;
3130                 }
3131                 if (RExC_flags16 & PMf_EXTENDED)
3132                     p = regwhite(p, RExC_end);
3133                 if (UTF && FOLD) {
3134                     toFOLD_uni(ender, tmpbuf, &ulen);
3135                     ender = utf8_to_uvchr(tmpbuf, 0);
3136                 }
3137                 if (ISMULT2(p)) { /* Back off on ?+*. */
3138                     if (len)
3139                         p = oldp;
3140                     else if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(ender)) && UTF) {
3141                         reguni(pRExC_state, ender, s, &numlen);
3142                         s += numlen;
3143                         len += numlen;
3144                     }
3145                     else {
3146                         len++;
3147                         REGC(ender, s++);
3148                     }
3149                     break;
3150                 }
3151                 if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(ender)) && UTF) {
3152                     reguni(pRExC_state, ender, s, &numlen);
3153                     s += numlen;
3154                     len += numlen - 1;
3155                 }
3156                 else
3157                     REGC(ender, s++);
3158             }
3159         loopdone:
3160             RExC_parse = p - 1;
3161             Set_Node_Cur_Length(ret); /* MJD */
3162             nextchar(pRExC_state);
3163             {
3164                 /* len is STRLEN which is unsigned, need to copy to signed */
3165                 IV iv = len;
3166                 if (iv < 0)
3167                     vFAIL("Internal disaster");
3168             }
3169             if (len > 0)
3170                 *flagp |= HASWIDTH;
3171             if (len == 1)
3172                 *flagp |= SIMPLE;
3173             if (!SIZE_ONLY)
3174                 STR_LEN(ret) = len;
3175             if (SIZE_ONLY)
3176                 RExC_size += STR_SZ(len);
3177             else
3178                 RExC_emit += STR_SZ(len);
3179         }
3180         break;
3181     }
3182
3183     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3184          STRLEN oldlen = STR_LEN(ret);
3185          SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3186
3187          if (RExC_utf8)
3188               SvUTF8_on(sv);
3189          if (sv_utf8_downgrade(sv, TRUE)) {
3190               char *s       = Perl_sv_recode_to_utf8(aTHX_ sv, PL_encoding);
3191               STRLEN newlen = SvCUR(sv);
3192          
3193               if (!SIZE_ONLY) {
3194                    DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3195                                          (int)oldlen, STRING(ret),
3196                                          (int)newlen, s));
3197                    Copy(s, STRING(ret), newlen, char);
3198                    STR_LEN(ret) += newlen - oldlen;
3199                    RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3200               } else
3201                    RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3202          }
3203     }
3204
3205     return(ret);
3206 }
3207
3208 STATIC char *
3209 S_regwhite(pTHX_ char *p, char *e)
3210 {
3211     while (p < e) {
3212         if (isSPACE(*p))
3213             ++p;
3214         else if (*p == '#') {
3215             do {
3216                 p++;
3217             } while (p < e && *p != '\n');
3218         }
3219         else
3220             break;
3221     }
3222     return p;
3223 }
3224
3225 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3226    Character classes ([:foo:]) can also be negated ([:^foo:]).
3227    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3228    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3229    but trigger failures because they are currently unimplemented. */
3230
3231 #define POSIXCC_DONE(c)   ((c) == ':')
3232 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3233 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3234
3235 STATIC I32
3236 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3237 {
3238     char *posixcc = 0;
3239     I32 namedclass = OOB_NAMEDCLASS;
3240
3241     if (value == '[' && RExC_parse + 1 < RExC_end &&
3242         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3243         POSIXCC(UCHARAT(RExC_parse))) {
3244         char  c = UCHARAT(RExC_parse);
3245         char* s = RExC_parse++;
3246         
3247         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3248             RExC_parse++;
3249         if (RExC_parse == RExC_end)
3250             /* Grandfather lone [:, [=, [. */
3251             RExC_parse = s;
3252         else {
3253             char* t = RExC_parse++; /* skip over the c */
3254
3255             if (UCHARAT(RExC_parse) == ']') {
3256                 RExC_parse++; /* skip over the ending ] */
3257                 posixcc = s + 1;
3258                 if (*s == ':') {
3259                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3260                     I32 skip = 5; /* the most common skip */
3261
3262                     switch (*posixcc) {
3263                     case 'a':
3264                         if (strnEQ(posixcc, "alnum", 5))
3265                             namedclass =
3266                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3267                         else if (strnEQ(posixcc, "alpha", 5))
3268                             namedclass =
3269                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3270                         else if (strnEQ(posixcc, "ascii", 5))
3271                             namedclass =
3272                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3273                         break;
3274                     case 'b':
3275                         if (strnEQ(posixcc, "blank", 5))
3276                             namedclass =
3277                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3278                         break;
3279                     case 'c':
3280                         if (strnEQ(posixcc, "cntrl", 5))
3281                             namedclass =
3282                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3283                         break;
3284                     case 'd':
3285                         if (strnEQ(posixcc, "digit", 5))
3286                             namedclass =
3287                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3288                         break;
3289                     case 'g':
3290                         if (strnEQ(posixcc, "graph", 5))
3291                             namedclass =
3292                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3293                         break;
3294                     case 'l':
3295                         if (strnEQ(posixcc, "lower", 5))
3296                             namedclass =
3297                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3298                         break;
3299                     case 'p':
3300                         if (strnEQ(posixcc, "print", 5))
3301                             namedclass =
3302                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3303                         else if (strnEQ(posixcc, "punct", 5))
3304                             namedclass =
3305                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3306                         break;
3307                     case 's':
3308                         if (strnEQ(posixcc, "space", 5))
3309                             namedclass =
3310                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3311                         break;
3312                     case 'u':
3313                         if (strnEQ(posixcc, "upper", 5))
3314                             namedclass =
3315                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3316                         break;
3317                     case 'w': /* this is not POSIX, this is the Perl \w */
3318                         if (strnEQ(posixcc, "word", 4)) {
3319                             namedclass =
3320                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3321                             skip = 4;
3322                         }
3323                         break;
3324                     case 'x':
3325                         if (strnEQ(posixcc, "xdigit", 6)) {
3326                             namedclass =
3327                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3328                             skip = 6;
3329                         }
3330                         break;
3331                     }
3332                     if (namedclass == OOB_NAMEDCLASS ||
3333                         posixcc[skip] != ':' ||
3334                         posixcc[skip+1] != ']')
3335                     {
3336                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3337                                       t - s - 1, s + 1);
3338                     }
3339                 } else if (!SIZE_ONLY) {
3340                     /* [[=foo=]] and [[.foo.]] are still future. */
3341
3342                     /* adjust RExC_parse so the warning shows after
3343                        the class closes */
3344                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3345                         RExC_parse++;
3346                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3347                 }
3348             } else {
3349                 /* Maternal grandfather:
3350                  * "[:" ending in ":" but not in ":]" */
3351                 RExC_parse = s;
3352             }
3353         }
3354     }
3355
3356     return namedclass;
3357 }
3358
3359 STATIC void
3360 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3361 {
3362     if (!SIZE_ONLY && ckWARN(WARN_REGEXP) &&
