regcomp.c

   1 /*    regcomp.c
   2  */
   3
   4 /*
   5  * "A fair jaw-cracker dwarf-language must be."  --Samwise Gamgee
   6  */
   7
   8 /* This file contains functions for compiling a regular expression.  See
   9  * also regexec.c which funnily enough, contains functions for executing
  10  * a regular expression.
  11  *
  12  * This file is also copied at build time to ext/re/re_comp.c, where
  13  * it's built with -DPERL_EXT_RE_BUILD -DPERL_EXT_RE_DEBUG -DPERL_EXT.
  14  * This causes the main functions to be compiled under new names and with
  15  * debugging support added, which makes "use re 'debug'" work.
  16  */
  17
  18 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
  19  * confused with the original package (see point 3 below).  Thanks, Henry!
  20  */
  21
  22 /* Additional note: this code is very heavily munged from Henry's version
  23  * in places.  In some spots I've traded clarity for efficiency, so don't
  24  * blame Henry for some of the lack of readability.
  25  */
  26
  27 /* The names of the functions have been changed from regcomp and
  28  * regexec to  pregcomp and pregexec in order to avoid conflicts
  29  * with the POSIX routines of the same names.
  30 */
  31
  32 #ifdef PERL_EXT_RE_BUILD
  33 /* need to replace pregcomp et al, so enable that */
  34 #  ifndef PERL_IN_XSUB_RE
  35 #    define PERL_IN_XSUB_RE
  36 #  endif
  37 /* need access to debugger hooks */
  38 #  if defined(PERL_EXT_RE_DEBUG) && !defined(DEBUGGING)
  39 #    define DEBUGGING
  40 #  endif
  41 #endif
  42
  43 #ifdef PERL_IN_XSUB_RE
  44 /* We *really* need to overwrite these symbols: */
  45 #  define Perl_pregcomp my_regcomp
  46 #  define Perl_regdump my_regdump
  47 #  define Perl_regprop my_regprop
  48 #  define Perl_pregfree my_regfree
  49 #  define Perl_re_intuit_string my_re_intuit_string
  50 /* *These* symbols are masked to allow static link. */
  51 #  define Perl_regnext my_regnext
  52 #  define Perl_save_re_context my_save_re_context
  53 #  define Perl_reginitcolors my_reginitcolors
  54
  55 #  define PERL_NO_GET_CONTEXT
  56 #endif
  57
  58 /*SUPPRESS 112*/
  59 /*
  60  * pregcomp and pregexec -- regsub and regerror are not used in perl
  61  *
  62  *      Copyright (c) 1986 by University of Toronto.
  63  *      Written by Henry Spencer.  Not derived from licensed software.
  64  *
  65  *      Permission is granted to anyone to use this software for any
  66  *      purpose on any computer system, and to redistribute it freely,
  67  *      subject to the following restrictions:
  68  *
  69  *      1. The author is not responsible for the consequences of use of
  70  *              this software, no matter how awful, even if they arise
  71  *              from defects in it.
  72  *
  73  *      2. The origin of this software must not be misrepresented, either
  74  *              by explicit claim or by omission.
  75  *
  76  *      3. Altered versions must be plainly marked as such, and must not
  77  *              be misrepresented as being the original software.
  78  *
  79  *
  80  ****    Alterations to Henry's code are...
  81  ****
  82  ****    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
  83  ****    2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
  84  ****
  85  ****    You may distribute under the terms of either the GNU General Public
  86  ****    License or the Artistic License, as specified in the README file.
  87
  88  *
  89  * Beware that some of this code is subtly aware of the way operator
  90  * precedence is structured in regular expressions.  Serious changes in
  91  * regular-expression syntax might require a total rethink.
  92  */
  93 #include "EXTERN.h"
  94 #define PERL_IN_REGCOMP_C
  95 #include "perl.h"
  96
  97 #ifndef PERL_IN_XSUB_RE
  98 #  include "INTERN.h"
  99 #endif
 100
 101 #define REG_COMP_C
 102 #include "regcomp.h"
 103
 104 #ifdef op
 105 #undef op
 106 #endif /* op */
 107
 108 #ifdef MSDOS
 109 #  if defined(BUGGY_MSC6)
 110  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
 111 #    pragma optimize("a",off)
 112  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
 113 #    pragma optimize("w",on )
 114 #  endif /* BUGGY_MSC6 */
 115 #endif /* MSDOS */
 116
 117 #ifndef STATIC
 118 #define STATIC  static
 119 #endif
 120
 121 typedef struct RExC_state_t {
 122     U32         flags;                  /* are we folding, multilining? */
 123     char        *precomp;               /* uncompiled string. */
 124     regexp      *rx;
 125     char        *start;                 /* Start of input for compile */
 126     char        *end;                   /* End of input for compile */
 127     char        *parse;                 /* Input-scan pointer. */
 128     I32         whilem_seen;            /* number of WHILEM in this expr */
 129     regnode     *emit_start;            /* Start of emitted-code area */
 130     regnode     *emit;                  /* Code-emit pointer; &regdummy = don't = compiling */
 131     I32         naughty;                /* How bad is this pattern? */
 132     I32         sawback;                /* Did we see \1, ...? */
 133     U32         seen;
 134     I32         size;                   /* Code size. */
 135     I32         npar;                   /* () count. */
 136     I32         extralen;
 137     I32         seen_zerolen;
 138     I32         seen_evals;
 139     I32         utf8;
 140 #if ADD_TO_REGEXEC
 141     char        *starttry;              /* -Dr: where regtry was called. */
 142 #define RExC_starttry   (pRExC_state->starttry)
 143 #endif
 144 } RExC_state_t;
 145
 146 #define RExC_flags      (pRExC_state->flags)
 147 #define RExC_precomp    (pRExC_state->precomp)
 148 #define RExC_rx         (pRExC_state->rx)
 149 #define RExC_start      (pRExC_state->start)
 150 #define RExC_end        (pRExC_state->end)
 151 #define RExC_parse      (pRExC_state->parse)
 152 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
 153 #define RExC_offsets    (pRExC_state->rx->offsets) /* I am not like the others */
 154 #define RExC_emit       (pRExC_state->emit)
 155 #define RExC_emit_start (pRExC_state->emit_start)
 156 #define RExC_naughty    (pRExC_state->naughty)
 157 #define RExC_sawback    (pRExC_state->sawback)
 158 #define RExC_seen       (pRExC_state->seen)
 159 #define RExC_size       (pRExC_state->size)
 160 #define RExC_npar       (pRExC_state->npar)
 161 #define RExC_extralen   (pRExC_state->extralen)
 162 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
 163 #define RExC_seen_evals (pRExC_state->seen_evals)
 164 #define RExC_utf8       (pRExC_state->utf8)
 165
 166 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 167 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
 168         ((*s) == '{' && regcurly(s)))
 169
 170 #ifdef SPSTART
 171 #undef SPSTART          /* dratted cpp namespace... */
 172 #endif
 173 /*
 174  * Flags to be passed up and down.
 175  */
 176 #define WORST           0       /* Worst case. */
 177 #define HASWIDTH        0x1     /* Known to match non-null strings. */
 178 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
 179 #define SPSTART         0x4     /* Starts with * or +. */
 180 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
 181
 182 /* Length of a variant. */
 183
 184 typedef struct scan_data_t {
 185     I32 len_min;
 186     I32 len_delta;
 187     I32 pos_min;
 188     I32 pos_delta;
 189     SV *last_found;
 190     I32 last_end;                       /* min value, <0 unless valid. */
 191     I32 last_start_min;
 192     I32 last_start_max;
 193     SV **longest;                       /* Either &l_fixed, or &l_float. */
 194     SV *longest_fixed;
 195     I32 offset_fixed;
 196     SV *longest_float;
 197     I32 offset_float_min;
 198     I32 offset_float_max;
 199     I32 flags;
 200     I32 whilem_c;
 201     I32 *last_closep;
 202     struct regnode_charclass_class *start_class;
 203 } scan_data_t;
 204
 205 /*
 206  * Forward declarations for pregcomp()'s friends.
 207  */
 208
 209 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 210                                       0, 0, 0, 0, 0, 0};
 211
 212 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 213 #define SF_BEFORE_SEOL          0x1
 214 #define SF_BEFORE_MEOL          0x2
 215 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
 216 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
 217
 218 #ifdef NO_UNARY_PLUS
 219 #  define SF_FIX_SHIFT_EOL      (0+2)
 220 #  define SF_FL_SHIFT_EOL               (0+4)
 221 #else
 222 #  define SF_FIX_SHIFT_EOL      (+2)
 223 #  define SF_FL_SHIFT_EOL               (+4)
 224 #endif
 225
 226 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
 227 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
 228
 229 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
 230 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
 231 #define SF_IS_INF               0x40
 232 #define SF_HAS_PAR              0x80
 233 #define SF_IN_PAR               0x100
 234 #define SF_HAS_EVAL             0x200
 235 #define SCF_DO_SUBSTR           0x400
 236 #define SCF_DO_STCLASS_AND      0x0800
 237 #define SCF_DO_STCLASS_OR       0x1000
 238 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 239 #define SCF_WHILEM_VISITED_POS  0x2000
 240
 241 #define UTF (RExC_utf8 != 0)
 242 #define LOC ((RExC_flags & PMf_LOCALE) != 0)
 243 #define FOLD ((RExC_flags & PMf_FOLD) != 0)
 244
 245 #define OOB_UNICODE             12345678
 246 #define OOB_NAMEDCLASS          -1
 247
 248 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 249 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 250
 251
 252 /* length of regex to show in messages that don't mark a position within */
 253 #define RegexLengthToShowInErrorMessages 127
 254
 255 /*
 256  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
 257  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
 258  * op/pragma/warn/regcomp.
 259  */
 260 #define MARKER1 "<-- HERE"    /* marker as it appears in the description */
 261 #define MARKER2 " <-- HERE "  /* marker as it appears within the regex */
 262
 263 #define REPORT_LOCATION " in regex; marked by " MARKER1 " in m/%.*s" MARKER2 "%s/"
 264
 265 /*
 266  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 267  * arg. Show regex, up to a maximum length. If it's too long, chop and add
 268  * "...".
 269  */
 270 #define FAIL(msg) STMT_START {                                          \
 271     char *ellipses = "";                                                \
 272     IV len = RExC_end - RExC_precomp;                                   \
 273                                                                         \
 274     if (!SIZE_ONLY)                                                     \
 275         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                      \
 276     if (len > RegexLengthToShowInErrorMessages) {                       \
 277         /* chop 10 shorter than the max, to ensure meaning of "..." */  \
 278         len = RegexLengthToShowInErrorMessages - 10;                    \
 279         ellipses = "...";                                               \
 280     }                                                                   \
 281     Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                           \
 282             msg, (int)len, RExC_precomp, ellipses);                     \
 283 } STMT_END
 284
 285 /*
 286  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 287  * args. Show regex, up to a maximum length. If it's too long, chop and add
 288  * "...".
 289  */
 290 #define FAIL2(pat,msg) STMT_START {                                     \
 291     char *ellipses = "";                                                \
 292     IV len = RExC_end - RExC_precomp;                                   \
 293                                                                         \
 294     if (!SIZE_ONLY)                                                     \
 295         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                      \
 296     if (len > RegexLengthToShowInErrorMessages) {                       \
 297         /* chop 10 shorter than the max, to ensure meaning of "..." */  \
 298         len = RegexLengthToShowInErrorMessages - 10;                    \
 299         ellipses = "...";                                               \
 300     }                                                                   \
 301     S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                       \
 302             msg, (int)len, RExC_precomp, ellipses);                     \
 303 } STMT_END
 304
 305
 306 /*
 307  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
 308  */
 309 #define Simple_vFAIL(m) STMT_START {                                    \
 310     IV offset = RExC_parse - RExC_precomp;                              \
 311     Perl_croak(aTHX_ "%s" REPORT_LOCATION,                              \
 312             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 313 } STMT_END
 314
 315 /*
 316  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
 317  */
 318 #define vFAIL(m) STMT_START {                           \
 319     if (!SIZE_ONLY)                                     \
 320         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 321     Simple_vFAIL(m);                                    \
 322 } STMT_END
 323
 324 /*
 325  * Like Simple_vFAIL(), but accepts two arguments.
 326  */
 327 #define Simple_vFAIL2(m,a1) STMT_START {                        \
 328     IV offset = RExC_parse - RExC_precomp;                      \
 329     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,                   \
 330             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 331 } STMT_END
 332
 333 /*
 334  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
 335  */
 336 #define vFAIL2(m,a1) STMT_START {                       \
 337     if (!SIZE_ONLY)                                     \
 338         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 339     Simple_vFAIL2(m, a1);                               \
 340 } STMT_END
 341
 342
 343 /*
 344  * Like Simple_vFAIL(), but accepts three arguments.
 345  */
 346 #define Simple_vFAIL3(m, a1, a2) STMT_START {                   \
 347     IV offset = RExC_parse - RExC_precomp;                      \
 348     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,               \
 349             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 350 } STMT_END
 351
 352 /*
 353  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
 354  */
 355 #define vFAIL3(m,a1,a2) STMT_START {                    \
 356     if (!SIZE_ONLY)                                     \
 357         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 358     Simple_vFAIL3(m, a1, a2);                           \
 359 } STMT_END
 360
 361 /*
 362  * Like Simple_vFAIL(), but accepts four arguments.
 363  */
 364 #define Simple_vFAIL4(m, a1, a2, a3) STMT_START {               \
 365     IV offset = RExC_parse - RExC_precomp;                      \
 366     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,           \
 367             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 368 } STMT_END
 369
 370 /*
 371  * Like Simple_vFAIL(), but accepts five arguments.
 372  */
 373 #define Simple_vFAIL5(m, a1, a2, a3, a4) STMT_START {           \
 374     IV offset = RExC_parse - RExC_precomp;                      \
 375     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,       \
 376             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 377 } STMT_END
 378
 379
 380 #define vWARN(loc,m) STMT_START {                                       \
 381     IV offset = loc - RExC_precomp;                                     \
 382     Perl_warner(aTHX_ packWARN(WARN_REGEXP), "%s" REPORT_LOCATION,      \
 383             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 384 } STMT_END
 385
 386 #define vWARNdep(loc,m) STMT_START {                                    \
 387     IV offset = loc - RExC_precomp;                                     \
 388     Perl_warner(aTHX_ packWARN2(WARN_DEPRECATED, WARN_REGEXP),          \
 389             "%s" REPORT_LOCATION,                                       \
 390             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 391 } STMT_END
 392
 393
 394 #define vWARN2(loc, m, a1) STMT_START {                                 \
 395     IV offset = loc - RExC_precomp;                                     \
 396     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 397             a1, (int)offset, RExC_precomp, RExC_precomp + offset);      \
 398 } STMT_END
 399
 400 #define vWARN3(loc, m, a1, a2) STMT_START {                             \
 401     IV offset = loc - RExC_precomp;                                     \
 402     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 403             a1, a2, (int)offset, RExC_precomp, RExC_precomp + offset);  \
 404 } STMT_END
 405
 406 #define vWARN4(loc, m, a1, a2, a3) STMT_START {                         \
 407     IV offset = loc - RExC_precomp;                                     \
 408     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 409             a1, a2, a3, (int)offset, RExC_precomp, RExC_precomp + offset); \
 410 } STMT_END
 411
 412 #define vWARN5(loc, m, a1, a2, a3, a4) STMT_START {                     \
 413     IV offset = loc - RExC_precomp;                                     \
 414     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 415             a1, a2, a3, a4, (int)offset, RExC_precomp, RExC_precomp + offset); \
 416 } STMT_END
 417
 418
 419 /* Allow for side effects in s */
 420 #define REGC(c,s) STMT_START {                  \
 421     if (!SIZE_ONLY) *(s) = (c); else (void)(s); \
 422 } STMT_END
 423
 424 /* Macros for recording node offsets.   20001227 mjd@plover.com
 425  * Nodes are numbered 1, 2, 3, 4.  Node #n's position is recorded in
 426  * element 2*n-1 of the array.  Element #2n holds the byte length node #n.
 427  * Element 0 holds the number n.
 428  */
 429
 430 #define MJD_OFFSET_DEBUG(x)
 431 /* #define MJD_OFFSET_DEBUG(x) Perl_warn_nocontext x */
 432
 433
 434 #define Set_Node_Offset_To_R(node,byte) STMT_START {                    \
 435     if (! SIZE_ONLY) {                                                  \
 436         MJD_OFFSET_DEBUG(("** (%d) offset of node %d is %d.\n",         \
 437                 __LINE__, (node), (byte)));                             \
 438         if((node) < 0) {                                                \
 439             Perl_croak(aTHX_ "value of node is %d in Offset macro", node); \
 440         } else {                                                        \
 441             RExC_offsets[2*(node)-1] = (byte);                          \
 442         }                                                               \
 443     }                                                                   \
 444 } STMT_END
 445
 446 #define Set_Node_Offset(node,byte) \
 447     Set_Node_Offset_To_R((node)-RExC_emit_start, (byte)-RExC_start)
 448 #define Set_Cur_Node_Offset Set_Node_Offset(RExC_emit, RExC_parse)
 449
 450 #define Set_Node_Length_To_R(node,len) STMT_START {                     \
 451     if (! SIZE_ONLY) {                                                  \
 452         MJD_OFFSET_DEBUG(("** (%d) size of node %d is %d.\n",           \
 453                 __LINE__, (node), (len)));                              \
 454         if((node) < 0) {                                                \
 455             Perl_croak(aTHX_ "value of node is %d in Length macro", node); \
 456         } else {                                                        \
 457             RExC_offsets[2*(node)] = (len);                             \
 458         }                                                               \
 459     }                                                                   \
 460 } STMT_END
 461
 462 #define Set_Node_Length(node,len) \
 463     Set_Node_Length_To_R((node)-RExC_emit_start, len)
 464 #define Set_Cur_Node_Length(len) Set_Node_Length(RExC_emit, len)
 465 #define Set_Node_Cur_Length(node) \
 466     Set_Node_Length(node, RExC_parse - parse_start)
 467
 468 /* Get offsets and lengths */
 469 #define Node_Offset(n) (RExC_offsets[2*((n)-RExC_emit_start)-1])
 470 #define Node_Length(n) (RExC_offsets[2*((n)-RExC_emit_start)])
 471
 472 static void clear_re(pTHX_ void *r);
 473
 474 /* Mark that we cannot extend a found fixed substring at this point.
 475    Updata the longest found anchored substring and the longest found
 476    floating substrings if needed. */
 477
 478 STATIC void
 479 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 480 {
 481     STRLEN l = CHR_SVLEN(data->last_found);
 482     STRLEN old_l = CHR_SVLEN(*data->longest);
 483
 484     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
 485         SvSetMagicSV(*data->longest, data->last_found);
 486         if (*data->longest == data->longest_fixed) {
 487             data->offset_fixed = l ? data->last_start_min : data->pos_min;
 488             if (data->flags & SF_BEFORE_EOL)
 489                 data->flags
 490                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
 491             else
 492                 data->flags &= ~SF_FIX_BEFORE_EOL;
 493         }
 494         else {
 495             data->offset_float_min = l ? data->last_start_min : data->pos_min;
 496             data->offset_float_max = (l
 497                                       ? data->last_start_max
 498                                       : data->pos_min + data->pos_delta);
 499             if ((U32)data->offset_float_max > (U32)I32_MAX)
 500                 data->offset_float_max = I32_MAX;
 501             if (data->flags & SF_BEFORE_EOL)
 502                 data->flags
 503                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
 504             else
 505                 data->flags &= ~SF_FL_BEFORE_EOL;
 506         }
 507     }
 508     SvCUR_set(data->last_found, 0);
 509     {
 510         SV * sv = data->last_found;
 511         MAGIC *mg =
 512             SvUTF8(sv) && SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_utf8) : NULL;
 513         if (mg && mg->mg_len > 0)
 514             mg->mg_len = 0;
 515     }
 516     data->last_end = -1;
 517     data->flags &= ~SF_BEFORE_EOL;
 518 }
 519
 520 /* Can match anything (initialization) */
 521 STATIC void
 522 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 523 {
 524     ANYOF_CLASS_ZERO(cl);
 525     ANYOF_BITMAP_SETALL(cl);
 526     cl->flags = ANYOF_EOS|ANYOF_UNICODE_ALL;
 527     if (LOC)
 528         cl->flags |= ANYOF_LOCALE;
 529 }
 530
 531 /* Can match anything (initialization) */
 532 STATIC int
 533 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
 534 {
 535     int value;
 536
 537     for (value = 0; value <= ANYOF_MAX; value += 2)
 538         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
 539             return 1;
 540     if (!(cl->flags & ANYOF_UNICODE_ALL))
 541         return 0;
 542     if (!ANYOF_BITMAP_TESTALLSET(cl))
 543         return 0;
 544     return 1;
 545 }
 546
 547 /* Can match anything (initialization) */
 548 STATIC void
 549 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 550 {
 551     Zero(cl, 1, struct regnode_charclass_class);
 552     cl->type = ANYOF;
 553     cl_anything(pRExC_state, cl);
 554 }
 555
 556 STATIC void
 557 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 558 {
 559     Zero(cl, 1, struct regnode_charclass_class);
 560     cl->type = ANYOF;
 561     cl_anything(pRExC_state, cl);
 562     if (LOC)
 563         cl->flags |= ANYOF_LOCALE;
 564 }
 565
 566 /* 'And' a given class with another one.  Can create false positives */
 567 /* We assume that cl is not inverted */
 568 STATIC void
 569 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 570          struct regnode_charclass_class *and_with)
 571 {
 572     if (!(and_with->flags & ANYOF_CLASS)
 573         && !(cl->flags & ANYOF_CLASS)
 574         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 575         && !(and_with->flags & ANYOF_FOLD)
 576         && !(cl->flags & ANYOF_FOLD)) {
 577         int i;
 578
 579         if (and_with->flags & ANYOF_INVERT)
 580             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 581                 cl->bitmap[i] &= ~and_with->bitmap[i];
 582         else
 583             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 584                 cl->bitmap[i] &= and_with->bitmap[i];
 585     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
 586     if (!(and_with->flags & ANYOF_EOS))
 587         cl->flags &= ~ANYOF_EOS;
 588
 589     if (cl->flags & ANYOF_UNICODE_ALL && and_with->flags & ANYOF_UNICODE &&
 590         !(and_with->flags & ANYOF_INVERT)) {
 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         !(and_with->flags & ANYOF_INVERT))
 597         cl->flags &= ~ANYOF_UNICODE_ALL;
 598     if (!(and_with->flags & (ANYOF_UNICODE|ANYOF_UNICODE_ALL)) &&
 599         !(and_with->flags & ANYOF_INVERT))
 600         cl->flags &= ~ANYOF_UNICODE;
 601 }
 602
 603 /* 'OR' a given class with another one.  Can create false positives */
 604 /* We assume that cl is not inverted */
 605 STATIC void
 606 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 607 {
 608     if (or_with->flags & ANYOF_INVERT) {
 609         /* We do not use
 610          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
 611          *   <= (B1 | !B2) | (CL1 | !CL2)
 612          * which is wasteful if CL2 is small, but we ignore CL2:
 613          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
 614          * XXXX Can we handle case-fold?  Unclear:
 615          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
 616          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
 617          */
 618         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 619              && !(or_with->flags & ANYOF_FOLD)
 620              && !(cl->flags & ANYOF_FOLD) ) {
 621             int i;
 622
 623             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 624                 cl->bitmap[i] |= ~or_with->bitmap[i];
 625         } /* XXXX: logic is complicated otherwise */
 626         else {
 627             cl_anything(pRExC_state, cl);
 628         }
 629     } else {
 630         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
 631         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 632              && (!(or_with->flags & ANYOF_FOLD)
 633                  || (cl->flags & ANYOF_FOLD)) ) {
 634             int i;
 635
 636             /* OR char bitmap and class bitmap separately */
 637             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 638                 cl->bitmap[i] |= or_with->bitmap[i];
 639             if (or_with->flags & ANYOF_CLASS) {
 640                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
 641                     cl->classflags[i] |= or_with->classflags[i];
 642                 cl->flags |= ANYOF_CLASS;
 643             }
 644         }
 645         else { /* XXXX: logic is complicated, leave it along for a moment. */
 646             cl_anything(pRExC_state, cl);
 647         }
 648     }
 649     if (or_with->flags & ANYOF_EOS)
 650         cl->flags |= ANYOF_EOS;
 651
 652     if (cl->flags & ANYOF_UNICODE && or_with->flags & ANYOF_UNICODE &&
 653         ARG(cl) != ARG(or_with)) {
 654         cl->flags |= ANYOF_UNICODE_ALL;
 655         cl->flags &= ~ANYOF_UNICODE;
 656     }
 657     if (or_with->flags & ANYOF_UNICODE_ALL) {
 658         cl->flags |= ANYOF_UNICODE_ALL;
 659         cl->flags &= ~ANYOF_UNICODE;
 660     }
 661 }
 662
 663 /*
 664  * There are strange code-generation bugs caused on sparc64 by gcc-2.95.2.
