regcomp.c

   1 /*    regcomp.c
   2  */
   3
   4 /*
   5  * "A fair jaw-cracker dwarf-language must be."  --Samwise Gamgee
   6  */
   7
   8 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
   9  * confused with the original package (see point 3 below).  Thanks, Henry!
  10  */
  11
  12 /* Additional note: this code is very heavily munged from Henry's version
  13  * in places.  In some spots I've traded clarity for efficiency, so don't
  14  * blame Henry for some of the lack of readability.
  15  */
  16
  17 /* The names of the functions have been changed from regcomp and
  18  * regexec to  pregcomp and pregexec in order to avoid conflicts
  19  * with the POSIX routines of the same names.
  20 */
  21
  22 #ifdef PERL_EXT_RE_BUILD
  23 /* need to replace pregcomp et al, so enable that */
  24 #  ifndef PERL_IN_XSUB_RE
  25 #    define PERL_IN_XSUB_RE
  26 #  endif
  27 /* need access to debugger hooks */
  28 #  if defined(PERL_EXT_RE_DEBUG) && !defined(DEBUGGING)
  29 #    define DEBUGGING
  30 #  endif
  31 #endif
  32
  33 #ifdef PERL_IN_XSUB_RE
  34 /* We *really* need to overwrite these symbols: */
  35 #  define Perl_pregcomp my_regcomp
  36 #  define Perl_regdump my_regdump
  37 #  define Perl_regprop my_regprop
  38 #  define Perl_pregfree my_regfree
  39 #  define Perl_re_intuit_string my_re_intuit_string
  40 /* *These* symbols are masked to allow static link. */
  41 #  define Perl_regnext my_regnext
  42 #  define Perl_save_re_context my_save_re_context
  43 #  define Perl_reginitcolors my_reginitcolors
  44
  45 #  define PERL_NO_GET_CONTEXT
  46 #endif
  47
  48 /*SUPPRESS 112*/
  49 /*
  50  * pregcomp and pregexec -- regsub and regerror are not used in perl
  51  *
  52  *      Copyright (c) 1986 by University of Toronto.
  53  *      Written by Henry Spencer.  Not derived from licensed software.
  54  *
  55  *      Permission is granted to anyone to use this software for any
  56  *      purpose on any computer system, and to redistribute it freely,
  57  *      subject to the following restrictions:
  58  *
  59  *      1. The author is not responsible for the consequences of use of
  60  *              this software, no matter how awful, even if they arise
  61  *              from defects in it.
  62  *
  63  *      2. The origin of this software must not be misrepresented, either
  64  *              by explicit claim or by omission.
  65  *
  66  *      3. Altered versions must be plainly marked as such, and must not
  67  *              be misrepresented as being the original software.
  68  *
  69  *
  70  ****    Alterations to Henry's code are...
  71  ****
  72  ****    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
  73  ****    2000, 2001, 2002, 2003, by Larry Wall and others
  74  ****
  75  ****    You may distribute under the terms of either the GNU General Public
  76  ****    License or the Artistic License, as specified in the README file.
  77
  78  *
  79  * Beware that some of this code is subtly aware of the way operator
  80  * precedence is structured in regular expressions.  Serious changes in
  81  * regular-expression syntax might require a total rethink.
  82  */
  83 #include "EXTERN.h"
  84 #define PERL_IN_REGCOMP_C
  85 #include "perl.h"
  86
  87 #ifndef PERL_IN_XSUB_RE
  88 #  include "INTERN.h"
  89 #endif
  90
  91 #define REG_COMP_C
  92 #include "regcomp.h"
  93
  94 #ifdef op
  95 #undef op
  96 #endif /* op */
  97
  98 #ifdef MSDOS
  99 #  if defined(BUGGY_MSC6)
 100  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
 101 #    pragma optimize("a",off)
 102  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
 103 #    pragma optimize("w",on )
 104 #  endif /* BUGGY_MSC6 */
 105 #endif /* MSDOS */
 106
 107 #ifndef STATIC
 108 #define STATIC  static
 109 #endif
 110
 111 typedef struct RExC_state_t {
 112     U32         flags;                  /* are we folding, multilining? */
 113     char        *precomp;               /* uncompiled string. */
 114     regexp      *rx;
 115     char        *start;                 /* Start of input for compile */
 116     char        *end;                   /* End of input for compile */
 117     char        *parse;                 /* Input-scan pointer. */
 118     I32         whilem_seen;            /* number of WHILEM in this expr */
 119     regnode     *emit_start;            /* Start of emitted-code area */
 120     regnode     *emit;                  /* Code-emit pointer; &regdummy = don't = compiling */
 121     I32         naughty;                /* How bad is this pattern? */
 122     I32         sawback;                /* Did we see \1, ...? */
 123     U32         seen;
 124     I32         size;                   /* Code size. */
 125     I32         npar;                   /* () count. */
 126     I32         extralen;
 127     I32         seen_zerolen;
 128     I32         seen_evals;
 129     I32         utf8;
 130 #if ADD_TO_REGEXEC
 131     char        *starttry;              /* -Dr: where regtry was called. */
 132 #define RExC_starttry   (pRExC_state->starttry)
 133 #endif
 134 } RExC_state_t;
 135
 136 #define RExC_flags      (pRExC_state->flags)
 137 #define RExC_precomp    (pRExC_state->precomp)
 138 #define RExC_rx         (pRExC_state->rx)
 139 #define RExC_start      (pRExC_state->start)
 140 #define RExC_end        (pRExC_state->end)
 141 #define RExC_parse      (pRExC_state->parse)
 142 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
 143 #define RExC_offsets    (pRExC_state->rx->offsets) /* I am not like the others */
 144 #define RExC_emit       (pRExC_state->emit)
 145 #define RExC_emit_start (pRExC_state->emit_start)
 146 #define RExC_naughty    (pRExC_state->naughty)
 147 #define RExC_sawback    (pRExC_state->sawback)
 148 #define RExC_seen       (pRExC_state->seen)
 149 #define RExC_size       (pRExC_state->size)
 150 #define RExC_npar       (pRExC_state->npar)
 151 #define RExC_extralen   (pRExC_state->extralen)
 152 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
 153 #define RExC_seen_evals (pRExC_state->seen_evals)
 154 #define RExC_utf8       (pRExC_state->utf8)
 155
 156 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 157 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
 158         ((*s) == '{' && regcurly(s)))
 159
 160 #ifdef SPSTART
 161 #undef SPSTART          /* dratted cpp namespace... */
 162 #endif
 163 /*
 164  * Flags to be passed up and down.
 165  */
 166 #define WORST           0       /* Worst case. */
 167 #define HASWIDTH        0x1     /* Known to match non-null strings. */
 168 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
 169 #define SPSTART         0x4     /* Starts with * or +. */
 170 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
 171
 172 /* Length of a variant. */
 173
 174 typedef struct scan_data_t {
 175     I32 len_min;
 176     I32 len_delta;
 177     I32 pos_min;
 178     I32 pos_delta;
 179     SV *last_found;
 180     I32 last_end;                       /* min value, <0 unless valid. */
 181     I32 last_start_min;
 182     I32 last_start_max;
 183     SV **longest;                       /* Either &l_fixed, or &l_float. */
 184     SV *longest_fixed;
 185     I32 offset_fixed;
 186     SV *longest_float;
 187     I32 offset_float_min;
 188     I32 offset_float_max;
 189     I32 flags;
 190     I32 whilem_c;
 191     I32 *last_closep;
 192     struct regnode_charclass_class *start_class;
 193 } scan_data_t;
 194
 195 /*
 196  * Forward declarations for pregcomp()'s friends.
 197  */
 198
 199 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 200                                       0, 0, 0, 0, 0, 0};
 201
 202 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 203 #define SF_BEFORE_SEOL          0x1
 204 #define SF_BEFORE_MEOL          0x2
 205 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
 206 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
 207
 208 #ifdef NO_UNARY_PLUS
 209 #  define SF_FIX_SHIFT_EOL      (0+2)
 210 #  define SF_FL_SHIFT_EOL               (0+4)
 211 #else
 212 #  define SF_FIX_SHIFT_EOL      (+2)
 213 #  define SF_FL_SHIFT_EOL               (+4)
 214 #endif
 215
 216 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
 217 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
 218
 219 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
 220 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
 221 #define SF_IS_INF               0x40
 222 #define SF_HAS_PAR              0x80
 223 #define SF_IN_PAR               0x100
 224 #define SF_HAS_EVAL             0x200
 225 #define SCF_DO_SUBSTR           0x400
 226 #define SCF_DO_STCLASS_AND      0x0800
 227 #define SCF_DO_STCLASS_OR       0x1000
 228 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 229 #define SCF_WHILEM_VISITED_POS  0x2000
 230
 231 #define UTF (RExC_utf8 != 0)
 232 #define LOC ((RExC_flags & PMf_LOCALE) != 0)
 233 #define FOLD ((RExC_flags & PMf_FOLD) != 0)
 234
 235 #define OOB_UNICODE             12345678
 236 #define OOB_NAMEDCLASS          -1
 237
 238 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 239 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 240
 241
 242 /* length of regex to show in messages that don't mark a position within */
 243 #define RegexLengthToShowInErrorMessages 127
 244
 245 /*
 246  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
 247  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
 248  * op/pragma/warn/regcomp.
 249  */
 250 #define MARKER1 "<-- HERE"    /* marker as it appears in the description */
 251 #define MARKER2 " <-- HERE "  /* marker as it appears within the regex */
 252
 253 #define REPORT_LOCATION " in regex; marked by " MARKER1 " in m/%.*s" MARKER2 "%s/"
 254
 255 /*
 256  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 257  * arg. Show regex, up to a maximum length. If it's too long, chop and add
 258  * "...".
 259  */
 260 #define FAIL(msg) STMT_START {                                          \
 261     char *ellipses = "";                                                \
 262     IV len = RExC_end - RExC_precomp;                                   \
 263                                                                         \
 264     if (!SIZE_ONLY)                                                     \
 265         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                      \
 266     if (len > RegexLengthToShowInErrorMessages) {                       \
 267         /* chop 10 shorter than the max, to ensure meaning of "..." */  \
 268         len = RegexLengthToShowInErrorMessages - 10;                    \
 269         ellipses = "...";                                               \
 270     }                                                                   \
 271     Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                           \
 272             msg, (int)len, RExC_precomp, ellipses);                     \
 273 } STMT_END
 274
 275 /*
 276  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 277  * args. Show regex, up to a maximum length. If it's too long, chop and add
 278  * "...".
 279  */
 280 #define FAIL2(pat,msg) STMT_START {                                     \
 281     char *ellipses = "";                                                \
 282     IV len = RExC_end - RExC_precomp;                                   \
 283                                                                         \
 284     if (!SIZE_ONLY)                                                     \
 285         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                      \
 286     if (len > RegexLengthToShowInErrorMessages) {                       \
 287         /* chop 10 shorter than the max, to ensure meaning of "..." */  \
 288         len = RegexLengthToShowInErrorMessages - 10;                    \
 289         ellipses = "...";                                               \
 290     }                                                                   \
 291     S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                       \
 292             msg, (int)len, RExC_precomp, ellipses);                     \
 293 } STMT_END
 294
 295
 296 /*
 297  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
 298  */
 299 #define Simple_vFAIL(m) STMT_START {                                    \
 300     IV offset = RExC_parse - RExC_precomp;                              \
 301     Perl_croak(aTHX_ "%s" REPORT_LOCATION,                              \
 302             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 303 } STMT_END
 304
 305 /*
 306  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
 307  */
 308 #define vFAIL(m) STMT_START {                           \
 309     if (!SIZE_ONLY)                                     \
 310         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 311     Simple_vFAIL(m);                                    \
 312 } STMT_END
 313
 314 /*
 315  * Like Simple_vFAIL(), but accepts two arguments.
 316  */
 317 #define Simple_vFAIL2(m,a1) STMT_START {                        \
 318     IV offset = RExC_parse - RExC_precomp;                      \
 319     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,                   \
 320             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 321 } STMT_END
 322
 323 /*
 324  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
 325  */
 326 #define vFAIL2(m,a1) STMT_START {                       \
 327     if (!SIZE_ONLY)                                     \
 328         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 329     Simple_vFAIL2(m, a1);                               \
 330 } STMT_END
 331
 332
 333 /*
 334  * Like Simple_vFAIL(), but accepts three arguments.
 335  */
 336 #define Simple_vFAIL3(m, a1, a2) STMT_START {                   \
 337     IV offset = RExC_parse - RExC_precomp;                      \
 338     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,               \
 339             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 340 } STMT_END
 341
 342 /*
 343  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
 344  */
 345 #define vFAIL3(m,a1,a2) STMT_START {                    \
 346     if (!SIZE_ONLY)                                     \
 347         SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);      \
 348     Simple_vFAIL3(m, a1, a2);                           \
 349 } STMT_END
 350
 351 /*
 352  * Like Simple_vFAIL(), but accepts four arguments.
 353  */
 354 #define Simple_vFAIL4(m, a1, a2, a3) STMT_START {               \
 355     IV offset = RExC_parse - RExC_precomp;                      \
 356     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,           \
 357             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 358 } STMT_END
 359
 360 /*
 361  * Like Simple_vFAIL(), but accepts five arguments.
 362  */
 363 #define Simple_vFAIL5(m, a1, a2, a3, a4) STMT_START {           \
 364     IV offset = RExC_parse - RExC_precomp;                      \
 365     S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,       \
 366             (int)offset, RExC_precomp, RExC_precomp + offset);  \
 367 } STMT_END
 368
 369
 370 #define vWARN(loc,m) STMT_START {                                       \
 371     IV offset = loc - RExC_precomp;                                     \
 372     Perl_warner(aTHX_ packWARN(WARN_REGEXP), "%s" REPORT_LOCATION,      \
 373             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 374 } STMT_END
 375
 376 #define vWARNdep(loc,m) STMT_START {                                    \
 377     IV offset = loc - RExC_precomp;                                     \
 378     Perl_warner(aTHX_ packWARN2(WARN_DEPRECATED, WARN_REGEXP),          \
 379             "%s" REPORT_LOCATION,                                       \
 380             m, (int)offset, RExC_precomp, RExC_precomp + offset);       \
 381 } STMT_END
 382
 383
 384 #define vWARN2(loc, m, a1) STMT_START {                                 \
 385     IV offset = loc - RExC_precomp;                                     \
 386     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 387             a1, (int)offset, RExC_precomp, RExC_precomp + offset);      \
 388 } STMT_END
 389
 390 #define vWARN3(loc, m, a1, a2) STMT_START {                             \
 391     IV offset = loc - RExC_precomp;                                     \
 392     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 393             a1, a2, (int)offset, RExC_precomp, RExC_precomp + offset);  \
 394 } STMT_END
 395
 396 #define vWARN4(loc, m, a1, a2, a3) STMT_START {                         \
 397     IV offset = loc - RExC_precomp;                                     \
 398     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 399             a1, a2, a3, (int)offset, RExC_precomp, RExC_precomp + offset); \
 400 } STMT_END
 401
 402 #define vWARN5(loc, m, a1, a2, a3, a4) STMT_START {                     \
 403     IV offset = loc - RExC_precomp;                                     \
 404     Perl_warner(aTHX_ packWARN(WARN_REGEXP), m REPORT_LOCATION,         \
 405             a1, a2, a3, a4, (int)offset, RExC_precomp, RExC_precomp + offset); \
 406 } STMT_END
 407
 408
 409 /* Allow for side effects in s */
 410 #define REGC(c,s) STMT_START {                  \
 411     if (!SIZE_ONLY) *(s) = (c); else (void)(s); \
 412 } STMT_END
 413
 414 /* Macros for recording node offsets.   20001227 mjd@plover.com
 415  * Nodes are numbered 1, 2, 3, 4.  Node #n's position is recorded in
 416  * element 2*n-1 of the array.  Element #2n holds the byte length node #n.