3363         POSIXCC(UCHARAT(RExC_parse))) {
3364         char *s = RExC_parse;
3365         char  c = *s++;
3366
3367         while(*s && isALNUM(*s))
3368             s++;
3369         if (*s && c == *s && s[1] == ']') {
3370             vWARN3(s+2, "POSIX syntax [%c %c] belongs inside character classes", c, c);
3371
3372             /* [[=foo=]] and [[.foo.]] are still future. */
3373             if (POSIXCC_NOTYET(c)) {
3374                 /* adjust RExC_parse so the error shows after
3375                    the class closes */
3376                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3377                     ;
3378                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3379             }
3380         }
3381     }
3382 }
3383
3384 STATIC regnode *
3385 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3386 {
3387     register UV value;
3388     register UV nextvalue;
3389     register IV prevvalue = OOB_UNICODE;
3390     register IV range = 0;
3391     register regnode *ret;
3392     STRLEN numlen;
3393     IV namedclass;
3394     char *rangebegin = 0;
3395     bool need_class = 0;
3396     SV *listsv = Nullsv;
3397     register char *e;
3398     UV n;
3399     bool optimize_invert = TRUE;
3400
3401     ret = reganode(pRExC_state, ANYOF, 0);
3402
3403     if (!SIZE_ONLY)
3404         ANYOF_FLAGS(ret) = 0;
3405
3406     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3407         RExC_naughty++;
3408         RExC_parse++;
3409         if (!SIZE_ONLY)
3410             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3411     }
3412
3413     if (SIZE_ONLY)
3414         RExC_size += ANYOF_SKIP;
3415     else {
3416         RExC_emit += ANYOF_SKIP;
3417         if (FOLD)
3418             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3419         if (LOC)
3420             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3421         ANYOF_BITMAP_ZERO(ret);
3422         listsv = newSVpvn("# comment\n", 10);
3423     }
3424
3425     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3426
3427     if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && POSIXCC(nextvalue))
3428         checkposixcc(pRExC_state);
3429
3430     if (UCHARAT(RExC_parse) == ']' || UCHARAT(RExC_parse) == '-')
3431         goto charclassloop;             /* allow 1st char to be ] or - */
3432
3433     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3434
3435     charclassloop:
3436
3437         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3438
3439         if (!range)
3440             rangebegin = RExC_parse;
3441         if (UTF) {
3442             value = utf8n_to_uvchr((U8*)RExC_parse,
3443                                    RExC_end - RExC_parse,
3444                                    &numlen, 0);
3445             RExC_parse += numlen;
3446         }
3447         else
3448             value = UCHARAT(RExC_parse++);
3449         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3450         if (value == '[' && POSIXCC(nextvalue))
3451             namedclass = regpposixcc(pRExC_state, value);
3452         else if (value == '\\') {
3453             if (UTF) {
3454                 value = utf8n_to_uvchr((U8*)RExC_parse,
3455                                    RExC_end - RExC_parse,
3456                                    &numlen, 0);
3457                 RExC_parse += numlen;
3458             }
3459             else
3460                 value = UCHARAT(RExC_parse++);
3461             /* Some compilers cannot handle switching on 64-bit integer
3462              * values, therefore value cannot be an UV.  Yes, this will
3463              * be a problem later if we want switch on Unicode.
3464              * A similar issue a little bit later when switching on
3465              * namedclass. --jhi */
3466             switch ((I32)value) {
3467             case 'w':   namedclass = ANYOF_ALNUM;       break;
3468             case 'W':   namedclass = ANYOF_NALNUM;      break;
3469             case 's':   namedclass = ANYOF_SPACE;       break;
3470             case 'S':   namedclass = ANYOF_NSPACE;      break;
3471             case 'd':   namedclass = ANYOF_DIGIT;       break;
3472             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3473             case 'p':
3474             case 'P':
3475                 if (*RExC_parse == '{') {
3476                     U8 c = (U8)value;
3477                     e = strchr(RExC_parse++, '}');
3478                     if (!e)
3479                         vFAIL2("Missing right brace on \\%c{}", c);
3480                     while (isSPACE(UCHARAT(RExC_parse)))
3481                         RExC_parse++;
3482                     if (e == RExC_parse)
3483                         vFAIL2("Empty \\%c{}", c);
3484                     n = e - RExC_parse;
3485                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3486                         n--;
3487                 }
3488                 else {
3489                     e = RExC_parse;
3490                     n = 1;
3491                 }
3492                 if (!SIZE_ONLY) {
3493                     if (UCHARAT(RExC_parse) == '^') {
3494                          RExC_parse++;
3495                          n--;
3496                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3497                          while (isSPACE(UCHARAT(RExC_parse))) {
3498                               RExC_parse++;
3499                               n--;
3500                          }
3501                     }
3502                     if (value == 'p')
3503                          Perl_sv_catpvf(aTHX_ listsv,
3504                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3505                     else
3506                          Perl_sv_catpvf(aTHX_ listsv,
3507                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3508                 }
3509                 RExC_parse = e + 1;
3510                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3511                 continue;
3512             case 'n':   value = '\n';                   break;
3513             case 'r':   value = '\r';                   break;
3514             case 't':   value = '\t';                   break;
3515             case 'f':   value = '\f';                   break;
3516             case 'b':   value = '\b';                   break;
3517             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3518             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3519             case 'x':
3520                 if (*RExC_parse == '{') {
3521                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3522                         | PERL_SCAN_DISALLOW_PREFIX;
3523                     e = strchr(RExC_parse++, '}');
3524                     if (!e)
3525                         vFAIL("Missing right brace on \\x{}");
3526
3527                     numlen = e - RExC_parse;
3528                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3529                     RExC_parse = e + 1;
3530                 }
3531                 else {
3532                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3533                     numlen = 2;
3534                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3535                     RExC_parse += numlen;
3536                 }
3537                 break;
3538             case 'c':
3539                 value = UCHARAT(RExC_parse++);
3540                 value = toCTRL(value);
3541                 break;
3542             case '0': case '1': case '2': case '3': case '4':
3543             case '5': case '6': case '7': case '8': case '9':
3544             {
3545                 I32 flags = 0;
3546                 numlen = 3;
3547                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3548                 RExC_parse += numlen;
3549                 break;
3550             }
3551             default:
3552                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3553                     vWARN2(RExC_parse,
3554                            "Unrecognized escape \\%c in character class passed through",
3555                            (int)value);
3556                 break;
3557             }
3558         } /* end of \blah */
3559
3560         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3561
3562             if (!SIZE_ONLY && !need_class)
3563                 ANYOF_CLASS_ZERO(ret);
3564
3565             need_class = 1;
3566
3567             /* a bad range like a-\d, a-[:digit:] ? */
3568             if (range) {
3569                 if (!SIZE_ONLY) {
3570                     if (ckWARN(WARN_REGEXP))
3571                         vWARN4(RExC_parse,
3572                                "False [] range \"%*.*s\"",
3573                                RExC_parse - rangebegin,
3574                                RExC_parse - rangebegin,
3575                                rangebegin);
3576                     if (prevvalue < 256) {
3577                         ANYOF_BITMAP_SET(ret, prevvalue);
3578                         ANYOF_BITMAP_SET(ret, '-');
3579                     }
3580                     else {
3581                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3582                         Perl_sv_catpvf(aTHX_ listsv,
3583                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3584                     }
3585                 }
3586
3587                 range = 0; /* this was not a true range */
3588             }
3589
3590             if (!SIZE_ONLY) {
3591                 if (namedclass > OOB_NAMEDCLASS)
3592                     optimize_invert = FALSE;
3593                 /* Possible truncation here but in some 64-bit environments
3594                  * the compiler gets heartburn about switch on 64-bit values.