 665  * These need to be revisited when a newer toolchain becomes available.
 666  */
 667 #if defined(__sparc64__) && defined(__GNUC__)
 668 #   if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
 669 #       undef  SPARC64_GCC_WORKAROUND
 670 #       define SPARC64_GCC_WORKAROUND 1
 671 #   endif
 672 #endif
 673
 674 /* REx optimizer.  Converts nodes into quickier variants "in place".
 675    Finds fixed substrings.  */
 676
 677 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
 678    to the position after last scanned or to NULL. */
 679
 680 STATIC I32
 681 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
 682                         /* scanp: Start here (read-write). */
 683                         /* deltap: Write maxlen-minlen here. */
 684                         /* last: Stop before this one. */
 685 {
 686     I32 min = 0, pars = 0, code;
 687     regnode *scan = *scanp, *next;
 688     I32 delta = 0;
 689     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
 690     int is_inf_internal = 0;            /* The studied chunk is infinite */
 691     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
 692     scan_data_t data_fake;
 693     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
 694
 695     while (scan && OP(scan) != END && scan < last) {
 696         /* Peephole optimizer: */
 697
 698         if (PL_regkind[(U8)OP(scan)] == EXACT) {
 699             /* Merge several consecutive EXACTish nodes into one. */
 700             regnode *n = regnext(scan);
 701             U32 stringok = 1;
 702 #ifdef DEBUGGING
 703             regnode *stop = scan;
 704 #endif
 705
 706             next = scan + NODE_SZ_STR(scan);
 707             /* Skip NOTHING, merge EXACT*. */
 708             while (n &&
 709                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
 710                      (stringok && (OP(n) == OP(scan))))
 711                    && NEXT_OFF(n)
 712                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
 713                 if (OP(n) == TAIL || n > next)
 714                     stringok = 0;
 715                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
 716                     NEXT_OFF(scan) += NEXT_OFF(n);
 717                     next = n + NODE_STEP_REGNODE;
 718 #ifdef DEBUGGING
 719                     if (stringok)
 720                         stop = n;
 721 #endif
 722                     n = regnext(n);
 723                 }
 724                 else if (stringok) {
 725                     int oldl = STR_LEN(scan);
 726                     regnode *nnext = regnext(n);
 727
 728                     if (oldl + STR_LEN(n) > U8_MAX)
 729                         break;
 730                     NEXT_OFF(scan) += NEXT_OFF(n);
 731                     STR_LEN(scan) += STR_LEN(n);
 732                     next = n + NODE_SZ_STR(n);
 733                     /* Now we can overwrite *n : */
 734                     Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
 735 #ifdef DEBUGGING
 736                     stop = next - 1;
 737 #endif
 738                     n = nnext;
 739                 }
 740             }
 741
 742             if (UTF && OP(scan) == EXACTF && STR_LEN(scan) >= 6) {
 743 /*
 744   Two problematic code points in Unicode casefolding of EXACT nodes:
 745
 746    U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
 747    U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
 748
 749    which casefold to
 750
 751    Unicode                      UTF-8
 752
 753    U+03B9 U+0308 U+0301         0xCE 0xB9 0xCC 0x88 0xCC 0x81
 754    U+03C5 U+0308 U+0301         0xCF 0x85 0xCC 0x88 0xCC 0x81
 755
 756    This means that in case-insensitive matching (or "loose matching",
 757    as Unicode calls it), an EXACTF of length six (the UTF-8 encoded byte
 758    length of the above casefolded versions) can match a target string
 759    of length two (the byte length of UTF-8 encoded U+0390 or U+03B0).
 760    This would rather mess up the minimum length computation.
 761
 762    What we'll do is to look for the tail four bytes, and then peek
 763    at the preceding two bytes to see whether we need to decrease
 764    the minimum length by four (six minus two).
 765
 766    Thanks to the design of UTF-8, there cannot be false matches:
 767    A sequence of valid UTF-8 bytes cannot be a subsequence of
 768    another valid sequence of UTF-8 bytes.
 769
 770 */
 771                  char *s0 = STRING(scan), *s, *t;
 772                  char *s1 = s0 + STR_LEN(scan) - 1, *s2 = s1 - 4;
 773                  char *t0 = "\xcc\x88\xcc\x81";
 774                  char *t1 = t0 + 3;
 775
 776                  for (s = s0 + 2;
 777                       s < s2 && (t = ninstr(s, s1, t0, t1));
 778                       s = t + 4) {
 779                       if (((U8)t[-1] == 0xB9 && (U8)t[-2] == 0xCE) ||
 780                           ((U8)t[-1] == 0x85 && (U8)t[-2] == 0xCF))
 781                            min -= 4;
 782                  }
 783             }
 784
 785 #ifdef DEBUGGING
 786             /* Allow dumping */
 787             n = scan + NODE_SZ_STR(scan);
 788             while (n <= stop) {
 789                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
 790                     OP(n) = OPTIMIZED;
 791                     NEXT_OFF(n) = 0;
 792                 }
 793                 n++;
 794             }
 795 #endif
 796         }
 797         /* Follow the next-chain of the current node and optimize
 798            away all the NOTHINGs from it.  */
 799         if (OP(scan) != CURLYX) {
 800             int max = (reg_off_by_arg[OP(scan)]
 801                        ? I32_MAX
 802                        /* I32 may be smaller than U16 on CRAYs! */
 803                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
 804             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
 805             int noff;
 806             regnode *n = scan;
 807
 808             /* Skip NOTHING and LONGJMP. */
 809             while ((n = regnext(n))
 810                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
 811                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
 812                    && off + noff < max)
 813                 off += noff;
 814             if (reg_off_by_arg[OP(scan)])
 815                 ARG(scan) = off;
 816             else
 817                 NEXT_OFF(scan) = off;
 818         }
 819         /* The principal pseudo-switch.  Cannot be a switch, since we
 820            look into several different things.  */
 821         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
 822                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
 823             next = regnext(scan);
 824             code = OP(scan);
 825
 826             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
 827                 I32 max1 = 0, min1 = I32_MAX, num = 0;
 828                 struct regnode_charclass_class accum;
 829
 830                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
 831                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
 832                 if (flags & SCF_DO_STCLASS)
 833                     cl_init_zero(pRExC_state, &accum);
 834                 while (OP(scan) == code) {
 835                     I32 deltanext, minnext, f = 0, fake;
 836                     struct regnode_charclass_class this_class;
 837
 838                     num++;
 839                     data_fake.flags = 0;
 840                     if (data) {
 841                         data_fake.whilem_c = data->whilem_c;
 842                         data_fake.last_closep = data->last_closep;
 843                     }
 844                     else
 845                         data_fake.last_closep = &fake;
 846                     next = regnext(scan);
 847                     scan = NEXTOPER(scan);
 848                     if (code != BRANCH)
 849                         scan = NEXTOPER(scan);
 850                     if (flags & SCF_DO_STCLASS) {
 851                         cl_init(pRExC_state, &this_class);
 852                         data_fake.start_class = &this_class;
 853                         f = SCF_DO_STCLASS_AND;
 854                     }
 855                     if (flags & SCF_WHILEM_VISITED_POS)
 856                         f |= SCF_WHILEM_VISITED_POS;
 857                     /* we suppose the run is continuous, last=next...*/
 858                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
 859                                           next, &data_fake, f);
 860                     if (min1 > minnext)
 861                         min1 = minnext;
 862                     if (max1 < minnext + deltanext)
 863                         max1 = minnext + deltanext;
 864                     if (deltanext == I32_MAX)
 865                         is_inf = is_inf_internal = 1;
 866                     scan = next;
 867                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
 868                         pars++;
 869                     if (data && (data_fake.flags & SF_HAS_EVAL))
 870                         data->flags |= SF_HAS_EVAL;
 871                     if (data)
 872                         data->whilem_c = data_fake.whilem_c;
 873                     if (flags & SCF_DO_STCLASS)
 874                         cl_or(pRExC_state, &accum, &this_class);
 875                     if (code == SUSPEND)
 876                         break;
 877                 }
 878                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
 879                     min1 = 0;
 880                 if (flags & SCF_DO_SUBSTR) {
 881                     data->pos_min += min1;
 882                     data->pos_delta += max1 - min1;
 883                     if (max1 != min1 || is_inf)
 884                         data->longest = &(data->longest_float);
 885                 }
 886                 min += min1;
 887                 delta += max1 - min1;
 888                 if (flags & SCF_DO_STCLASS_OR) {
 889                     cl_or(pRExC_state, data->start_class, &accum);
 890                     if (min1) {
 891                         cl_and(data->start_class, &and_with);
 892                         flags &= ~SCF_DO_STCLASS;
 893                     }
 894                 }
 895                 else if (flags & SCF_DO_STCLASS_AND) {
 896                     if (min1) {
 897                         cl_and(data->start_class, &accum);
 898                         flags &= ~SCF_DO_STCLASS;
 899                     }
 900                     else {
 901                         /* Switch to OR mode: cache the old value of
 902                          * data->start_class */
 903                         StructCopy(data->start_class, &and_with,
 904                                    struct regnode_charclass_class);
 905                         flags &= ~SCF_DO_STCLASS_AND;
 906                         StructCopy(&accum, data->start_class,
 907                                    struct regnode_charclass_class);
 908                         flags |= SCF_DO_STCLASS_OR;
 909                         data->start_class->flags |= ANYOF_EOS;
 910                     }
 911                 }
 912             }
 913             else if (code == BRANCHJ)   /* single branch is optimized. */
 914                 scan = NEXTOPER(NEXTOPER(scan));
 915             else                        /* single branch is optimized. */
 916                 scan = NEXTOPER(scan);
 917             continue;
 918         }
 919         else if (OP(scan) == EXACT) {
 920             I32 l = STR_LEN(scan);
 921             UV uc = *((U8*)STRING(scan));
 922             if (UTF) {
 923                 U8 *s = (U8*)STRING(scan);
 924                 l = utf8_length(s, s + l);
 925                 uc = utf8_to_uvchr(s, NULL);
 926             }
 927             min += l;
 928             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
 929                 /* The code below prefers earlier match for fixed
 930                    offset, later match for variable offset.  */
 931                 if (data->last_end == -1) { /* Update the start info. */
 932                     data->last_start_min = data->pos_min;
 933                     data->last_start_max = is_inf
 934                         ? I32_MAX : data->pos_min + data->pos_delta;
 935                 }
 936                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
 937                 {
 938                     SV * sv = data->last_found;
 939                     MAGIC *mg = SvUTF8(sv) && SvMAGICAL(sv) ?
 940                         mg_find(sv, PERL_MAGIC_utf8) : NULL;
 941                     if (mg && mg->mg_len >= 0)
 942                         mg->mg_len += utf8_length((U8*)STRING(scan),
 943                                                   (U8*)STRING(scan)+STR_LEN(scan));
 944                 }
 945                 if (UTF)
 946                     SvUTF8_on(data->last_found);
 947                 data->last_end = data->pos_min + l;
 948                 data->pos_min += l; /* As in the first entry. */
 949                 data->flags &= ~SF_BEFORE_EOL;
 950             }
 951             if (flags & SCF_DO_STCLASS_AND) {
 952                 /* Check whether it is compatible with what we know already! */
 953                 int compat = 1;
 954
 955                 if (uc >= 0x100 ||
 956                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 957                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 958                     && (!(data->start_class->flags & ANYOF_FOLD)
 959                         || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 960                     )
 961                     compat = 0;
 962                 ANYOF_CLASS_ZERO(data->start_class);
 963                 ANYOF_BITMAP_ZERO(data->start_class);
 964                 if (compat)
 965                     ANYOF_BITMAP_SET(data->start_class, uc);
 966                 data->start_class->flags &= ~ANYOF_EOS;
 967                 if (uc < 0x100)
 968                   data->start_class->flags &= ~ANYOF_UNICODE_ALL;
 969             }
 970             else if (flags & SCF_DO_STCLASS_OR) {
 971                 /* false positive possible if the class is case-folded */
 972                 if (uc < 0x100)
 973                     ANYOF_BITMAP_SET(data->start_class, uc);
 974                 else
 975                     data->start_class->flags |= ANYOF_UNICODE_ALL;
 976                 data->start_class->flags &= ~ANYOF_EOS;
 977                 cl_and(data->start_class, &and_with);
 978             }
 979             flags &= ~SCF_DO_STCLASS;
 980         }
 981         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
 982             I32 l = STR_LEN(scan);
 983             UV uc = *((U8*)STRING(scan));
 984
 985             /* Search for fixed substrings supports EXACT only. */
 986             if (flags & SCF_DO_SUBSTR)
 987                 scan_commit(pRExC_state, data);
 988             if (UTF) {
 989                 U8 *s = (U8 *)STRING(scan);
 990                 l = utf8_length(s, s + l);
 991                 uc = utf8_to_uvchr(s, NULL);
 992             }
 993             min += l;
 994             if (data && (flags & SCF_DO_SUBSTR))
 995                 data->pos_min += l;
 996             if (flags & SCF_DO_STCLASS_AND) {
 997                 /* Check whether it is compatible with what we know already! */
 998                 int compat = 1;
 999
1000                 if (uc >= 0x100 ||
1001                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
1002                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
1003                      && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
1004                     compat = 0;
1005                 ANYOF_CLASS_ZERO(data->start_class);
1006                 ANYOF_BITMAP_ZERO(data->start_class);
1007                 if (compat) {
1008                     ANYOF_BITMAP_SET(data->start_class, uc);
1009                     data->start_class->flags &= ~ANYOF_EOS;
1010                     data->start_class->flags |= ANYOF_FOLD;
1011                     if (OP(scan) == EXACTFL)
1012                         data->start_class->flags |= ANYOF_LOCALE;
1013                 }
1014             }
1015             else if (flags & SCF_DO_STCLASS_OR) {
1016                 if (data->start_class->flags & ANYOF_FOLD) {
1017                     /* false positive possible if the class is case-folded.
1018                        Assume that the locale settings are the same... */
1019                     if (uc < 0x100)
1020                         ANYOF_BITMAP_SET(data->start_class, uc);
1021                     data->start_class->flags &= ~ANYOF_EOS;
1022                 }
1023                 cl_and(data->start_class, &and_with);
1024             }
1025             flags &= ~SCF_DO_STCLASS;
1026         }
1027         else if (strchr((char*)PL_varies,OP(scan))) {
1028             I32 mincount, maxcount, minnext, deltanext, fl = 0;
1029             I32 f = flags, pos_before = 0;
1030             regnode *oscan = scan;
1031             struct regnode_charclass_class this_class;
1032             struct regnode_charclass_class *oclass = NULL;
1033             I32 next_is_eval = 0;
1034
1035             switch (PL_regkind[(U8)OP(scan)]) {
1036             case WHILEM:                /* End of (?:...)* . */
1037                 scan = NEXTOPER(scan);
1038                 goto finish;
1039             case PLUS:
1040                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
1041                     next = NEXTOPER(scan);
1042                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
1043                         mincount = 1;
1044                         maxcount = REG_INFTY;
1045                         next = regnext(scan);
1046                         scan = NEXTOPER(scan);
1047                         goto do_curly;
1048                     }
1049                 }
1050                 if (flags & SCF_DO_SUBSTR)
1051                     data->pos_min++;
1052                 min++;
1053                 /* Fall through. */
1054             case STAR:
1055                 if (flags & SCF_DO_STCLASS) {
1056                     mincount = 0;
1057                     maxcount = REG_INFTY;
1058                     next = regnext(scan);
1059                     scan = NEXTOPER(scan);
1060                     goto do_curly;
1061                 }
1062                 is_inf = is_inf_internal = 1;
1063                 scan = regnext(scan);
1064                 if (flags & SCF_DO_SUBSTR) {
1065                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
1066                     data->longest = &(data->longest_float);
1067                 }
1068                 goto optimize_curly_tail;
1069             case CURLY:
1070                 mincount = ARG1(scan);
1071                 maxcount = ARG2(scan);
1072                 next = regnext(scan);
1073                 if (OP(scan) == CURLYX) {
1074                     I32 lp = (data ? *(data->last_closep) : 0);
1075
1076                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
1077                 }
1078                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
1079                 next_is_eval = (OP(scan) == EVAL);
1080               do_curly:
1081                 if (flags & SCF_DO_SUBSTR) {
1082                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
1083                     pos_before = data->pos_min;
1084                 }
1085                 if (data) {
1086                     fl = data->flags;
1087                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
1088                     if (is_inf)
1089                         data->flags |= SF_IS_INF;
1090                 }
1091                 if (flags & SCF_DO_STCLASS) {
1092                     cl_init(pRExC_state, &this_class);
1093                     oclass = data->start_class;
1094                     data->start_class = &this_class;
1095                     f |= SCF_DO_STCLASS_AND;
1096                     f &= ~SCF_DO_STCLASS_OR;
1097                 }
1098                 /* These are the cases when once a subexpression
1099                    fails at a particular position, it cannot succeed
1100                    even after backtracking at the enclosing scope.
1101
1102                    XXXX what if minimal match and we are at the
1103                         initial run of {n,m}? */
1104                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
1105                     f &= ~SCF_WHILEM_VISITED_POS;
1106
1107                 /* This will finish on WHILEM, setting scan, or on NULL: */
1108                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
1109                                       mincount == 0
1110                                         ? (f & ~SCF_DO_SUBSTR) : f);
1111
1112                 if (flags & SCF_DO_STCLASS)
1113                     data->start_class = oclass;
1114                 if (mincount == 0 || minnext == 0) {
1115                     if (flags & SCF_DO_STCLASS_OR) {
1116                         cl_or(pRExC_state, data->start_class, &this_class);
1117                     }
1118                     else if (flags & SCF_DO_STCLASS_AND) {
1119                         /* Switch to OR mode: cache the old value of
1120                          * data->start_class */
1121                         StructCopy(data->start_class, &and_with,
1122                                    struct regnode_charclass_class);
1123                         flags &= ~SCF_DO_STCLASS_AND;
1124                         StructCopy(&this_class, data->start_class,
1125                                    struct regnode_charclass_class);
1126                         flags |= SCF_DO_STCLASS_OR;
1127                         data->start_class->flags |= ANYOF_EOS;
1128                     }
1129                 } else {                /* Non-zero len */
1130                     if (flags & SCF_DO_STCLASS_OR) {
1131                         cl_or(pRExC_state, data->start_class, &this_class);
1132                         cl_and(data->start_class, &and_with);
1133                     }
1134                     else if (flags & SCF_DO_STCLASS_AND)
1135                         cl_and(data->start_class, &this_class);
1136                     flags &= ~SCF_DO_STCLASS;
1137                 }
1138                 if (!scan)              /* It was not CURLYX, but CURLY. */
1139                     scan = next;
1140                 if (ckWARN(WARN_REGEXP)
1141                        /* ? quantifier ok, except for (?{ ... }) */
1142                     && (next_is_eval || !(mincount == 0 && maxcount == 1))
1143                     && (minnext == 0) && (deltanext == 0)
1144                     && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1145                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1146                 {
1147                     vWARN(RExC_parse,
1148                           "Quantifier unexpected on zero-length expression");
1149                 }
1150
1151                 min += minnext * mincount;
1152                 is_inf_internal |= ((maxcount == REG_INFTY
1153                                      && (minnext + deltanext) > 0)
1154                                     || deltanext == I32_MAX);
1155                 is_inf |= is_inf_internal;
1156                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1157
1158                 /* Try powerful optimization CURLYX => CURLYN. */
1159                 if (  OP(oscan) == CURLYX && data
1160                       && data->flags & SF_IN_PAR
1161                       && !(data->flags & SF_HAS_EVAL)
1162                       && !deltanext && minnext == 1 ) {
1163                     /* Try to optimize to CURLYN.  */
1164                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1165                     regnode *nxt1 = nxt;
1166 #ifdef DEBUGGING
1167                     regnode *nxt2;
1168 #endif
1169
1170                     /* Skip open. */
1171                     nxt = regnext(nxt);
1172                     if (!strchr((char*)PL_simple,OP(nxt))
1173                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1174                              && STR_LEN(nxt) == 1))
1175                         goto nogo;
1176 #ifdef DEBUGGING
1177                     nxt2 = nxt;
1178 #endif
1179                     nxt = regnext(nxt);
1180                     if (OP(nxt) != CLOSE)
1181                         goto nogo;
1182                     /* Now we know that nxt2 is the only contents: */
1183                     oscan->flags = (U8)ARG(nxt);
1184                     OP(oscan) = CURLYN;
1185                     OP(nxt1) = NOTHING; /* was OPEN. */
1186 #ifdef DEBUGGING
1187                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1188                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1189                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1190                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1191                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1192                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1193 #endif
1194                 }
1195               nogo:
1196
1197                 /* Try optimization CURLYX => CURLYM. */
1198                 if (  OP(oscan) == CURLYX && data
1199                       && !(data->flags & SF_HAS_PAR)
1200                       && !(data->flags & SF_HAS_EVAL)
1201                       && !deltanext     /* atom is fixed width */
1202                       && minnext != 0   /* CURLYM can't handle zero width */
1203                 ) {
1204                     /* XXXX How to optimize if data == 0? */
1205                     /* Optimize to a simpler form.  */
1206                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1207                     regnode *nxt2;
1208
1209                     OP(oscan) = CURLYM;
1210                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1211                             && (OP(nxt2) != WHILEM))
1212                         nxt = nxt2;
1213                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1214                     /* Need to optimize away parenths. */
1215                     if (data->flags & SF_IN_PAR) {
1216                         /* Set the parenth number.  */
1217                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1218
1219                         if (OP(nxt) != CLOSE)
1220                             FAIL("Panic opt close");
1221                         oscan->flags = (U8)ARG(nxt);
1222                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1223                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1224 #ifdef DEBUGGING
1225                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1226                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1227                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1228                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1229 #endif
1230 #if 0
1231                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1232                             regnode *nnxt = regnext(nxt1);
1233
1234                             if (nnxt == nxt) {
1235                                 if (reg_off_by_arg[OP(nxt1)])
1236                                     ARG_SET(nxt1, nxt2 - nxt1);
1237                                 else if (nxt2 - nxt1 < U16_MAX)
1238                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1239                                 else
1240                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1241                             }
1242                             nxt1 = nnxt;
1243                         }
1244 #endif
1245                         /* Optimize again: */
1246                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1247                                     NULL, 0);
1248                     }
1249                     else
1250                         oscan->flags = 0;
1251                 }
1252                 else if ((OP(oscan) == CURLYX)
1253                          && (flags & SCF_WHILEM_VISITED_POS)
1254                          /* See the comment on a similar expression above.