 417  * Element 0 holds the number n.
 418  */
 419
 420 #define MJD_OFFSET_DEBUG(x)
 421 /* #define MJD_OFFSET_DEBUG(x) Perl_warn_nocontext x */
 422
 423
 424 #define Set_Node_Offset_To_R(node,byte) STMT_START {                    \
 425     if (! SIZE_ONLY) {                                                  \
 426         MJD_OFFSET_DEBUG(("** (%d) offset of node %d is %d.\n",         \
 427                 __LINE__, (node), (byte)));                             \
 428         if((node) < 0) {                                                \
 429             Perl_croak(aTHX_ "value of node is %d in Offset macro", node); \
 430         } else {                                                        \
 431             RExC_offsets[2*(node)-1] = (byte);                          \
 432         }                                                               \
 433     }                                                                   \
 434 } STMT_END
 435
 436 #define Set_Node_Offset(node,byte) \
 437     Set_Node_Offset_To_R((node)-RExC_emit_start, (byte)-RExC_start)
 438 #define Set_Cur_Node_Offset Set_Node_Offset(RExC_emit, RExC_parse)
 439
 440 #define Set_Node_Length_To_R(node,len) STMT_START {                     \
 441     if (! SIZE_ONLY) {                                                  \
 442         MJD_OFFSET_DEBUG(("** (%d) size of node %d is %d.\n",           \
 443                 __LINE__, (node), (len)));                              \
 444         if((node) < 0) {                                                \
 445             Perl_croak(aTHX_ "value of node is %d in Length macro", node); \
 446         } else {                                                        \
 447             RExC_offsets[2*(node)] = (len);                             \
 448         }                                                               \
 449     }                                                                   \
 450 } STMT_END
 451
 452 #define Set_Node_Length(node,len) \
 453     Set_Node_Length_To_R((node)-RExC_emit_start, len)
 454 #define Set_Cur_Node_Length(len) Set_Node_Length(RExC_emit, len)
 455 #define Set_Node_Cur_Length(node) \
 456     Set_Node_Length(node, RExC_parse - parse_start)
 457
 458 /* Get offsets and lengths */
 459 #define Node_Offset(n) (RExC_offsets[2*((n)-RExC_emit_start)-1])
 460 #define Node_Length(n) (RExC_offsets[2*((n)-RExC_emit_start)])
 461
 462 static void clear_re(pTHX_ void *r);
 463
 464 /* Mark that we cannot extend a found fixed substring at this point.
 465    Updata the longest found anchored substring and the longest found
 466    floating substrings if needed. */
 467
 468 STATIC void
 469 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 470 {
 471     STRLEN l = CHR_SVLEN(data->last_found);
 472     STRLEN old_l = CHR_SVLEN(*data->longest);
 473
 474     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
 475         SvSetMagicSV(*data->longest, data->last_found);
 476         if (*data->longest == data->longest_fixed) {
 477             data->offset_fixed = l ? data->last_start_min : data->pos_min;
 478             if (data->flags & SF_BEFORE_EOL)
 479                 data->flags
 480                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
 481             else
 482                 data->flags &= ~SF_FIX_BEFORE_EOL;
 483         }
 484         else {
 485             data->offset_float_min = l ? data->last_start_min : data->pos_min;
 486             data->offset_float_max = (l
 487                                       ? data->last_start_max
 488                                       : data->pos_min + data->pos_delta);
 489             if ((U32)data->offset_float_max > (U32)I32_MAX)
 490                 data->offset_float_max = I32_MAX;
 491             if (data->flags & SF_BEFORE_EOL)
 492                 data->flags
 493                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
 494             else
 495                 data->flags &= ~SF_FL_BEFORE_EOL;
 496         }
 497     }
 498     SvCUR_set(data->last_found, 0);
 499     {
 500         SV * sv = data->last_found;
 501         MAGIC *mg =
 502             SvUTF8(sv) && SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_utf8) : NULL;
 503         if (mg && mg->mg_len > 0)
 504             mg->mg_len = 0;
 505     }
 506     data->last_end = -1;
 507     data->flags &= ~SF_BEFORE_EOL;
 508 }
 509
 510 /* Can match anything (initialization) */
 511 STATIC void
 512 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 513 {
 514     ANYOF_CLASS_ZERO(cl);
 515     ANYOF_BITMAP_SETALL(cl);
 516     cl->flags = ANYOF_EOS|ANYOF_UNICODE_ALL;
 517     if (LOC)
 518         cl->flags |= ANYOF_LOCALE;
 519 }
 520
 521 /* Can match anything (initialization) */
 522 STATIC int
 523 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
 524 {
 525     int value;
 526
 527     for (value = 0; value <= ANYOF_MAX; value += 2)
 528         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
 529             return 1;
 530     if (!(cl->flags & ANYOF_UNICODE_ALL))
 531         return 0;
 532     if (!ANYOF_BITMAP_TESTALLSET(cl))
 533         return 0;
 534     return 1;
 535 }
 536
 537 /* Can match anything (initialization) */
 538 STATIC void
 539 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 540 {
 541     Zero(cl, 1, struct regnode_charclass_class);
 542     cl->type = ANYOF;
 543     cl_anything(pRExC_state, cl);
 544 }
 545
 546 STATIC void
 547 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 548 {
 549     Zero(cl, 1, struct regnode_charclass_class);
 550     cl->type = ANYOF;
 551     cl_anything(pRExC_state, cl);
 552     if (LOC)
 553         cl->flags |= ANYOF_LOCALE;
 554 }
 555
 556 /* 'And' a given class with another one.  Can create false positives */
 557 /* We assume that cl is not inverted */
 558 STATIC void
 559 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 560          struct regnode_charclass_class *and_with)
 561 {
 562     if (!(and_with->flags & ANYOF_CLASS)
 563         && !(cl->flags & ANYOF_CLASS)
 564         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 565         && !(and_with->flags & ANYOF_FOLD)
 566         && !(cl->flags & ANYOF_FOLD)) {
 567         int i;
 568
 569         if (and_with->flags & ANYOF_INVERT)
 570             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 571                 cl->bitmap[i] &= ~and_with->bitmap[i];
 572         else
 573             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 574                 cl->bitmap[i] &= and_with->bitmap[i];
 575     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
 576     if (!(and_with->flags & ANYOF_EOS))
 577         cl->flags &= ~ANYOF_EOS;
 578
 579     if (cl->flags & ANYOF_UNICODE_ALL && and_with->flags & ANYOF_UNICODE &&
 580         !(and_with->flags & ANYOF_INVERT)) {
 581         cl->flags &= ~ANYOF_UNICODE_ALL;
 582         cl->flags |= ANYOF_UNICODE;
 583         ARG_SET(cl, ARG(and_with));
 584     }
 585     if (!(and_with->flags & ANYOF_UNICODE_ALL) &&
 586         !(and_with->flags & ANYOF_INVERT))
 587         cl->flags &= ~ANYOF_UNICODE_ALL;
 588     if (!(and_with->flags & (ANYOF_UNICODE|ANYOF_UNICODE_ALL)) &&
 589         !(and_with->flags & ANYOF_INVERT))
 590         cl->flags &= ~ANYOF_UNICODE;
 591 }
 592
 593 /* 'OR' a given class with another one.  Can create false positives */
 594 /* We assume that cl is not inverted */
 595 STATIC void
 596 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 597 {
 598     if (or_with->flags & ANYOF_INVERT) {
 599         /* We do not use
 600          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
 601          *   <= (B1 | !B2) | (CL1 | !CL2)
 602          * which is wasteful if CL2 is small, but we ignore CL2:
 603          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
 604          * XXXX Can we handle case-fold?  Unclear:
 605          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
 606          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
 607          */
 608         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 609              && !(or_with->flags & ANYOF_FOLD)
 610              && !(cl->flags & ANYOF_FOLD) ) {
 611             int i;
 612
 613             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 614                 cl->bitmap[i] |= ~or_with->bitmap[i];
 615         } /* XXXX: logic is complicated otherwise */
 616         else {
 617             cl_anything(pRExC_state, cl);
 618         }
 619     } else {
 620         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
 621         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 622              && (!(or_with->flags & ANYOF_FOLD)
 623                  || (cl->flags & ANYOF_FOLD)) ) {
 624             int i;
 625
 626             /* OR char bitmap and class bitmap separately */
 627             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 628                 cl->bitmap[i] |= or_with->bitmap[i];
 629             if (or_with->flags & ANYOF_CLASS) {
 630                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
 631                     cl->classflags[i] |= or_with->classflags[i];
 632                 cl->flags |= ANYOF_CLASS;
 633             }
 634         }
 635         else { /* XXXX: logic is complicated, leave it along for a moment. */
 636             cl_anything(pRExC_state, cl);
 637         }
 638     }
 639     if (or_with->flags & ANYOF_EOS)
 640         cl->flags |= ANYOF_EOS;
 641
 642     if (cl->flags & ANYOF_UNICODE && or_with->flags & ANYOF_UNICODE &&
 643         ARG(cl) != ARG(or_with)) {
 644         cl->flags |= ANYOF_UNICODE_ALL;
 645         cl->flags &= ~ANYOF_UNICODE;
 646     }
 647     if (or_with->flags & ANYOF_UNICODE_ALL) {
 648         cl->flags |= ANYOF_UNICODE_ALL;
 649         cl->flags &= ~ANYOF_UNICODE;
 650     }
 651 }
 652
 653 /*
 654  * There are strange code-generation bugs caused on sparc64 by gcc-2.95.2.
 655  * These need to be revisited when a newer toolchain becomes available.
 656  */
 657 #if defined(__sparc64__) && defined(__GNUC__)
 658 #   if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
 659 #       undef  SPARC64_GCC_WORKAROUND
 660 #       define SPARC64_GCC_WORKAROUND 1
 661 #   endif
 662 #endif
 663
 664 /* REx optimizer.  Converts nodes into quickier variants "in place".
 665    Finds fixed substrings.  */
 666
 667 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
 668    to the position after last scanned or to NULL. */
 669
 670 STATIC I32
 671 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
 672                         /* scanp: Start here (read-write). */
 673                         /* deltap: Write maxlen-minlen here. */
 674                         /* last: Stop before this one. */
 675 {
 676     I32 min = 0, pars = 0, code;
 677     regnode *scan = *scanp, *next;
 678     I32 delta = 0;
 679     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
 680     int is_inf_internal = 0;            /* The studied chunk is infinite */
 681     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
 682     scan_data_t data_fake;
 683     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
 684
 685     while (scan && OP(scan) != END && scan < last) {
 686         /* Peephole optimizer: */
 687
 688         if (PL_regkind[(U8)OP(scan)] == EXACT) {
 689             /* Merge several consecutive EXACTish nodes into one. */
 690             regnode *n = regnext(scan);
 691             U32 stringok = 1;
 692 #ifdef DEBUGGING
 693             regnode *stop = scan;
 694 #endif
 695
 696             next = scan + NODE_SZ_STR(scan);
 697             /* Skip NOTHING, merge EXACT*. */
 698             while (n &&
 699                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
 700                      (stringok && (OP(n) == OP(scan))))
 701                    && NEXT_OFF(n)
 702                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
 703                 if (OP(n) == TAIL || n > next)
 704                     stringok = 0;
 705                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
 706                     NEXT_OFF(scan) += NEXT_OFF(n);
 707                     next = n + NODE_STEP_REGNODE;
 708 #ifdef DEBUGGING
 709                     if (stringok)
 710                         stop = n;
 711 #endif
 712                     n = regnext(n);
 713                 }
 714                 else if (stringok) {
 715                     int oldl = STR_LEN(scan);
 716                     regnode *nnext = regnext(n);
 717
 718                     if (oldl + STR_LEN(n) > U8_MAX)
 719                         break;
 720                     NEXT_OFF(scan) += NEXT_OFF(n);
 721                     STR_LEN(scan) += STR_LEN(n);
 722                     next = n + NODE_SZ_STR(n);
 723                     /* Now we can overwrite *n : */
 724                     Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
 725 #ifdef DEBUGGING
 726                     stop = next - 1;
 727 #endif
 728                     n = nnext;
 729                 }
 730             }
 731
 732             if (UTF && OP(scan) == EXACTF && STR_LEN(scan) >= 6) {
 733 /*
 734   Two problematic code points in Unicode casefolding of EXACT nodes:
 735
 736    U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
 737    U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
 738
 739    which casefold to
 740
 741    Unicode                      UTF-8
 742
 743    U+03B9 U+0308 U+0301         0xCE 0xB9 0xCC 0x88 0xCC 0x81
 744    U+03C5 U+0308 U+0301         0xCF 0x85 0xCC 0x88 0xCC 0x81
 745
 746    This means that in case-insensitive matching (or "loose matching",
 747    as Unicode calls it), an EXACTF of length six (the UTF-8 encoded byte
 748    length of the above casefolded versions) can match a target string
 749    of length two (the byte length of UTF-8 encoded U+0390 or U+03B0).
 750    This would rather mess up the minimum length computation.
 751
 752    What we'll do is to look for the tail four bytes, and then peek
 753    at the preceding two bytes to see whether we need to decrease
 754    the minimum length by four (six minus two).
 755
 756    Thanks to the design of UTF-8, there cannot be false matches:
 757    A sequence of valid UTF-8 bytes cannot be a subsequence of
 758    another valid sequence of UTF-8 bytes.