3595                  * A similar issue a little earlier when switching on value.
3596                  * --jhi */
3597                 switch ((I32)namedclass) {
3598                 case ANYOF_ALNUM:
3599                     if (LOC)
3600                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3601                     else {
3602                         for (value = 0; value < 256; value++)
3603                             if (isALNUM(value))
3604                                 ANYOF_BITMAP_SET(ret, value);
3605                     }
3606                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");    
3607                     break;
3608                 case ANYOF_NALNUM:
3609                     if (LOC)
3610                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3611                     else {
3612                         for (value = 0; value < 256; value++)
3613                             if (!isALNUM(value))
3614                                 ANYOF_BITMAP_SET(ret, value);
3615                     }
3616                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3617                     break;
3618                 case ANYOF_ALNUMC:
3619                     if (LOC)
3620                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3621                     else {
3622                         for (value = 0; value < 256; value++)
3623                             if (isALNUMC(value))
3624                                 ANYOF_BITMAP_SET(ret, value);
3625                     }
3626                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3627                     break;
3628                 case ANYOF_NALNUMC:
3629                     if (LOC)
3630                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3631                     else {
3632                         for (value = 0; value < 256; value++)
3633                             if (!isALNUMC(value))
3634                                 ANYOF_BITMAP_SET(ret, value);
3635                     }
3636                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3637                     break;
3638                 case ANYOF_ALPHA:
3639                     if (LOC)
3640                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3641                     else {
3642                         for (value = 0; value < 256; value++)
3643                             if (isALPHA(value))
3644                                 ANYOF_BITMAP_SET(ret, value);
3645                     }
3646                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3647                     break;
3648                 case ANYOF_NALPHA:
3649                     if (LOC)
3650                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3651                     else {
3652                         for (value = 0; value < 256; value++)
3653                             if (!isALPHA(value))
3654                                 ANYOF_BITMAP_SET(ret, value);
3655                     }
3656                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3657                     break;
3658                 case ANYOF_ASCII:
3659                     if (LOC)
3660                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3661                     else {
3662 #ifndef EBCDIC
3663                         for (value = 0; value < 128; value++)
3664                             ANYOF_BITMAP_SET(ret, value);
3665 #else  /* EBCDIC */
3666                         for (value = 0; value < 256; value++) {
3667                             if (isASCII(value))
3668                                 ANYOF_BITMAP_SET(ret, value);
3669                         }
3670 #endif /* EBCDIC */
3671                     }
3672                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3673                     break;
3674                 case ANYOF_NASCII:
3675                     if (LOC)
3676                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3677                     else {
3678 #ifndef EBCDIC
3679                         for (value = 128; value < 256; value++)
3680                             ANYOF_BITMAP_SET(ret, value);
3681 #else  /* EBCDIC */
3682                         for (value = 0; value < 256; value++) {
3683                             if (!isASCII(value))
3684                                 ANYOF_BITMAP_SET(ret, value);
3685                         }
3686 #endif /* EBCDIC */
3687                     }
3688                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3689                     break;
3690                 case ANYOF_BLANK:
3691                     if (LOC)
3692                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3693                     else {
3694                         for (value = 0; value < 256; value++)
3695                             if (isBLANK(value))
3696                                 ANYOF_BITMAP_SET(ret, value);
3697                     }
3698                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3699                     break;
3700                 case ANYOF_NBLANK:
3701                     if (LOC)
3702                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3703                     else {
3704                         for (value = 0; value < 256; value++)
3705                             if (!isBLANK(value))
3706                                 ANYOF_BITMAP_SET(ret, value);
3707                     }
3708                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3709                     break;
3710                 case ANYOF_CNTRL:
3711                     if (LOC)
3712                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3713                     else {
3714                         for (value = 0; value < 256; value++)
3715                             if (isCNTRL(value))
3716                                 ANYOF_BITMAP_SET(ret, value);
3717                     }
3718                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3719                     break;
3720                 case ANYOF_NCNTRL:
3721                     if (LOC)
3722                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3723                     else {
3724                         for (value = 0; value < 256; value++)
3725                             if (!isCNTRL(value))
3726                                 ANYOF_BITMAP_SET(ret, value);
3727                     }
3728                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3729                     break;
3730                 case ANYOF_DIGIT:
3731                     if (LOC)
3732                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3733                     else {
3734                         /* consecutive digits assumed */
3735                         for (value = '0'; value <= '9'; value++)
3736                             ANYOF_BITMAP_SET(ret, value);
3737                     }
3738                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3739                     break;
3740                 case ANYOF_NDIGIT:
3741                     if (LOC)
3742                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3743                     else {
3744                         /* consecutive digits assumed */
3745                         for (value = 0; value < '0'; value++)
3746                             ANYOF_BITMAP_SET(ret, value);
3747                         for (value = '9' + 1; value < 256; value++)
3748                             ANYOF_BITMAP_SET(ret, value);
3749                     }
3750                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3751                     break;
3752                 case ANYOF_GRAPH:
3753                     if (LOC)
3754                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3755                     else {
3756                         for (value = 0; value < 256; value++)
3757                             if (isGRAPH(value))
3758                                 ANYOF_BITMAP_SET(ret, value);
3759                     }
3760                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3761                     break;
3762                 case ANYOF_NGRAPH:
3763                     if (LOC)
3764                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3765                     else {
3766                         for (value = 0; value < 256; value++)
3767                             if (!isGRAPH(value))
3768                                 ANYOF_BITMAP_SET(ret, value);
3769                     }
3770                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3771                     break;