1255                             However, this time it not a subexpression
1256                             we care about, but the expression itself. */
1257                          && (maxcount == REG_INFTY)
1258                          && data && ++data->whilem_c < 16) {
1259                     /* This stays as CURLYX, we can put the count/of pair. */
1260                     /* Find WHILEM (as in regexec.c) */
1261                     regnode *nxt = oscan + NEXT_OFF(oscan);
1262
1263                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1264                         nxt += ARG(nxt);
1265                     PREVOPER(nxt)->flags = (U8)(data->whilem_c
1266                         | (RExC_whilem_seen << 4)); /* On WHILEM */
1267                 }
1268                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1269                     pars++;
1270                 if (flags & SCF_DO_SUBSTR) {
1271                     SV *last_str = Nullsv;
1272                     int counted = mincount != 0;
1273
1274                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1275 #if defined(SPARC64_GCC_WORKAROUND)
1276                         I32 b = 0;
1277                         STRLEN l = 0;
1278                         char *s = NULL;
1279                         I32 old = 0;
1280
1281                         if (pos_before >= data->last_start_min)
1282                             b = pos_before;
1283                         else
1284                             b = data->last_start_min;
1285
1286                         l = 0;
1287                         s = SvPV(data->last_found, l);
1288                         old = b - data->last_start_min;
1289
1290 #else
1291                         I32 b = pos_before >= data->last_start_min
1292                             ? pos_before : data->last_start_min;
1293                         STRLEN l;
1294                         char *s = SvPV(data->last_found, l);
1295                         I32 old = b - data->last_start_min;
1296 #endif
1297
1298                         if (UTF)
1299                             old = utf8_hop((U8*)s, old) - (U8*)s;
1300
1301                         l -= old;
1302                         /* Get the added string: */
1303                         last_str = newSVpvn(s  + old, l);
1304                         if (UTF)
1305                             SvUTF8_on(last_str);
1306                         if (deltanext == 0 && pos_before == b) {
1307                             /* What was added is a constant string */
1308                             if (mincount > 1) {
1309                                 SvGROW(last_str, (mincount * l) + 1);
1310                                 repeatcpy(SvPVX(last_str) + l,
1311                                           SvPVX(last_str), l, mincount - 1);
1312                                 SvCUR(last_str) *= mincount;
1313                                 /* Add additional parts. */
1314                                 SvCUR_set(data->last_found,
1315                                           SvCUR(data->last_found) - l);
1316                                 sv_catsv(data->last_found, last_str);
1317                                 {
1318                                     SV * sv = data->last_found;
1319                                     MAGIC *mg =
1320                                         SvUTF8(sv) && SvMAGICAL(sv) ?
1321                                         mg_find(sv, PERL_MAGIC_utf8) : NULL;
1322                                     if (mg && mg->mg_len >= 0)
1323                                         mg->mg_len += CHR_SVLEN(last_str);
1324                                 }
1325                                 data->last_end += l * (mincount - 1);
1326                             }
1327                         } else {
1328                             /* start offset must point into the last copy */
1329                             data->last_start_min += minnext * (mincount - 1);
1330                             data->last_start_max += is_inf ? I32_MAX
1331                                 : (maxcount - 1) * (minnext + data->pos_delta);
1332                         }
1333                     }
1334                     /* It is counted once already... */
1335                     data->pos_min += minnext * (mincount - counted);
1336                     data->pos_delta += - counted * deltanext +
1337                         (minnext + deltanext) * maxcount - minnext * mincount;
1338                     if (mincount != maxcount) {
1339                          /* Cannot extend fixed substrings found inside
1340                             the group.  */
1341                         scan_commit(pRExC_state,data);
1342                         if (mincount && last_str) {
1343                             sv_setsv(data->last_found, last_str);
1344                             data->last_end = data->pos_min;
1345                             data->last_start_min =
1346                                 data->pos_min - CHR_SVLEN(last_str);
1347                             data->last_start_max = is_inf
1348                                 ? I32_MAX
1349                                 : data->pos_min + data->pos_delta
1350                                 - CHR_SVLEN(last_str);
1351                         }
1352                         data->longest = &(data->longest_float);
1353                     }
1354                     SvREFCNT_dec(last_str);
1355                 }
1356                 if (data && (fl & SF_HAS_EVAL))
1357                     data->flags |= SF_HAS_EVAL;
1358               optimize_curly_tail:
1359                 if (OP(oscan) != CURLYX) {
1360                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1361                            && NEXT_OFF(next))
1362                         NEXT_OFF(oscan) += NEXT_OFF(next);
1363                 }
1364                 continue;
1365             default:                    /* REF and CLUMP only? */
1366                 if (flags & SCF_DO_SUBSTR) {
1367                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1368                     data->longest = &(data->longest_float);
1369                 }
1370                 is_inf = is_inf_internal = 1;
1371                 if (flags & SCF_DO_STCLASS_OR)
1372                     cl_anything(pRExC_state, data->start_class);
1373                 flags &= ~SCF_DO_STCLASS;
1374                 break;
1375             }
1376         }
1377         else if (strchr((char*)PL_simple,OP(scan))) {
1378             int value = 0;
1379
1380             if (flags & SCF_DO_SUBSTR) {
1381                 scan_commit(pRExC_state,data);
1382                 data->pos_min++;
1383             }
1384             min++;
1385             if (flags & SCF_DO_STCLASS) {
1386                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1387
1388                 /* Some of the logic below assumes that switching
1389                    locale on will only add false positives. */
1390                 switch (PL_regkind[(U8)OP(scan)]) {
1391                 case SANY:
1392                 default:
1393                   do_default:
1394                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1395                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1396                         cl_anything(pRExC_state, data->start_class);
1397                     break;
1398                 case REG_ANY:
1399                     if (OP(scan) == SANY)
1400                         goto do_default;
1401                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1402                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1403                                  || (data->start_class->flags & ANYOF_CLASS));
1404                         cl_anything(pRExC_state, data->start_class);
1405                     }
1406                     if (flags & SCF_DO_STCLASS_AND || !value)
1407                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1408                     break;
1409                 case ANYOF:
1410                     if (flags & SCF_DO_STCLASS_AND)
1411                         cl_and(data->start_class,
1412                                (struct regnode_charclass_class*)scan);
1413                     else
1414                         cl_or(pRExC_state, data->start_class,
1415                               (struct regnode_charclass_class*)scan);
1416                     break;
1417                 case ALNUM:
1418                     if (flags & SCF_DO_STCLASS_AND) {
1419                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1420                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1421                             for (value = 0; value < 256; value++)
1422                                 if (!isALNUM(value))
1423                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1424                         }
1425                     }
1426                     else {
1427                         if (data->start_class->flags & ANYOF_LOCALE)
1428                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1429                         else {
1430                             for (value = 0; value < 256; value++)
1431                                 if (isALNUM(value))
1432                                     ANYOF_BITMAP_SET(data->start_class, value);
1433                         }
1434                     }
1435                     break;
1436                 case ALNUML:
1437                     if (flags & SCF_DO_STCLASS_AND) {
1438                         if (data->start_class->flags & ANYOF_LOCALE)
1439                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1440                     }
1441                     else {
1442                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1443                         data->start_class->flags |= ANYOF_LOCALE;
1444                     }
1445                     break;
1446                 case NALNUM:
1447                     if (flags & SCF_DO_STCLASS_AND) {
1448                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1449                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1450                             for (value = 0; value < 256; value++)
1451                                 if (isALNUM(value))
1452                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1453                         }
1454                     }
1455                     else {
1456                         if (data->start_class->flags & ANYOF_LOCALE)
1457                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1458                         else {
1459                             for (value = 0; value < 256; value++)
1460                                 if (!isALNUM(value))
1461                                     ANYOF_BITMAP_SET(data->start_class, value);
1462                         }
1463                     }
1464                     break;
1465                 case NALNUML:
1466                     if (flags & SCF_DO_STCLASS_AND) {
1467                         if (data->start_class->flags & ANYOF_LOCALE)
1468                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1469                     }
1470                     else {
1471                         data->start_class->flags |= ANYOF_LOCALE;
1472                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1473                     }
1474                     break;
1475                 case SPACE:
1476                     if (flags & SCF_DO_STCLASS_AND) {
1477                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1478                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1479                             for (value = 0; value < 256; value++)
1480                                 if (!isSPACE(value))
1481                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1482                         }
1483                     }
1484                     else {
1485                         if (data->start_class->flags & ANYOF_LOCALE)
1486                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1487                         else {
1488                             for (value = 0; value < 256; value++)
1489                                 if (isSPACE(value))
1490                                     ANYOF_BITMAP_SET(data->start_class, value);
1491                         }
1492                     }
1493                     break;
1494                 case SPACEL:
1495                     if (flags & SCF_DO_STCLASS_AND) {
1496                         if (data->start_class->flags & ANYOF_LOCALE)
1497                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1498                     }
1499                     else {
1500                         data->start_class->flags |= ANYOF_LOCALE;
1501                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1502                     }
1503                     break;
1504                 case NSPACE:
1505                     if (flags & SCF_DO_STCLASS_AND) {
1506                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1507                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1508                             for (value = 0; value < 256; value++)
1509                                 if (isSPACE(value))
1510                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1511                         }
1512                     }
1513                     else {
1514                         if (data->start_class->flags & ANYOF_LOCALE)
1515                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1516                         else {
1517                             for (value = 0; value < 256; value++)
1518                                 if (!isSPACE(value))
1519                                     ANYOF_BITMAP_SET(data->start_class, value);
1520                         }
1521                     }
1522                     break;
1523                 case NSPACEL:
1524                     if (flags & SCF_DO_STCLASS_AND) {
1525                         if (data->start_class->flags & ANYOF_LOCALE) {
1526                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1527                             for (value = 0; value < 256; value++)
1528                                 if (!isSPACE(value))
1529                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1530                         }
1531                     }
1532                     else {
1533                         data->start_class->flags |= ANYOF_LOCALE;
1534                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1535                     }
1536                     break;
1537                 case DIGIT:
1538                     if (flags & SCF_DO_STCLASS_AND) {
1539                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1540                         for (value = 0; value < 256; value++)
1541                             if (!isDIGIT(value))
1542                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1543                     }
1544                     else {
1545                         if (data->start_class->flags & ANYOF_LOCALE)
1546                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1547                         else {
1548                             for (value = 0; value < 256; value++)
1549                                 if (isDIGIT(value))
1550                                     ANYOF_BITMAP_SET(data->start_class, value);
1551                         }
1552                     }
1553                     break;
1554                 case NDIGIT:
1555                     if (flags & SCF_DO_STCLASS_AND) {
1556                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1557                         for (value = 0; value < 256; value++)
1558                             if (isDIGIT(value))
1559                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1560                     }
1561                     else {
1562                         if (data->start_class->flags & ANYOF_LOCALE)
1563                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1564                         else {
1565                             for (value = 0; value < 256; value++)
1566                                 if (!isDIGIT(value))
1567                                     ANYOF_BITMAP_SET(data->start_class, value);
1568                         }
1569                     }
1570                     break;
1571                 }
1572                 if (flags & SCF_DO_STCLASS_OR)
1573                     cl_and(data->start_class, &and_with);
1574                 flags &= ~SCF_DO_STCLASS;
1575             }
1576         }
1577         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1578             data->flags |= (OP(scan) == MEOL
1579                             ? SF_BEFORE_MEOL
1580                             : SF_BEFORE_SEOL);
1581         }
1582         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1583                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1584                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1585                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1586             /* Lookahead/lookbehind */
1587             I32 deltanext, minnext, fake = 0;
1588             regnode *nscan;
1589             struct regnode_charclass_class intrnl;
1590             int f = 0;
1591
1592             data_fake.flags = 0;
1593             if (data) {
1594                 data_fake.whilem_c = data->whilem_c;
1595                 data_fake.last_closep = data->last_closep;
1596             }
1597             else
1598                 data_fake.last_closep = &fake;
1599             if ( flags & SCF_DO_STCLASS && !scan->flags
1600                  && OP(scan) == IFMATCH ) { /* Lookahead */
1601                 cl_init(pRExC_state, &intrnl);
1602                 data_fake.start_class = &intrnl;
1603                 f |= SCF_DO_STCLASS_AND;
1604             }
1605             if (flags & SCF_WHILEM_VISITED_POS)
1606                 f |= SCF_WHILEM_VISITED_POS;
1607             next = regnext(scan);
1608             nscan = NEXTOPER(NEXTOPER(scan));
1609             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1610             if (scan->flags) {
1611                 if (deltanext) {
1612                     vFAIL("Variable length lookbehind not implemented");
1613                 }
1614                 else if (minnext > U8_MAX) {
1615                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1616                 }
1617                 scan->flags = (U8)minnext;
1618             }
1619             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1620                 pars++;
1621             if (data && (data_fake.flags & SF_HAS_EVAL))
1622                 data->flags |= SF_HAS_EVAL;
1623             if (data)
1624                 data->whilem_c = data_fake.whilem_c;
1625             if (f & SCF_DO_STCLASS_AND) {
1626                 int was = (data->start_class->flags & ANYOF_EOS);
1627
1628                 cl_and(data->start_class, &intrnl);
1629                 if (was)
1630                     data->start_class->flags |= ANYOF_EOS;
1631             }
1632         }
1633         else if (OP(scan) == OPEN) {
1634             pars++;
1635         }
1636         else if (OP(scan) == CLOSE) {
1637             if ((I32)ARG(scan) == is_par) {
1638                 next = regnext(scan);
1639
1640                 if ( next && (OP(next) != WHILEM) && next < last)
1641                     is_par = 0;         /* Disable optimization */
1642             }
1643             if (data)
1644                 *(data->last_closep) = ARG(scan);
1645         }
1646         else if (OP(scan) == EVAL) {
1647                 if (data)
1648                     data->flags |= SF_HAS_EVAL;
1649         }
1650         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1651                 if (flags & SCF_DO_SUBSTR) {
1652                     scan_commit(pRExC_state,data);
1653                     data->longest = &(data->longest_float);
1654                 }
1655                 is_inf = is_inf_internal = 1;
1656                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1657                     cl_anything(pRExC_state, data->start_class);
1658                 flags &= ~SCF_DO_STCLASS;
1659         }
1660         /* Else: zero-length, ignore. */
1661         scan = regnext(scan);
1662     }
1663
1664   finish:
1665     *scanp = scan;
1666     *deltap = is_inf_internal ? I32_MAX : delta;
1667     if (flags & SCF_DO_SUBSTR && is_inf)
1668         data->pos_delta = I32_MAX - data->pos_min;
1669     if (is_par > U8_MAX)
1670         is_par = 0;
1671     if (is_par && pars==1 && data) {
1672         data->flags |= SF_IN_PAR;
1673         data->flags &= ~SF_HAS_PAR;
1674     }
1675     else if (pars && data) {
1676         data->flags |= SF_HAS_PAR;
1677         data->flags &= ~SF_IN_PAR;
1678     }
1679     if (flags & SCF_DO_STCLASS_OR)
1680         cl_and(data->start_class, &and_with);
1681     return min;
1682 }
1683
1684 STATIC I32
1685 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1686 {
1687     if (RExC_rx->data) {
1688         Renewc(RExC_rx->data,
1689                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1690                char, struct reg_data);
1691         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1692         RExC_rx->data->count += n;
1693     }
1694     else {
1695         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1696              char, struct reg_data);
1697         New(1208, RExC_rx->data->what, n, U8);
1698         RExC_rx->data->count = n;
1699     }
1700     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1701     return RExC_rx->data->count - n;
1702 }
1703
1704 void
1705 Perl_reginitcolors(pTHX)
1706 {
1707     int i = 0;
1708     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1709
1710     if (s) {
1711         PL_colors[0] = s = savepv(s);
1712         while (++i < 6) {
1713             s = strchr(s, '\t');
1714             if (s) {
1715                 *s = '\0';
1716                 PL_colors[i] = ++s;
1717             }
1718             else
1719                 PL_colors[i] = s = "";
1720         }
1721     } else {
1722         while (i < 6)
1723             PL_colors[i++] = "";
1724     }
1725     PL_colorset = 1;
1726 }
1727
1728
1729 /*
1730  - pregcomp - compile a regular expression into internal code
1731  *
1732  * We can't allocate space until we know how big the compiled form will be,
1733  * but we can't compile it (and thus know how big it is) until we've got a
1734  * place to put the code.  So we cheat:  we compile it twice, once with code
1735  * generation turned off and size counting turned on, and once "for real".
1736  * This also means that we don't allocate space until we are sure that the
1737  * thing really will compile successfully, and we never have to move the
1738  * code and thus invalidate pointers into it.  (Note that it has to be in
1739  * one piece because free() must be able to free it all.) [NB: not true in perl]
1740  *
1741  * Beware that the optimization-preparation code in here knows about some
1742  * of the structure of the compiled regexp.  [I'll say.]
1743  */
1744 regexp *
1745 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1746 {
1747     register regexp *r;
1748     regnode *scan;
1749     regnode *first;
1750     I32 flags;
1751     I32 minlen = 0;
1752     I32 sawplus = 0;
1753     I32 sawopen = 0;
1754     scan_data_t data;
1755     RExC_state_t RExC_state;
1756     RExC_state_t *pRExC_state = &RExC_state;
1757
1758     if (exp == NULL)
1759         FAIL("NULL regexp argument");
1760
1761     RExC_utf8 = pm->op_pmdynflags & PMdf_CMP_UTF8;
1762
1763     RExC_precomp = exp;
1764     DEBUG_r({
1765          if (!PL_colorset) reginitcolors();
1766          PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1767                        PL_colors[4],PL_colors[5],PL_colors[0],
1768                        (int)(xend - exp), RExC_precomp, PL_colors[1]);
1769     });
1770     RExC_flags = pm->op_pmflags;
1771     RExC_sawback = 0;
1772
1773     RExC_seen = 0;
1774     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1775     RExC_seen_evals = 0;
1776     RExC_extralen = 0;
1777
1778     /* First pass: determine size, legality. */
1779     RExC_parse = exp;
1780     RExC_start = exp;
1781     RExC_end = xend;
1782     RExC_naughty = 0;
1783     RExC_npar = 1;
1784     RExC_size = 0L;
1785     RExC_emit = &PL_regdummy;
1786     RExC_whilem_seen = 0;
1787 #if 0 /* REGC() is (currently) a NOP at the first pass.
1788        * Clever compilers notice this and complain. --jhi */
1789     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1790 #endif
1791     if (reg(pRExC_state, 0, &flags) == NULL) {
1792         RExC_precomp = Nullch;
1793         return(NULL);
1794     }
1795     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1796
1797     /* Small enough for pointer-storage convention?