 759
 760 */
 761                  char *s0 = STRING(scan), *s, *t;
 762                  char *s1 = s0 + STR_LEN(scan) - 1, *s2 = s1 - 4;
 763                  char *t0 = "\xcc\x88\xcc\x81";
 764                  char *t1 = t0 + 3;
 765
 766                  for (s = s0 + 2;
 767                       s < s2 && (t = ninstr(s, s1, t0, t1));
 768                       s = t + 4) {
 769                       if (((U8)t[-1] == 0xB9 && (U8)t[-2] == 0xCE) ||
 770                           ((U8)t[-1] == 0x85 && (U8)t[-2] == 0xCF))
 771                            min -= 4;
 772                  }
 773             }
 774
 775 #ifdef DEBUGGING
 776             /* Allow dumping */
 777             n = scan + NODE_SZ_STR(scan);
 778             while (n <= stop) {
 779                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
 780                     OP(n) = OPTIMIZED;
 781                     NEXT_OFF(n) = 0;
 782                 }
 783                 n++;
 784             }
 785 #endif
 786         }
 787         /* Follow the next-chain of the current node and optimize
 788            away all the NOTHINGs from it.  */
 789         if (OP(scan) != CURLYX) {
 790             int max = (reg_off_by_arg[OP(scan)]
 791                        ? I32_MAX
 792                        /* I32 may be smaller than U16 on CRAYs! */
 793                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
 794             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
 795             int noff;
 796             regnode *n = scan;
 797
 798             /* Skip NOTHING and LONGJMP. */
 799             while ((n = regnext(n))
 800                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
 801                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
 802                    && off + noff < max)
 803                 off += noff;
 804             if (reg_off_by_arg[OP(scan)])
 805                 ARG(scan) = off;
 806             else
 807                 NEXT_OFF(scan) = off;
 808         }
 809         /* The principal pseudo-switch.  Cannot be a switch, since we
 810            look into several different things.  */
 811         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
 812                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
 813             next = regnext(scan);
 814             code = OP(scan);
 815
 816             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
 817                 I32 max1 = 0, min1 = I32_MAX, num = 0;
 818                 struct regnode_charclass_class accum;
 819
 820                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
 821                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
 822                 if (flags & SCF_DO_STCLASS)
 823                     cl_init_zero(pRExC_state, &accum);
 824                 while (OP(scan) == code) {
 825                     I32 deltanext, minnext, f = 0, fake;
 826                     struct regnode_charclass_class this_class;
 827
 828                     num++;
 829                     data_fake.flags = 0;
 830                     if (data) {
 831                         data_fake.whilem_c = data->whilem_c;
 832                         data_fake.last_closep = data->last_closep;
 833                     }
 834                     else
 835                         data_fake.last_closep = &fake;
 836                     next = regnext(scan);
 837                     scan = NEXTOPER(scan);
 838                     if (code != BRANCH)
 839                         scan = NEXTOPER(scan);
 840                     if (flags & SCF_DO_STCLASS) {
 841                         cl_init(pRExC_state, &this_class);
 842                         data_fake.start_class = &this_class;
 843                         f = SCF_DO_STCLASS_AND;
 844                     }
 845                     if (flags & SCF_WHILEM_VISITED_POS)
 846                         f |= SCF_WHILEM_VISITED_POS;
 847                     /* we suppose the run is continuous, last=next...*/
 848                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
 849                                           next, &data_fake, f);
 850                     if (min1 > minnext)
 851                         min1 = minnext;
 852                     if (max1 < minnext + deltanext)
 853                         max1 = minnext + deltanext;
 854                     if (deltanext == I32_MAX)
 855                         is_inf = is_inf_internal = 1;
 856                     scan = next;
 857                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
 858                         pars++;
 859                     if (data && (data_fake.flags & SF_HAS_EVAL))
 860                         data->flags |= SF_HAS_EVAL;
 861                     if (data)
 862                         data->whilem_c = data_fake.whilem_c;
 863                     if (flags & SCF_DO_STCLASS)
 864                         cl_or(pRExC_state, &accum, &this_class);
 865                     if (code == SUSPEND)
 866                         break;
 867                 }
 868                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
 869                     min1 = 0;
 870                 if (flags & SCF_DO_SUBSTR) {
 871                     data->pos_min += min1;
 872                     data->pos_delta += max1 - min1;
 873                     if (max1 != min1 || is_inf)
 874                         data->longest = &(data->longest_float);
 875                 }
 876                 min += min1;
 877                 delta += max1 - min1;
 878                 if (flags & SCF_DO_STCLASS_OR) {
 879                     cl_or(pRExC_state, data->start_class, &accum);
 880                     if (min1) {
 881                         cl_and(data->start_class, &and_with);
 882                         flags &= ~SCF_DO_STCLASS;
 883                     }
 884                 }
 885                 else if (flags & SCF_DO_STCLASS_AND) {
 886                     if (min1) {
 887                         cl_and(data->start_class, &accum);
 888                         flags &= ~SCF_DO_STCLASS;
 889                     }
 890                     else {
 891                         /* Switch to OR mode: cache the old value of
 892                          * data->start_class */
 893                         StructCopy(data->start_class, &and_with,
 894                                    struct regnode_charclass_class);
 895                         flags &= ~SCF_DO_STCLASS_AND;
 896                         StructCopy(&accum, data->start_class,
 897                                    struct regnode_charclass_class);
 898                         flags |= SCF_DO_STCLASS_OR;
 899                         data->start_class->flags |= ANYOF_EOS;
 900                     }
 901                 }
 902             }
 903             else if (code == BRANCHJ)   /* single branch is optimized. */
 904                 scan = NEXTOPER(NEXTOPER(scan));
 905             else                        /* single branch is optimized. */
 906                 scan = NEXTOPER(scan);
 907             continue;
 908         }
 909         else if (OP(scan) == EXACT) {
 910             I32 l = STR_LEN(scan);
 911             UV uc = *((U8*)STRING(scan));
 912             if (UTF) {
 913                 U8 *s = (U8*)STRING(scan);
 914                 l = utf8_length(s, s + l);
 915                 uc = utf8_to_uvchr(s, NULL);
 916             }
 917             min += l;
 918             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
 919                 /* The code below prefers earlier match for fixed
 920                    offset, later match for variable offset.  */
 921                 if (data->last_end == -1) { /* Update the start info. */
 922                     data->last_start_min = data->pos_min;
 923                     data->last_start_max = is_inf
 924                         ? I32_MAX : data->pos_min + data->pos_delta;
 925                 }
 926                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
 927                 {
 928                     SV * sv = data->last_found;
 929                     MAGIC *mg = SvUTF8(sv) && SvMAGICAL(sv) ?
 930                         mg_find(sv, PERL_MAGIC_utf8) : NULL;
 931                     if (mg && mg->mg_len >= 0)
 932                         mg->mg_len += utf8_length((U8*)STRING(scan),
 933                                                   (U8*)STRING(scan)+STR_LEN(scan));
 934                 }
 935                 if (UTF)
 936                     SvUTF8_on(data->last_found);
 937                 data->last_end = data->pos_min + l;
 938                 data->pos_min += l; /* As in the first entry. */
 939                 data->flags &= ~SF_BEFORE_EOL;
 940             }
 941             if (flags & SCF_DO_STCLASS_AND) {
 942                 /* Check whether it is compatible with what we know already! */
 943                 int compat = 1;
 944
 945                 if (uc >= 0x100 ||
 946                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 947                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 948                     && (!(data->start_class->flags & ANYOF_FOLD)
 949                         || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 950                     )
 951                     compat = 0;
 952                 ANYOF_CLASS_ZERO(data->start_class);
 953                 ANYOF_BITMAP_ZERO(data->start_class);
 954                 if (compat)
 955                     ANYOF_BITMAP_SET(data->start_class, uc);
 956                 data->start_class->flags &= ~ANYOF_EOS;
 957                 if (uc < 0x100)
 958                   data->start_class->flags &= ~ANYOF_UNICODE_ALL;
 959             }
 960             else if (flags & SCF_DO_STCLASS_OR) {
 961                 /* false positive possible if the class is case-folded */
 962                 if (uc < 0x100)
 963                     ANYOF_BITMAP_SET(data->start_class, uc);
 964                 else
 965                     data->start_class->flags |= ANYOF_UNICODE_ALL;
 966                 data->start_class->flags &= ~ANYOF_EOS;
 967                 cl_and(data->start_class, &and_with);
 968             }
 969             flags &= ~SCF_DO_STCLASS;
 970         }
 971         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
 972             I32 l = STR_LEN(scan);
 973             UV uc = *((U8*)STRING(scan));
 974
 975             /* Search for fixed substrings supports EXACT only. */
 976             if (flags & SCF_DO_SUBSTR)
 977                 scan_commit(pRExC_state, data);
 978             if (UTF) {
 979                 U8 *s = (U8 *)STRING(scan);
 980                 l = utf8_length(s, s + l);
 981                 uc = utf8_to_uvchr(s, NULL);
 982             }
 983             min += l;
 984             if (data && (flags & SCF_DO_SUBSTR))
 985                 data->pos_min += l;
 986             if (flags & SCF_DO_STCLASS_AND) {
 987                 /* Check whether it is compatible with what we know already! */
 988                 int compat = 1;
 989
 990                 if (uc >= 0x100 ||
 991                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 992                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 993                      && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 994                     compat = 0;
 995                 ANYOF_CLASS_ZERO(data->start_class);
 996                 ANYOF_BITMAP_ZERO(data->start_class);
 997                 if (compat) {
 998                     ANYOF_BITMAP_SET(data->start_class, uc);
 999                     data->start_class->flags &= ~ANYOF_EOS;
1000                     data->start_class->flags |= ANYOF_FOLD;
1001                     if (OP(scan) == EXACTFL)
1002                         data->start_class->flags |= ANYOF_LOCALE;
1003                 }
1004             }
1005             else if (flags & SCF_DO_STCLASS_OR) {
1006                 if (data->start_class->flags & ANYOF_FOLD) {
1007                     /* false positive possible if the class is case-folded.
1008                        Assume that the locale settings are the same... */
1009                     if (uc < 0x100)
1010                         ANYOF_BITMAP_SET(data->start_class, uc);
1011                     data->start_class->flags &= ~ANYOF_EOS;
1012                 }
1013                 cl_and(data->start_class, &and_with);
1014             }
1015             flags &= ~SCF_DO_STCLASS;
1016         }
1017         else if (strchr((char*)PL_varies,OP(scan))) {
1018             I32 mincount, maxcount, minnext, deltanext, fl = 0;
1019             I32 f = flags, pos_before = 0;
1020             regnode *oscan = scan;
1021             struct regnode_charclass_class this_class;
1022             struct regnode_charclass_class *oclass = NULL;
1023             I32 next_is_eval = 0;
1024
1025             switch (PL_regkind[(U8)OP(scan)]) {
1026             case WHILEM:                /* End of (?:...)* . */
1027                 scan = NEXTOPER(scan);
1028                 goto finish;
1029             case PLUS:
1030                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
1031                     next = NEXTOPER(scan);
1032                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
1033                         mincount = 1;
1034                         maxcount = REG_INFTY;
1035                         next = regnext(scan);
1036                         scan = NEXTOPER(scan);
1037                         goto do_curly;
1038                     }
1039                 }
1040                 if (flags & SCF_DO_SUBSTR)
1041                     data->pos_min++;
1042                 min++;
1043                 /* Fall through. */
1044             case STAR:
1045                 if (flags & SCF_DO_STCLASS) {
1046                     mincount = 0;
1047                     maxcount = REG_INFTY;
1048                     next = regnext(scan);
1049                     scan = NEXTOPER(scan);
1050                     goto do_curly;
1051                 }
1052                 is_inf = is_inf_internal = 1;
1053                 scan = regnext(scan);
1054                 if (flags & SCF_DO_SUBSTR) {
1055                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
1056                     data->longest = &(data->longest_float);
1057                 }
1058                 goto optimize_curly_tail;
1059             case CURLY:
1060                 mincount = ARG1(scan);
1061                 maxcount = ARG2(scan);
1062                 next = regnext(scan);
1063                 if (OP(scan) == CURLYX) {
1064                     I32 lp = (data ? *(data->last_closep) : 0);
1065
1066                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
1067                 }
1068                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
1069                 next_is_eval = (OP(scan) == EVAL);
1070               do_curly:
1071                 if (flags & SCF_DO_SUBSTR) {
1072                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
1073                     pos_before = data->pos_min;
1074                 }
1075                 if (data) {
1076                     fl = data->flags;
1077                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
1078                     if (is_inf)
1079                         data->flags |= SF_IS_INF;
1080                 }
1081                 if (flags & SCF_DO_STCLASS) {
1082                     cl_init(pRExC_state, &this_class);
1083                     oclass = data->start_class;
1084                     data->start_class = &this_class;
1085                     f |= SCF_DO_STCLASS_AND;
1086                     f &= ~SCF_DO_STCLASS_OR;
1087                 }
1088                 /* These are the cases when once a subexpression
1089                    fails at a particular position, it cannot succeed
1090                    even after backtracking at the enclosing scope.