3772                 case ANYOF_LOWER:
3773                     if (LOC)
3774                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3775                     else {
3776                         for (value = 0; value < 256; value++)
3777                             if (isLOWER(value))
3778                                 ANYOF_BITMAP_SET(ret, value);
3779                     }
3780                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3781                     break;
3782                 case ANYOF_NLOWER:
3783                     if (LOC)
3784                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3785                     else {
3786                         for (value = 0; value < 256; value++)
3787                             if (!isLOWER(value))
3788                                 ANYOF_BITMAP_SET(ret, value);
3789                     }
3790                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3791                     break;
3792                 case ANYOF_PRINT:
3793                     if (LOC)
3794                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3795                     else {
3796                         for (value = 0; value < 256; value++)
3797                             if (isPRINT(value))
3798                                 ANYOF_BITMAP_SET(ret, value);
3799                     }
3800                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3801                     break;
3802                 case ANYOF_NPRINT:
3803                     if (LOC)
3804                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3805                     else {
3806                         for (value = 0; value < 256; value++)
3807                             if (!isPRINT(value))
3808                                 ANYOF_BITMAP_SET(ret, value);
3809                     }
3810                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3811                     break;
3812                 case ANYOF_PSXSPC:
3813                     if (LOC)
3814                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3815                     else {
3816                         for (value = 0; value < 256; value++)
3817                             if (isPSXSPC(value))
3818                                 ANYOF_BITMAP_SET(ret, value);
3819                     }
3820                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3821                     break;
3822                 case ANYOF_NPSXSPC:
3823                     if (LOC)
3824                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3825                     else {
3826                         for (value = 0; value < 256; value++)
3827                             if (!isPSXSPC(value))
3828                                 ANYOF_BITMAP_SET(ret, value);
3829                     }
3830                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3831                     break;
3832                 case ANYOF_PUNCT:
3833                     if (LOC)
3834                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3835                     else {
3836                         for (value = 0; value < 256; value++)
3837                             if (isPUNCT(value))
3838                                 ANYOF_BITMAP_SET(ret, value);
3839                     }
3840                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3841                     break;
3842                 case ANYOF_NPUNCT:
3843                     if (LOC)
3844                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3845                     else {
3846                         for (value = 0; value < 256; value++)
3847                             if (!isPUNCT(value))
3848                                 ANYOF_BITMAP_SET(ret, value);
3849                     }
3850                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
3851                     break;
3852                 case ANYOF_SPACE:
3853                     if (LOC)
3854                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
3855                     else {
3856                         for (value = 0; value < 256; value++)
3857                             if (isSPACE(value))
3858                                 ANYOF_BITMAP_SET(ret, value);
3859                     }
3860                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
3861                     break;
3862                 case ANYOF_NSPACE:
3863                     if (LOC)
3864                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
3865                     else {
3866                         for (value = 0; value < 256; value++)
3867                             if (!isSPACE(value))
3868                                 ANYOF_BITMAP_SET(ret, value);
3869                     }
3870                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
3871                     break;
3872                 case ANYOF_UPPER:
3873                     if (LOC)
3874                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
3875                     else {
3876                         for (value = 0; value < 256; value++)
3877                             if (isUPPER(value))
3878                                 ANYOF_BITMAP_SET(ret, value);
3879                     }
3880                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
3881                     break;
3882                 case ANYOF_NUPPER:
3883                     if (LOC)
3884                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
3885                     else {
3886                         for (value = 0; value < 256; value++)
3887                             if (!isUPPER(value))
3888                                 ANYOF_BITMAP_SET(ret, value);
3889                     }
3890                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
3891                     break;
3892                 case ANYOF_XDIGIT:
3893                     if (LOC)
3894                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
3895                     else {
3896                         for (value = 0; value < 256; value++)
3897                             if (isXDIGIT(value))
3898                                 ANYOF_BITMAP_SET(ret, value);
3899                     }
3900                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
3901                     break;
3902                 case ANYOF_NXDIGIT:
3903                     if (LOC)
3904                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
3905                     else {
3906                         for (value = 0; value < 256; value++)
3907                             if (!isXDIGIT(value))
3908                                 ANYOF_BITMAP_SET(ret, value);
3909                     }
3910                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
3911                     break;
3912                 default:
3913                     vFAIL("Invalid [::] class");
3914                     break;
3915                 }
3916                 if (LOC)
3917                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
3918                 continue;
3919             }
3920         } /* end of namedclass \blah */
3921
3922         if (range) {
3923             if (prevvalue > value) /* b-a */ {
3924                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3925                               RExC_parse - rangebegin,
3926                               RExC_parse - rangebegin,
3927                               rangebegin);
3928                 range = 0; /* not a valid range */
3929             }
3930         }
3931         else {
3932             prevvalue = value; /* save the beginning of the range */
3933             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
3934                 RExC_parse[1] != ']') {
3935                 RExC_parse++;
3936
3937                 /* a bad range like \w-, [:word:]- ? */
3938                 if (namedclass > OOB_NAMEDCLASS) {
3939                     if (ckWARN(WARN_REGEXP))
3940                         vWARN4(RExC_parse,
3941                                "False [] range \"%*.*s\"",
3942                                RExC_parse - rangebegin,
3943                                RExC_parse - rangebegin,
3944                                rangebegin);
3945                     if (!SIZE_ONLY)
3946                         ANYOF_BITMAP_SET(ret, '-');
3947                 } else
3948                     range = 1;  /* yeah, it's a range! */
3949                 continue;       /* but do it the next time */
3950             }
3951         }
3952