1798        If extralen==0, this means that we will not need long jumps. */
1799     if (RExC_size >= 0x10000L && RExC_extralen)
1800         RExC_size += RExC_extralen;
1801     else
1802         RExC_extralen = 0;
1803     if (RExC_whilem_seen > 15)
1804         RExC_whilem_seen = 15;
1805
1806     /* Allocate space and initialize. */
1807     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1808          char, regexp);
1809     if (r == NULL)
1810         FAIL("Regexp out of space");
1811
1812 #ifdef DEBUGGING
1813     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1814     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1815 #endif
1816     r->refcnt = 1;
1817     r->prelen = xend - exp;
1818     r->precomp = savepvn(RExC_precomp, r->prelen);
1819     r->subbeg = NULL;
1820 #ifdef PERL_COPY_ON_WRITE
1821     r->saved_copy = Nullsv;
1822 #endif
1823     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1824     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1825
1826     r->substrs = 0;                     /* Useful during FAIL. */
1827     r->startp = 0;                      /* Useful during FAIL. */
1828     r->endp = 0;                        /* Useful during FAIL. */
1829
1830     Newz(1304, r->offsets, 2*RExC_size+1, U32); /* MJD 20001228 */
1831     if (r->offsets) {
1832       r->offsets[0] = RExC_size;
1833     }
1834     DEBUG_r(PerlIO_printf(Perl_debug_log,
1835                           "%s %"UVuf" bytes for offset annotations.\n",
1836                           r->offsets ? "Got" : "Couldn't get",
1837                           (UV)((2*RExC_size+1) * sizeof(U32))));
1838
1839     RExC_rx = r;
1840
1841     /* Second pass: emit code. */
1842     RExC_flags = pm->op_pmflags;        /* don't let top level (?i) bleed */
1843     RExC_parse = exp;
1844     RExC_end = xend;
1845     RExC_naughty = 0;
1846     RExC_npar = 1;
1847     RExC_emit_start = r->program;
1848     RExC_emit = r->program;
1849     /* Store the count of eval-groups for security checks: */
1850     RExC_emit->next_off = (U16)((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1851     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1852     r->data = 0;
1853     if (reg(pRExC_state, 0, &flags) == NULL)
1854         return(NULL);
1855
1856     /* Dig out information for optimizations. */
1857     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1858     pm->op_pmflags = RExC_flags;
1859     if (UTF)
1860         r->reganch |= ROPT_UTF8;        /* Unicode in it? */
1861     r->regstclass = NULL;
1862     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1863         r->reganch |= ROPT_NAUGHTY;
1864     scan = r->program + 1;              /* First BRANCH. */
1865
1866     /* XXXX To minimize changes to RE engine we always allocate
1867        3-units-long substrs field. */
1868     Newz(1004, r->substrs, 1, struct reg_substr_data);
1869
1870     StructCopy(&zero_scan_data, &data, scan_data_t);
1871     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1872     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1873         I32 fake;
1874         STRLEN longest_float_length, longest_fixed_length;
1875         struct regnode_charclass_class ch_class;
1876         int stclass_flag;
1877         I32 last_close = 0;
1878
1879         first = scan;
1880         /* Skip introductions and multiplicators >= 1. */
1881         while ((OP(first) == OPEN && (sawopen = 1)) ||
1882                /* An OR of *one* alternative - should not happen now. */
1883             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1884             (OP(first) == PLUS) ||
1885             (OP(first) == MINMOD) ||
1886                /* An {n,m} with n>0 */
1887             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1888                 if (OP(first) == PLUS)
1889                     sawplus = 1;
1890                 else
1891                     first += regarglen[(U8)OP(first)];
1892                 first = NEXTOPER(first);
1893         }
1894
1895         /* Starting-point info. */
1896       again:
1897         if (PL_regkind[(U8)OP(first)] == EXACT) {
1898             if (OP(first) == EXACT)
1899                 ;       /* Empty, get anchored substr later. */
1900             else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
1901                 r->regstclass = first;
1902         }
1903         else if (strchr((char*)PL_simple,OP(first)))
1904             r->regstclass = first;
1905         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1906                  PL_regkind[(U8)OP(first)] == NBOUND)
1907             r->regstclass = first;
1908         else if (PL_regkind[(U8)OP(first)] == BOL) {
1909             r->reganch |= (OP(first) == MBOL
1910                            ? ROPT_ANCH_MBOL
1911                            : (OP(first) == SBOL
1912                               ? ROPT_ANCH_SBOL
1913                               : ROPT_ANCH_BOL));
1914             first = NEXTOPER(first);
1915             goto again;
1916         }
1917         else if (OP(first) == GPOS) {
1918             r->reganch |= ROPT_ANCH_GPOS;
1919             first = NEXTOPER(first);
1920             goto again;
1921         }
1922         else if (!sawopen && (OP(first) == STAR &&
1923             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1924             !(r->reganch & ROPT_ANCH) )
1925         {
1926             /* turn .* into ^.* with an implied $*=1 */
1927             int type = OP(NEXTOPER(first));
1928
1929             if (type == REG_ANY)
1930                 type = ROPT_ANCH_MBOL;
1931             else
1932                 type = ROPT_ANCH_SBOL;
1933
1934             r->reganch |= type | ROPT_IMPLICIT;
1935             first = NEXTOPER(first);
1936             goto again;
1937         }
1938         if (sawplus && (!sawopen || !RExC_sawback)
1939             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1940             /* x+ must match at the 1st pos of run of x's */
1941             r->reganch |= ROPT_SKIP;
1942
1943         /* Scan is after the zeroth branch, first is atomic matcher. */
1944         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1945                               (IV)(first - scan + 1)));
1946         /*
1947         * If there's something expensive in the r.e., find the
1948         * longest literal string that must appear and make it the
1949         * regmust.  Resolve ties in favor of later strings, since
1950         * the regstart check works with the beginning of the r.e.
1951         * and avoiding duplication strengthens checking.  Not a
1952         * strong reason, but sufficient in the absence of others.
1953         * [Now we resolve ties in favor of the earlier string if
1954         * it happens that c_offset_min has been invalidated, since the
1955         * earlier string may buy us something the later one won't.]
1956         */
1957         minlen = 0;
1958
1959         data.longest_fixed = newSVpvn("",0);
1960         data.longest_float = newSVpvn("",0);
1961         data.last_found = newSVpvn("",0);
1962         data.longest = &(data.longest_fixed);
1963         first = scan;
1964         if (!r->regstclass) {
1965             cl_init(pRExC_state, &ch_class);
1966             data.start_class = &ch_class;
1967             stclass_flag = SCF_DO_STCLASS_AND;
1968         } else                          /* XXXX Check for BOUND? */
1969             stclass_flag = 0;
1970         data.last_closep = &last_close;
1971
1972         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1973                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1974         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1975              && data.last_start_min == 0 && data.last_end > 0
1976              && !RExC_seen_zerolen
1977              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1978             r->reganch |= ROPT_CHECK_ALL;
1979         scan_commit(pRExC_state, &data);
1980         SvREFCNT_dec(data.last_found);
1981
1982         longest_float_length = CHR_SVLEN(data.longest_float);
1983         if (longest_float_length
1984             || (data.flags & SF_FL_BEFORE_EOL
1985                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1986                     || (RExC_flags & PMf_MULTILINE)))) {
1987             int t;
1988
1989             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1990                 && data.offset_fixed == data.offset_float_min
1991                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1992                     goto remove_float;          /* As in (a)+. */
1993
1994             if (SvUTF8(data.longest_float)) {
1995                 r->float_utf8 = data.longest_float;
1996                 r->float_substr = Nullsv;
1997             } else {
1998                 r->float_substr = data.longest_float;
1999                 r->float_utf8 = Nullsv;
2000             }
2001             r->float_min_offset = data.offset_float_min;
2002             r->float_max_offset = data.offset_float_max;
2003             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
2004                        && (!(data.flags & SF_FL_BEFORE_MEOL)
2005                            || (RExC_flags & PMf_MULTILINE)));
2006             fbm_compile(data.longest_float, t ? FBMcf_TAIL : 0);
2007         }
2008         else {
2009           remove_float:
2010             r->float_substr = r->float_utf8 = Nullsv;
2011             SvREFCNT_dec(data.longest_float);
2012             longest_float_length = 0;
2013         }
2014
2015         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
2016         if (longest_fixed_length
2017             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
2018                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
2019                     || (RExC_flags & PMf_MULTILINE)))) {
2020             int t;
2021
2022             if (SvUTF8(data.longest_fixed)) {
2023                 r->anchored_utf8 = data.longest_fixed;
2024                 r->anchored_substr = Nullsv;
2025             } else {
2026                 r->anchored_substr = data.longest_fixed;
2027                 r->anchored_utf8 = Nullsv;
2028             }
2029             r->anchored_offset = data.offset_fixed;
2030             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
2031                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
2032                      || (RExC_flags & PMf_MULTILINE)));
2033             fbm_compile(data.longest_fixed, t ? FBMcf_TAIL : 0);
2034         }
2035         else {
2036             r->anchored_substr = r->anchored_utf8 = Nullsv;
2037             SvREFCNT_dec(data.longest_fixed);
2038             longest_fixed_length = 0;
2039         }
2040         if (r->regstclass
2041             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == SANY))
2042             r->regstclass = NULL;
2043         if ((!(r->anchored_substr || r->anchored_utf8) || r->anchored_offset)
2044             && stclass_flag
2045             && !(data.start_class->flags & ANYOF_EOS)
2046             && !cl_is_anything(data.start_class))
2047         {
2048             I32 n = add_data(pRExC_state, 1, "f");
2049
2050             New(1006, RExC_rx->data->data[n], 1,
2051                 struct regnode_charclass_class);
2052             StructCopy(data.start_class,
2053                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2054                        struct regnode_charclass_class);
2055             r->regstclass = (regnode*)RExC_rx->data->data[n];
2056             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2057             PL_regdata = r->data; /* for regprop() */
2058             DEBUG_r({ SV *sv = sv_newmortal();
2059                       regprop(sv, (regnode*)data.start_class);
2060                       PerlIO_printf(Perl_debug_log,
2061                                     "synthetic stclass `%s'.\n",
2062                                     SvPVX(sv));});
2063         }
2064
2065         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
2066         if (longest_fixed_length > longest_float_length) {
2067             r->check_substr = r->anchored_substr;
2068             r->check_utf8 = r->anchored_utf8;
2069             r->check_offset_min = r->check_offset_max = r->anchored_offset;
2070             if (r->reganch & ROPT_ANCH_SINGLE)
2071                 r->reganch |= ROPT_NOSCAN;
2072         }
2073         else {
2074             r->check_substr = r->float_substr;
2075             r->check_utf8 = r->float_utf8;
2076             r->check_offset_min = data.offset_float_min;
2077             r->check_offset_max = data.offset_float_max;
2078         }
2079         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
2080            This should be changed ASAP!  */
2081         if ((r->check_substr || r->check_utf8) && !(r->reganch & ROPT_ANCH_GPOS)) {
2082             r->reganch |= RE_USE_INTUIT;
2083             if (SvTAIL(r->check_substr ? r->check_substr : r->check_utf8))
2084                 r->reganch |= RE_INTUIT_TAIL;
2085         }
2086     }
2087     else {
2088         /* Several toplevels. Best we can is to set minlen. */
2089         I32 fake;
2090         struct regnode_charclass_class ch_class;
2091         I32 last_close = 0;
2092
2093         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
2094         scan = r->program + 1;
2095         cl_init(pRExC_state, &ch_class);
2096         data.start_class = &ch_class;
2097         data.last_closep = &last_close;
2098         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
2099         r->check_substr = r->check_utf8 = r->anchored_substr = r->anchored_utf8
2100                 = r->float_substr = r->float_utf8 = Nullsv;
2101         if (!(data.start_class->flags & ANYOF_EOS)
2102             && !cl_is_anything(data.start_class))
2103         {
2104             I32 n = add_data(pRExC_state, 1, "f");
2105
2106             New(1006, RExC_rx->data->data[n], 1,
2107                 struct regnode_charclass_class);
2108             StructCopy(data.start_class,
2109                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2110                        struct regnode_charclass_class);
2111             r->regstclass = (regnode*)RExC_rx->data->data[n];
2112             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2113             DEBUG_r({ SV* sv = sv_newmortal();
2114                       regprop(sv, (regnode*)data.start_class);
2115                       PerlIO_printf(Perl_debug_log,
2116                                     "synthetic stclass `%s'.\n",
2117                                     SvPVX(sv));});
2118         }
2119     }
2120
2121     r->minlen = minlen;
2122     if (RExC_seen & REG_SEEN_GPOS)
2123         r->reganch |= ROPT_GPOS_SEEN;
2124     if (RExC_seen & REG_SEEN_LOOKBEHIND)
2125         r->reganch |= ROPT_LOOKBEHIND_SEEN;
2126     if (RExC_seen & REG_SEEN_EVAL)
2127         r->reganch |= ROPT_EVAL_SEEN;
2128     if (RExC_seen & REG_SEEN_CANY)
2129         r->reganch |= ROPT_CANY_SEEN;
2130     Newz(1002, r->startp, RExC_npar, I32);
2131     Newz(1002, r->endp, RExC_npar, I32);
2132     PL_regdata = r->data; /* for regprop() */
2133     DEBUG_r(regdump(r));
2134     return(r);
2135 }
2136
2137 /*
2138  - reg - regular expression, i.e. main body or parenthesized thing
2139  *
2140  * Caller must absorb opening parenthesis.
2141  *
2142  * Combining parenthesis handling with the base level of regular expression
2143  * is a trifle forced, but the need to tie the tails of the branches to what
2144  * follows makes it hard to avoid.
2145  */
2146 STATIC regnode *
2147 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
2148     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
2149 {
2150     register regnode *ret;              /* Will be the head of the group. */
2151     register regnode *br;
2152     register regnode *lastbr;
2153     register regnode *ender = 0;
2154     register I32 parno = 0;
2155     I32 flags, oregflags = RExC_flags, have_branch = 0, open = 0;
2156
2157     /* for (?g), (?gc), and (?o) warnings; warning
2158        about (?c) will warn about (?g) -- japhy    */
2159
2160     I32 wastedflags = 0x00,
2161         wasted_o    = 0x01,
2162         wasted_g    = 0x02,
2163         wasted_gc   = 0x02 | 0x04,
2164         wasted_c    = 0x04;
2165
2166     char * parse_start = RExC_parse; /* MJD */
2167     char *oregcomp_parse = RExC_parse;
2168     char c;
2169
2170     *flagp = 0;                         /* Tentatively. */
2171
2172
2173     /* Make an OPEN node, if parenthesized. */
2174     if (paren) {
2175         if (*RExC_parse == '?') { /* (?...) */
2176             U32 posflags = 0, negflags = 0;
2177             U32 *flagsp = &posflags;
2178             int logical = 0;
2179             char *seqstart = RExC_parse;
2180
2181             RExC_parse++;
2182             paren = *RExC_parse++;
2183             ret = NULL;                 /* For look-ahead/behind. */
2184             switch (paren) {
2185             case '<':           /* (?<...) */
2186                 RExC_seen |= REG_SEEN_LOOKBEHIND;
2187                 if (*RExC_parse == '!')
2188                     paren = ',';
2189                 if (*RExC_parse != '=' && *RExC_parse != '!')
2190                     goto unknown;
2191                 RExC_parse++;
2192             case '=':           /* (?=...) */
2193             case '!':           /* (?!...) */
2194                 RExC_seen_zerolen++;
2195             case ':':           /* (?:...) */
2196             case '>':           /* (?>...) */
2197                 break;
2198             case '$':           /* (?$...) */
2199             case '@':           /* (?@...) */
2200                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
2201                 break;
2202             case '#':           /* (?#...) */
2203                 while (*RExC_parse && *RExC_parse != ')')
2204                     RExC_parse++;
2205                 if (*RExC_parse != ')')
2206                     FAIL("Sequence (?#... not terminated");
2207                 nextchar(pRExC_state);
2208                 *flagp = TRYAGAIN;
2209                 return NULL;
2210             case 'p':           /* (?p...) */
2211                 if (SIZE_ONLY && ckWARN2(WARN_DEPRECATED, WARN_REGEXP))
2212                     vWARNdep(RExC_parse, "(?p{}) is deprecated - use (??{})");
2213                 /* FALL THROUGH*/
2214             case '?':           /* (??...) */
2215                 logical = 1;
2216                 if (*RExC_parse != '{')
2217                     goto unknown;
2218                 paren = *RExC_parse++;
2219                 /* FALL THROUGH */
2220             case '{':           /* (?{...}) */
2221             {
2222                 I32 count = 1, n = 0;
2223                 char c;
2224                 char *s = RExC_parse;
2225                 SV *sv;
2226                 OP_4tree *sop, *rop;
2227
2228                 RExC_seen_zerolen++;
2229                 RExC_seen |= REG_SEEN_EVAL;
2230                 while (count && (c = *RExC_parse)) {
2231                     if (c == '\\' && RExC_parse[1])
2232                         RExC_parse++;
2233                     else if (c == '{')
2234                         count++;
2235                     else if (c == '}')
2236                         count--;
2237                     RExC_parse++;
2238                 }
2239                 if (*RExC_parse != ')')
2240                 {
2241                     RExC_parse = s;
2242                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2243                 }
2244                 if (!SIZE_ONLY) {
2245                     PAD *pad;
2246
2247                     if (RExC_parse - 1 - s)
2248                         sv = newSVpvn(s, RExC_parse - 1 - s);
2249                     else
2250                         sv = newSVpvn("", 0);
2251
2252                     ENTER;
2253                     Perl_save_re_context(aTHX);
2254                     rop = sv_compile_2op(sv, &sop, "re", &pad);
2255                     sop->op_private |= OPpREFCOUNTED;
2256                     /* re_dup will OpREFCNT_inc */
2257                     OpREFCNT_set(sop, 1);
2258                     LEAVE;
2259
2260                     n = add_data(pRExC_state, 3, "nop");
2261                     RExC_rx->data->data[n] = (void*)rop;
2262                     RExC_rx->data->data[n+1] = (void*)sop;
2263                     RExC_rx->data->data[n+2] = (void*)pad;
2264                     SvREFCNT_dec(sv);
2265                 }
2266                 else {                                          /* First pass */
2267                     if (PL_reginterp_cnt < ++RExC_seen_evals
2268                         && IN_PERL_RUNTIME)
2269                         /* No compiled RE interpolated, has runtime
2270                            components ===> unsafe.  */
2271                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2272                     if (PL_tainting && PL_tainted)
2273                         FAIL("Eval-group in insecure regular expression");
2274                     if (IN_PERL_COMPILETIME)
2275                         PL_cv_has_eval = 1;
2276                 }
2277
2278                 nextchar(pRExC_state);
2279                 if (logical) {
2280                     ret = reg_node(pRExC_state, LOGICAL);
2281                     if (!SIZE_ONLY)
2282                         ret->flags = 2;
2283                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2284                     /* deal with the length of this later - MJD */
2285                     return ret;
2286                 }
2287                 ret = reganode(pRExC_state, EVAL, n);
2288                 Set_Node_Length(ret, RExC_parse - parse_start + 1);
2289                 Set_Node_Offset(ret, parse_start);
2290                 return ret;
2291             }
2292             case '(':           /* (?(?{...})...) and (?(?=...)...) */
2293             {
2294                 if (RExC_parse[0] == '?') {        /* (?(?...)) */
2295                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2296                         || RExC_parse[1] == '<'
2297                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2298                         I32 flag;
2299
2300                         ret = reg_node(pRExC_state, LOGICAL);
2301                         if (!SIZE_ONLY)
2302                             ret->flags = 1;
2303                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2304                         goto insert_if;
2305                     }
2306                 }
2307                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2308                     /* (?(1)...) */
2309                     parno = atoi(RExC_parse++);
2310
2311                     while (isDIGIT(*RExC_parse))
2312                         RExC_parse++;
2313                     ret = reganode(pRExC_state, GROUPP, parno);
2314
2315                     if ((c = *nextchar(pRExC_state)) != ')')
2316                         vFAIL("Switch condition not recognized");
2317                   insert_if:
2318                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2319                     br = regbranch(pRExC_state, &flags, 1);
2320                     if (br == NULL)
2321                         br = reganode(pRExC_state, LONGJMP, 0);
2322                     else
2323                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2324                     c = *nextchar(pRExC_state);
2325                     if (flags&HASWIDTH)
2326                         *flagp |= HASWIDTH;
2327                     if (c == '|') {
2328                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2329                         regbranch(pRExC_state, &flags, 1);
2330                         regtail(pRExC_state, ret, lastbr);
2331                         if (flags&HASWIDTH)
2332                             *flagp |= HASWIDTH;
2333                         c = *nextchar(pRExC_state);
2334                     }
2335                     else
2336                         lastbr = NULL;
2337                     if (c != ')')
2338                         vFAIL("Switch (?(condition)... contains too many branches");
2339                     ender = reg_node(pRExC_state, TAIL);
2340                     regtail(pRExC_state, br, ender);
2341                     if (lastbr) {
2342                         regtail(pRExC_state, lastbr, ender);
2343                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2344                     }
2345                     else
2346                         regtail(pRExC_state, ret, ender);
2347                     return ret;
2348                 }
2349                 else {
2350                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2351                 }
2352             }
2353             case 0:
2354                 RExC_parse--; /* for vFAIL to print correctly */
2355                 vFAIL("Sequence (? incomplete");
2356                 break;
2357             default:
2358                 --RExC_parse;
2359               parse_flags:      /* (?i) */
2360                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2361                     /* (?g), (?gc) and (?o) are useless here
2362                        and must be globally applied -- japhy */
2363
2364                     if (*RExC_parse == 'o' || *RExC_parse == 'g') {
2365                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2366                             I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
2367                             if (! (wastedflags & wflagbit) ) {
2368                                 wastedflags |= wflagbit;
2369                                 vWARN5(
2370                                     RExC_parse + 1,
2371                                     "Useless (%s%c) - %suse /%c modifier",
2372                                     flagsp == &negflags ? "?-" : "?",
2373                                     *RExC_parse,
2374                                     flagsp == &negflags ? "don't " : "",
2375                                     *RExC_parse
2376                                 );
2377                             }
2378                         }
2379                     }
2380                     else if (*RExC_parse == 'c') {
2381                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2382                             if (! (wastedflags & wasted_c) ) {
2383                                 wastedflags |= wasted_gc;
2384                                 vWARN3(
2385                                     RExC_parse + 1,
2386                                     "Useless (%sc) - %suse /gc modifier",
2387                                     flagsp == &negflags ? "?-" : "?",
2388                                     flagsp == &negflags ? "don't " : ""
2389                                 );
2390                             }
2391                         }
2392                     }
2393                     else { pmflag(flagsp, *RExC_parse); }
2394
2395                     ++RExC_parse;
2396                 }
2397                 if (*RExC_parse == '-') {
2398                     flagsp = &negflags;
2399                     wastedflags = 0;  /* reset so (?g-c) warns twice */
2400                     ++RExC_parse;
2401                     goto parse_flags;
2402                 }
2403                 RExC_flags |= posflags;
2404                 RExC_flags &= ~negflags;
2405                 if (*RExC_parse == ':') {
2406                     RExC_parse++;
2407                     paren = ':';
2408                     break;
2409                 }
2410               unknown:
2411                 if (*RExC_parse != ')') {
2412                     RExC_parse++;
2413                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2414                 }
2415                 nextchar(pRExC_state);
2416                 *flagp = TRYAGAIN;
2417                 return NULL;
2418             }
2419         }
2420         else {                  /* (...) */
2421             parno = RExC_npar;
2422             RExC_npar++;
2423             ret = reganode(pRExC_state, OPEN, parno);
2424             Set_Node_Length(ret, 1); /* MJD */
2425             Set_Node_Offset(ret, RExC_parse); /* MJD */
2426             open = 1;
2427         }
2428     }
2429     else                        /* ! paren */
2430         ret = NULL;
2431
2432     /* Pick up the branches, linking them together. */
2433     parse_start = RExC_parse;   /* MJD */
2434     br = regbranch(pRExC_state, &flags, 1);
2435     /*     branch_len = (paren != 0); */
2436
2437     if (br == NULL)
2438         return(NULL);
2439     if (*RExC_parse == '|') {
2440         if (!SIZE_ONLY && RExC_extralen) {
2441             reginsert(pRExC_state, BRANCHJ, br);
2442         }
2443         else {                  /* MJD */
2444             reginsert(pRExC_state, BRANCH, br);
2445             Set_Node_Length(br, paren != 0);
2446             Set_Node_Offset_To_R(br-RExC_emit_start, parse_start-RExC_start);
2447         }
2448         have_branch = 1;
2449         if (SIZE_ONLY)
2450             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2451     }
2452     else if (paren == ':') {
2453         *flagp |= flags&SIMPLE;
2454     }
2455     if (open) {                         /* Starts with OPEN. */
2456         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2457     }
2458     else if (paren != '?')              /* Not Conditional */
2459         ret = br;
2460     *flagp |= flags & (SPSTART | HASWIDTH);
2461     lastbr = br;
2462     while (*RExC_parse == '|') {
2463         if (!SIZE_ONLY && RExC_extralen) {
2464             ender = reganode(pRExC_state, LONGJMP,0);
2465             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2466         }
2467         if (SIZE_ONLY)
2468             RExC_extralen += 2;         /* Account for LONGJMP. */
2469         nextchar(pRExC_state);
2470         br = regbranch(pRExC_state, &flags, 0);
2471
2472         if (br == NULL)
2473             return(NULL);
2474         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2475         lastbr = br;
2476         if (flags&HASWIDTH)
2477             *flagp |= HASWIDTH;
2478         *flagp |= flags&SPSTART;
2479     }
2480
2481     if (have_branch || paren != ':') {
2482         /* Make a closing node, and hook it on the end. */
2483         switch (paren) {
2484         case ':':
2485             ender = reg_node(pRExC_state, TAIL);
2486             break;
2487         case 1:
2488             ender = reganode(pRExC_state, CLOSE, parno);
2489             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
2490             Set_Node_Length(ender,1); /* MJD */
2491             break;
2492         case '<':
2493         case ',':
2494         case '=':
2495         case '!':
2496             *flagp &= ~HASWIDTH;
2497             /* FALL THROUGH */
2498         case '>':
2499             ender = reg_node(pRExC_state, SUCCEED);
2500             break;
2501         case 0:
2502             ender = reg_node(pRExC_state, END);
2503             break;
2504         }
2505         regtail(pRExC_state, lastbr, ender);
2506
2507         if (have_branch) {
2508             /* Hook the tails of the branches to the closing node. */
2509             for (br = ret; br != NULL; br = regnext(br)) {
2510                 regoptail(pRExC_state, br, ender);
2511             }
2512         }
2513     }
2514
2515     {
2516         char *p;
2517         static char parens[] = "=!<,>";
2518
2519         if (paren && (p = strchr(parens, paren))) {
2520             U8 node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2521             int flag = (p - parens) > 1;
2522
2523             if (paren == '>')
2524                 node = SUSPEND, flag = 0;
2525             reginsert(pRExC_state, node,ret);
2526             Set_Node_Cur_Length(ret);
2527             Set_Node_Offset(ret, parse_start + 1);
2528             ret->flags = flag;
2529             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2530         }
2531     }
2532
2533     /* Check for proper termination. */
2534     if (paren) {
2535         RExC_flags = oregflags;
2536         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2537             RExC_parse = oregcomp_parse;
2538             vFAIL("Unmatched (");
2539         }
2540     }
2541     else if (!paren && RExC_parse < RExC_end) {
2542         if (*RExC_parse == ')') {
2543             RExC_parse++;
2544             vFAIL("Unmatched )");
2545         }
2546         else
2547             FAIL("Junk on end of regexp");      /* "Can't happen". */
2548         /* NOTREACHED */
2549     }
2550
2551     return(ret);
2552 }
2553
2554 /*
2555  - regbranch - one alternative of an | operator
2556  *
2557  * Implements the concatenation operator.