1091
1092                    XXXX what if minimal match and we are at the
1093                         initial run of {n,m}? */
1094                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
1095                     f &= ~SCF_WHILEM_VISITED_POS;
1096
1097                 /* This will finish on WHILEM, setting scan, or on NULL: */
1098                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
1099                                       mincount == 0
1100                                         ? (f & ~SCF_DO_SUBSTR) : f);
1101
1102                 if (flags & SCF_DO_STCLASS)
1103                     data->start_class = oclass;
1104                 if (mincount == 0 || minnext == 0) {
1105                     if (flags & SCF_DO_STCLASS_OR) {
1106                         cl_or(pRExC_state, data->start_class, &this_class);
1107                     }
1108                     else if (flags & SCF_DO_STCLASS_AND) {
1109                         /* Switch to OR mode: cache the old value of
1110                          * data->start_class */
1111                         StructCopy(data->start_class, &and_with,
1112                                    struct regnode_charclass_class);
1113                         flags &= ~SCF_DO_STCLASS_AND;
1114                         StructCopy(&this_class, data->start_class,
1115                                    struct regnode_charclass_class);
1116                         flags |= SCF_DO_STCLASS_OR;
1117                         data->start_class->flags |= ANYOF_EOS;
1118                     }
1119                 } else {                /* Non-zero len */
1120                     if (flags & SCF_DO_STCLASS_OR) {
1121                         cl_or(pRExC_state, data->start_class, &this_class);
1122                         cl_and(data->start_class, &and_with);
1123                     }
1124                     else if (flags & SCF_DO_STCLASS_AND)
1125                         cl_and(data->start_class, &this_class);
1126                     flags &= ~SCF_DO_STCLASS;
1127                 }
1128                 if (!scan)              /* It was not CURLYX, but CURLY. */
1129                     scan = next;
1130                 if (ckWARN(WARN_REGEXP)
1131                        /* ? quantifier ok, except for (?{ ... }) */
1132                     && (next_is_eval || !(mincount == 0 && maxcount == 1))
1133                     && (minnext == 0) && (deltanext == 0)
1134                     && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1135                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1136                 {
1137                     vWARN(RExC_parse,
1138                           "Quantifier unexpected on zero-length expression");
1139                 }
1140
1141                 min += minnext * mincount;
1142                 is_inf_internal |= ((maxcount == REG_INFTY
1143                                      && (minnext + deltanext) > 0)
1144                                     || deltanext == I32_MAX);
1145                 is_inf |= is_inf_internal;
1146                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1147
1148                 /* Try powerful optimization CURLYX => CURLYN. */
1149                 if (  OP(oscan) == CURLYX && data
1150                       && data->flags & SF_IN_PAR
1151                       && !(data->flags & SF_HAS_EVAL)
1152                       && !deltanext && minnext == 1 ) {
1153                     /* Try to optimize to CURLYN.  */
1154                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1155                     regnode *nxt1 = nxt;
1156 #ifdef DEBUGGING
1157                     regnode *nxt2;
1158 #endif
1159
1160                     /* Skip open. */
1161                     nxt = regnext(nxt);
1162                     if (!strchr((char*)PL_simple,OP(nxt))
1163                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1164                              && STR_LEN(nxt) == 1))
1165                         goto nogo;
1166 #ifdef DEBUGGING
1167                     nxt2 = nxt;
1168 #endif
1169                     nxt = regnext(nxt);
1170                     if (OP(nxt) != CLOSE)
1171                         goto nogo;
1172                     /* Now we know that nxt2 is the only contents: */
1173                     oscan->flags = (U8)ARG(nxt);
1174                     OP(oscan) = CURLYN;
1175                     OP(nxt1) = NOTHING; /* was OPEN. */
1176 #ifdef DEBUGGING
1177                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1178                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1179                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1180                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1181                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1182                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1183 #endif
1184                 }
1185               nogo:
1186
1187                 /* Try optimization CURLYX => CURLYM. */
1188                 if (  OP(oscan) == CURLYX && data
1189                       && !(data->flags & SF_HAS_PAR)
1190                       && !(data->flags & SF_HAS_EVAL)
1191                       && !deltanext     /* atom is fixed width */
1192                       && minnext != 0   /* CURLYM can't handle zero width */
1193                 ) {
1194                     /* XXXX How to optimize if data == 0? */
1195                     /* Optimize to a simpler form.  */
1196                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1197                     regnode *nxt2;
1198
1199                     OP(oscan) = CURLYM;
1200                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1201                             && (OP(nxt2) != WHILEM))
1202                         nxt = nxt2;
1203                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1204                     /* Need to optimize away parenths. */
1205                     if (data->flags & SF_IN_PAR) {
1206                         /* Set the parenth number.  */
1207                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1208
1209                         if (OP(nxt) != CLOSE)
1210                             FAIL("Panic opt close");
1211                         oscan->flags = (U8)ARG(nxt);
1212                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1213                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1214 #ifdef DEBUGGING
1215                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1216                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1217                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1218                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1219 #endif
1220 #if 0
1221                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1222                             regnode *nnxt = regnext(nxt1);
1223
1224                             if (nnxt == nxt) {
1225                                 if (reg_off_by_arg[OP(nxt1)])
1226                                     ARG_SET(nxt1, nxt2 - nxt1);
1227                                 else if (nxt2 - nxt1 < U16_MAX)
1228                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1229                                 else
1230                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1231                             }
1232                             nxt1 = nnxt;
1233                         }
1234 #endif
1235                         /* Optimize again: */
1236                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1237                                     NULL, 0);
1238                     }
1239                     else
1240                         oscan->flags = 0;
1241                 }
1242                 else if ((OP(oscan) == CURLYX)
1243                          && (flags & SCF_WHILEM_VISITED_POS)
1244                          /* See the comment on a similar expression above.
1245                             However, this time it not a subexpression
1246                             we care about, but the expression itself. */
1247                          && (maxcount == REG_INFTY)
1248                          && data && ++data->whilem_c < 16) {
1249                     /* This stays as CURLYX, we can put the count/of pair. */
1250                     /* Find WHILEM (as in regexec.c) */
1251                     regnode *nxt = oscan + NEXT_OFF(oscan);
1252
1253                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1254                         nxt += ARG(nxt);
1255                     PREVOPER(nxt)->flags = (U8)(data->whilem_c
1256                         | (RExC_whilem_seen << 4)); /* On WHILEM */
1257                 }
1258                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1259                     pars++;
1260                 if (flags & SCF_DO_SUBSTR) {
1261                     SV *last_str = Nullsv;
1262                     int counted = mincount != 0;
1263
1264                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1265 #if defined(SPARC64_GCC_WORKAROUND)
1266                         I32 b = 0;
1267                         STRLEN l = 0;
1268                         char *s = NULL;
1269                         I32 old = 0;
1270
1271                         if (pos_before >= data->last_start_min)
1272                             b = pos_before;
1273                         else
1274                             b = data->last_start_min;
1275
1276                         l = 0;
1277                         s = SvPV(data->last_found, l);
1278                         old = b - data->last_start_min;
1279
1280 #else
1281                         I32 b = pos_before >= data->last_start_min
1282                             ? pos_before : data->last_start_min;
1283                         STRLEN l;
1284                         char *s = SvPV(data->last_found, l);
1285                         I32 old = b - data->last_start_min;
1286 #endif
1287
1288                         if (UTF)
1289                             old = utf8_hop((U8*)s, old) - (U8*)s;
1290
1291                         l -= old;
1292                         /* Get the added string: */
1293                         last_str = newSVpvn(s  + old, l);
1294                         if (UTF)
1295                             SvUTF8_on(last_str);
1296                         if (deltanext == 0 && pos_before == b) {
1297                             /* What was added is a constant string */
1298                             if (mincount > 1) {
1299                                 SvGROW(last_str, (mincount * l) + 1);
1300                                 repeatcpy(SvPVX(last_str) + l,
1301                                           SvPVX(last_str), l, mincount - 1);
1302                                 SvCUR(last_str) *= mincount;
1303                                 /* Add additional parts. */
1304                                 SvCUR_set(data->last_found,
1305                                           SvCUR(data->last_found) - l);
1306                                 sv_catsv(data->last_found, last_str);
1307                                 {
1308                                     SV * sv = data->last_found;
1309                                     MAGIC *mg =
1310                                         SvUTF8(sv) && SvMAGICAL(sv) ?
1311                                         mg_find(sv, PERL_MAGIC_utf8) : NULL;
1312                                     if (mg && mg->mg_len >= 0)
1313                                         mg->mg_len += CHR_SVLEN(last_str);
1314                                 }
1315                                 data->last_end += l * (mincount - 1);
1316                             }
1317                         } else {
1318                             /* start offset must point into the last copy */
1319                             data->last_start_min += minnext * (mincount - 1);
1320                             data->last_start_max += is_inf ? I32_MAX
1321                                 : (maxcount - 1) * (minnext + data->pos_delta);
1322                         }
1323                     }
1324                     /* It is counted once already... */
1325                     data->pos_min += minnext * (mincount - counted);
1326                     data->pos_delta += - counted * deltanext +
1327                         (minnext + deltanext) * maxcount - minnext * mincount;
1328                     if (mincount != maxcount) {
1329                          /* Cannot extend fixed substrings found inside
1330                             the group.  */
1331                         scan_commit(pRExC_state,data);
1332                         if (mincount && last_str) {
1333                             sv_setsv(data->last_found, last_str);
1334                             data->last_end = data->pos_min;
1335                             data->last_start_min =
1336                                 data->pos_min - CHR_SVLEN(last_str);
1337                             data->last_start_max = is_inf
1338                                 ? I32_MAX
1339                                 : data->pos_min + data->pos_delta
1340                                 - CHR_SVLEN(last_str);
1341                         }
1342                         data->longest = &(data->longest_float);
1343                     }
1344                     SvREFCNT_dec(last_str);
1345                 }
1346                 if (data && (fl & SF_HAS_EVAL))
1347                     data->flags |= SF_HAS_EVAL;
1348               optimize_curly_tail:
1349                 if (OP(oscan) != CURLYX) {
1350                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1351                            && NEXT_OFF(next))
1352                         NEXT_OFF(oscan) += NEXT_OFF(next);
1353                 }
1354                 continue;
1355             default:                    /* REF and CLUMP only? */
1356                 if (flags & SCF_DO_SUBSTR) {
1357                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1358                     data->longest = &(data->longest_float);
1359                 }
1360                 is_inf = is_inf_internal = 1;
1361                 if (flags & SCF_DO_STCLASS_OR)
1362                     cl_anything(pRExC_state, data->start_class);
1363                 flags &= ~SCF_DO_STCLASS;
1364                 break;
1365             }
1366         }
1367         else if (strchr((char*)PL_simple,OP(scan))) {
1368             int value = 0;
1369
1370             if (flags & SCF_DO_SUBSTR) {
1371                 scan_commit(pRExC_state,data);
1372                 data->pos_min++;
1373             }
1374             min++;
1375             if (flags & SCF_DO_STCLASS) {
1376                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1377
1378                 /* Some of the logic below assumes that switching
1379                    locale on will only add false positives. */
1380                 switch (PL_regkind[(U8)OP(scan)]) {
1381                 case SANY:
1382                 default:
1383                   do_default:
1384                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1385                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1386                         cl_anything(pRExC_state, data->start_class);
1387                     break;
1388                 case REG_ANY:
1389                     if (OP(scan) == SANY)
1390                         goto do_default;
1391                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1392                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1393                                  || (data->start_class->flags & ANYOF_CLASS));
1394                         cl_anything(pRExC_state, data->start_class);
1395                     }
1396                     if (flags & SCF_DO_STCLASS_AND || !value)
1397                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1398                     break;
1399                 case ANYOF:
1400                     if (flags & SCF_DO_STCLASS_AND)
1401                         cl_and(data->start_class,
1402                                (struct regnode_charclass_class*)scan);
1403                     else
1404                         cl_or(pRExC_state, data->start_class,
1405                               (struct regnode_charclass_class*)scan);
1406                     break;
1407                 case ALNUM:
1408                     if (flags & SCF_DO_STCLASS_AND) {
1409                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1410                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1411                             for (value = 0; value < 256; value++)
1412                                 if (!isALNUM(value))
1413                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1414                         }
1415                     }
1416                     else {
1417                         if (data->start_class->flags & ANYOF_LOCALE)
1418                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1419                         else {
1420                             for (value = 0; value < 256; value++)
1421                                 if (isALNUM(value))
1422                                     ANYOF_BITMAP_SET(data->start_class, value);
1423                         }
1424                     }
1425                     break;
1426                 case ALNUML:
1427                     if (flags & SCF_DO_STCLASS_AND) {
1428                         if (data->start_class->flags & ANYOF_LOCALE)
1429                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1430                     }
1431                     else {
1432                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1433                         data->start_class->flags |= ANYOF_LOCALE;
1434                     }
1435                     break;
1436                 case NALNUM:
1437                     if (flags & SCF_DO_STCLASS_AND) {
1438                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1439                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1440                             for (value = 0; value < 256; value++)
1441                                 if (isALNUM(value))
1442                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1443                         }
1444                     }
1445                     else {
1446                         if (data->start_class->flags & ANYOF_LOCALE)
1447                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1448                         else {
1449                             for (value = 0; value < 256; value++)
1450                                 if (!isALNUM(value))
1451                                     ANYOF_BITMAP_SET(data->start_class, value);
1452                         }
1453                     }
1454                     break;
1455                 case NALNUML:
1456                     if (flags & SCF_DO_STCLASS_AND) {
1457                         if (data->start_class->flags & ANYOF_LOCALE)
1458                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1459                     }
1460                     else {
1461                         data->start_class->flags |= ANYOF_LOCALE;
1462                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1463                     }
1464                     break;
1465                 case SPACE:
1466                     if (flags & SCF_DO_STCLASS_AND) {
1467                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1468                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1469                             for (value = 0; value < 256; value++)
1470                                 if (!isSPACE(value))
1471                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1472                         }
1473                     }