3953         /* now is the next time */
3954         if (!SIZE_ONLY) {
3955             IV i;
3956
3957             if (prevvalue < 256) {
3958                 IV ceilvalue = value < 256 ? value : 255;
3959
3960 #ifdef EBCDIC
3961                 if ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
3962                     (isUPPER(prevvalue) && isUPPER(ceilvalue)))
3963                 {
3964                     if (isLOWER(prevvalue)) {
3965                         for (i = prevvalue; i <= ceilvalue; i++)
3966                             if (isLOWER(i))
3967                                 ANYOF_BITMAP_SET(ret, i);
3968                     } else {
3969                         for (i = prevvalue; i <= ceilvalue; i++)
3970                             if (isUPPER(i))
3971                                 ANYOF_BITMAP_SET(ret, i);
3972                     }
3973                 }
3974                 else
3975 #endif
3976                       for (i = prevvalue; i <= ceilvalue; i++)
3977                           ANYOF_BITMAP_SET(ret, i);
3978           }
3979           if (value > 255 || UTF) {
3980                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3981                 if (prevvalue < value)
3982                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
3983                                    (UV)prevvalue, (UV)value);
3984                 else if (prevvalue == value)
3985                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
3986                                    (UV)value);
3987             }
3988         }
3989
3990         range = 0; /* this range (if it was one) is done now */
3991     }
3992
3993     if (need_class) {
3994         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
3995         if (SIZE_ONLY)
3996             RExC_size += ANYOF_CLASS_ADD_SKIP;
3997         else
3998             RExC_emit += ANYOF_CLASS_ADD_SKIP;
3999     }
4000
4001     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4002     if (!SIZE_ONLY &&
4003          /* If the only flag is folding (plus possibly inversion). */
4004         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4005        ) {
4006         for (value = 0; value < 256; ++value) {
4007             if (ANYOF_BITMAP_TEST(ret, value)) {
4008                 IV fold = PL_fold[value];
4009
4010                 if (fold != value)
4011                     ANYOF_BITMAP_SET(ret, fold);
4012             }
4013         }
4014         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4015     }
4016
4017     /* optimize inverted simple patterns (e.g. [^a-z]) */
4018     if (!SIZE_ONLY && optimize_invert &&
4019         /* If the only flag is inversion. */
4020         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4021         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4022             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4023         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4024     }
4025
4026     if (!SIZE_ONLY) {
4027         AV *av = newAV();
4028         SV *rv;
4029
4030         av_store(av, 0, listsv);
4031         av_store(av, 1, NULL);
4032         rv = newRV_noinc((SV*)av);
4033         n = add_data(pRExC_state, 1, "s");
4034         RExC_rx->data->data[n] = (void*)rv;
4035         ARG_SET(ret, n);
4036     }
4037
4038     return ret;
4039 }
4040
4041 STATIC char*
4042 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4043 {
4044     char* retval = RExC_parse++;
4045
4046     for (;;) {
4047         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4048                 RExC_parse[2] == '#') {
4049             while (*RExC_parse && *RExC_parse != ')')
4050                 RExC_parse++;
4051             RExC_parse++;
4052             continue;
4053         }
4054         if (RExC_flags16 & PMf_EXTENDED) {
4055             if (isSPACE(*RExC_parse)) {
4056                 RExC_parse++;
4057                 continue;
4058             }
4059             else if (*RExC_parse == '#') {
4060                 while (*RExC_parse && *RExC_parse != '\n')
4061                     RExC_parse++;
4062                 RExC_parse++;
4063                 continue;
4064             }
4065         }
4066         return retval;
4067     }
4068 }
4069
4070 /*
4071 - reg_node - emit a node
4072 */
4073 STATIC regnode *                        /* Location. */
4074 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4075 {
4076     register regnode *ret;
4077     register regnode *ptr;
4078
4079     ret = RExC_emit;
4080     if (SIZE_ONLY) {
4081         SIZE_ALIGN(RExC_size);
4082         RExC_size += 1;
4083         return(ret);
4084     }
4085
4086     NODE_ALIGN_FILL(ret);
4087     ptr = ret;
4088     FILL_ADVANCE_NODE(ptr, op);
4089     if (RExC_offsets) {         /* MJD */
4090       MJD_OFFSET_DEBUG((stderr, "%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n", 
4091               "reg_node", __LINE__, 
4092               reg_name[op],
4093               RExC_emit - RExC_emit_start > RExC_offsets[0] 
4094               ? "Overwriting end of array!\n" : "OK",
4095               RExC_emit - RExC_emit_start,
4096               RExC_parse - RExC_start,
4097               RExC_offsets[0])); 
4098       Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4099     }
4100             
4101     RExC_emit = ptr;
4102
4103     return(ret);
4104 }
4105
4106 /*
4107 - reganode - emit a node with an argument
4108 */
4109 STATIC regnode *                        /* Location. */
4110 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4111 {
4112     register regnode *ret;
4113     register regnode *ptr;
4114
4115     ret = RExC_emit;
4116     if (SIZE_ONLY) {
4117         SIZE_ALIGN(RExC_size);
4118         RExC_size += 2;
4119         return(ret);
4120     }
4121
4122     NODE_ALIGN_FILL(ret);
4123     ptr = ret;
4124     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4125     if (RExC_offsets) {         /* MJD */
4126       MJD_OFFSET_DEBUG((stderr, "%s: %s %u <- %u (max %u).\n", 
4127               "reganode",
4128               RExC_emit - RExC_emit_start > RExC_offsets[0] ? 
4129               "Overwriting end of array!\n" : "OK",
4130               RExC_emit - RExC_emit_start,
4131               RExC_parse - RExC_start,
4132               RExC_offsets[0])); 
4133       Set_Cur_Node_Offset;
4134     }
4135             
4136     RExC_emit = ptr;
4137
4138     return(ret);
4139 }
4140
4141 /*
4142 - reguni - emit (if appropriate) a Unicode character
4143 */
4144 STATIC void
4145 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4146 {
4147     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4148 }
4149
4150 /*
4151 - reginsert - insert an operator in front of already-emitted operand
4152 *
4153 * Means relocating the operand.
4154 */
4155 STATIC void
4156 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4157 {
4158     register regnode *src;
4159     register regnode *dst;
4160     register regnode *place;
4161     register int offset = regarglen[(U8)op];
4162
4163 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4164
4165     if (SIZE_ONLY) {
4166         RExC_size += NODE_STEP_REGNODE + offset;
4167         return;
4168     }
4169
4170     src = RExC_emit;
4171     RExC_emit += NODE_STEP_REGNODE + offset;
4172     dst = RExC_emit;
4173     while (src > opnd) {
4174         StructCopy(--src, --dst, regnode);
4175         if (RExC_offsets) {     /* MJD 20010112 */
4176           MJD_OFFSET_DEBUG((stderr, "%s: %s copy %u -> %u (max %u).\n", 
4177                   "reg_insert",
4178                   dst - RExC_emit_start > RExC_offsets[0] 
4179                   ? "Overwriting end of array!\n" : "OK",
4180                   src - RExC_emit_start,
4181                   dst - RExC_emit_start,
4182                   RExC_offsets[0])); 
4183           Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4184           Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4185         }
4186     }
4187     
4188
4189     place = opnd;               /* Op node, where operand used to be. */
4190     if (RExC_offsets) {         /* MJD */
4191       MJD_OFFSET_DEBUG((stderr, "%s: %s %u <- %u (max %u).\n", 
4192               "reginsert",
4193               place - RExC_emit_start > RExC_offsets[0] 
4194               ? "Overwriting end of array!\n" : "OK",
4195               place - RExC_emit_start,
4196               RExC_parse - RExC_start,
4197               RExC_offsets[0])); 
4198       Set_Node_Offset(place, RExC_parse);
4199     }
4200     src = NEXTOPER(place);
4201     FILL_ADVANCE_NODE(place, op);
4202     Zero(src, offset, regnode);
4203 }
4204
4205 /*
4206 - regtail - set the next-pointer at the end of a node chain of p to val.