2558  */
2559 STATIC regnode *
2560 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2561 {
2562     register regnode *ret;
2563     register regnode *chain = NULL;
2564     register regnode *latest;
2565     I32 flags = 0, c = 0;
2566
2567     if (first)
2568         ret = NULL;
2569     else {
2570         if (!SIZE_ONLY && RExC_extralen)
2571             ret = reganode(pRExC_state, BRANCHJ,0);
2572         else {
2573             ret = reg_node(pRExC_state, BRANCH);
2574             Set_Node_Length(ret, 1);
2575         }
2576     }
2577
2578     if (!first && SIZE_ONLY)
2579         RExC_extralen += 1;                     /* BRANCHJ */
2580
2581     *flagp = WORST;                     /* Tentatively. */
2582
2583     RExC_parse--;
2584     nextchar(pRExC_state);
2585     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2586         flags &= ~TRYAGAIN;
2587         latest = regpiece(pRExC_state, &flags);
2588         if (latest == NULL) {
2589             if (flags & TRYAGAIN)
2590                 continue;
2591             return(NULL);
2592         }
2593         else if (ret == NULL)
2594             ret = latest;
2595         *flagp |= flags&HASWIDTH;
2596         if (chain == NULL)      /* First piece. */
2597             *flagp |= flags&SPSTART;
2598         else {
2599             RExC_naughty++;
2600             regtail(pRExC_state, chain, latest);
2601         }
2602         chain = latest;
2603         c++;
2604     }
2605     if (chain == NULL) {        /* Loop ran zero times. */
2606         chain = reg_node(pRExC_state, NOTHING);
2607         if (ret == NULL)
2608             ret = chain;
2609     }
2610     if (c == 1) {
2611         *flagp |= flags&SIMPLE;
2612     }
2613
2614     return(ret);
2615 }
2616
2617 /*
2618  - regpiece - something followed by possible [*+?]
2619  *
2620  * Note that the branching code sequences used for ? and the general cases
2621  * of * and + are somewhat optimized:  they use the same NOTHING node as
2622  * both the endmarker for their branch list and the body of the last branch.
2623  * It might seem that this node could be dispensed with entirely, but the
2624  * endmarker role is not redundant.
2625  */
2626 STATIC regnode *
2627 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2628 {
2629     register regnode *ret;
2630     register char op;
2631     register char *next;
2632     I32 flags;
2633     char *origparse = RExC_parse;
2634     char *maxpos;
2635     I32 min;
2636     I32 max = REG_INFTY;
2637     char *parse_start;
2638
2639     ret = regatom(pRExC_state, &flags);
2640     if (ret == NULL) {
2641         if (flags & TRYAGAIN)
2642             *flagp |= TRYAGAIN;
2643         return(NULL);
2644     }
2645
2646     op = *RExC_parse;
2647
2648     if (op == '{' && regcurly(RExC_parse)) {
2649         parse_start = RExC_parse; /* MJD */
2650         next = RExC_parse + 1;
2651         maxpos = Nullch;
2652         while (isDIGIT(*next) || *next == ',') {
2653             if (*next == ',') {
2654                 if (maxpos)
2655                     break;
2656                 else
2657                     maxpos = next;
2658             }
2659             next++;
2660         }
2661         if (*next == '}') {             /* got one */
2662             if (!maxpos)
2663                 maxpos = next;
2664             RExC_parse++;
2665             min = atoi(RExC_parse);
2666             if (*maxpos == ',')
2667                 maxpos++;
2668             else
2669                 maxpos = RExC_parse;
2670             max = atoi(maxpos);
2671             if (!max && *maxpos != '0')
2672                 max = REG_INFTY;                /* meaning "infinity" */
2673             else if (max >= REG_INFTY)
2674                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2675             RExC_parse = next;
2676             nextchar(pRExC_state);
2677
2678         do_curly:
2679             if ((flags&SIMPLE)) {
2680                 RExC_naughty += 2 + RExC_naughty / 2;
2681                 reginsert(pRExC_state, CURLY, ret);
2682                 Set_Node_Offset(ret, parse_start+1); /* MJD */
2683                 Set_Node_Cur_Length(ret);
2684             }
2685             else {
2686                 regnode *w = reg_node(pRExC_state, WHILEM);
2687
2688                 w->flags = 0;
2689                 regtail(pRExC_state, ret, w);
2690                 if (!SIZE_ONLY && RExC_extralen) {
2691                     reginsert(pRExC_state, LONGJMP,ret);
2692                     reginsert(pRExC_state, NOTHING,ret);
2693                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2694                 }
2695                 reginsert(pRExC_state, CURLYX,ret);
2696                                 /* MJD hk */
2697                 Set_Node_Offset(ret, parse_start+1);
2698                 Set_Node_Length(ret,
2699                                 op == '{' ? (RExC_parse - parse_start) : 1);
2700
2701                 if (!SIZE_ONLY && RExC_extralen)
2702                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2703                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2704                 if (SIZE_ONLY)
2705                     RExC_whilem_seen++, RExC_extralen += 3;
2706                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2707             }
2708             ret->flags = 0;
2709
2710             if (min > 0)
2711                 *flagp = WORST;
2712             if (max > 0)
2713                 *flagp |= HASWIDTH;
2714             if (max && max < min)
2715                 vFAIL("Can't do {n,m} with n > m");
2716             if (!SIZE_ONLY) {
2717                 ARG1_SET(ret, (U16)min);
2718                 ARG2_SET(ret, (U16)max);
2719             }
2720
2721             goto nest_check;
2722         }
2723     }
2724
2725     if (!ISMULT1(op)) {
2726         *flagp = flags;
2727         return(ret);
2728     }
2729
2730 #if 0                           /* Now runtime fix should be reliable. */
2731
2732     /* if this is reinstated, don't forget to put this back into perldiag:
2733
2734             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2735
2736            (F) The part of the regexp subject to either the * or + quantifier
2737            could match an empty string. The {#} shows in the regular
2738            expression about where the problem was discovered.
2739
2740     */
2741
2742     if (!(flags&HASWIDTH) && op != '?')
2743       vFAIL("Regexp *+ operand could be empty");
2744 #endif
2745
2746     parse_start = RExC_parse;
2747     nextchar(pRExC_state);
2748
2749     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2750
2751     if (op == '*' && (flags&SIMPLE)) {
2752         reginsert(pRExC_state, STAR, ret);
2753         ret->flags = 0;
2754         RExC_naughty += 4;
2755     }
2756     else if (op == '*') {
2757         min = 0;
2758         goto do_curly;
2759     }
2760     else if (op == '+' && (flags&SIMPLE)) {
2761         reginsert(pRExC_state, PLUS, ret);
2762         ret->flags = 0;
2763         RExC_naughty += 3;
2764     }
2765     else if (op == '+') {
2766         min = 1;
2767         goto do_curly;
2768     }
2769     else if (op == '?') {
2770         min = 0; max = 1;
2771         goto do_curly;
2772     }
2773   nest_check:
2774     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2775         vWARN3(RExC_parse,
2776                "%.*s matches null string many times",
2777                RExC_parse - origparse,
2778                origparse);
2779     }
2780
2781     if (*RExC_parse == '?') {
2782         nextchar(pRExC_state);
2783         reginsert(pRExC_state, MINMOD, ret);
2784         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2785     }
2786     if (ISMULT2(RExC_parse)) {
2787         RExC_parse++;
2788         vFAIL("Nested quantifiers");
2789     }
2790
2791     return(ret);
2792 }
2793
2794 /*
2795  - regatom - the lowest level
2796  *
2797  * Optimization:  gobbles an entire sequence of ordinary characters so that
2798  * it can turn them into a single node, which is smaller to store and
2799  * faster to run.  Backslashed characters are exceptions, each becoming a
2800  * separate node; the code is simpler that way and it's not worth fixing.
2801  *
2802  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2803 STATIC regnode *
2804 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2805 {
2806     register regnode *ret = 0;
2807     I32 flags;
2808     char *parse_start = RExC_parse;
2809
2810     *flagp = WORST;             /* Tentatively. */
2811
2812 tryagain:
2813     switch (*RExC_parse) {
2814     case '^':
2815         RExC_seen_zerolen++;
2816         nextchar(pRExC_state);
2817         if (RExC_flags & PMf_MULTILINE)
2818             ret = reg_node(pRExC_state, MBOL);
2819         else if (RExC_flags & PMf_SINGLELINE)
2820             ret = reg_node(pRExC_state, SBOL);
2821         else
2822             ret = reg_node(pRExC_state, BOL);
2823         Set_Node_Length(ret, 1); /* MJD */
2824         break;
2825     case '$':
2826         nextchar(pRExC_state);
2827         if (*RExC_parse)
2828             RExC_seen_zerolen++;
2829         if (RExC_flags & PMf_MULTILINE)
2830             ret = reg_node(pRExC_state, MEOL);
2831         else if (RExC_flags & PMf_SINGLELINE)
2832             ret = reg_node(pRExC_state, SEOL);
2833         else
2834             ret = reg_node(pRExC_state, EOL);
2835         Set_Node_Length(ret, 1); /* MJD */
2836         break;
2837     case '.':
2838         nextchar(pRExC_state);
2839         if (RExC_flags & PMf_SINGLELINE)
2840             ret = reg_node(pRExC_state, SANY);
2841         else
2842             ret = reg_node(pRExC_state, REG_ANY);
2843         *flagp |= HASWIDTH|SIMPLE;
2844         RExC_naughty++;
2845         Set_Node_Length(ret, 1); /* MJD */
2846         break;
2847     case '[':
2848     {
2849         char *oregcomp_parse = ++RExC_parse;
2850         ret = regclass(pRExC_state);
2851         if (*RExC_parse != ']') {
2852             RExC_parse = oregcomp_parse;
2853             vFAIL("Unmatched [");
2854         }
2855         nextchar(pRExC_state);
2856         *flagp |= HASWIDTH|SIMPLE;
2857         Set_Node_Length(ret, RExC_parse - oregcomp_parse + 1); /* MJD */
2858         break;
2859     }
2860     case '(':
2861         nextchar(pRExC_state);
2862         ret = reg(pRExC_state, 1, &flags);
2863         if (ret == NULL) {
2864                 if (flags & TRYAGAIN) {
2865                     if (RExC_parse == RExC_end) {
2866                          /* Make parent create an empty node if needed. */
2867                         *flagp |= TRYAGAIN;
2868                         return(NULL);
2869                     }
2870                     goto tryagain;
2871                 }
2872                 return(NULL);
2873         }
2874         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2875         break;
2876     case '|':
2877     case ')':
2878         if (flags & TRYAGAIN) {
2879             *flagp |= TRYAGAIN;
2880             return NULL;
2881         }
2882         vFAIL("Internal urp");
2883                                 /* Supposed to be caught earlier. */
2884         break;
2885     case '{':
2886         if (!regcurly(RExC_parse)) {
2887             RExC_parse++;
2888             goto defchar;
2889         }
2890         /* FALL THROUGH */
2891     case '?':
2892     case '+':
2893     case '*':
2894         RExC_parse++;
2895         vFAIL("Quantifier follows nothing");
2896         break;
2897     case '\\':
2898         switch (*++RExC_parse) {
2899         case 'A':
2900             RExC_seen_zerolen++;
2901             ret = reg_node(pRExC_state, SBOL);
2902             *flagp |= SIMPLE;
2903             nextchar(pRExC_state);
2904             Set_Node_Length(ret, 2); /* MJD */
2905             break;
2906         case 'G':
2907             ret = reg_node(pRExC_state, GPOS);
2908             RExC_seen |= REG_SEEN_GPOS;
2909             *flagp |= SIMPLE;
2910             nextchar(pRExC_state);
2911             Set_Node_Length(ret, 2); /* MJD */
2912             break;
2913         case 'Z':
2914             ret = reg_node(pRExC_state, SEOL);
2915             *flagp |= SIMPLE;
2916             RExC_seen_zerolen++;                /* Do not optimize RE away */
2917             nextchar(pRExC_state);
2918             break;
2919         case 'z':
2920             ret = reg_node(pRExC_state, EOS);
2921             *flagp |= SIMPLE;
2922             RExC_seen_zerolen++;                /* Do not optimize RE away */
2923             nextchar(pRExC_state);
2924             Set_Node_Length(ret, 2); /* MJD */
2925             break;
2926         case 'C':
2927             ret = reg_node(pRExC_state, CANY);
2928             RExC_seen |= REG_SEEN_CANY;
2929             *flagp |= HASWIDTH|SIMPLE;
2930             nextchar(pRExC_state);
2931             Set_Node_Length(ret, 2); /* MJD */
2932             break;
2933         case 'X':
2934             ret = reg_node(pRExC_state, CLUMP);
2935             *flagp |= HASWIDTH;
2936             nextchar(pRExC_state);
2937             Set_Node_Length(ret, 2); /* MJD */
2938             break;
2939         case 'w':
2940             ret = reg_node(pRExC_state, (U8)(LOC ? ALNUML     : ALNUM));
2941             *flagp |= HASWIDTH|SIMPLE;
2942             nextchar(pRExC_state);
2943             Set_Node_Length(ret, 2); /* MJD */
2944             break;
2945         case 'W':
2946             ret = reg_node(pRExC_state, (U8)(LOC ? NALNUML    : NALNUM));
2947             *flagp |= HASWIDTH|SIMPLE;
2948             nextchar(pRExC_state);
2949             Set_Node_Length(ret, 2); /* MJD */
2950             break;
2951         case 'b':
2952             RExC_seen_zerolen++;
2953             RExC_seen |= REG_SEEN_LOOKBEHIND;
2954             ret = reg_node(pRExC_state, (U8)(LOC ? BOUNDL     : BOUND));
2955             *flagp |= SIMPLE;
2956             nextchar(pRExC_state);
2957             Set_Node_Length(ret, 2); /* MJD */
2958             break;
2959         case 'B':
2960             RExC_seen_zerolen++;
2961             RExC_seen |= REG_SEEN_LOOKBEHIND;
2962             ret = reg_node(pRExC_state, (U8)(LOC ? NBOUNDL    : NBOUND));
2963             *flagp |= SIMPLE;
2964             nextchar(pRExC_state);
2965             Set_Node_Length(ret, 2); /* MJD */
2966             break;
2967         case 's':
2968             ret = reg_node(pRExC_state, (U8)(LOC ? SPACEL     : SPACE));
2969             *flagp |= HASWIDTH|SIMPLE;
2970             nextchar(pRExC_state);
2971             Set_Node_Length(ret, 2); /* MJD */
2972             break;
2973         case 'S':
2974             ret = reg_node(pRExC_state, (U8)(LOC ? NSPACEL    : NSPACE));
2975             *flagp |= HASWIDTH|SIMPLE;
2976             nextchar(pRExC_state);
2977             Set_Node_Length(ret, 2); /* MJD */
2978             break;
2979         case 'd':
2980             ret = reg_node(pRExC_state, DIGIT);
2981             *flagp |= HASWIDTH|SIMPLE;
2982             nextchar(pRExC_state);
2983             Set_Node_Length(ret, 2); /* MJD */
2984             break;
2985         case 'D':
2986             ret = reg_node(pRExC_state, NDIGIT);
2987             *flagp |= HASWIDTH|SIMPLE;
2988             nextchar(pRExC_state);
2989             Set_Node_Length(ret, 2); /* MJD */
2990             break;
2991         case 'p':
2992         case 'P':
2993             {
2994                 char* oldregxend = RExC_end;
2995                 char* parse_start = RExC_parse - 2;
2996
2997                 if (RExC_parse[1] == '{') {
2998                   /* a lovely hack--pretend we saw [\pX] instead */
2999                     RExC_end = strchr(RExC_parse, '}');
3000                     if (!RExC_end) {
3001                         U8 c = (U8)*RExC_parse;
3002                         RExC_parse += 2;
3003                         RExC_end = oldregxend;
3004                         vFAIL2("Missing right brace on \\%c{}", c);
3005                     }
3006                     RExC_end++;
3007                 }
3008                 else {
3009                     RExC_end = RExC_parse + 2;
3010                     if (RExC_end > oldregxend)
3011                         RExC_end = oldregxend;
3012                 }
3013                 RExC_parse--;
3014
3015                 ret = regclass(pRExC_state);
3016
3017                 RExC_end = oldregxend;
3018                 RExC_parse--;
3019
3020                 Set_Node_Offset(ret, parse_start + 2);
3021                 Set_Node_Cur_Length(ret);
3022                 nextchar(pRExC_state);
3023                 *flagp |= HASWIDTH|SIMPLE;
3024             }
3025             break;
3026         case 'n':
3027         case 'r':
3028         case 't':
3029         case 'f':
3030         case 'e':
3031         case 'a':
3032         case 'x':
3033         case 'c':
3034         case '0':
3035             goto defchar;
3036         case '1': case '2': case '3': case '4':
3037         case '5': case '6': case '7': case '8': case '9':
3038             {
3039                 I32 num = atoi(RExC_parse);
3040
3041                 if (num > 9 && num >= RExC_npar)
3042                     goto defchar;
3043                 else {
3044                     char * parse_start = RExC_parse - 1; /* MJD */
3045                     while (isDIGIT(*RExC_parse))
3046                         RExC_parse++;
3047
3048                     if (!SIZE_ONLY && num > (I32)RExC_rx->nparens)
3049                         vFAIL("Reference to nonexistent group");
3050                     RExC_sawback = 1;
3051                     ret = reganode(pRExC_state,
3052                                    (U8)(FOLD ? (LOC ? REFFL : REFF) : REF),
3053                                    num);
3054                     *flagp |= HASWIDTH;
3055
3056                     /* override incorrect value set in reganode MJD */
3057                     Set_Node_Offset(ret, parse_start+1);
3058                     Set_Node_Cur_Length(ret); /* MJD */
3059                     RExC_parse--;
3060                     nextchar(pRExC_state);
3061                 }
3062             }
3063             break;
3064         case '\0':
3065             if (RExC_parse >= RExC_end)
3066                 FAIL("Trailing \\");
3067             /* FALL THROUGH */
3068         default:
3069             /* Do not generate `unrecognized' warnings here, we fall
3070                back into the quick-grab loop below */
3071             parse_start--;
3072             goto defchar;
3073         }
3074         break;
3075
3076     case '#':
3077         if (RExC_flags & PMf_EXTENDED) {
3078             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
3079             if (RExC_parse < RExC_end)
3080                 goto tryagain;
3081         }
3082         /* FALL THROUGH */
3083
3084     default: {
3085             register STRLEN len;
3086             register UV ender;
3087             register char *p;
3088             char *oldp, *s;
3089             STRLEN numlen;
3090             STRLEN foldlen;
3091             U8 tmpbuf[UTF8_MAXLEN_FOLD+1], *foldbuf;
3092
3093             parse_start = RExC_parse - 1;
3094
3095             RExC_parse++;
3096
3097         defchar:
3098             ender = 0;
3099             ret = reg_node(pRExC_state,
3100                            (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
3101             s = STRING(ret);
3102             for (len = 0, p = RExC_parse - 1;
3103               len < 127 && p < RExC_end;
3104               len++)
3105             {
3106                 oldp = p;
3107
3108                 if (RExC_flags & PMf_EXTENDED)
3109                     p = regwhite(p, RExC_end);
3110                 switch (*p) {
3111                 case '^':
3112                 case '$':
3113                 case '.':
3114                 case '[':
3115                 case '(':
3116                 case ')':
3117                 case '|':
3118                     goto loopdone;
3119                 case '\\':
3120                     switch (*++p) {
3121                     case 'A':
3122                     case 'C':
3123                     case 'X':
3124                     case 'G':
3125                     case 'Z':
3126                     case 'z':
3127                     case 'w':
3128                     case 'W':
3129                     case 'b':
3130                     case 'B':
3131                     case 's':
3132                     case 'S':
3133                     case 'd':
3134                     case 'D':
3135                     case 'p':
3136                     case 'P':
3137                         --p;
3138                         goto loopdone;
3139                     case 'n':
3140                         ender = '\n';
3141                         p++;
3142                         break;
3143                     case 'r':
3144                         ender = '\r';
3145                         p++;
3146                         break;
3147                     case 't':
3148                         ender = '\t';
3149                         p++;
3150                         break;
3151                     case 'f':
3152                         ender = '\f';
3153                         p++;
3154                         break;
3155                     case 'e':
3156                           ender = ASCII_TO_NATIVE('\033');
3157                         p++;
3158                         break;
3159                     case 'a':
3160                           ender = ASCII_TO_NATIVE('\007');
3161                         p++;
3162                         break;
3163                     case 'x':
3164                         if (*++p == '{') {
3165                             char* e = strchr(p, '}');
3166
3167                             if (!e) {
3168                                 RExC_parse = p + 1;
3169                                 vFAIL("Missing right brace on \\x{}");
3170                             }
3171                             else {
3172                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3173                                     | PERL_SCAN_DISALLOW_PREFIX;
3174                                 numlen = e - p - 1;
3175                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3176                                 if (ender > 0xff)
3177                                     RExC_utf8 = 1;
3178                                 p = e + 1;
3179                             }
3180                         }
3181                         else {
3182                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3183                             numlen = 2;
3184                             ender = grok_hex(p, &numlen, &flags, NULL);
3185                             p += numlen;
3186                         }
3187                         break;
3188                     case 'c':
3189                         p++;
3190                         ender = UCHARAT(p++);
3191                         ender = toCTRL(ender);
3192                         break;
3193                     case '0': case '1': case '2': case '3':case '4':
3194                     case '5': case '6': case '7': case '8':case '9':
3195                         if (*p == '0' ||
3196                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3197                             I32 flags = 0;
3198                             numlen = 3;
3199                             ender = grok_oct(p, &numlen, &flags, NULL);
3200                             p += numlen;
3201                         }
3202                         else {
3203                             --p;
3204                             goto loopdone;
3205                         }
3206                         break;
3207                     case '\0':