1474                     else {
1475                         if (data->start_class->flags & ANYOF_LOCALE)
1476                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1477                         else {
1478                             for (value = 0; value < 256; value++)
1479                                 if (isSPACE(value))
1480                                     ANYOF_BITMAP_SET(data->start_class, value);
1481                         }
1482                     }
1483                     break;
1484                 case SPACEL:
1485                     if (flags & SCF_DO_STCLASS_AND) {
1486                         if (data->start_class->flags & ANYOF_LOCALE)
1487                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1488                     }
1489                     else {
1490                         data->start_class->flags |= ANYOF_LOCALE;
1491                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1492                     }
1493                     break;
1494                 case NSPACE:
1495                     if (flags & SCF_DO_STCLASS_AND) {
1496                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1497                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1498                             for (value = 0; value < 256; value++)
1499                                 if (isSPACE(value))
1500                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1501                         }
1502                     }
1503                     else {
1504                         if (data->start_class->flags & ANYOF_LOCALE)
1505                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1506                         else {
1507                             for (value = 0; value < 256; value++)
1508                                 if (!isSPACE(value))
1509                                     ANYOF_BITMAP_SET(data->start_class, value);
1510                         }
1511                     }
1512                     break;
1513                 case NSPACEL:
1514                     if (flags & SCF_DO_STCLASS_AND) {
1515                         if (data->start_class->flags & ANYOF_LOCALE) {
1516                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1517                             for (value = 0; value < 256; value++)
1518                                 if (!isSPACE(value))
1519                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1520                         }
1521                     }
1522                     else {
1523                         data->start_class->flags |= ANYOF_LOCALE;
1524                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1525                     }
1526                     break;
1527                 case DIGIT:
1528                     if (flags & SCF_DO_STCLASS_AND) {
1529                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1530                         for (value = 0; value < 256; value++)
1531                             if (!isDIGIT(value))
1532                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1533                     }
1534                     else {
1535                         if (data->start_class->flags & ANYOF_LOCALE)
1536                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1537                         else {
1538                             for (value = 0; value < 256; value++)
1539                                 if (isDIGIT(value))
1540                                     ANYOF_BITMAP_SET(data->start_class, value);
1541                         }
1542                     }
1543                     break;
1544                 case NDIGIT:
1545                     if (flags & SCF_DO_STCLASS_AND) {
1546                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1547                         for (value = 0; value < 256; value++)
1548                             if (isDIGIT(value))
1549                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1550                     }
1551                     else {
1552                         if (data->start_class->flags & ANYOF_LOCALE)
1553                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1554                         else {
1555                             for (value = 0; value < 256; value++)
1556                                 if (!isDIGIT(value))
1557                                     ANYOF_BITMAP_SET(data->start_class, value);
1558                         }
1559                     }
1560                     break;
1561                 }
1562                 if (flags & SCF_DO_STCLASS_OR)
1563                     cl_and(data->start_class, &and_with);
1564                 flags &= ~SCF_DO_STCLASS;
1565             }
1566         }
1567         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1568             data->flags |= (OP(scan) == MEOL
1569                             ? SF_BEFORE_MEOL
1570                             : SF_BEFORE_SEOL);
1571         }
1572         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1573                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1574                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1575                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1576             /* Lookahead/lookbehind */
1577             I32 deltanext, minnext, fake = 0;
1578             regnode *nscan;
1579             struct regnode_charclass_class intrnl;
1580             int f = 0;
1581
1582             data_fake.flags = 0;
1583             if (data) {
1584                 data_fake.whilem_c = data->whilem_c;
1585                 data_fake.last_closep = data->last_closep;
1586             }
1587             else
1588                 data_fake.last_closep = &fake;
1589             if ( flags & SCF_DO_STCLASS && !scan->flags
1590                  && OP(scan) == IFMATCH ) { /* Lookahead */
1591                 cl_init(pRExC_state, &intrnl);
1592                 data_fake.start_class = &intrnl;
1593                 f |= SCF_DO_STCLASS_AND;
1594             }
1595             if (flags & SCF_WHILEM_VISITED_POS)
1596                 f |= SCF_WHILEM_VISITED_POS;
1597             next = regnext(scan);
1598             nscan = NEXTOPER(NEXTOPER(scan));
1599             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1600             if (scan->flags) {
1601                 if (deltanext) {
1602                     vFAIL("Variable length lookbehind not implemented");
1603                 }
1604                 else if (minnext > U8_MAX) {
1605                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1606                 }
1607                 scan->flags = (U8)minnext;
1608             }
1609             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1610                 pars++;
1611             if (data && (data_fake.flags & SF_HAS_EVAL))
1612                 data->flags |= SF_HAS_EVAL;
1613             if (data)
1614                 data->whilem_c = data_fake.whilem_c;
1615             if (f & SCF_DO_STCLASS_AND) {
1616                 int was = (data->start_class->flags & ANYOF_EOS);
1617
1618                 cl_and(data->start_class, &intrnl);
1619                 if (was)
1620                     data->start_class->flags |= ANYOF_EOS;
1621             }
1622         }
1623         else if (OP(scan) == OPEN) {
1624             pars++;
1625         }
1626         else if (OP(scan) == CLOSE) {
1627             if ((I32)ARG(scan) == is_par) {
1628                 next = regnext(scan);
1629
1630                 if ( next && (OP(next) != WHILEM) && next < last)
1631                     is_par = 0;         /* Disable optimization */
1632             }
1633             if (data)
1634                 *(data->last_closep) = ARG(scan);
1635         }
1636         else if (OP(scan) == EVAL) {
1637                 if (data)
1638                     data->flags |= SF_HAS_EVAL;
1639         }
1640         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1641                 if (flags & SCF_DO_SUBSTR) {
1642                     scan_commit(pRExC_state,data);
1643                     data->longest = &(data->longest_float);
1644                 }
1645                 is_inf = is_inf_internal = 1;
1646                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1647                     cl_anything(pRExC_state, data->start_class);
1648                 flags &= ~SCF_DO_STCLASS;
1649         }
1650         /* Else: zero-length, ignore. */
1651         scan = regnext(scan);
1652     }
1653
1654   finish:
1655     *scanp = scan;
1656     *deltap = is_inf_internal ? I32_MAX : delta;
1657     if (flags & SCF_DO_SUBSTR && is_inf)
1658         data->pos_delta = I32_MAX - data->pos_min;
1659     if (is_par > U8_MAX)
1660         is_par = 0;
1661     if (is_par && pars==1 && data) {
1662         data->flags |= SF_IN_PAR;
1663         data->flags &= ~SF_HAS_PAR;
1664     }
1665     else if (pars && data) {
1666         data->flags |= SF_HAS_PAR;
1667         data->flags &= ~SF_IN_PAR;
1668     }
1669     if (flags & SCF_DO_STCLASS_OR)
1670         cl_and(data->start_class, &and_with);
1671     return min;
1672 }
1673
1674 STATIC I32
1675 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1676 {
1677     if (RExC_rx->data) {
1678         Renewc(RExC_rx->data,
1679                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1680                char, struct reg_data);
1681         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1682         RExC_rx->data->count += n;
1683     }
1684     else {
1685         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1686              char, struct reg_data);
1687         New(1208, RExC_rx->data->what, n, U8);
1688         RExC_rx->data->count = n;
1689     }
1690     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1691     return RExC_rx->data->count - n;
1692 }
1693
1694 void
1695 Perl_reginitcolors(pTHX)
1696 {
1697     int i = 0;
1698     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1699
1700     if (s) {
1701         PL_colors[0] = s = savepv(s);
1702         while (++i < 6) {
1703             s = strchr(s, '\t');
1704             if (s) {
1705                 *s = '\0';
1706                 PL_colors[i] = ++s;
1707             }
1708             else
1709                 PL_colors[i] = s = "";
1710         }
1711     } else {
1712         while (i < 6)
1713             PL_colors[i++] = "";
1714     }
1715     PL_colorset = 1;
1716 }
1717
1718
1719 /*
1720  - pregcomp - compile a regular expression into internal code
1721  *
1722  * We can't allocate space until we know how big the compiled form will be,
1723  * but we can't compile it (and thus know how big it is) until we've got a
1724  * place to put the code.  So we cheat:  we compile it twice, once with code
1725  * generation turned off and size counting turned on, and once "for real".
1726  * This also means that we don't allocate space until we are sure that the
1727  * thing really will compile successfully, and we never have to move the
1728  * code and thus invalidate pointers into it.  (Note that it has to be in
1729  * one piece because free() must be able to free it all.) [NB: not true in perl]
1730  *
1731  * Beware that the optimization-preparation code in here knows about some
1732  * of the structure of the compiled regexp.  [I'll say.]
1733  */
1734 regexp *
1735 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1736 {
1737     register regexp *r;
1738     regnode *scan;
1739     regnode *first;
1740     I32 flags;
1741     I32 minlen = 0;
1742     I32 sawplus = 0;
1743     I32 sawopen = 0;
1744     scan_data_t data;
1745     RExC_state_t RExC_state;
1746     RExC_state_t *pRExC_state = &RExC_state;
1747
1748     if (exp == NULL)
1749         FAIL("NULL regexp argument");
1750
1751     RExC_utf8 = pm->op_pmdynflags & PMdf_CMP_UTF8;
1752
1753     RExC_precomp = exp;
1754     DEBUG_r({
1755          if (!PL_colorset) reginitcolors();
1756          PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1757                        PL_colors[4],PL_colors[5],PL_colors[0],
1758                        (int)(xend - exp), RExC_precomp, PL_colors[1]);
1759     });
1760     RExC_flags = pm->op_pmflags;
1761     RExC_sawback = 0;
1762
1763     RExC_seen = 0;
1764     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1765     RExC_seen_evals = 0;
1766     RExC_extralen = 0;
1767
1768     /* First pass: determine size, legality. */
1769     RExC_parse = exp;
1770     RExC_start = exp;
1771     RExC_end = xend;
1772     RExC_naughty = 0;
1773     RExC_npar = 1;
1774     RExC_size = 0L;
1775     RExC_emit = &PL_regdummy;
1776     RExC_whilem_seen = 0;
1777 #if 0 /* REGC() is (currently) a NOP at the first pass.
1778        * Clever compilers notice this and complain. --jhi */
1779     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1780 #endif
1781     if (reg(pRExC_state, 0, &flags) == NULL) {
1782         RExC_precomp = Nullch;
1783         return(NULL);
1784     }
1785     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1786
1787     /* Small enough for pointer-storage convention?
1788        If extralen==0, this means that we will not need long jumps. */
1789     if (RExC_size >= 0x10000L && RExC_extralen)
1790         RExC_size += RExC_extralen;
1791     else
1792         RExC_extralen = 0;
1793     if (RExC_whilem_seen > 15)
1794         RExC_whilem_seen = 15;
1795
1796     /* Allocate space and initialize. */
1797     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1798          char, regexp);
1799     if (r == NULL)
1800         FAIL("Regexp out of space");
1801
1802 #ifdef DEBUGGING
1803     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1804     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1805 #endif
1806     r->refcnt = 1;
1807     r->prelen = xend - exp;
1808     r->precomp = savepvn(RExC_precomp, r->prelen);
1809     r->subbeg = NULL;
1810 #ifdef PERL_COPY_ON_WRITE
1811     r->saved_copy = Nullsv;
1812 #endif
1813     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1814     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1815
1816     r->substrs = 0;                     /* Useful during FAIL. */
1817     r->startp = 0;                      /* Useful during FAIL. */
1818     r->endp = 0;                        /* Useful during FAIL. */
1819
1820     Newz(1304, r->offsets, 2*RExC_size+1, U32); /* MJD 20001228 */
1821     if (r->offsets) {
1822       r->offsets[0] = RExC_size;
1823     }
1824     DEBUG_r(PerlIO_printf(Perl_debug_log,
1825                           "%s %"UVuf" bytes for offset annotations.\n",
1826                           r->offsets ? "Got" : "Couldn't get",
1827                           (UV)((2*RExC_size+1) * sizeof(U32))));
1828
1829     RExC_rx = r;
1830
1831     /* Second pass: emit code. */
1832     RExC_flags = pm->op_pmflags;        /* don't let top level (?i) bleed */
1833     RExC_parse = exp;
1834     RExC_end = xend;
1835     RExC_naughty = 0;
1836     RExC_npar = 1;
1837     RExC_emit_start = r->program;
1838     RExC_emit = r->program;
1839     /* Store the count of eval-groups for security checks: */
1840     RExC_emit->next_off = (U16)((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1841     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1842     r->data = 0;
1843     if (reg(pRExC_state, 0, &flags) == NULL)
1844         return(NULL);
1845
1846     /* Dig out information for optimizations. */
1847     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1848     pm->op_pmflags = RExC_flags;
1849     if (UTF)
1850         r->reganch |= ROPT_UTF8;        /* Unicode in it? */
1851     r->regstclass = NULL;
1852     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1853         r->reganch |= ROPT_NAUGHTY;
1854     scan = r->program + 1;              /* First BRANCH. */
1855
1856     /* XXXX To minimize changes to RE engine we always allocate
1857        3-units-long substrs field. */
1858     Newz(1004, r->substrs, 1, struct reg_substr_data);
1859
1860     StructCopy(&zero_scan_data, &data, scan_data_t);
1861     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1862     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1863         I32 fake;
1864         STRLEN longest_float_length, longest_fixed_length;
1865         struct regnode_charclass_class ch_class;
1866         int stclass_flag;
1867         I32 last_close = 0;
1868
1869         first = scan;
1870         /* Skip introductions and multiplicators >= 1. */
1871         while ((OP(first) == OPEN && (sawopen = 1)) ||
1872                /* An OR of *one* alternative - should not happen now. */
1873             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1874             (OP(first) == PLUS) ||
1875             (OP(first) == MINMOD) ||
1876                /* An {n,m} with n>0 */
1877             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1878                 if (OP(first) == PLUS)
1879                     sawplus = 1;
1880                 else
1881                     first += regarglen[(U8)OP(first)];
1882                 first = NEXTOPER(first);
1883         }
1884
1885         /* Starting-point info. */
1886       again:
1887         if (PL_regkind[(U8)OP(first)] == EXACT) {
1888             if (OP(first) == EXACT)
1889                 ;       /* Empty, get anchored substr later. */
1890             else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
1891                 r->regstclass = first;
1892         }
1893         else if (strchr((char*)PL_simple,OP(first)))
1894             r->regstclass = first;
1895         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1896                  PL_regkind[(U8)OP(first)] == NBOUND)
1897             r->regstclass = first;
1898         else if (PL_regkind[(U8)OP(first)] == BOL) {
1899             r->reganch |= (OP(first) == MBOL
1900                            ? ROPT_ANCH_MBOL
1901                            : (OP(first) == SBOL
1902                               ? ROPT_ANCH_SBOL
1903                               : ROPT_ANCH_BOL));
1904             first = NEXTOPER(first);
1905             goto again;
1906         }
1907         else if (OP(first) == GPOS) {
1908             r->reganch |= ROPT_ANCH_GPOS;
1909             first = NEXTOPER(first);
1910             goto again;
1911         }
1912         else if (!sawopen && (OP(first) == STAR &&
1913             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1914             !(r->reganch & ROPT_ANCH) )
1915         {
1916             /* turn .* into ^.* with an implied $*=1 */
1917             int type = OP(NEXTOPER(first));
1918
1919             if (type == REG_ANY)
1920                 type = ROPT_ANCH_MBOL;
1921             else
1922                 type = ROPT_ANCH_SBOL;
1923
1924             r->reganch |= type | ROPT_IMPLICIT;
1925             first = NEXTOPER(first);
1926             goto again;
1927         }
1928         if (sawplus && (!sawopen || !RExC_sawback)
1929             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1930             /* x+ must match at the 1st pos of run of x's */
1931             r->reganch |= ROPT_SKIP;
1932
1933         /* Scan is after the zeroth branch, first is atomic matcher. */
1934         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1935                               (IV)(first - scan + 1)));
1936         /*
1937         * If there's something expensive in the r.e., find the
1938         * longest literal string that must appear and make it the
1939         * regmust.  Resolve ties in favor of later strings, since
1940         * the regstart check works with the beginning of the r.e.
1941         * and avoiding duplication strengthens checking.  Not a
1942         * strong reason, but sufficient in the absence of others.
1943         * [Now we resolve ties in favor of the earlier string if
1944         * it happens that c_offset_min has been invalidated, since the
1945         * earlier string may buy us something the later one won't.]