4207 */
4208 STATIC void
4209 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4210 {
4211     register regnode *scan;
4212     register regnode *temp;
4213
4214     if (SIZE_ONLY)
4215         return;
4216
4217     /* Find last node. */
4218     scan = p;
4219     for (;;) {
4220         temp = regnext(scan);
4221         if (temp == NULL)
4222             break;
4223         scan = temp;
4224     }
4225
4226     if (reg_off_by_arg[OP(scan)]) {
4227         ARG_SET(scan, val - scan);
4228     }
4229     else {
4230         NEXT_OFF(scan) = val - scan;
4231     }
4232 }
4233
4234 /*
4235 - regoptail - regtail on operand of first argument; nop if operandless
4236 */
4237 STATIC void
4238 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4239 {
4240     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4241     if (p == NULL || SIZE_ONLY)
4242         return;
4243     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4244         regtail(pRExC_state, NEXTOPER(p), val);
4245     }
4246     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4247         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4248     }
4249     else
4250         return;
4251 }
4252
4253 /*
4254  - regcurly - a little FSA that accepts {\d+,?\d*}
4255  */
4256 STATIC I32
4257 S_regcurly(pTHX_ register char *s)
4258 {
4259     if (*s++ != '{')
4260         return FALSE;
4261     if (!isDIGIT(*s))
4262         return FALSE;
4263     while (isDIGIT(*s))
4264         s++;
4265     if (*s == ',')
4266         s++;
4267     while (isDIGIT(*s))
4268         s++;
4269     if (*s != '}')
4270         return FALSE;
4271     return TRUE;
4272 }
4273
4274
4275 #ifdef DEBUGGING
4276
4277 STATIC regnode *
4278 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4279 {
4280     register U8 op = EXACT;     /* Arbitrary non-END op. */
4281     register regnode *next;
4282
4283     while (op != END && (!last || node < last)) {
4284         /* While that wasn't END last time... */
4285
4286         NODE_ALIGN(node);
4287         op = OP(node);
4288         if (op == CLOSE)
4289             l--;        
4290         next = regnext(node);
4291         /* Where, what. */
4292         if (OP(node) == OPTIMIZED)
4293             goto after_print;
4294         regprop(sv, node);
4295         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4296                       (int)(2*l + 1), "", SvPVX(sv));
4297         if (next == NULL)               /* Next ptr. */
4298             PerlIO_printf(Perl_debug_log, "(0)");
4299         else
4300             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4301         (void)PerlIO_putc(Perl_debug_log, '\n');
4302       after_print:
4303         if (PL_regkind[(U8)op] == BRANCHJ) {
4304             register regnode *nnode = (OP(next) == LONGJMP
4305                                        ? regnext(next)
4306                                        : next);
4307             if (last && nnode > last)
4308                 nnode = last;
4309             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4310         }
4311         else if (PL_regkind[(U8)op] == BRANCH) {
4312             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4313         }
4314         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4315             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4316                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4317         }
4318         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4319             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4320                              next, sv, l + 1);
4321         }
4322         else if ( op == PLUS || op == STAR) {
4323             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4324         }
4325         else if (op == ANYOF) {
4326             /* arglen 1 + class block */
4327             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4328                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4329             node = NEXTOPER(node);
4330         }
4331         else if (PL_regkind[(U8)op] == EXACT) {
4332             /* Literal string, where present. */
4333             node += NODE_SZ_STR(node) - 1;
4334             node = NEXTOPER(node);
4335         }
4336         else {
4337             node = NEXTOPER(node);
4338             node += regarglen[(U8)op];
4339         }
4340         if (op == CURLYX || op == OPEN)
4341             l++;
4342         else if (op == WHILEM)
4343             l--;
4344     }
4345     return node;
4346 }
4347
4348 #endif  /* DEBUGGING */
4349
4350 /*
4351  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4352  */
4353 void
4354 Perl_regdump(pTHX_ regexp *r)
4355 {
4356 #ifdef DEBUGGING
4357     SV *sv = sv_newmortal();
4358
4359     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4360
4361     /* Header fields of interest. */
4362     if (r->anchored_substr)
4363         PerlIO_printf(Perl_debug_log,
4364                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4365                       PL_colors[0],
4366                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4367                       SvPVX(r->anchored_substr),
4368                       PL_colors[1],
4369                       SvTAIL(r->anchored_substr) ? "$" : "",
4370                       (IV)r->anchored_offset);
4371     if (r->float_substr)
4372         PerlIO_printf(Perl_debug_log,
4373                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4374                       PL_colors[0],
4375                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4376                       SvPVX(r->float_substr),
4377                       PL_colors[1],
4378                       SvTAIL(r->float_substr) ? "$" : "",
4379                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4380     if (r->check_substr)
4381         PerlIO_printf(Perl_debug_log,
4382                       r->check_substr == r->float_substr
4383                       ? "(checking floating" : "(checking anchored");
4384     if (r->reganch & ROPT_NOSCAN)
4385         PerlIO_printf(Perl_debug_log, " noscan");
4386     if (r->reganch & ROPT_CHECK_ALL)
4387         PerlIO_printf(Perl_debug_log, " isall");
4388     if (r->check_substr)
4389         PerlIO_printf(Perl_debug_log, ") ");
4390
4391     if (r->regstclass) {
4392         regprop(sv, r->regstclass);
4393         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4394     }
4395     if (r->reganch & ROPT_ANCH) {
4396         PerlIO_printf(Perl_debug_log, "anchored");
4397         if (r->reganch & ROPT_ANCH_BOL)
4398             PerlIO_printf(Perl_debug_log, "(BOL)");
4399         if (r->reganch & ROPT_ANCH_MBOL)
4400             PerlIO_printf(Perl_debug_log, "(MBOL)");
4401         if (r->reganch & ROPT_ANCH_SBOL)
4402             PerlIO_printf(Perl_debug_log, "(SBOL)");
4403         if (r->reganch & ROPT_ANCH_GPOS)
4404             PerlIO_printf(Perl_debug_log, "(GPOS)");
4405         PerlIO_putc(Perl_debug_log, ' ');
4406     }
4407     if (r->reganch & ROPT_GPOS_SEEN)
4408         PerlIO_printf(Perl_debug_log, "GPOS ");
4409     if (r->reganch & ROPT_SKIP)
4410         PerlIO_printf(Perl_debug_log, "plus ");
4411     if (r->reganch & ROPT_IMPLICIT)
4412         PerlIO_printf(Perl_debug_log, "implicit ");
4413     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4414     if (r->reganch & ROPT_EVAL_SEEN)
4415         PerlIO_printf(Perl_debug_log, "with eval ");
4416     PerlIO_printf(Perl_debug_log, "\n");
4417     if (r->offsets) {
4418       U32 i;
4419       U32 len = r->offsets[0];
4420       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4421       for (i = 1; i <= len; i++)
4422         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ", 
4423                       (UV)r->offsets[i*2-1], 
4424                       (UV)r->offsets[i*2]);
4425       PerlIO_printf(Perl_debug_log, "\n");
4426     }
4427 #endif  /* DEBUGGING */
4428 }
4429
4430 #ifdef DEBUGGING
4431
4432 STATIC void
4433 S_put_byte(pTHX_ SV *sv, int c)
4434 {
4435     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4436         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4437     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4438         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4439     else
4440         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4441 }
4442
4443 #endif  /* DEBUGGING */
4444
4445 /*
4446 - regprop - printable representation of opcode
4447 */
4448 void
4449 Perl_regprop(pTHX_ SV *sv, regnode *o)
4450 {
4451 #ifdef DEBUGGING
4452     register int k;
4453
4454     sv_setpvn(sv, "", 0);
4455     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4456         /* It would be nice to FAIL() here, but this may be called from
4457            regexec.c, and it would be hard to supply pRExC_state. */
4458         Perl_croak(aTHX_ "Corrupted regexp opcode");
4459     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4460
4461     k = PL_regkind[(U8)OP(o)];
4462
4463     if (k == EXACT) {
4464         SV *dsv = sv_2mortal(newSVpvn("", 0));
4465         bool do_utf8 = DO_UTF8(sv);
4466         char *s    = do_utf8 ?