3208                         if (p >= RExC_end)
3209                             FAIL("Trailing \\");
3210                         /* FALL THROUGH */
3211                     default:
3212                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3213                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3214                         goto normal_default;
3215                     }
3216                     break;
3217                 default:
3218                   normal_default:
3219                     if (UTF8_IS_START(*p) && UTF) {
3220                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3221                                                &numlen, 0);
3222                         p += numlen;
3223                     }
3224                     else
3225                         ender = *p++;
3226                     break;
3227                 }
3228                 if (RExC_flags & PMf_EXTENDED)
3229                     p = regwhite(p, RExC_end);
3230                 if (UTF && FOLD) {
3231                     /* Prime the casefolded buffer. */
3232                     ender = toFOLD_uni(ender, tmpbuf, &foldlen);
3233                 }
3234                 if (ISMULT2(p)) { /* Back off on ?+*. */
3235                     if (len)
3236                         p = oldp;
3237                     else if (UTF) {
3238                          STRLEN unilen;
3239
3240                          if (FOLD) {
3241                               /* Emit all the Unicode characters. */
3242                               for (foldbuf = tmpbuf;
3243                                    foldlen;
3244                                    foldlen -= numlen) {
3245                                    ender = utf8_to_uvchr(foldbuf, &numlen);
3246                                    if (numlen > 0) {
3247                                         reguni(pRExC_state, ender, s, &unilen);
3248                                         s       += unilen;
3249                                         len     += unilen;
3250                                         /* In EBCDIC the numlen
3251                                          * and unilen can differ. */
3252                                         foldbuf += numlen;
3253                                         if (numlen >= foldlen)
3254                                              break;
3255                                    }
3256                                    else
3257                                         break; /* "Can't happen." */
3258                               }
3259                          }
3260                          else {
3261                               reguni(pRExC_state, ender, s, &unilen);
3262                               if (unilen > 0) {
3263                                    s   += unilen;
3264                                    len += unilen;
3265                               }
3266                          }
3267                     }
3268                     else {
3269                         len++;
3270                         REGC((char)ender, s++);
3271                     }
3272                     break;
3273                 }
3274                 if (UTF) {
3275                      STRLEN unilen;
3276
3277                      if (FOLD) {
3278                           /* Emit all the Unicode characters. */
3279                           for (foldbuf = tmpbuf;
3280                                foldlen;
3281                                foldlen -= numlen) {
3282                                ender = utf8_to_uvchr(foldbuf, &numlen);
3283                                if (numlen > 0) {
3284                                     reguni(pRExC_state, ender, s, &unilen);
3285                                     len     += unilen;
3286                                     s       += unilen;
3287                                     /* In EBCDIC the numlen
3288                                      * and unilen can differ. */
3289                                     foldbuf += numlen;
3290                                     if (numlen >= foldlen)
3291                                          break;
3292                                }
3293                                else
3294                                     break;
3295                           }
3296                      }
3297                      else {
3298                           reguni(pRExC_state, ender, s, &unilen);
3299                           if (unilen > 0) {
3300                                s   += unilen;
3301                                len += unilen;
3302                           }
3303                      }
3304                      len--;
3305                 }
3306                 else
3307                     REGC((char)ender, s++);
3308             }
3309         loopdone:
3310             RExC_parse = p - 1;
3311             Set_Node_Cur_Length(ret); /* MJD */
3312             nextchar(pRExC_state);
3313             {
3314                 /* len is STRLEN which is unsigned, need to copy to signed */
3315                 IV iv = len;
3316                 if (iv < 0)
3317                     vFAIL("Internal disaster");
3318             }
3319             if (len > 0)
3320                 *flagp |= HASWIDTH;
3321             if (len == 1 && UNI_IS_INVARIANT(ender))
3322                 *flagp |= SIMPLE;
3323             if (!SIZE_ONLY)
3324                 STR_LEN(ret) = len;
3325             if (SIZE_ONLY)
3326                 RExC_size += STR_SZ(len);
3327             else
3328                 RExC_emit += STR_SZ(len);
3329         }
3330         break;
3331     }
3332
3333     /* If the encoding pragma is in effect recode the text of
3334      * any EXACT-kind nodes. */
3335     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3336         STRLEN oldlen = STR_LEN(ret);
3337         SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3338
3339         if (RExC_utf8)
3340             SvUTF8_on(sv);
3341         if (sv_utf8_downgrade(sv, TRUE)) {
3342             char *s       = sv_recode_to_utf8(sv, PL_encoding);
3343             STRLEN newlen = SvCUR(sv);
3344
3345             if (SvUTF8(sv))
3346                 RExC_utf8 = 1;
3347             if (!SIZE_ONLY) {
3348                 DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3349                                       (int)oldlen, STRING(ret),
3350                                       (int)newlen, s));
3351                 Copy(s, STRING(ret), newlen, char);
3352                 STR_LEN(ret) += newlen - oldlen;
3353                 RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3354             } else
3355                 RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3356         }
3357     }
3358
3359     return(ret);
3360 }
3361
3362 STATIC char *
3363 S_regwhite(pTHX_ char *p, char *e)
3364 {
3365     while (p < e) {
3366         if (isSPACE(*p))
3367             ++p;
3368         else if (*p == '#') {
3369             do {
3370                 p++;
3371             } while (p < e && *p != '\n');
3372         }
3373         else
3374             break;
3375     }
3376     return p;
3377 }
3378
3379 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3380    Character classes ([:foo:]) can also be negated ([:^foo:]).
3381    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3382    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3383    but trigger failures because they are currently unimplemented. */
3384
3385 #define POSIXCC_DONE(c)   ((c) == ':')
3386 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3387 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3388
3389 STATIC I32
3390 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3391 {
3392     char *posixcc = 0;
3393     I32 namedclass = OOB_NAMEDCLASS;
3394
3395     if (value == '[' && RExC_parse + 1 < RExC_end &&
3396         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3397         POSIXCC(UCHARAT(RExC_parse))) {
3398         char  c = UCHARAT(RExC_parse);
3399         char* s = RExC_parse++;
3400
3401         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3402             RExC_parse++;
3403         if (RExC_parse == RExC_end)
3404             /* Grandfather lone [:, [=, [. */
3405             RExC_parse = s;
3406         else {
3407             char* t = RExC_parse++; /* skip over the c */
3408
3409             if (UCHARAT(RExC_parse) == ']') {
3410                 RExC_parse++; /* skip over the ending ] */
3411                 posixcc = s + 1;
3412                 if (*s == ':') {
3413                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3414                     I32 skip = 5; /* the most common skip */
3415
3416                     switch (*posixcc) {
3417                     case 'a':
3418                         if (strnEQ(posixcc, "alnum", 5))
3419                             namedclass =
3420                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3421                         else if (strnEQ(posixcc, "alpha", 5))
3422                             namedclass =
3423                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3424                         else if (strnEQ(posixcc, "ascii", 5))
3425                             namedclass =
3426                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3427                         break;
3428                     case 'b':
3429                         if (strnEQ(posixcc, "blank", 5))
3430                             namedclass =
3431                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3432                         break;
3433                     case 'c':
3434                         if (strnEQ(posixcc, "cntrl", 5))
3435                             namedclass =
3436                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3437                         break;
3438                     case 'd':
3439                         if (strnEQ(posixcc, "digit", 5))
3440                             namedclass =
3441                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3442                         break;
3443                     case 'g':
3444                         if (strnEQ(posixcc, "graph", 5))
3445                             namedclass =
3446                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3447                         break;
3448                     case 'l':
3449                         if (strnEQ(posixcc, "lower", 5))
3450                             namedclass =
3451                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3452                         break;
3453                     case 'p':
3454                         if (strnEQ(posixcc, "print", 5))
3455                             namedclass =
3456                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3457                         else if (strnEQ(posixcc, "punct", 5))
3458                             namedclass =
3459                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3460                         break;
3461                     case 's':
3462                         if (strnEQ(posixcc, "space", 5))
3463                             namedclass =
3464                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3465                         break;
3466                     case 'u':
3467                         if (strnEQ(posixcc, "upper", 5))
3468                             namedclass =
3469                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3470                         break;
3471                     case 'w': /* this is not POSIX, this is the Perl \w */
3472                         if (strnEQ(posixcc, "word", 4)) {
3473                             namedclass =
3474                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3475                             skip = 4;
3476                         }
3477                         break;
3478                     case 'x':
3479                         if (strnEQ(posixcc, "xdigit", 6)) {
3480                             namedclass =
3481                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3482                             skip = 6;
3483                         }
3484                         break;
3485                     }
3486                     if (namedclass == OOB_NAMEDCLASS ||
3487                         posixcc[skip] != ':' ||
3488                         posixcc[skip+1] != ']')
3489                     {
3490                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3491                                       t - s - 1, s + 1);
3492                     }
3493                 } else if (!SIZE_ONLY) {
3494                     /* [[=foo=]] and [[.foo.]] are still future. */
3495
3496                     /* adjust RExC_parse so the warning shows after
3497                        the class closes */
3498                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3499                         RExC_parse++;
3500                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3501                 }
3502             } else {
3503                 /* Maternal grandfather:
3504                  * "[:" ending in ":" but not in ":]" */
3505                 RExC_parse = s;
3506             }
3507         }
3508     }
3509
3510     return namedclass;
3511 }
3512
3513 STATIC void
3514 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3515 {
3516     if (!SIZE_ONLY && POSIXCC(UCHARAT(RExC_parse))) {
3517         char *s = RExC_parse;
3518         char  c = *s++;
3519
3520         while(*s && isALNUM(*s))
3521             s++;
3522         if (*s && c == *s && s[1] == ']') {
3523             if (ckWARN(WARN_REGEXP))
3524                 vWARN3(s+2,
3525                         "POSIX syntax [%c %c] belongs inside character classes",
3526                         c, c);
3527
3528             /* [[=foo=]] and [[.foo.]] are still future. */
3529             if (POSIXCC_NOTYET(c)) {
3530                 /* adjust RExC_parse so the error shows after
3531                    the class closes */
3532                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3533                     ;
3534                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3535             }
3536         }
3537     }
3538 }
3539
3540 STATIC regnode *
3541 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3542 {
3543     register UV value;
3544     register UV nextvalue;
3545     register IV prevvalue = OOB_UNICODE;
3546     register IV range = 0;
3547     register regnode *ret;
3548     STRLEN numlen;
3549     IV namedclass;
3550     char *rangebegin = 0;
3551     bool need_class = 0;
3552     SV *listsv = Nullsv;
3553     register char *e;
3554     UV n;
3555     bool optimize_invert   = TRUE;
3556     AV* unicode_alternate  = 0;
3557 #ifdef EBCDIC
3558     UV literal_endpoint = 0;
3559 #endif
3560
3561     ret = reganode(pRExC_state, ANYOF, 0);
3562
3563     if (!SIZE_ONLY)
3564         ANYOF_FLAGS(ret) = 0;
3565
3566     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3567         RExC_naughty++;
3568         RExC_parse++;
3569         if (!SIZE_ONLY)
3570             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3571     }
3572
3573     if (SIZE_ONLY)
3574         RExC_size += ANYOF_SKIP;
3575     else {
3576         RExC_emit += ANYOF_SKIP;
3577         if (FOLD)
3578             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3579         if (LOC)
3580             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3581         ANYOF_BITMAP_ZERO(ret);
3582         listsv = newSVpvn("# comment\n", 10);
3583     }
3584
3585     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3586
3587     if (!SIZE_ONLY && POSIXCC(nextvalue))
3588         checkposixcc(pRExC_state);
3589
3590     /* allow 1st char to be ] (allowing it to be - is dealt with later) */
3591     if (UCHARAT(RExC_parse) == ']')
3592         goto charclassloop;
3593
3594     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3595
3596     charclassloop:
3597
3598         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3599
3600         if (!range)
3601             rangebegin = RExC_parse;
3602         if (UTF) {
3603             value = utf8n_to_uvchr((U8*)RExC_parse,
3604                                    RExC_end - RExC_parse,
3605                                    &numlen, 0);
3606             RExC_parse += numlen;
3607         }
3608         else
3609             value = UCHARAT(RExC_parse++);
3610         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3611         if (value == '[' && POSIXCC(nextvalue))
3612             namedclass = regpposixcc(pRExC_state, value);
3613         else if (value == '\\') {
3614             if (UTF) {
3615                 value = utf8n_to_uvchr((U8*)RExC_parse,
3616                                    RExC_end - RExC_parse,
3617                                    &numlen, 0);
3618                 RExC_parse += numlen;
3619             }
3620             else
3621                 value = UCHARAT(RExC_parse++);
3622             /* Some compilers cannot handle switching on 64-bit integer
3623              * values, therefore value cannot be an UV.  Yes, this will
3624              * be a problem later if we want switch on Unicode.
3625              * A similar issue a little bit later when switching on
3626              * namedclass. --jhi */
3627             switch ((I32)value) {
3628             case 'w':   namedclass = ANYOF_ALNUM;       break;
3629             case 'W':   namedclass = ANYOF_NALNUM;      break;
3630             case 's':   namedclass = ANYOF_SPACE;       break;
3631             case 'S':   namedclass = ANYOF_NSPACE;      break;
3632             case 'd':   namedclass = ANYOF_DIGIT;       break;
3633             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3634             case 'p':
3635             case 'P':
3636                 if (RExC_parse >= RExC_end)
3637                     vFAIL2("Empty \\%c{}", (U8)value);
3638                 if (*RExC_parse == '{') {
3639                     U8 c = (U8)value;
3640                     e = strchr(RExC_parse++, '}');
3641                     if (!e)
3642                         vFAIL2("Missing right brace on \\%c{}", c);
3643                     while (isSPACE(UCHARAT(RExC_parse)))
3644                         RExC_parse++;
3645                     if (e == RExC_parse)
3646                         vFAIL2("Empty \\%c{}", c);
3647                     n = e - RExC_parse;
3648                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3649                         n--;
3650                 }
3651                 else {
3652                     e = RExC_parse;
3653                     n = 1;
3654                 }
3655                 if (!SIZE_ONLY) {
3656                     if (UCHARAT(RExC_parse) == '^') {
3657                          RExC_parse++;
3658                          n--;
3659                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3660                          while (isSPACE(UCHARAT(RExC_parse))) {
3661                               RExC_parse++;
3662                               n--;
3663                          }
3664                     }
3665                     if (value == 'p')
3666                          Perl_sv_catpvf(aTHX_ listsv,
3667                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3668                     else
3669                          Perl_sv_catpvf(aTHX_ listsv,
3670                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3671                 }
3672                 RExC_parse = e + 1;
3673                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3674                 namedclass = ANYOF_MAX;  /* no official name, but it's named */
3675                 break;
3676             case 'n':   value = '\n';                   break;
3677             case 'r':   value = '\r';                   break;
3678             case 't':   value = '\t';                   break;
3679             case 'f':   value = '\f';                   break;
3680             case 'b':   value = '\b';                   break;
3681             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3682             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3683             case 'x':
3684                 if (*RExC_parse == '{') {
3685                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3686                         | PERL_SCAN_DISALLOW_PREFIX;
3687                     e = strchr(RExC_parse++, '}');
3688                     if (!e)
3689                         vFAIL("Missing right brace on \\x{}");
3690
3691                     numlen = e - RExC_parse;
3692                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3693                     RExC_parse = e + 1;
3694                 }
3695                 else {
3696                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3697                     numlen = 2;
3698                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3699                     RExC_parse += numlen;
3700                 }
3701                 break;
3702             case 'c':
3703                 value = UCHARAT(RExC_parse++);
3704                 value = toCTRL(value);
3705                 break;
3706             case '0': case '1': case '2': case '3': case '4':
3707             case '5': case '6': case '7': case '8': case '9':
3708             {
3709                 I32 flags = 0;
3710                 numlen = 3;
3711                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3712                 RExC_parse += numlen;
3713                 break;
3714             }
3715             default:
3716                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3717                     vWARN2(RExC_parse,
3718                            "Unrecognized escape \\%c in character class passed through",
3719                            (int)value);
3720                 break;
3721             }
3722         } /* end of \blah */
3723 #ifdef EBCDIC
3724         else
3725             literal_endpoint++;
3726 #endif
3727
3728         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3729
3730             if (!SIZE_ONLY && !need_class)
3731                 ANYOF_CLASS_ZERO(ret);
3732
3733             need_class = 1;
3734
3735             /* a bad range like a-\d, a-[:digit:] ? */
3736             if (range) {
3737                 if (!SIZE_ONLY) {
3738                     if (ckWARN(WARN_REGEXP))
3739                         vWARN4(RExC_parse,
3740                                "False [] range \"%*.*s\"",
3741                                RExC_parse - rangebegin,
3742                                RExC_parse - rangebegin,
3743                                rangebegin);
3744                     if (prevvalue < 256) {
3745                         ANYOF_BITMAP_SET(ret, prevvalue);
3746                         ANYOF_BITMAP_SET(ret, '-');
3747                     }
3748                     else {
3749                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3750                         Perl_sv_catpvf(aTHX_ listsv,
3751                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3752                     }
3753                 }
3754
3755                 range = 0; /* this was not a true range */
3756             }
3757
3758             if (!SIZE_ONLY) {
3759                 const char *what = NULL;
3760                 char yesno = 0;
3761
3762                 if (namedclass > OOB_NAMEDCLASS)
3763                     optimize_invert = FALSE;
3764                 /* Possible truncation here but in some 64-bit environments
3765                  * the compiler gets heartburn about switch on 64-bit values.
3766                  * A similar issue a little earlier when switching on value.