1946         */
1947         minlen = 0;
1948
1949         data.longest_fixed = newSVpvn("",0);
1950         data.longest_float = newSVpvn("",0);
1951         data.last_found = newSVpvn("",0);
1952         data.longest = &(data.longest_fixed);
1953         first = scan;
1954         if (!r->regstclass) {
1955             cl_init(pRExC_state, &ch_class);
1956             data.start_class = &ch_class;
1957             stclass_flag = SCF_DO_STCLASS_AND;
1958         } else                          /* XXXX Check for BOUND? */
1959             stclass_flag = 0;
1960         data.last_closep = &last_close;
1961
1962         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1963                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1964         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1965              && data.last_start_min == 0 && data.last_end > 0
1966              && !RExC_seen_zerolen
1967              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1968             r->reganch |= ROPT_CHECK_ALL;
1969         scan_commit(pRExC_state, &data);
1970         SvREFCNT_dec(data.last_found);
1971
1972         longest_float_length = CHR_SVLEN(data.longest_float);
1973         if (longest_float_length
1974             || (data.flags & SF_FL_BEFORE_EOL
1975                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1976                     || (RExC_flags & PMf_MULTILINE)))) {
1977             int t;
1978
1979             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1980                 && data.offset_fixed == data.offset_float_min
1981                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1982                     goto remove_float;          /* As in (a)+. */
1983
1984             if (SvUTF8(data.longest_float)) {
1985                 r->float_utf8 = data.longest_float;
1986                 r->float_substr = Nullsv;
1987             } else {
1988                 r->float_substr = data.longest_float;
1989                 r->float_utf8 = Nullsv;
1990             }
1991             r->float_min_offset = data.offset_float_min;
1992             r->float_max_offset = data.offset_float_max;
1993             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1994                        && (!(data.flags & SF_FL_BEFORE_MEOL)
1995                            || (RExC_flags & PMf_MULTILINE)));
1996             fbm_compile(data.longest_float, t ? FBMcf_TAIL : 0);
1997         }
1998         else {
1999           remove_float:
2000             r->float_substr = r->float_utf8 = Nullsv;
2001             SvREFCNT_dec(data.longest_float);
2002             longest_float_length = 0;
2003         }
2004
2005         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
2006         if (longest_fixed_length
2007             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
2008                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
2009                     || (RExC_flags & PMf_MULTILINE)))) {
2010             int t;
2011
2012             if (SvUTF8(data.longest_fixed)) {
2013                 r->anchored_utf8 = data.longest_fixed;
2014                 r->anchored_substr = Nullsv;
2015             } else {
2016                 r->anchored_substr = data.longest_fixed;
2017                 r->anchored_utf8 = Nullsv;
2018             }
2019             r->anchored_offset = data.offset_fixed;
2020             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
2021                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
2022                      || (RExC_flags & PMf_MULTILINE)));
2023             fbm_compile(data.longest_fixed, t ? FBMcf_TAIL : 0);
2024         }
2025         else {
2026             r->anchored_substr = r->anchored_utf8 = Nullsv;
2027             SvREFCNT_dec(data.longest_fixed);
2028             longest_fixed_length = 0;
2029         }
2030         if (r->regstclass
2031             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == SANY))
2032             r->regstclass = NULL;
2033         if ((!(r->anchored_substr || r->anchored_utf8) || r->anchored_offset)
2034             && stclass_flag
2035             && !(data.start_class->flags & ANYOF_EOS)
2036             && !cl_is_anything(data.start_class))
2037         {
2038             I32 n = add_data(pRExC_state, 1, "f");
2039
2040             New(1006, RExC_rx->data->data[n], 1,
2041                 struct regnode_charclass_class);
2042             StructCopy(data.start_class,
2043                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2044                        struct regnode_charclass_class);
2045             r->regstclass = (regnode*)RExC_rx->data->data[n];
2046             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2047             PL_regdata = r->data; /* for regprop() */
2048             DEBUG_r({ SV *sv = sv_newmortal();
2049                       regprop(sv, (regnode*)data.start_class);
2050                       PerlIO_printf(Perl_debug_log,
2051                                     "synthetic stclass `%s'.\n",
2052                                     SvPVX(sv));});
2053         }
2054
2055         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
2056         if (longest_fixed_length > longest_float_length) {
2057             r->check_substr = r->anchored_substr;
2058             r->check_utf8 = r->anchored_utf8;
2059             r->check_offset_min = r->check_offset_max = r->anchored_offset;
2060             if (r->reganch & ROPT_ANCH_SINGLE)
2061                 r->reganch |= ROPT_NOSCAN;
2062         }
2063         else {
2064             r->check_substr = r->float_substr;
2065             r->check_utf8 = r->float_utf8;
2066             r->check_offset_min = data.offset_float_min;
2067             r->check_offset_max = data.offset_float_max;
2068         }
2069         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
2070            This should be changed ASAP!  */
2071         if ((r->check_substr || r->check_utf8) && !(r->reganch & ROPT_ANCH_GPOS)) {
2072             r->reganch |= RE_USE_INTUIT;
2073             if (SvTAIL(r->check_substr ? r->check_substr : r->check_utf8))
2074                 r->reganch |= RE_INTUIT_TAIL;
2075         }
2076     }
2077     else {
2078         /* Several toplevels. Best we can is to set minlen. */
2079         I32 fake;
2080         struct regnode_charclass_class ch_class;
2081         I32 last_close = 0;
2082
2083         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
2084         scan = r->program + 1;
2085         cl_init(pRExC_state, &ch_class);
2086         data.start_class = &ch_class;
2087         data.last_closep = &last_close;
2088         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
2089         r->check_substr = r->check_utf8 = r->anchored_substr = r->anchored_utf8
2090                 = r->float_substr = r->float_utf8 = Nullsv;
2091         if (!(data.start_class->flags & ANYOF_EOS)
2092             && !cl_is_anything(data.start_class))
2093         {
2094             I32 n = add_data(pRExC_state, 1, "f");
2095
2096             New(1006, RExC_rx->data->data[n], 1,
2097                 struct regnode_charclass_class);
2098             StructCopy(data.start_class,
2099                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2100                        struct regnode_charclass_class);
2101             r->regstclass = (regnode*)RExC_rx->data->data[n];
2102             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2103             DEBUG_r({ SV* sv = sv_newmortal();
2104                       regprop(sv, (regnode*)data.start_class);
2105                       PerlIO_printf(Perl_debug_log,
2106                                     "synthetic stclass `%s'.\n",
2107                                     SvPVX(sv));});
2108         }
2109     }
2110
2111     r->minlen = minlen;
2112     if (RExC_seen & REG_SEEN_GPOS)
2113         r->reganch |= ROPT_GPOS_SEEN;
2114     if (RExC_seen & REG_SEEN_LOOKBEHIND)
2115         r->reganch |= ROPT_LOOKBEHIND_SEEN;
2116     if (RExC_seen & REG_SEEN_EVAL)
2117         r->reganch |= ROPT_EVAL_SEEN;
2118     if (RExC_seen & REG_SEEN_CANY)
2119         r->reganch |= ROPT_CANY_SEEN;
2120     Newz(1002, r->startp, RExC_npar, I32);
2121     Newz(1002, r->endp, RExC_npar, I32);
2122     PL_regdata = r->data; /* for regprop() */
2123     DEBUG_r(regdump(r));
2124     return(r);
2125 }
2126
2127 /*
2128  - reg - regular expression, i.e. main body or parenthesized thing
2129  *
2130  * Caller must absorb opening parenthesis.
2131  *
2132  * Combining parenthesis handling with the base level of regular expression
2133  * is a trifle forced, but the need to tie the tails of the branches to what
2134  * follows makes it hard to avoid.
2135  */
2136 STATIC regnode *
2137 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
2138     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
2139 {
2140     register regnode *ret;              /* Will be the head of the group. */
2141     register regnode *br;
2142     register regnode *lastbr;
2143     register regnode *ender = 0;
2144     register I32 parno = 0;
2145     I32 flags, oregflags = RExC_flags, have_branch = 0, open = 0;
2146
2147     /* for (?g), (?gc), and (?o) warnings; warning
2148        about (?c) will warn about (?g) -- japhy    */
2149
2150     I32 wastedflags = 0x00,
2151         wasted_o    = 0x01,
2152         wasted_g    = 0x02,
2153         wasted_gc   = 0x02 | 0x04,
2154         wasted_c    = 0x04;
2155
2156     char * parse_start = RExC_parse; /* MJD */
2157     char *oregcomp_parse = RExC_parse;
2158     char c;
2159
2160     *flagp = 0;                         /* Tentatively. */
2161
2162
2163     /* Make an OPEN node, if parenthesized. */
2164     if (paren) {
2165         if (*RExC_parse == '?') { /* (?...) */
2166             U32 posflags = 0, negflags = 0;
2167             U32 *flagsp = &posflags;
2168             int logical = 0;
2169             char *seqstart = RExC_parse;
2170
2171             RExC_parse++;
2172             paren = *RExC_parse++;
2173             ret = NULL;                 /* For look-ahead/behind. */
2174             switch (paren) {
2175             case '<':           /* (?<...) */
2176                 RExC_seen |= REG_SEEN_LOOKBEHIND;
2177                 if (*RExC_parse == '!')
2178                     paren = ',';
2179                 if (*RExC_parse != '=' && *RExC_parse != '!')
2180                     goto unknown;
2181                 RExC_parse++;
2182             case '=':           /* (?=...) */
2183             case '!':           /* (?!...) */
2184                 RExC_seen_zerolen++;
2185             case ':':           /* (?:...) */
2186             case '>':           /* (?>...) */
2187                 break;
2188             case '$':           /* (?$...) */
2189             case '@':           /* (?@...) */
2190                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
2191                 break;
2192             case '#':           /* (?#...) */
2193                 while (*RExC_parse && *RExC_parse != ')')
2194                     RExC_parse++;
2195                 if (*RExC_parse != ')')
2196                     FAIL("Sequence (?#... not terminated");
2197                 nextchar(pRExC_state);
2198                 *flagp = TRYAGAIN;
2199                 return NULL;
2200             case 'p':           /* (?p...) */
2201                 if (SIZE_ONLY && ckWARN2(WARN_DEPRECATED, WARN_REGEXP))
2202                     vWARNdep(RExC_parse, "(?p{}) is deprecated - use (??{})");
2203                 /* FALL THROUGH*/
2204             case '?':           /* (??...) */
2205                 logical = 1;
2206                 if (*RExC_parse != '{')
2207                     goto unknown;
2208                 paren = *RExC_parse++;
2209                 /* FALL THROUGH */
2210             case '{':           /* (?{...}) */
2211             {
2212                 I32 count = 1, n = 0;
2213                 char c;
2214                 char *s = RExC_parse;
2215                 SV *sv;
2216                 OP_4tree *sop, *rop;
2217
2218                 RExC_seen_zerolen++;
2219                 RExC_seen |= REG_SEEN_EVAL;
2220                 while (count && (c = *RExC_parse)) {
2221                     if (c == '\\' && RExC_parse[1])
2222                         RExC_parse++;
2223                     else if (c == '{')
2224                         count++;
2225                     else if (c == '}')
2226                         count--;
2227                     RExC_parse++;
2228                 }
2229                 if (*RExC_parse != ')')
2230                 {
2231                     RExC_parse = s;
2232                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2233                 }
2234                 if (!SIZE_ONLY) {
2235                     PAD *pad;
2236
2237                     if (RExC_parse - 1 - s)
2238                         sv = newSVpvn(s, RExC_parse - 1 - s);
2239                     else
2240                         sv = newSVpvn("", 0);
2241
2242                     ENTER;
2243                     Perl_save_re_context(aTHX);
2244                     rop = sv_compile_2op(sv, &sop, "re", &pad);
2245                     sop->op_private |= OPpREFCOUNTED;
2246                     /* re_dup will OpREFCNT_inc */
2247                     OpREFCNT_set(sop, 1);
2248                     LEAVE;
2249
2250                     n = add_data(pRExC_state, 3, "nop");
2251                     RExC_rx->data->data[n] = (void*)rop;
2252                     RExC_rx->data->data[n+1] = (void*)sop;
2253                     RExC_rx->data->data[n+2] = (void*)pad;
2254                     SvREFCNT_dec(sv);
2255                 }
2256                 else {                                          /* First pass */
2257                     if (PL_reginterp_cnt < ++RExC_seen_evals
2258                         && IN_PERL_RUNTIME)
2259                         /* No compiled RE interpolated, has runtime
2260                            components ===> unsafe.  */
2261                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2262                     if (PL_tainting && PL_tainted)
2263                         FAIL("Eval-group in insecure regular expression");
2264                     if (IN_PERL_COMPILETIME)
2265                         PL_cv_has_eval = 1;
2266                 }
2267
2268                 nextchar(pRExC_state);
2269                 if (logical) {
2270                     ret = reg_node(pRExC_state, LOGICAL);
2271                     if (!SIZE_ONLY)
2272                         ret->flags = 2;
2273                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2274                     /* deal with the length of this later - MJD */
2275                     return ret;
2276                 }
2277                 ret = reganode(pRExC_state, EVAL, n);
2278                 Set_Node_Length(ret, RExC_parse - parse_start + 1);
2279                 Set_Node_Offset(ret, parse_start);
2280                 return ret;
2281             }
2282             case '(':           /* (?(?{...})...) and (?(?=...)...) */
2283             {
2284                 if (RExC_parse[0] == '?') {        /* (?(?...)) */
2285                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2286                         || RExC_parse[1] == '<'
2287                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2288                         I32 flag;
2289
2290                         ret = reg_node(pRExC_state, LOGICAL);
2291                         if (!SIZE_ONLY)
2292                             ret->flags = 1;
2293                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2294                         goto insert_if;
2295                     }
2296                 }
2297                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2298                     /* (?(1)...) */
2299                     parno = atoi(RExC_parse++);
2300
2301                     while (isDIGIT(*RExC_parse))
2302                         RExC_parse++;
2303                     ret = reganode(pRExC_state, GROUPP, parno);
2304
2305                     if ((c = *nextchar(pRExC_state)) != ')')
2306                         vFAIL("Switch condition not recognized");
2307                   insert_if:
2308                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2309                     br = regbranch(pRExC_state, &flags, 1);
2310                     if (br == NULL)
2311                         br = reganode(pRExC_state, LONGJMP, 0);
2312                     else
2313                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2314                     c = *nextchar(pRExC_state);
2315                     if (flags&HASWIDTH)
2316                         *flagp |= HASWIDTH;
2317                     if (c == '|') {
2318                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2319                         regbranch(pRExC_state, &flags, 1);
2320                         regtail(pRExC_state, ret, lastbr);
2321                         if (flags&HASWIDTH)
2322                             *flagp |= HASWIDTH;