4467           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60, 0) :
4468           STRING(o);
4469         int len = do_utf8 ?
4470           strlen(s) :
4471           STR_LEN(o);
4472         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4473                        PL_colors[0],
4474                        len, s,
4475                        PL_colors[1]);
4476     }
4477     else if (k == CURLY) {
4478         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4479             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4480         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4481     }
4482     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4483         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4484     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4485         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4486     else if (k == LOGICAL)
4487         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4488     else if (k == ANYOF) {
4489         int i, rangestart = -1;
4490         U8 flags = ANYOF_FLAGS(o);
4491         const char * const anyofs[] = { /* Should be syncronized with
4492                                          * ANYOF_ #xdefines in regcomp.h */
4493             "\\w",
4494             "\\W",
4495             "\\s",
4496             "\\S",
4497             "\\d",
4498             "\\D",
4499             "[:alnum:]",
4500             "[:^alnum:]",
4501             "[:alpha:]",
4502             "[:^alpha:]",
4503             "[:ascii:]",
4504             "[:^ascii:]",
4505             "[:ctrl:]",
4506             "[:^ctrl:]",
4507             "[:graph:]",
4508             "[:^graph:]",
4509             "[:lower:]",
4510             "[:^lower:]",
4511             "[:print:]",
4512             "[:^print:]",
4513             "[:punct:]",
4514             "[:^punct:]",
4515             "[:upper:]",
4516             "[:^upper:]",
4517             "[:xdigit:]",
4518             "[:^xdigit:]",
4519             "[:space:]",
4520             "[:^space:]",
4521             "[:blank:]",
4522             "[:^blank:]"
4523         };
4524
4525         if (flags & ANYOF_LOCALE)
4526             sv_catpv(sv, "{loc}");
4527         if (flags & ANYOF_FOLD)
4528             sv_catpv(sv, "{i}");
4529         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4530         if (flags & ANYOF_INVERT)
4531             sv_catpv(sv, "^");
4532         for (i = 0; i <= 256; i++) {
4533             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4534                 if (rangestart == -1)
4535                     rangestart = i;
4536             } else if (rangestart != -1) {
4537                 if (i <= rangestart + 3)
4538                     for (; rangestart < i; rangestart++)
4539                         put_byte(sv, rangestart);
4540                 else {
4541                     put_byte(sv, rangestart);
4542                     sv_catpv(sv, "-");
4543                     put_byte(sv, i - 1);
4544                 }
4545                 rangestart = -1;
4546             }
4547         }
4548
4549         if (o->flags & ANYOF_CLASS)
4550             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4551                 if (ANYOF_CLASS_TEST(o,i))
4552                     sv_catpv(sv, anyofs[i]);
4553
4554         if (flags & ANYOF_UNICODE)
4555             sv_catpv(sv, "{unicode}");
4556         else if (flags & ANYOF_UNICODE_ALL)
4557             sv_catpv(sv, "{unicode_all}");
4558
4559         {
4560             SV *lv;
4561             SV *sw = regclass_swash(o, FALSE, &lv);
4562         
4563             if (lv) {
4564                 if (sw) {
4565                     UV i;
4566                     U8 s[UTF8_MAXLEN+1];
4567                 
4568                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4569                         U8 *e = uvchr_to_utf8(s, i);
4570                         
4571                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4572                             if (rangestart == -1)
4573                                 rangestart = i;
4574                         } else if (rangestart != -1) {
4575                             U8 *p;
4576                         
4577                             if (i <= rangestart + 3)
4578                                 for (; rangestart < i; rangestart++) {
4579                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4580                                         put_byte(sv, *p);
4581                                 }
4582                             else {
4583                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4584                                     put_byte(sv, *p);
4585                                 sv_catpv(sv, "-");
4586                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4587                                         put_byte(sv, *p);
4588                                 }
4589                                 rangestart = -1;
4590                             }
4591                         }
4592                         
4593                     sv_catpv(sv, "..."); /* et cetera */
4594                 }
4595
4596                 {
4597                     char *s = savepv(SvPVX(lv));
4598                     char *origs = s;
4599                 
4600                     while(*s && *s != '\n') s++;
4601                 
4602                     if (*s == '\n') {
4603                         char *t = ++s;
4604                         
4605                         while (*s) {
4606                             if (*s == '\n')
4607                                 *s = ' ';
4608                             s++;
4609                         }
4610                         if (s[-1] == ' ')
4611                             s[-1] = 0;
4612                         
4613                         sv_catpv(sv, t);
4614                     }
4615                 
4616                     Safefree(origs);
4617                 }
4618             }
4619         }
4620
4621         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4622     }
4623     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4624         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4625 #endif  /* DEBUGGING */
4626 }
4627
4628 SV *
4629 Perl_re_intuit_string(pTHX_ regexp *prog)
4630 {                               /* Assume that RE_INTUIT is set */
4631     DEBUG_r(
4632         {   STRLEN n_a;
4633             char *s = SvPV(prog->check_substr,n_a);
4634
4635             if (!PL_colorset) reginitcolors();
4636             PerlIO_printf(Perl_debug_log,
4637                       "%sUsing REx substr:%s `%s%.60s%s%s'\n",
4638                       PL_colors[4],PL_colors[5],PL_colors[0],
4639                       s,
4640                       PL_colors[1],
4641                       (strlen(s) > 60 ? "..." : ""));
4642         } );
4643
4644     return prog->check_substr;
4645 }
4646
4647 void
4648 Perl_pregfree(pTHX_ struct regexp *r)
4649 {
4650     DEBUG_r(if (!PL_colorset) reginitcolors());
4651
4652     if (!r || (--r->refcnt > 0))
4653         return;