3767                  * --jhi */
3768                 switch ((I32)namedclass) {
3769                 case ANYOF_ALNUM:
3770                     if (LOC)
3771                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3772                     else {
3773                         for (value = 0; value < 256; value++)
3774                             if (isALNUM(value))
3775                                 ANYOF_BITMAP_SET(ret, value);
3776                     }
3777                     yesno = '+';
3778                     what = "Word";
3779                     break;
3780                 case ANYOF_NALNUM:
3781                     if (LOC)
3782                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3783                     else {
3784                         for (value = 0; value < 256; value++)
3785                             if (!isALNUM(value))
3786                                 ANYOF_BITMAP_SET(ret, value);
3787                     }
3788                     yesno = '!';
3789                     what = "Word";
3790                     break;
3791                 case ANYOF_ALNUMC:
3792                     if (LOC)
3793                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3794                     else {
3795                         for (value = 0; value < 256; value++)
3796                             if (isALNUMC(value))
3797                                 ANYOF_BITMAP_SET(ret, value);
3798                     }
3799                     yesno = '+';
3800                     what = "Alnum";
3801                     break;
3802                 case ANYOF_NALNUMC:
3803                     if (LOC)
3804                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3805                     else {
3806                         for (value = 0; value < 256; value++)
3807                             if (!isALNUMC(value))
3808                                 ANYOF_BITMAP_SET(ret, value);
3809                     }
3810                     yesno = '!';
3811                     what = "Alnum";
3812                     break;
3813                 case ANYOF_ALPHA:
3814                     if (LOC)
3815                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3816                     else {
3817                         for (value = 0; value < 256; value++)
3818                             if (isALPHA(value))
3819                                 ANYOF_BITMAP_SET(ret, value);
3820                     }
3821                     yesno = '+';
3822                     what = "Alpha";
3823                     break;
3824                 case ANYOF_NALPHA:
3825                     if (LOC)
3826                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3827                     else {
3828                         for (value = 0; value < 256; value++)
3829                             if (!isALPHA(value))
3830                                 ANYOF_BITMAP_SET(ret, value);
3831                     }
3832                     yesno = '!';
3833                     what = "Alpha";
3834                     break;
3835                 case ANYOF_ASCII:
3836                     if (LOC)
3837                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3838                     else {
3839 #ifndef EBCDIC
3840                         for (value = 0; value < 128; value++)
3841                             ANYOF_BITMAP_SET(ret, value);
3842 #else  /* EBCDIC */
3843                         for (value = 0; value < 256; value++) {
3844                             if (isASCII(value))
3845                                 ANYOF_BITMAP_SET(ret, value);
3846                         }
3847 #endif /* EBCDIC */
3848                     }
3849                     yesno = '+';
3850                     what = "ASCII";
3851                     break;
3852                 case ANYOF_NASCII:
3853                     if (LOC)
3854                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3855                     else {
3856 #ifndef EBCDIC
3857                         for (value = 128; value < 256; value++)
3858                             ANYOF_BITMAP_SET(ret, value);
3859 #else  /* EBCDIC */
3860                         for (value = 0; value < 256; value++) {
3861                             if (!isASCII(value))
3862                                 ANYOF_BITMAP_SET(ret, value);
3863                         }
3864 #endif /* EBCDIC */
3865                     }
3866                     yesno = '!';
3867                     what = "ASCII";
3868                     break;
3869                 case ANYOF_BLANK:
3870                     if (LOC)
3871                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3872                     else {
3873                         for (value = 0; value < 256; value++)
3874                             if (isBLANK(value))
3875                                 ANYOF_BITMAP_SET(ret, value);
3876                     }
3877                     yesno = '+';
3878                     what = "Blank";
3879                     break;
3880                 case ANYOF_NBLANK:
3881                     if (LOC)
3882                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3883                     else {
3884                         for (value = 0; value < 256; value++)
3885                             if (!isBLANK(value))
3886                                 ANYOF_BITMAP_SET(ret, value);
3887                     }
3888                     yesno = '!';
3889                     what = "Blank";
3890                     break;
3891                 case ANYOF_CNTRL:
3892                     if (LOC)
3893                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3894                     else {
3895                         for (value = 0; value < 256; value++)
3896                             if (isCNTRL(value))
3897                                 ANYOF_BITMAP_SET(ret, value);
3898                     }
3899                     yesno = '+';
3900                     what = "Cntrl";
3901                     break;
3902                 case ANYOF_NCNTRL:
3903                     if (LOC)
3904                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3905                     else {
3906                         for (value = 0; value < 256; value++)
3907                             if (!isCNTRL(value))
3908                                 ANYOF_BITMAP_SET(ret, value);
3909                     }
3910                     yesno = '!';
3911                     what = "Cntrl";
3912                     break;
3913                 case ANYOF_DIGIT:
3914                     if (LOC)
3915                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3916                     else {
3917                         /* consecutive digits assumed */
3918                         for (value = '0'; value <= '9'; value++)
3919                             ANYOF_BITMAP_SET(ret, value);
3920                     }
3921                     yesno = '+';
3922                     what = "Digit";
3923                     break;
3924                 case ANYOF_NDIGIT:
3925                     if (LOC)
3926                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3927                     else {
3928                         /* consecutive digits assumed */
3929                         for (value = 0; value < '0'; value++)
3930                             ANYOF_BITMAP_SET(ret, value);
3931                         for (value = '9' + 1; value < 256; value++)
3932                             ANYOF_BITMAP_SET(ret, value);
3933                     }
3934                     yesno = '!';
3935                     what = "Digit";
3936                     break;
3937                 case ANYOF_GRAPH:
3938                     if (LOC)
3939                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3940                     else {
3941                         for (value = 0; value < 256; value++)
3942                             if (isGRAPH(value))
3943                                 ANYOF_BITMAP_SET(ret, value);
3944                     }
3945                     yesno = '+';
3946                     what = "Graph";
3947                     break;
3948                 case ANYOF_NGRAPH:
3949                     if (LOC)
3950                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3951                     else {
3952                         for (value = 0; value < 256; value++)
3953                             if (!isGRAPH(value))
3954                                 ANYOF_BITMAP_SET(ret, value);
3955                     }
3956                     yesno = '!';
3957                     what = "Graph";
3958                     break;
3959                 case ANYOF_LOWER:
3960                     if (LOC)
3961                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3962                     else {
3963                         for (value = 0; value < 256; value++)
3964                             if (isLOWER(value))
3965                                 ANYOF_BITMAP_SET(ret, value);
3966                     }
3967                     yesno = '+';
3968                     what = "Lower";
3969                     break;
3970                 case ANYOF_NLOWER:
3971                     if (LOC)
3972                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3973                     else {
3974                         for (value = 0; value < 256; value++)
3975                             if (!isLOWER(value))
3976                                 ANYOF_BITMAP_SET(ret, value);
3977                     }
3978                     yesno = '!';
3979                     what = "Lower";
3980                     break;
3981                 case ANYOF_PRINT:
3982                     if (LOC)
3983                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3984                     else {
3985                         for (value = 0; value < 256; value++)
3986                             if (isPRINT(value))
3987                                 ANYOF_BITMAP_SET(ret, value);
3988                     }
3989                     yesno = '+';
3990                     what = "Print";
3991                     break;
3992                 case ANYOF_NPRINT:
3993                     if (LOC)
3994                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3995                     else {
3996                         for (value = 0; value < 256; value++)
3997                             if (!isPRINT(value))
3998                                 ANYOF_BITMAP_SET(ret, value);
3999                     }
4000                     yesno = '!';
4001                     what = "Print";
4002                     break;
4003                 case ANYOF_PSXSPC:
4004                     if (LOC)
4005                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
4006                     else {
4007                         for (value = 0; value < 256; value++)
4008                             if (isPSXSPC(value))
4009                                 ANYOF_BITMAP_SET(ret, value);
4010                     }
4011                     yesno = '+';
4012                     what = "Space";
4013                     break;
4014                 case ANYOF_NPSXSPC:
4015                     if (LOC)
4016                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
4017                     else {
4018                         for (value = 0; value < 256; value++)
4019                             if (!isPSXSPC(value))
4020                                 ANYOF_BITMAP_SET(ret, value);
4021                     }
4022                     yesno = '!';
4023                     what = "Space";
4024                     break;
4025                 case ANYOF_PUNCT:
4026                     if (LOC)
4027                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
4028                     else {
4029                         for (value = 0; value < 256; value++)
4030                             if (isPUNCT(value))
4031                                 ANYOF_BITMAP_SET(ret, value);
4032                     }
4033                     yesno = '+';
4034                     what = "Punct";
4035                     break;
4036                 case ANYOF_NPUNCT:
4037                     if (LOC)
4038                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
4039                     else {
4040                         for (value = 0; value < 256; value++)
4041                             if (!isPUNCT(value))
4042                                 ANYOF_BITMAP_SET(ret, value);
4043                     }
4044                     yesno = '!';
4045                     what = "Punct";
4046                     break;
4047                 case ANYOF_SPACE:
4048                     if (LOC)
4049                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
4050                     else {
4051                         for (value = 0; value < 256; value++)
4052                             if (isSPACE(value))
4053                                 ANYOF_BITMAP_SET(ret, value);
4054                     }
4055                     yesno = '+';
4056                     what = "SpacePerl";
4057                     break;
4058                 case ANYOF_NSPACE:
4059                     if (LOC)
4060                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
4061                     else {
4062                         for (value = 0; value < 256; value++)
4063                             if (!isSPACE(value))
4064                                 ANYOF_BITMAP_SET(ret, value);
4065                     }
4066                     yesno = '!';
4067                     what = "SpacePerl";
4068                     break;
4069                 case ANYOF_UPPER:
4070                     if (LOC)
4071                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
4072                     else {
4073                         for (value = 0; value < 256; value++)
4074                             if (isUPPER(value))
4075                                 ANYOF_BITMAP_SET(ret, value);
4076                     }
4077                     yesno = '+';
4078                     what = "Upper";
4079                     break;
4080                 case ANYOF_NUPPER:
4081                     if (LOC)
4082                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
4083                     else {
4084                         for (value = 0; value < 256; value++)
4085                             if (!isUPPER(value))
4086                                 ANYOF_BITMAP_SET(ret, value);
4087                     }
4088                     yesno = '!';
4089                     what = "Upper";
4090                     break;
4091                 case ANYOF_XDIGIT:
4092                     if (LOC)
4093                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
4094                     else {
4095                         for (value = 0; value < 256; value++)
4096                             if (isXDIGIT(value))
4097                                 ANYOF_BITMAP_SET(ret, value);
4098                     }
4099                     yesno = '+';
4100                     what = "XDigit";
4101                     break;
4102                 case ANYOF_NXDIGIT:
4103                     if (LOC)
4104                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
4105                     else {
4106                         for (value = 0; value < 256; value++)
4107                             if (!isXDIGIT(value))
4108                                 ANYOF_BITMAP_SET(ret, value);
4109                     }
4110                     yesno = '!';
4111                     what = "XDigit";
4112                     break;
4113                 case ANYOF_MAX:
4114                     /* this is to handle \p and \P */
4115                     break;
4116                 default:
4117                     vFAIL("Invalid [::] class");
4118                     break;
4119                 }
4120                 if (what) {
4121                     /* Strings such as "+utf8::isWord\n" */
4122                     Perl_sv_catpvf(aTHX_ listsv, "%cutf8::Is%s\n", yesno, what);
4123                 }
4124                 if (LOC)
4125                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
4126                 continue;
4127             }
4128         } /* end of namedclass \blah */
4129
4130         if (range) {
4131             if (prevvalue > (IV)value) /* b-a */ {
4132                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
4133                               RExC_parse - rangebegin,
4134                               RExC_parse - rangebegin,
4135                               rangebegin);
4136                 range = 0; /* not a valid range */
4137             }
4138         }
4139         else {
4140             prevvalue = value; /* save the beginning of the range */
4141             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
4142                 RExC_parse[1] != ']') {
4143                 RExC_parse++;
4144
4145                 /* a bad range like \w-, [:word:]- ? */
4146                 if (namedclass > OOB_NAMEDCLASS) {
4147                     if (ckWARN(WARN_REGEXP))
4148                         vWARN4(RExC_parse,
4149                                "False [] range \"%*.*s\"",
4150                                RExC_parse - rangebegin,
4151                                RExC_parse - rangebegin,
4152                                rangebegin);
4153                     if (!SIZE_ONLY)
4154                         ANYOF_BITMAP_SET(ret, '-');
4155                 } else
4156                     range = 1;  /* yeah, it's a range! */
4157                 continue;       /* but do it the next time */
4158             }
4159         }
4160
4161         /* now is the next time */
4162         if (!SIZE_ONLY) {
4163             IV i;
4164
4165             if (prevvalue < 256) {
4166                 IV ceilvalue = value < 256 ? value : 255;
4167
4168 #ifdef EBCDIC
4169                 /* In EBCDIC [\x89-\x91] should include
4170                  * the \x8e but [i-j] should not. */
4171                 if (literal_endpoint == 2 &&
4172                     ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
4173                      (isUPPER(prevvalue) && isUPPER(ceilvalue))))
4174                 {
4175                     if (isLOWER(prevvalue)) {
4176                         for (i = prevvalue; i <= ceilvalue; i++)
4177                             if (isLOWER(i))
4178                                 ANYOF_BITMAP_SET(ret, i);
4179                     } else {
4180                         for (i = prevvalue; i <= ceilvalue; i++)
4181                             if (isUPPER(i))
4182                                 ANYOF_BITMAP_SET(ret, i);
4183                     }
4184                 }
4185                 else
4186 #endif
4187                       for (i = prevvalue; i <= ceilvalue; i++)
4188                           ANYOF_BITMAP_SET(ret, i);
4189           }
4190           if (value > 255 || UTF) {
4191                 UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
4192                 UV natvalue      = NATIVE_TO_UNI(value);
4193
4194                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
4195                 if (prevnatvalue < natvalue) { /* what about > ? */
4196                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
4197                                    prevnatvalue, natvalue);
4198                 }
4199                 else if (prevnatvalue == natvalue) {
4200                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", natvalue);
4201                     if (FOLD) {
4202                          U8 foldbuf[UTF8_MAXLEN_FOLD+1];
4203                          STRLEN foldlen;
4204                          UV f = to_uni_fold(natvalue, foldbuf, &foldlen);
4205
4206                          /* If folding and foldable and a single
4207                           * character, insert also the folded version
4208                           * to the charclass. */
4209                          if (f != value) {
4210                               if (foldlen == (STRLEN)UNISKIP(f))
4211                                   Perl_sv_catpvf(aTHX_ listsv,
4212                                                  "%04"UVxf"\n", f);
4213                               else {
4214                                   /* Any multicharacter foldings
4215                                    * require the following transform:
4216                                    * [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst)
4217                                    * where E folds into "pq" and F folds
4218                                    * into "rst", all other characters
4219                                    * fold to single characters.  We save
4220                                    * away these multicharacter foldings,
4221                                    * to be later saved as part of the
4222                                    * additional "s" data. */
4223                                   SV *sv;
4224
4225                                   if (!unicode_alternate)
4226                                       unicode_alternate = newAV();
4227                                   sv = newSVpvn((char*)foldbuf, foldlen);
4228                                   SvUTF8_on(sv);
4229                                   av_push(unicode_alternate, sv);
4230                               }
4231                          }
4232
4233                          /* If folding and the value is one of the Greek
4234                           * sigmas insert a few more sigmas to make the
4235                           * folding rules of the sigmas to work right.
4236                           * Note that not all the possible combinations
4237                           * are handled here: some of them are handled
4238                           * by the standard folding rules, and some of
4239                           * them (literal or EXACTF cases) are handled
4240                           * during runtime in regexec.c:S_find_byclass(). */
4241                          if (value == UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA) {
4242                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4243                                              (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA);
4244                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4245                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4246                          }
4247                          else if (value == UNICODE_GREEK_CAPITAL_LETTER_SIGMA)
4248                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4249                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4250                     }
4251                 }
4252             }
4253 #ifdef EBCDIC
4254             literal_endpoint = 0;
4255 #endif
4256         }
4257
4258         range = 0; /* this range (if it was one) is done now */
4259     }
4260
4261     if (need_class) {
4262         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
4263         if (SIZE_ONLY)
4264             RExC_size += ANYOF_CLASS_ADD_SKIP;
4265         else
4266             RExC_emit += ANYOF_CLASS_ADD_SKIP;
4267     }
4268
4269     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4270     if (!SIZE_ONLY &&
4271          /* If the only flag is folding (plus possibly inversion). */
4272         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4273        ) {
4274         for (value = 0; value < 256; ++value) {
4275             if (ANYOF_BITMAP_TEST(ret, value)) {
4276                 UV fold = PL_fold[value];
4277
4278                 if (fold != value)
4279                     ANYOF_BITMAP_SET(ret, fold);
4280             }
4281         }
4282         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4283     }
4284
4285     /* optimize inverted simple patterns (e.g. [^a-z]) */
4286     if (!SIZE_ONLY && optimize_invert &&
4287         /* If the only flag is inversion. */
4288         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4289         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4290             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4291         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4292     }
4293
4294     if (!SIZE_ONLY) {
4295         AV *av = newAV();
4296         SV *rv;
4297
4298         /* The 0th element stores the character class description
4299          * in its textual form: used later (regexec.c:Perl_regclass_swash())
4300          * to initialize the appropriate swash (which gets stored in
4301          * the 1st element), and also useful for dumping the regnode.
4302          * The 2nd element stores the multicharacter foldings,
4303          * used later (regexec.c:S_reginclass()). */
4304         av_store(av, 0, listsv);
4305         av_store(av, 1, NULL);
4306         av_store(av, 2, (SV*)unicode_alternate);
4307         rv = newRV_noinc((SV*)av);
4308         n = add_data(pRExC_state, 1, "s");
4309         RExC_rx->data->data[n] = (void*)rv;
4310         ARG_SET(ret, n);
4311     }
4312
4313     return ret;
4314 }
4315
4316 STATIC char*
4317 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4318 {
4319     char* retval = RExC_parse++;
4320
4321     for (;;) {
4322         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4323                 RExC_parse[2] == '#') {
4324             while (*RExC_parse != ')') {
4325                 if (RExC_parse == RExC_end)
4326                     FAIL("Sequence (?#... not terminated");
4327                 RExC_parse++;
4328             }
4329             RExC_parse++;
4330             continue;
4331         }
4332         if (RExC_flags & PMf_EXTENDED) {
4333             if (isSPACE(*RExC_parse)) {
4334                 RExC_parse++;
4335                 continue;
4336             }
4337             else if (*RExC_parse == '#') {
4338                 while (RExC_parse < RExC_end)
4339                     if (*RExC_parse++ == '\n') break;
4340                 continue;
4341             }
4342         }
4343         return retval;
4344     }
4345 }
4346
4347 /*
4348 - reg_node - emit a node
4349 */
4350 STATIC regnode *                        /* Location. */
4351 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4352 {
4353     register regnode *ret;
4354     register regnode *ptr;
4355
4356     ret = RExC_emit;
4357     if (SIZE_ONLY) {
4358         SIZE_ALIGN(RExC_size);
4359         RExC_size += 1;
4360         return(ret);
4361     }
4362
4363     NODE_ALIGN_FILL(ret);
4364     ptr = ret;
4365     FILL_ADVANCE_NODE(ptr, op);
4366     if (RExC_offsets) {         /* MJD */
4367         MJD_OFFSET_DEBUG(("%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n",
4368               "reg_node", __LINE__,
4369               reg_name[op],
4370               RExC_emit - RExC_emit_start > RExC_offsets[0]
4371               ? "Overwriting end of array!\n" : "OK",
4372               RExC_emit - RExC_emit_start,
4373               RExC_parse - RExC_start,
4374               RExC_offsets[0]));
4375         Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4376     }
4377
4378     RExC_emit = ptr;
4379
4380     return(ret);
4381 }
4382
4383 /*
4384 - reganode - emit a node with an argument
4385 */
4386 STATIC regnode *                        /* Location. */
4387 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4388 {
4389     register regnode *ret;
4390     register regnode *ptr;
4391
4392     ret = RExC_emit;
4393     if (SIZE_ONLY) {
4394         SIZE_ALIGN(RExC_size);
4395         RExC_size += 2;
4396         return(ret);
4397     }
4398
4399     NODE_ALIGN_FILL(ret);
4400     ptr = ret;
4401     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4402     if (RExC_offsets) {         /* MJD */
4403         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4404               "reganode",
4405               __LINE__,
4406               reg_name[op],
4407               RExC_emit - RExC_emit_start > RExC_offsets[0] ?
4408               "Overwriting end of array!\n" : "OK",
4409               RExC_emit - RExC_emit_start,
4410               RExC_parse - RExC_start,
4411               RExC_offsets[0]));
4412         Set_Cur_Node_Offset;
4413     }
4414
4415     RExC_emit = ptr;
4416
4417     return(ret);
4418 }
4419
4420 /*
4421 - reguni - emit (if appropriate) a Unicode character
4422 */
4423 STATIC void
4424 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4425 {
4426     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4427 }
4428
4429 /*
4430 - reginsert - insert an operator in front of already-emitted operand
4431 *
4432 * Means relocating the operand.
4433 */
4434 STATIC void
4435 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4436 {
4437     register regnode *src;
4438     register regnode *dst;
4439     register regnode *place;
4440     register int offset = regarglen[(U8)op];
4441
4442 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4443
4444     if (SIZE_ONLY) {
4445         RExC_size += NODE_STEP_REGNODE + offset;
4446         return;
4447     }
4448
4449     src = RExC_emit;
4450     RExC_emit += NODE_STEP_REGNODE + offset;
4451     dst = RExC_emit;
4452     while (src > opnd) {
4453         StructCopy(--src, --dst, regnode);
4454         if (RExC_offsets) {     /* MJD 20010112 */
4455             MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s copy %u -> %u (max %u).\n",
4456                   "reg_insert",
4457                   __LINE__,
4458                   reg_name[op],
4459                   dst - RExC_emit_start > RExC_offsets[0]
4460                   ? "Overwriting end of array!\n" : "OK",
4461                   src - RExC_emit_start,
4462                   dst - RExC_emit_start,
4463                   RExC_offsets[0]));
4464             Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4465             Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4466         }
4467     }
4468
4469
4470     place = opnd;               /* Op node, where operand used to be. */
4471     if (RExC_offsets) {         /* MJD */
4472         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4473               "reginsert",
4474               __LINE__,
4475               reg_name[op],
4476               place - RExC_emit_start > RExC_offsets[0]
4477               ? "Overwriting end of array!\n" : "OK",
4478               place - RExC_emit_start,
4479               RExC_parse - RExC_start,
4480               RExC_offsets[0]));
4481         Set_Node_Offset(place, RExC_parse);
4482         Set_Node_Length(place, 1);
4483     }
4484     src = NEXTOPER(place);
4485     FILL_ADVANCE_NODE(place, op);
4486     Zero(src, offset, regnode);
4487 }
4488
4489 /*
4490 - regtail - set the next-pointer at the end of a node chain of p to val.