2323                         c = *nextchar(pRExC_state);
2324                     }
2325                     else
2326                         lastbr = NULL;
2327                     if (c != ')')
2328                         vFAIL("Switch (?(condition)... contains too many branches");
2329                     ender = reg_node(pRExC_state, TAIL);
2330                     regtail(pRExC_state, br, ender);
2331                     if (lastbr) {
2332                         regtail(pRExC_state, lastbr, ender);
2333                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2334                     }
2335                     else
2336                         regtail(pRExC_state, ret, ender);
2337                     return ret;
2338                 }
2339                 else {
2340                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2341                 }
2342             }
2343             case 0:
2344                 RExC_parse--; /* for vFAIL to print correctly */
2345                 vFAIL("Sequence (? incomplete");
2346                 break;
2347             default:
2348                 --RExC_parse;
2349               parse_flags:      /* (?i) */
2350                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2351                     /* (?g), (?gc) and (?o) are useless here
2352                        and must be globally applied -- japhy */
2353
2354                     if (*RExC_parse == 'o' || *RExC_parse == 'g') {
2355                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2356                             I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
2357                             if (! (wastedflags & wflagbit) ) {
2358                                 wastedflags |= wflagbit;
2359                                 vWARN5(
2360                                     RExC_parse + 1,
2361                                     "Useless (%s%c) - %suse /%c modifier",
2362                                     flagsp == &negflags ? "?-" : "?",
2363                                     *RExC_parse,
2364                                     flagsp == &negflags ? "don't " : "",
2365                                     *RExC_parse
2366                                 );
2367                             }
2368                         }
2369                     }
2370                     else if (*RExC_parse == 'c') {
2371                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2372                             if (! (wastedflags & wasted_c) ) {
2373                                 wastedflags |= wasted_gc;
2374                                 vWARN3(
2375                                     RExC_parse + 1,
2376                                     "Useless (%sc) - %suse /gc modifier",
2377                                     flagsp == &negflags ? "?-" : "?",
2378                                     flagsp == &negflags ? "don't " : ""
2379                                 );
2380                             }
2381                         }
2382                     }
2383                     else { pmflag(flagsp, *RExC_parse); }
2384
2385                     ++RExC_parse;
2386                 }
2387                 if (*RExC_parse == '-') {
2388                     flagsp = &negflags;
2389                     wastedflags = 0;  /* reset so (?g-c) warns twice */
2390                     ++RExC_parse;
2391                     goto parse_flags;
2392                 }
2393                 RExC_flags |= posflags;
2394                 RExC_flags &= ~negflags;
2395                 if (*RExC_parse == ':') {
2396                     RExC_parse++;
2397                     paren = ':';
2398                     break;
2399                 }
2400               unknown:
2401                 if (*RExC_parse != ')') {
2402                     RExC_parse++;
2403                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2404                 }
2405                 nextchar(pRExC_state);
2406                 *flagp = TRYAGAIN;
2407                 return NULL;
2408             }
2409         }
2410         else {                  /* (...) */
2411             parno = RExC_npar;
2412             RExC_npar++;
2413             ret = reganode(pRExC_state, OPEN, parno);
2414             Set_Node_Length(ret, 1); /* MJD */
2415             Set_Node_Offset(ret, RExC_parse); /* MJD */
2416             open = 1;
2417         }
2418     }
2419     else                        /* ! paren */
2420         ret = NULL;
2421
2422     /* Pick up the branches, linking them together. */
2423     parse_start = RExC_parse;   /* MJD */
2424     br = regbranch(pRExC_state, &flags, 1);
2425     /*     branch_len = (paren != 0); */
2426
2427     if (br == NULL)
2428         return(NULL);
2429     if (*RExC_parse == '|') {
2430         if (!SIZE_ONLY && RExC_extralen) {
2431             reginsert(pRExC_state, BRANCHJ, br);
2432         }
2433         else {                  /* MJD */
2434             reginsert(pRExC_state, BRANCH, br);
2435             Set_Node_Length(br, paren != 0);
2436             Set_Node_Offset_To_R(br-RExC_emit_start, parse_start-RExC_start);
2437         }
2438         have_branch = 1;
2439         if (SIZE_ONLY)
2440             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2441     }
2442     else if (paren == ':') {
2443         *flagp |= flags&SIMPLE;
2444     }
2445     if (open) {                         /* Starts with OPEN. */
2446         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2447     }
2448     else if (paren != '?')              /* Not Conditional */
2449         ret = br;
2450     *flagp |= flags & (SPSTART | HASWIDTH);
2451     lastbr = br;
2452     while (*RExC_parse == '|') {
2453         if (!SIZE_ONLY && RExC_extralen) {
2454             ender = reganode(pRExC_state, LONGJMP,0);
2455             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2456         }
2457         if (SIZE_ONLY)
2458             RExC_extralen += 2;         /* Account for LONGJMP. */
2459         nextchar(pRExC_state);
2460         br = regbranch(pRExC_state, &flags, 0);
2461
2462         if (br == NULL)
2463             return(NULL);
2464         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2465         lastbr = br;
2466         if (flags&HASWIDTH)
2467             *flagp |= HASWIDTH;
2468         *flagp |= flags&SPSTART;
2469     }
2470
2471     if (have_branch || paren != ':') {
2472         /* Make a closing node, and hook it on the end. */
2473         switch (paren) {
2474         case ':':
2475             ender = reg_node(pRExC_state, TAIL);
2476             break;
2477         case 1:
2478             ender = reganode(pRExC_state, CLOSE, parno);
2479             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
2480             Set_Node_Length(ender,1); /* MJD */
2481             break;
2482         case '<':
2483         case ',':
2484         case '=':
2485         case '!':
2486             *flagp &= ~HASWIDTH;
2487             /* FALL THROUGH */
2488         case '>':
2489             ender = reg_node(pRExC_state, SUCCEED);
2490             break;
2491         case 0:
2492             ender = reg_node(pRExC_state, END);
2493             break;
2494         }
2495         regtail(pRExC_state, lastbr, ender);
2496
2497         if (have_branch) {
2498             /* Hook the tails of the branches to the closing node. */
2499             for (br = ret; br != NULL; br = regnext(br)) {
2500                 regoptail(pRExC_state, br, ender);
2501             }
2502         }
2503     }
2504
2505     {
2506         char *p;
2507         static char parens[] = "=!<,>";
2508
2509         if (paren && (p = strchr(parens, paren))) {
2510             U8 node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2511             int flag = (p - parens) > 1;
2512
2513             if (paren == '>')
2514                 node = SUSPEND, flag = 0;
2515             reginsert(pRExC_state, node,ret);
2516             Set_Node_Cur_Length(ret);
2517             Set_Node_Offset(ret, parse_start + 1);
2518             ret->flags = flag;
2519             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2520         }
2521     }
2522
2523     /* Check for proper termination. */
2524     if (paren) {
2525         RExC_flags = oregflags;
2526         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2527             RExC_parse = oregcomp_parse;
2528             vFAIL("Unmatched (");
2529         }
2530     }
2531     else if (!paren && RExC_parse < RExC_end) {
2532         if (*RExC_parse == ')') {
2533             RExC_parse++;
2534             vFAIL("Unmatched )");
2535         }
2536         else
2537             FAIL("Junk on end of regexp");      /* "Can't happen". */
2538         /* NOTREACHED */
2539     }
2540
2541     return(ret);
2542 }
2543
2544 /*
2545  - regbranch - one alternative of an | operator
2546  *
2547  * Implements the concatenation operator.
2548  */
2549 STATIC regnode *
2550 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2551 {
2552     register regnode *ret;
2553     register regnode *chain = NULL;
2554     register regnode *latest;
2555     I32 flags = 0, c = 0;
2556
2557     if (first)
2558         ret = NULL;
2559     else {
2560         if (!SIZE_ONLY && RExC_extralen)
2561             ret = reganode(pRExC_state, BRANCHJ,0);
2562         else {
2563             ret = reg_node(pRExC_state, BRANCH);
2564             Set_Node_Length(ret, 1);
2565         }
2566     }
2567
2568     if (!first && SIZE_ONLY)
2569         RExC_extralen += 1;                     /* BRANCHJ */
2570
2571     *flagp = WORST;                     /* Tentatively. */
2572
2573     RExC_parse--;
2574     nextchar(pRExC_state);
2575     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2576         flags &= ~TRYAGAIN;
2577         latest = regpiece(pRExC_state, &flags);
2578         if (latest == NULL) {
2579             if (flags & TRYAGAIN)
2580                 continue;
2581             return(NULL);
2582         }
2583         else if (ret == NULL)
2584             ret = latest;
2585         *flagp |= flags&HASWIDTH;
2586         if (chain == NULL)      /* First piece. */
2587             *flagp |= flags&SPSTART;
2588         else {
2589             RExC_naughty++;
2590             regtail(pRExC_state, chain, latest);
2591         }
2592         chain = latest;
2593         c++;
2594     }
2595     if (chain == NULL) {        /* Loop ran zero times. */
2596         chain = reg_node(pRExC_state, NOTHING);
2597         if (ret == NULL)
2598             ret = chain;
2599     }
2600     if (c == 1) {
2601         *flagp |= flags&SIMPLE;
2602     }
2603
2604     return(ret);
2605 }
2606
2607 /*
2608  - regpiece - something followed by possible [*+?]
2609  *
2610  * Note that the branching code sequences used for ? and the general cases
2611  * of * and + are somewhat optimized:  they use the same NOTHING node as
2612  * both the endmarker for their branch list and the body of the last branch.
2613  * It might seem that this node could be dispensed with entirely, but the
2614  * endmarker role is not redundant.
2615  */
2616 STATIC regnode *
2617 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2618 {
2619     register regnode *ret;
2620     register char op;
2621     register char *next;
2622     I32 flags;
2623     char *origparse = RExC_parse;
2624     char *maxpos;
2625     I32 min;
2626     I32 max = REG_INFTY;
2627     char *parse_start;
2628
2629     ret = regatom(pRExC_state, &flags);
2630     if (ret == NULL) {
2631         if (flags & TRYAGAIN)
2632             *flagp |= TRYAGAIN;
2633         return(NULL);
2634     }
2635
2636     op = *RExC_parse;
2637
2638     if (op == '{' && regcurly(RExC_parse)) {
2639         parse_start = RExC_parse; /* MJD */
2640         next = RExC_parse + 1;
2641         maxpos = Nullch;
2642         while (isDIGIT(*next) || *next == ',') {
2643             if (*next == ',') {
2644                 if (maxpos)
2645                     break;
2646                 else
2647                     maxpos = next;
2648             }
2649             next++;
2650         }
2651         if (*next == '}') {             /* got one */
2652             if (!maxpos)
2653                 maxpos = next;
2654             RExC_parse++;
2655             min = atoi(RExC_parse);
2656             if (*maxpos == ',')
2657                 maxpos++;
2658             else
2659                 maxpos = RExC_parse;
2660             max = atoi(maxpos);
2661             if (!max && *maxpos != '0')
2662                 max = REG_INFTY;                /* meaning "infinity" */
2663             else if (max >= REG_INFTY)
2664                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2665             RExC_parse = next;
2666             nextchar(pRExC_state);
2667
2668         do_curly:
2669             if ((flags&SIMPLE)) {
2670                 RExC_naughty += 2 + RExC_naughty / 2;
2671                 reginsert(pRExC_state, CURLY, ret);
2672                 Set_Node_Offset(ret, parse_start+1); /* MJD */
2673                 Set_Node_Cur_Length(ret);
2674             }
2675             else {
2676                 regnode *w = reg_node(pRExC_state, WHILEM);
2677
2678                 w->flags = 0;
2679                 regtail(pRExC_state, ret, w);
2680                 if (!SIZE_ONLY && RExC_extralen) {
2681                     reginsert(pRExC_state, LONGJMP,ret);
2682                     reginsert(pRExC_state, NOTHING,ret);
2683                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2684                 }
2685                 reginsert(pRExC_state, CURLYX,ret);
2686                                 /* MJD hk */
2687                 Set_Node_Offset(ret, parse_start+1);
2688                 Set_Node_Length(ret,
2689                                 op == '{' ? (RExC_parse - parse_start) : 1);
2690
2691                 if (!SIZE_ONLY && RExC_extralen)
2692                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2693                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2694                 if (SIZE_ONLY)
2695                     RExC_whilem_seen++, RExC_extralen += 3;
2696                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2697             }
2698             ret->flags = 0;
2699
2700             if (min > 0)
2701                 *flagp = WORST;
2702             if (max > 0)
2703                 *flagp |= HASWIDTH;
2704             if (max && max < min)
2705                 vFAIL("Can't do {n,m} with n > m");
2706             if (!SIZE_ONLY) {
2707                 ARG1_SET(ret, (U16)min);
2708                 ARG2_SET(ret, (U16)max);
2709             }
2710
2711             goto nest_check;
2712         }
2713     }
2714
2715     if (!ISMULT1(op)) {
2716         *flagp = flags;
2717         return(ret);
2718     }
2719
2720 #if 0                           /* Now runtime fix should be reliable. */
2721
2722     /* if this is reinstated, don't forget to put this back into perldiag:
2723
2724             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2725
2726            (F) The part of the regexp subject to either the * or + quantifier
2727            could match an empty string. The {#} shows in the regular
2728            expression about where the problem was discovered.
2729
2730     */
2731
2732     if (!(flags&HASWIDTH) && op != '?')
2733       vFAIL("Regexp *+ operand could be empty");
2734 #endif
2735
2736     parse_start = RExC_parse;
2737     nextchar(pRExC_state);
2738
2739     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2740
2741     if (op == '*' && (flags&SIMPLE)) {
2742         reginsert(pRExC_state, STAR, ret);
2743         ret->flags = 0;
2744         RExC_naughty += 4;
2745     }
2746     else if (op == '*') {
2747         min = 0;
2748         goto do_curly;
2749     }
2750     else if (op == '+' && (flags&SIMPLE)) {
2751         reginsert(pRExC_state, PLUS, ret);
2752         ret->flags = 0;
2753         RExC_naughty += 3;
2754     }
2755     else if (op == '+') {
2756         min = 1;
2757         goto do_curly;
2758     }
2759     else if (op == '?') {
2760         min = 0; max = 1;
2761         goto do_curly;
2762     }
2763   nest_check:
2764     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2765         vWARN3(RExC_parse,
2766                "%.*s matches null string many times",
2767                RExC_parse - origparse,
2768                origparse);
2769     }
2770
2771     if (*RExC_parse == '?') {
2772         nextchar(pRExC_state);
2773         reginsert(pRExC_state, MINMOD, ret);
2774         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2775     }
2776     if (ISMULT2(RExC_parse)) {
2777         RExC_parse++;
2778         vFAIL("Nested quantifiers");
2779     }
2780
2781     return(ret);
2782 }
2783
2784 /*
2785  - regatom - the lowest level
2786  *
2787  * Optimization:  gobbles an entire sequence of ordinary characters so that
2788  * it can turn them into a single node, which is smaller to store and
2789  * faster to run.  Backslashed characters are exceptions, each becoming a
2790  * separate node; the code is simpler that way and it's not worth fixing.