4654     DEBUG_r(PerlIO_printf(Perl_debug_log,
4655                       "%sFreeing REx:%s `%s%.60s%s%s'\n",
4656                       PL_colors[4],PL_colors[5],PL_colors[0],
4657                       r->precomp,
4658                       PL_colors[1],
4659                       (strlen(r->precomp) > 60 ? "..." : "")));
4660
4661     if (r->precomp)
4662         Safefree(r->precomp);
4663     if (r->offsets)             /* 20010421 MJD */
4664         Safefree(r->offsets);
4665     if (RX_MATCH_COPIED(r))
4666         Safefree(r->subbeg);
4667     if (r->substrs) {
4668         if (r->anchored_substr)
4669             SvREFCNT_dec(r->anchored_substr);
4670         if (r->float_substr)
4671             SvREFCNT_dec(r->float_substr);
4672         Safefree(r->substrs);
4673     }
4674     if (r->data) {
4675         int n = r->data->count;
4676         AV* new_comppad = NULL;
4677         AV* old_comppad;
4678         SV** old_curpad;
4679
4680         while (--n >= 0) {
4681           /* If you add a ->what type here, update the comment in regcomp.h */
4682             switch (r->data->what[n]) {
4683             case 's':
4684                 SvREFCNT_dec((SV*)r->data->data[n]);
4685                 break;
4686             case 'f':
4687                 Safefree(r->data->data[n]);
4688                 break;
4689             case 'p':
4690                 new_comppad = (AV*)r->data->data[n];
4691                 break;
4692             case 'o':
4693                 if (new_comppad == NULL)
4694                     Perl_croak(aTHX_ "panic: pregfree comppad");
4695                 old_comppad = PL_comppad;
4696                 old_curpad = PL_curpad;
4697                 /* Watch out for global destruction's random ordering. */
4698                 if (SvTYPE(new_comppad) == SVt_PVAV) {
4699                     PL_comppad = new_comppad;
4700                     PL_curpad = AvARRAY(new_comppad);
4701                 }
4702                 else
4703                     PL_curpad = NULL;
4704
4705                 if (!OpREFCNT_dec((OP_4tree*)r->data->data[n])) {
4706                     op_free((OP_4tree*)r->data->data[n]);
4707                 }
4708
4709                 PL_comppad = old_comppad;
4710                 PL_curpad = old_curpad;
4711                 SvREFCNT_dec((SV*)new_comppad);
4712                 new_comppad = NULL;
4713                 break;
4714             case 'n':
4715                 break;
4716             default:
4717                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4718             }
4719         }
4720         Safefree(r->data->what);
4721         Safefree(r->data);
4722     }
4723     Safefree(r->startp);
4724     Safefree(r->endp);
4725     Safefree(r);
4726 }
4727
4728 /*
4729  - regnext - dig the "next" pointer out of a node
4730  *
4731  * [Note, when REGALIGN is defined there are two places in regmatch()
4732  * that bypass this code for speed.]
4733  */
4734 regnode *
4735 Perl_regnext(pTHX_ register regnode *p)
4736 {
4737     register I32 offset;
4738
4739     if (p == &PL_regdummy)
4740         return(NULL);
4741
4742     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
4743     if (offset == 0)
4744         return(NULL);
4745
4746     return(p+offset);
4747 }
4748
4749 STATIC void     
4750 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
4751 {
4752     va_list args;
4753     STRLEN l1 = strlen(pat1);
4754     STRLEN l2 = strlen(pat2);
4755     char buf[512];
4756     SV *msv;
4757     char *message;
4758
4759     if (l1 > 510)
4760         l1 = 510;
4761     if (l1 + l2 > 510)
4762         l2 = 510 - l1;
4763     Copy(pat1, buf, l1 , char);
4764     Copy(pat2, buf + l1, l2 , char);
4765     buf[l1 + l2] = '\n';
4766     buf[l1 + l2 + 1] = '\0';
4767 #ifdef I_STDARG
4768     /* ANSI variant takes additional second argument */
4769     va_start(args, pat2);
4770 #else
4771     va_start(args);
4772 #endif
4773     msv = vmess(buf, &args);
4774     va_end(args);
4775     message = SvPV(msv,l1);
4776     if (l1 > 512)
4777         l1 = 512;
4778     Copy(message, buf, l1 , char);
4779     buf[l1] = '\0';                     /* Overwrite \n */
4780     Perl_croak(aTHX_ "%s", buf);
4781 }
4782
4783 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
4784
4785 void
4786 Perl_save_re_context(pTHX)
4787 {
4788 #if 0
4789     SAVEPPTR(RExC_precomp);             /* uncompiled string. */
4790     SAVEI32(RExC_npar);         /* () count. */
4791     SAVEI32(RExC_size);         /* Code size. */
4792     SAVEI16(RExC_flags16);              /* are we folding, multilining? */
4793     SAVEVPTR(RExC_rx);          /* from regcomp.c */
4794     SAVEI32(RExC_seen);         /* from regcomp.c */
4795     SAVEI32(RExC_sawback);              /* Did we see \1, ...? */
4796     SAVEI32(RExC_naughty);              /* How bad is this pattern? */
4797     SAVEVPTR(RExC_emit);                /* Code-emit pointer; &regdummy = don't */
4798     SAVEPPTR(RExC_end);         /* End of input for compile */
4799     SAVEPPTR(RExC_parse);               /* Input-scan pointer. */
4800 #endif
4801
4802     SAVEI32(PL_reg_flags);              /* from regexec.c */
4803     SAVEPPTR(PL_bostr);
4804     SAVEPPTR(PL_reginput);              /* String-input pointer. */
4805     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
4806     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
4807     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
4808     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
4809     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
4810     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
4811     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
4812     PL_reg_start_tmp = 0;
4813     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
4814     PL_reg_start_tmpl = 0;
4815     SAVEVPTR(PL_regdata);
4816     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
4817     SAVEI32(PL_regnarrate);             /* from regexec.c */
4818     SAVEVPTR(PL_regprogram);            /* from regexec.c */
4819     SAVEINT(PL_regindent);              /* from regexec.c */
4820     SAVEVPTR(PL_regcc);                 /* from regexec.c */
4821     SAVEVPTR(PL_curcop);
4822     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
4823     SAVEVPTR(PL_reg_re);                /* from regexec.c */
4824     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
4825     SAVESPTR(PL_reg_sv);                /* from regexec.c */
4826     SAVEI8(PL_reg_match_utf8);          /* from regexec.c */
4827     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
4828     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
4829     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
4830     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
4831     SAVEI32(PL_regnpar);                /* () count. */
4832     SAVEI32(PL_regsize);                /* from regexec.c */
4833 #ifdef DEBUGGING
4834     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
4835 #endif
4836 }
4837
4838 static void
4839 clear_re(pTHX_ void *r)
4840 {
4841     ReREFCNT_dec((regexp *)r);
4842 }
4843