4491 */
4492 STATIC void
4493 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4494 {
4495     register regnode *scan;
4496     register regnode *temp;
4497
4498     if (SIZE_ONLY)
4499         return;
4500
4501     /* Find last node. */
4502     scan = p;
4503     for (;;) {
4504         temp = regnext(scan);
4505         if (temp == NULL)
4506             break;
4507         scan = temp;
4508     }
4509
4510     if (reg_off_by_arg[OP(scan)]) {
4511         ARG_SET(scan, val - scan);
4512     }
4513     else {
4514         NEXT_OFF(scan) = val - scan;
4515     }
4516 }
4517
4518 /*
4519 - regoptail - regtail on operand of first argument; nop if operandless
4520 */
4521 STATIC void
4522 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4523 {
4524     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4525     if (p == NULL || SIZE_ONLY)
4526         return;
4527     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4528         regtail(pRExC_state, NEXTOPER(p), val);
4529     }
4530     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4531         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4532     }
4533     else
4534         return;
4535 }
4536
4537 /*
4538  - regcurly - a little FSA that accepts {\d+,?\d*}
4539  */
4540 STATIC I32
4541 S_regcurly(pTHX_ register char *s)
4542 {
4543     if (*s++ != '{')
4544         return FALSE;
4545     if (!isDIGIT(*s))
4546         return FALSE;
4547     while (isDIGIT(*s))
4548         s++;
4549     if (*s == ',')
4550         s++;
4551     while (isDIGIT(*s))
4552         s++;
4553     if (*s != '}')
4554         return FALSE;
4555     return TRUE;
4556 }
4557
4558
4559 #ifdef DEBUGGING
4560
4561 STATIC regnode *
4562 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4563 {
4564     register U8 op = EXACT;     /* Arbitrary non-END op. */
4565     register regnode *next;
4566
4567     while (op != END && (!last || node < last)) {
4568         /* While that wasn't END last time... */
4569
4570         NODE_ALIGN(node);
4571         op = OP(node);
4572         if (op == CLOSE)
4573             l--;
4574         next = regnext(node);
4575         /* Where, what. */
4576         if (OP(node) == OPTIMIZED)
4577             goto after_print;
4578         regprop(sv, node);
4579         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4580                       (int)(2*l + 1), "", SvPVX(sv));
4581         if (next == NULL)               /* Next ptr. */
4582             PerlIO_printf(Perl_debug_log, "(0)");
4583         else
4584             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4585         (void)PerlIO_putc(Perl_debug_log, '\n');
4586       after_print:
4587         if (PL_regkind[(U8)op] == BRANCHJ) {
4588             register regnode *nnode = (OP(next) == LONGJMP
4589                                        ? regnext(next)
4590                                        : next);
4591             if (last && nnode > last)
4592                 nnode = last;
4593             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4594         }
4595         else if (PL_regkind[(U8)op] == BRANCH) {
4596             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4597         }
4598         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4599             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4600                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4601         }
4602         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4603             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4604                              next, sv, l + 1);
4605         }
4606         else if ( op == PLUS || op == STAR) {
4607             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4608         }
4609         else if (op == ANYOF) {
4610             /* arglen 1 + class block */
4611             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4612                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4613             node = NEXTOPER(node);
4614         }
4615         else if (PL_regkind[(U8)op] == EXACT) {
4616             /* Literal string, where present. */
4617             node += NODE_SZ_STR(node) - 1;
4618             node = NEXTOPER(node);
4619         }
4620         else {
4621             node = NEXTOPER(node);
4622             node += regarglen[(U8)op];
4623         }
4624         if (op == CURLYX || op == OPEN)
4625             l++;
4626         else if (op == WHILEM)
4627             l--;
4628     }
4629     return node;
4630 }
4631
4632 #endif  /* DEBUGGING */
4633
4634 /*
4635  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4636  */
4637 void
4638 Perl_regdump(pTHX_ regexp *r)
4639 {
4640 #ifdef DEBUGGING
4641     SV *sv = sv_newmortal();
4642
4643     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4644
4645     /* Header fields of interest. */
4646     if (r->anchored_substr)
4647         PerlIO_printf(Perl_debug_log,
4648                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4649                       PL_colors[0],
4650                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4651                       SvPVX(r->anchored_substr),
4652                       PL_colors[1],
4653                       SvTAIL(r->anchored_substr) ? "$" : "",
4654                       (IV)r->anchored_offset);
4655     else if (r->anchored_utf8)
4656         PerlIO_printf(Perl_debug_log,
4657                       "anchored utf8 `%s%.*s%s'%s at %"IVdf" ",
4658                       PL_colors[0],
4659                       (int)(SvCUR(r->anchored_utf8) - (SvTAIL(r->anchored_utf8)!=0)),
4660                       SvPVX(r->anchored_utf8),
4661                       PL_colors[1],
4662                       SvTAIL(r->anchored_utf8) ? "$" : "",
4663                       (IV)r->anchored_offset);
4664     if (r->float_substr)
4665         PerlIO_printf(Perl_debug_log,
4666                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4667                       PL_colors[0],
4668                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4669                       SvPVX(r->float_substr),
4670                       PL_colors[1],
4671                       SvTAIL(r->float_substr) ? "$" : "",
4672                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4673     else if (r->float_utf8)
4674         PerlIO_printf(Perl_debug_log,
4675                       "floating utf8 `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4676                       PL_colors[0],
4677                       (int)(SvCUR(r->float_utf8) - (SvTAIL(r->float_utf8)!=0)),
4678                       SvPVX(r->float_utf8),
4679                       PL_colors[1],
4680                       SvTAIL(r->float_utf8) ? "$" : "",
4681                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4682     if (r->check_substr || r->check_utf8)
4683         PerlIO_printf(Perl_debug_log,
4684                       r->check_substr == r->float_substr
4685                       && r->check_utf8 == r->float_utf8
4686                       ? "(checking floating" : "(checking anchored");
4687     if (r->reganch & ROPT_NOSCAN)
4688         PerlIO_printf(Perl_debug_log, " noscan");
4689     if (r->reganch & ROPT_CHECK_ALL)
4690         PerlIO_printf(Perl_debug_log, " isall");
4691     if (r->check_substr || r->check_utf8)
4692         PerlIO_printf(Perl_debug_log, ") ");
4693
4694     if (r->regstclass) {
4695         regprop(sv, r->regstclass);
4696         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4697     }
4698     if (r->reganch & ROPT_ANCH) {
4699         PerlIO_printf(Perl_debug_log, "anchored");
4700         if (r->reganch & ROPT_ANCH_BOL)
4701             PerlIO_printf(Perl_debug_log, "(BOL)");
4702         if (r->reganch & ROPT_ANCH_MBOL)
4703             PerlIO_printf(Perl_debug_log, "(MBOL)");
4704         if (r->reganch & ROPT_ANCH_SBOL)
4705             PerlIO_printf(Perl_debug_log, "(SBOL)");
4706         if (r->reganch & ROPT_ANCH_GPOS)
4707             PerlIO_printf(Perl_debug_log, "(GPOS)");
4708         PerlIO_putc(Perl_debug_log, ' ');
4709     }
4710     if (r->reganch & ROPT_GPOS_SEEN)
4711         PerlIO_printf(Perl_debug_log, "GPOS ");
4712     if (r->reganch & ROPT_SKIP)
4713         PerlIO_printf(Perl_debug_log, "plus ");
4714     if (r->reganch & ROPT_IMPLICIT)
4715         PerlIO_printf(Perl_debug_log, "implicit ");
4716     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4717     if (r->reganch & ROPT_EVAL_SEEN)
4718         PerlIO_printf(Perl_debug_log, "with eval ");
4719     PerlIO_printf(Perl_debug_log, "\n");
4720     if (r->offsets) {
4721       U32 i;
4722       U32 len = r->offsets[0];
4723       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4724       for (i = 1; i <= len; i++)
4725         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ",
4726                       (UV)r->offsets[i*2-1],
4727                       (UV)r->offsets[i*2]);
4728       PerlIO_printf(Perl_debug_log, "\n");
4729     }
4730 #endif  /* DEBUGGING */
4731 }
4732
4733 #ifdef DEBUGGING
4734
4735 STATIC void
4736 S_put_byte(pTHX_ SV *sv, int c)
4737 {
4738     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4739         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4740     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4741         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4742     else
4743         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4744 }
4745
4746 #endif  /* DEBUGGING */
4747
4748 /*
4749 - regprop - printable representation of opcode
4750 */
4751 void
4752 Perl_regprop(pTHX_ SV *sv, regnode *o)
4753 {
4754 #ifdef DEBUGGING
4755     register int k;
4756
4757     sv_setpvn(sv, "", 0);
4758     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4759         /* It would be nice to FAIL() here, but this may be called from
4760            regexec.c, and it would be hard to supply pRExC_state. */
4761         Perl_croak(aTHX_ "Corrupted regexp opcode");
4762     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4763
4764     k = PL_regkind[(U8)OP(o)];
4765
4766     if (k == EXACT) {
4767         SV *dsv = sv_2mortal(newSVpvn("", 0));
4768         /* Using is_utf8_string() is a crude hack but it may
4769          * be the best for now since we have no flag "this EXACTish
4770          * node was UTF-8" --jhi */
4771         bool do_utf8 = is_utf8_string((U8*)STRING(o), STR_LEN(o));
4772         char *s    = do_utf8 ?
4773           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60,
4774                          UNI_DISPLAY_REGEX) :
4775           STRING(o);
4776         int len = do_utf8 ?
4777           strlen(s) :
4778           STR_LEN(o);
4779         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4780                        PL_colors[0],
4781                        len, s,
4782                        PL_colors[1]);
4783     }
4784     else if (k == CURLY) {
4785         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4786             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4787         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4788     }
4789     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4790         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4791     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4792         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4793     else if (k == LOGICAL)
4794         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4795     else if (k == ANYOF) {
4796         int i, rangestart = -1;
4797         U8 flags = ANYOF_FLAGS(o);
4798         const char * const anyofs[] = { /* Should be synchronized with
4799                                          * ANYOF_ #xdefines in regcomp.h */
4800             "\\w",
4801             "\\W",
4802             "\\s",
4803             "\\S",
4804             "\\d",
4805             "\\D",
4806             "[:alnum:]",
4807             "[:^alnum:]",
4808             "[:alpha:]",
4809             "[:^alpha:]",
4810             "[:ascii:]",
4811             "[:^ascii:]",
4812             "[:ctrl:]",
4813             "[:^ctrl:]",
4814             "[:graph:]",
4815             "[:^graph:]",
4816             "[:lower:]",
4817             "[:^lower:]",
4818             "[:print:]",
4819             "[:^print:]",
4820             "[:punct:]",
4821             "[:^punct:]",
4822             "[:upper:]",
4823             "[:^upper:]",
4824             "[:xdigit:]",
4825             "[:^xdigit:]",
4826             "[:space:]",
4827             "[:^space:]",
4828             "[:blank:]",
4829             "[:^blank:]"
4830         };
4831
4832         if (flags & ANYOF_LOCALE)
4833             sv_catpv(sv, "{loc}");
4834         if (flags & ANYOF_FOLD)
4835             sv_catpv(sv, "{i}");
4836         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4837         if (flags & ANYOF_INVERT)
4838             sv_catpv(sv, "^");
4839         for (i = 0; i <= 256; i++) {
4840             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4841                 if (rangestart == -1)
4842                     rangestart = i;
4843             } else if (rangestart != -1) {
4844                 if (i <= rangestart + 3)
4845                     for (; rangestart < i; rangestart++)
4846                         put_byte(sv, rangestart);
4847                 else {
4848                     put_byte(sv, rangestart);
4849                     sv_catpv(sv, "-");
4850                     put_byte(sv, i - 1);
4851                 }
4852                 rangestart = -1;
4853             }
4854         }
4855
4856         if (o->flags & ANYOF_CLASS)
4857             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4858                 if (ANYOF_CLASS_TEST(o,i))
4859                     sv_catpv(sv, anyofs[i]);
4860
4861         if (flags & ANYOF_UNICODE)
4862             sv_catpv(sv, "{unicode}");
4863         else if (flags & ANYOF_UNICODE_ALL)
4864             sv_catpv(sv, "{unicode_all}");
4865
4866         {
4867             SV *lv;
4868             SV *sw = regclass_swash(o, FALSE, &lv, 0);
4869
4870             if (lv) {
4871                 if (sw) {
4872                     U8 s[UTF8_MAXLEN+1];
4873
4874                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4875                         U8 *e = uvchr_to_utf8(s, i);
4876
4877                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4878                             if (rangestart == -1)
4879                                 rangestart = i;
4880                         } else if (rangestart != -1) {
4881                             U8 *p;
4882
4883                             if (i <= rangestart + 3)
4884                                 for (; rangestart < i; rangestart++) {
4885                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4886                                         put_byte(sv, *p);
4887                                 }
4888                             else {
4889                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4890                                     put_byte(sv, *p);
4891                                 sv_catpv(sv, "-");
4892                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4893                                         put_byte(sv, *p);
4894                                 }
4895                                 rangestart = -1;
4896                             }
4897                         }
4898
4899                     sv_catpv(sv, "..."); /* et cetera */
4900                 }
4901
4902                 {
4903                     char *s = savesvpv(lv);
4904                     char *origs = s;
4905
4906                     while(*s && *s != '\n') s++;
4907
4908                     if (*s == '\n') {
4909                         char *t = ++s;
4910
4911                         while (*s) {
4912                             if (*s == '\n')
4913                                 *s = ' ';
4914                             s++;
4915                         }
4916                         if (s[-1] == ' ')
4917                             s[-1] = 0;
4918
4919                         sv_catpv(sv, t);
4920                     }
4921
4922                     Safefree(origs);
4923                 }
4924             }
4925         }
4926
4927         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4928     }
4929     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4930         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4931 #endif  /* DEBUGGING */
4932 }
4933
4934 SV *
4935 Perl_re_intuit_string(pTHX_ regexp *prog)
4936 {                               /* Assume that RE_INTUIT is set */
4937     DEBUG_r(
4938         {   STRLEN n_a;
4939             char *s = SvPV(prog->check_substr
4940                       ? prog->check_substr : prog->check_utf8, n_a);
4941
4942             if (!PL_colorset) reginitcolors();
4943             PerlIO_printf(Perl_debug_log,
4944                       "%sUsing REx %ssubstr:%s `%s%.60s%s%s'\n",
4945                       PL_colors[4],
4946                       prog->check_substr ? "" : "utf8 ",
4947                       PL_colors[5],PL_colors[0],
4948                       s,
4949                       PL_colors[1],
4950                       (strlen(s) > 60 ? "..." : ""));
4951         } );
4952
4953     return prog->check_substr ? prog->check_substr : prog->check_utf8;
4954 }
4955
4956 void
4957 Perl_pregfree(pTHX_ struct regexp *r)
4958 {
4959 #ifdef DEBUGGING
4960     SV *dsv = PERL_DEBUG_PAD_ZERO(0);
4961 #endif
4962
4963     if (!r || (--r->refcnt > 0))
4964         return;
4965     DEBUG_r({
4966          int len;
4967          char *s;
4968
4969          s = (r->reganch & ROPT_UTF8) ? pv_uni_display(dsv, (U8*)r->precomp,
4970                 r->prelen, 60, UNI_DISPLAY_REGEX)
4971             : pv_display(dsv, r->precomp, r->prelen, 0, 60);
4972          len = SvCUR(dsv);
4973          if (!PL_colorset)
4974               reginitcolors();
4975          PerlIO_printf(Perl_debug_log,
4976                        "%sFreeing REx:%s `%s%*.*s%s%s'\n",
4977                        PL_colors[4],PL_colors[5],PL_colors[0],
4978                        len, len, s,
4979                        PL_colors[1],
4980                        len > 60 ? "..." : "");
4981     });
4982
4983     if (r->precomp)
4984         Safefree(r->precomp);
4985     if (r->offsets)             /* 20010421 MJD */
4986         Safefree(r->offsets);
4987     RX_MATCH_COPY_FREE(r);
4988 #ifdef PERL_COPY_ON_WRITE
4989     if (r->saved_copy)
4990         SvREFCNT_dec(r->saved_copy);
4991 #endif
4992     if (r->substrs) {
4993         if (r->anchored_substr)
4994             SvREFCNT_dec(r->anchored_substr);
4995         if (r->anchored_utf8)
4996             SvREFCNT_dec(r->anchored_utf8);
4997         if (r->float_substr)
4998             SvREFCNT_dec(r->float_substr);
4999         if (r->float_utf8)
5000             SvREFCNT_dec(r->float_utf8);
5001         Safefree(r->substrs);
5002     }
5003     if (r->data) {
5004         int n = r->data->count;
5005         PAD* new_comppad = NULL;
5006         PAD* old_comppad;
5007         PADOFFSET refcnt;
5008
5009         while (--n >= 0) {
5010           /* If you add a ->what type here, update the comment in regcomp.h */
5011             switch (r->data->what[n]) {
5012             case 's':
5013                 SvREFCNT_dec((SV*)r->data->data[n]);
5014                 break;
5015             case 'f':
5016                 Safefree(r->data->data[n]);
5017                 break;
5018             case 'p':
5019                 new_comppad = (AV*)r->data->data[n];
5020                 break;
5021             case 'o':
5022                 if (new_comppad == NULL)
5023                     Perl_croak(aTHX_ "panic: pregfree comppad");
5024                 PAD_SAVE_LOCAL(old_comppad,
5025                     /* Watch out for global destruction's random ordering. */
5026                     (SvTYPE(new_comppad) == SVt_PVAV) ?
5027                                 new_comppad : Null(PAD *)
5028                 );
5029                 OP_REFCNT_LOCK;
5030                 refcnt = OpREFCNT_dec((OP_4tree*)r->data->data[n]);
5031                 OP_REFCNT_UNLOCK;
5032                 if (!refcnt)
5033                     op_free((OP_4tree*)r->data->data[n]);
5034
5035                 PAD_RESTORE_LOCAL(old_comppad);
5036                 SvREFCNT_dec((SV*)new_comppad);
5037                 new_comppad = NULL;
5038                 break;
5039             case 'n':
5040                 break;
5041             default:
5042                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
5043             }
5044         }
5045         Safefree(r->data->what);
5046         Safefree(r->data);
5047     }
5048     Safefree(r->startp);
5049     Safefree(r->endp);
5050     Safefree(r);
5051 }
5052
5053 /*
5054  - regnext - dig the "next" pointer out of a node
5055  *
5056  * [Note, when REGALIGN is defined there are two places in regmatch()
5057  * that bypass this code for speed.]
5058  */
5059 regnode *
5060 Perl_regnext(pTHX_ register regnode *p)
5061 {
5062     register I32 offset;
5063
5064     if (p == &PL_regdummy)
5065         return(NULL);
5066
5067     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
5068     if (offset == 0)
5069         return(NULL);
5070
5071     return(p+offset);
5072 }
5073
5074 STATIC void
5075 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
5076 {
5077     va_list args;
5078     STRLEN l1 = strlen(pat1);
5079     STRLEN l2 = strlen(pat2);
5080     char buf[512];
5081     SV *msv;
5082     char *message;
5083
5084     if (l1 > 510)
5085         l1 = 510;
5086     if (l1 + l2 > 510)
5087         l2 = 510 - l1;
5088     Copy(pat1, buf, l1 , char);
5089     Copy(pat2, buf + l1, l2 , char);
5090     buf[l1 + l2] = '\n';
5091     buf[l1 + l2 + 1] = '\0';
5092 #ifdef I_STDARG
5093     /* ANSI variant takes additional second argument */
5094     va_start(args, pat2);
5095 #else
5096     va_start(args);
5097 #endif
5098     msv = vmess(buf, &args);
5099     va_end(args);
5100     message = SvPV(msv,l1);
5101     if (l1 > 512)
5102         l1 = 512;
5103     Copy(message, buf, l1 , char);
5104     buf[l1-1] = '\0';                   /* Overwrite \n */
5105     Perl_croak(aTHX_ "%s", buf);
5106 }
5107
5108 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
5109
5110 void
5111 Perl_save_re_context(pTHX)
5112 {
5113     SAVEI32(PL_reg_flags);              /* from regexec.c */
5114     SAVEPPTR(PL_bostr);
5115     SAVEPPTR(PL_reginput);              /* String-input pointer. */
5116     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
5117     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
5118     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
5119     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
5120     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
5121     SAVEVPTR(PL_reglastcloseparen);     /* Similarly for lastcloseparen. */
5122     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
5123     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
5124     PL_reg_start_tmp = 0;
5125     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
5126     PL_reg_start_tmpl = 0;
5127     SAVEVPTR(PL_regdata);
5128     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
5129     SAVEI32(PL_regnarrate);             /* from regexec.c */
5130     SAVEVPTR(PL_regprogram);            /* from regexec.c */
5131     SAVEINT(PL_regindent);              /* from regexec.c */
5132     SAVEVPTR(PL_regcc);                 /* from regexec.c */
5133     SAVEVPTR(PL_curcop);
5134     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
5135     SAVEVPTR(PL_reg_re);                /* from regexec.c */
5136     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
5137     SAVESPTR(PL_reg_sv);                /* from regexec.c */
5138     SAVEBOOL(PL_reg_match_utf8);        /* from regexec.c */
5139     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
5140     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
5141     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
5142     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
5143     SAVEPPTR(PL_reg_oldsaved);          /* old saved substr during match */
5144     PL_reg_oldsaved = Nullch;
5145     SAVEI32(PL_reg_oldsavedlen);        /* old length of saved substr during match */
5146     PL_reg_oldsavedlen = 0;
5147 #ifdef PERL_COPY_ON_WRITE
5148     SAVESPTR(PL_nrs);
5149     PL_nrs = Nullsv;
5150 #endif
5151     SAVEI32(PL_reg_maxiter);            /* max wait until caching pos */
5152     PL_reg_maxiter = 0;
5153     SAVEI32(PL_reg_leftiter);           /* wait until caching pos */
5154     PL_reg_leftiter = 0;
5155     SAVEGENERICPV(PL_reg_poscache);     /* cache of pos of WHILEM */
5156     PL_reg_poscache = Nullch;
5157     SAVEI32(PL_reg_poscache_size);      /* size of pos cache of WHILEM */
5158     PL_reg_poscache_size = 0;
5159     SAVEPPTR(PL_regprecomp);            /* uncompiled string. */
5160     SAVEI32(PL_regnpar);                /* () count. */
5161     SAVEI32(PL_regsize);                /* from regexec.c */
5162
5163     {
5164         /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
5165         U32 i;
5166         GV *mgv;
5167         REGEXP *rx;
5168         char digits[TYPE_CHARS(long)];
5169
5170         if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
5171             for (i = 1; i <= rx->nparens; i++) {
5172                 sprintf(digits, "%lu", (long)i);
5173                 if ((mgv = gv_fetchpv(digits, FALSE, SVt_PV)))
5174                     save_scalar(mgv);
5175             }
5176         }
5177     }
5178
5179 #ifdef DEBUGGING
5180     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
5181 #endif
5182 }
5183
5184 static void
5185 clear_re(pTHX_ void *r)
5186 {
5187     ReREFCNT_dec((regexp *)r);
5188 }
5189
5190 /*
5191  * Local variables:
5192  * c-indentation-style: bsd
5193  * c-basic-offset: 4
5194  * indent-tabs-mode: t
5195  * End:
5196  *
5197  * vim: shiftwidth=4:
5198 */