2791  *
2792  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2793 STATIC regnode *
2794 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2795 {
2796     register regnode *ret = 0;
2797     I32 flags;
2798     char *parse_start = RExC_parse;
2799
2800     *flagp = WORST;             /* Tentatively. */
2801
2802 tryagain:
2803     switch (*RExC_parse) {
2804     case '^':
2805         RExC_seen_zerolen++;
2806         nextchar(pRExC_state);
2807         if (RExC_flags & PMf_MULTILINE)
2808             ret = reg_node(pRExC_state, MBOL);
2809         else if (RExC_flags & PMf_SINGLELINE)
2810             ret = reg_node(pRExC_state, SBOL);
2811         else
2812             ret = reg_node(pRExC_state, BOL);
2813         Set_Node_Length(ret, 1); /* MJD */
2814         break;
2815     case '$':
2816         nextchar(pRExC_state);
2817         if (*RExC_parse)
2818             RExC_seen_zerolen++;
2819         if (RExC_flags & PMf_MULTILINE)
2820             ret = reg_node(pRExC_state, MEOL);
2821         else if (RExC_flags & PMf_SINGLELINE)
2822             ret = reg_node(pRExC_state, SEOL);
2823         else
2824             ret = reg_node(pRExC_state, EOL);
2825         Set_Node_Length(ret, 1); /* MJD */
2826         break;
2827     case '.':
2828         nextchar(pRExC_state);
2829         if (RExC_flags & PMf_SINGLELINE)
2830             ret = reg_node(pRExC_state, SANY);
2831         else
2832             ret = reg_node(pRExC_state, REG_ANY);
2833         *flagp |= HASWIDTH|SIMPLE;
2834         RExC_naughty++;
2835         Set_Node_Length(ret, 1); /* MJD */
2836         break;
2837     case '[':
2838     {
2839         char *oregcomp_parse = ++RExC_parse;
2840         ret = regclass(pRExC_state);
2841         if (*RExC_parse != ']') {
2842             RExC_parse = oregcomp_parse;
2843             vFAIL("Unmatched [");
2844         }
2845         nextchar(pRExC_state);
2846         *flagp |= HASWIDTH|SIMPLE;
2847         Set_Node_Length(ret, RExC_parse - oregcomp_parse + 1); /* MJD */
2848         break;
2849     }
2850     case '(':
2851         nextchar(pRExC_state);
2852         ret = reg(pRExC_state, 1, &flags);
2853         if (ret == NULL) {
2854                 if (flags & TRYAGAIN) {
2855                     if (RExC_parse == RExC_end) {
2856                          /* Make parent create an empty node if needed. */
2857                         *flagp |= TRYAGAIN;
2858                         return(NULL);
2859                     }
2860                     goto tryagain;
2861                 }
2862                 return(NULL);
2863         }
2864         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2865         break;
2866     case '|':
2867     case ')':
2868         if (flags & TRYAGAIN) {
2869             *flagp |= TRYAGAIN;
2870             return NULL;
2871         }
2872         vFAIL("Internal urp");
2873                                 /* Supposed to be caught earlier. */
2874         break;
2875     case '{':
2876         if (!regcurly(RExC_parse)) {
2877             RExC_parse++;
2878             goto defchar;
2879         }
2880         /* FALL THROUGH */
2881     case '?':
2882     case '+':
2883     case '*':
2884         RExC_parse++;
2885         vFAIL("Quantifier follows nothing");
2886         break;
2887     case '\\':
2888         switch (*++RExC_parse) {
2889         case 'A':
2890             RExC_seen_zerolen++;
2891             ret = reg_node(pRExC_state, SBOL);
2892             *flagp |= SIMPLE;
2893             nextchar(pRExC_state);
2894             Set_Node_Length(ret, 2); /* MJD */
2895             break;
2896         case 'G':
2897             ret = reg_node(pRExC_state, GPOS);
2898             RExC_seen |= REG_SEEN_GPOS;
2899             *flagp |= SIMPLE;
2900             nextchar(pRExC_state);
2901             Set_Node_Length(ret, 2); /* MJD */
2902             break;
2903         case 'Z':
2904             ret = reg_node(pRExC_state, SEOL);
2905             *flagp |= SIMPLE;
2906             RExC_seen_zerolen++;                /* Do not optimize RE away */
2907             nextchar(pRExC_state);
2908             break;
2909         case 'z':
2910             ret = reg_node(pRExC_state, EOS);
2911             *flagp |= SIMPLE;
2912             RExC_seen_zerolen++;                /* Do not optimize RE away */
2913             nextchar(pRExC_state);
2914             Set_Node_Length(ret, 2); /* MJD */
2915             break;
2916         case 'C':
2917             ret = reg_node(pRExC_state, CANY);
2918             RExC_seen |= REG_SEEN_CANY;
2919             *flagp |= HASWIDTH|SIMPLE;
2920             nextchar(pRExC_state);
2921             Set_Node_Length(ret, 2); /* MJD */
2922             break;
2923         case 'X':
2924             ret = reg_node(pRExC_state, CLUMP);
2925             *flagp |= HASWIDTH;
2926             nextchar(pRExC_state);
2927             Set_Node_Length(ret, 2); /* MJD */
2928             break;
2929         case 'w':
2930             ret = reg_node(pRExC_state, (U8)(LOC ? ALNUML     : ALNUM));
2931             *flagp |= HASWIDTH|SIMPLE;
2932             nextchar(pRExC_state);
2933             Set_Node_Length(ret, 2); /* MJD */
2934             break;
2935         case 'W':
2936             ret = reg_node(pRExC_state, (U8)(LOC ? NALNUML    : NALNUM));
2937             *flagp |= HASWIDTH|SIMPLE;
2938             nextchar(pRExC_state);
2939             Set_Node_Length(ret, 2); /* MJD */
2940             break;
2941         case 'b':
2942             RExC_seen_zerolen++;
2943             RExC_seen |= REG_SEEN_LOOKBEHIND;
2944             ret = reg_node(pRExC_state, (U8)(LOC ? BOUNDL     : BOUND));
2945             *flagp |= SIMPLE;
2946             nextchar(pRExC_state);
2947             Set_Node_Length(ret, 2); /* MJD */
2948             break;
2949         case 'B':
2950             RExC_seen_zerolen++;
2951             RExC_seen |= REG_SEEN_LOOKBEHIND;
2952             ret = reg_node(pRExC_state, (U8)(LOC ? NBOUNDL    : NBOUND));
2953             *flagp |= SIMPLE;
2954             nextchar(pRExC_state);
2955             Set_Node_Length(ret, 2); /* MJD */
2956             break;
2957         case 's':
2958             ret = reg_node(pRExC_state, (U8)(LOC ? SPACEL     : SPACE));
2959             *flagp |= HASWIDTH|SIMPLE;
2960             nextchar(pRExC_state);
2961             Set_Node_Length(ret, 2); /* MJD */
2962             break;
2963         case 'S':
2964             ret = reg_node(pRExC_state, (U8)(LOC ? NSPACEL    : NSPACE));
2965             *flagp |= HASWIDTH|SIMPLE;
2966             nextchar(pRExC_state);
2967             Set_Node_Length(ret, 2); /* MJD */
2968             break;
2969         case 'd':
2970             ret = reg_node(pRExC_state, DIGIT);
2971             *flagp |= HASWIDTH|SIMPLE;
2972             nextchar(pRExC_state);
2973             Set_Node_Length(ret, 2); /* MJD */
2974             break;
2975         case 'D':
2976             ret = reg_node(pRExC_state, NDIGIT);
2977             *flagp |= HASWIDTH|SIMPLE;
2978             nextchar(pRExC_state);
2979             Set_Node_Length(ret, 2); /* MJD */
2980             break;
2981         case 'p':
2982         case 'P':
2983             {
2984                 char* oldregxend = RExC_end;
2985                 char* parse_start = RExC_parse - 2;
2986
2987                 if (RExC_parse[1] == '{') {
2988                   /* a lovely hack--pretend we saw [\pX] instead */
2989                     RExC_end = strchr(RExC_parse, '}');
2990                     if (!RExC_end) {
2991                         U8 c = (U8)*RExC_parse;
2992                         RExC_parse += 2;
2993                         RExC_end = oldregxend;
2994                         vFAIL2("Missing right brace on \\%c{}", c);
2995                     }
2996                     RExC_end++;
2997                 }
2998                 else {
2999                     RExC_end = RExC_parse + 2;
3000                     if (RExC_end > oldregxend)
3001                         RExC_end = oldregxend;
3002                 }
3003                 RExC_parse--;
3004
3005                 ret = regclass(pRExC_state);
3006
3007                 RExC_end = oldregxend;
3008                 RExC_parse--;
3009
3010                 Set_Node_Offset(ret, parse_start + 2);
3011                 Set_Node_Cur_Length(ret);
3012                 nextchar(pRExC_state);
3013                 *flagp |= HASWIDTH|SIMPLE;
3014             }
3015             break;
3016         case 'n':
3017         case 'r':
3018         case 't':
3019         case 'f':
3020         case 'e':
3021         case 'a':
3022         case 'x':
3023         case 'c':
3024         case '0':
3025             goto defchar;
3026         case '1': case '2': case '3': case '4':
3027         case '5': case '6': case '7': case '8': case '9':
3028             {
3029                 I32 num = atoi(RExC_parse);
3030
3031                 if (num > 9 && num >= RExC_npar)
3032                     goto defchar;
3033                 else {
3034                     char * parse_start = RExC_parse - 1; /* MJD */
3035                     while (isDIGIT(*RExC_parse))
3036                         RExC_parse++;
3037
3038                     if (!SIZE_ONLY && num > (I32)RExC_rx->nparens)
3039                         vFAIL("Reference to nonexistent group");
3040                     RExC_sawback = 1;
3041                     ret = reganode(pRExC_state,
3042                                    (U8)(FOLD ? (LOC ? REFFL : REFF) : REF),
3043                                    num);
3044                     *flagp |= HASWIDTH;
3045
3046                     /* override incorrect value set in reganode MJD */
3047                     Set_Node_Offset(ret, parse_start+1);
3048                     Set_Node_Cur_Length(ret); /* MJD */
3049                     RExC_parse--;
3050                     nextchar(pRExC_state);
3051                 }
3052             }
3053             break;
3054         case '\0':
3055             if (RExC_parse >= RExC_end)
3056                 FAIL("Trailing \\");
3057             /* FALL THROUGH */
3058         default:
3059             /* Do not generate `unrecognized' warnings here, we fall
3060                back into the quick-grab loop below */
3061             parse_start--;
3062             goto defchar;
3063         }
3064         break;
3065
3066     case '#':
3067         if (RExC_flags & PMf_EXTENDED) {
3068             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
3069             if (RExC_parse < RExC_end)
3070                 goto tryagain;
3071         }
3072         /* FALL THROUGH */
3073
3074     default: {
3075             register STRLEN len;
3076             register UV ender;
3077             register char *p;
3078             char *oldp, *s;
3079             STRLEN numlen;
3080             STRLEN foldlen;
3081             U8 tmpbuf[UTF8_MAXLEN_FOLD+1], *foldbuf;
3082
3083             parse_start = RExC_parse - 1;
3084
3085             RExC_parse++;
3086
3087         defchar:
3088             ender = 0;
3089             ret = reg_node(pRExC_state,
3090                            (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
3091             s = STRING(ret);
3092             for (len = 0, p = RExC_parse - 1;
3093               len < 127 && p < RExC_end;
3094               len++)
3095             {
3096                 oldp = p;
3097
3098                 if (RExC_flags & PMf_EXTENDED)
3099                     p = regwhite(p, RExC_end);
3100                 switch (*p) {
3101                 case '^':
3102                 case '$':
3103                 case '.':
3104                 case '[':
3105                 case '(':
3106                 case ')':
3107                 case '|':
3108                     goto loopdone;
3109                 case '\\':
3110                     switch (*++p) {
3111                     case 'A':
3112                     case 'C':
3113                     case 'X':
3114                     case 'G':
3115                     case 'Z':
3116                     case 'z':
3117                     case 'w':
3118                     case 'W':
3119                     case 'b':
3120                     case 'B':
3121                     case 's':
3122                     case 'S':
3123                     case 'd':
3124                     case 'D':
3125                     case 'p':
3126                     case 'P':
3127                         --p;
3128                         goto loopdone;
3129                     case 'n':
3130                         ender = '\n';
3131                         p++;
3132                         break;
3133                     case 'r':
3134                         ender = '\r';
3135                         p++;
3136                         break;
3137                     case 't':
3138                         ender = '\t';
3139                         p++;
3140                         break;
3141                     case 'f':
3142                         ender = '\f';
3143                         p++;
3144                         break;
3145                     case 'e':
3146                           ender = ASCII_TO_NATIVE('\033');
3147                         p++;
3148                         break;
3149                     case 'a':
3150                           ender = ASCII_TO_NATIVE('\007');
3151                         p++;
3152                         break;
3153                     case 'x':
3154                         if (*++p == '{') {
3155                             char* e = strchr(p, '}');
3156
3157                             if (!e) {
3158                                 RExC_parse = p + 1;
3159                                 vFAIL("Missing right brace on \\x{}");
3160                             }
3161                             else {
3162                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3163                                     | PERL_SCAN_DISALLOW_PREFIX;
3164                                 numlen = e - p - 1;
3165                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3166                                 if (ender > 0xff)
3167                                     RExC_utf8 = 1;
3168                                 p = e + 1;
3169                             }
3170                         }
3171                         else {
3172                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3173                             numlen = 2;
3174                             ender = grok_hex(p, &numlen, &flags, NULL);
3175                             p += numlen;
3176                         }
3177                         break;
3178                     case 'c':
3179                         p++;
3180                         ender = UCHARAT(p++);
3181                         ender = toCTRL(ender);
3182                         break;
3183                     case '0': case '1': case '2': case '3':case '4':
3184                     case '5': case '6': case '7': case '8':case '9':
3185                         if (*p == '0' ||
3186                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3187                             I32 flags = 0;
3188                             numlen = 3;
3189                             ender = grok_oct(p, &numlen, &flags, NULL);
3190                             p += numlen;
3191                         }
3192                         else {
3193                             --p;
3194                             goto loopdone;
3195                         }
3196                         break;
3197                     case '\0':
3198                         if (p >= RExC_end)
3199                             FAIL("Trailing \\");
3200                         /* FALL THROUGH */
3201                     default:
3202                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3203                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3204                         goto normal_default;
3205                     }
3206                     break;
3207                 default:
3208                   normal_default:
3209                     if (UTF8_IS_START(*p) && UTF) {
3210                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3211                                                &numlen, 0);
3212                         p += numlen;
3213                     }
3214                     else
3215                         ender = *p++;
3216                     break;
3217                 }
3218                 if (RExC_flags & PMf_EXTENDED)
3219                     p = regwhite(p, RExC_end);
3220                 if (UTF && FOLD) {
3221                     /* Prime the casefolded buffer. */
3222                     ender = toFOLD_uni(ender, tmpbuf, &foldlen);
3223                 }
3224                 if (ISMULT2(p)) { /* Back off on ?+*. */
3225                     if (len)
3226                         p = oldp;
3227                     else if (UTF) {
3228                          STRLEN unilen;
3229
3230                          if (FOLD) {
3231                               /* Emit all the Unicode characters. */
3232                               for (foldbuf = tmpbuf;
3233                                    foldlen;
3234                                    foldlen -= numlen) {
3235                                    ender = utf8_to_uvchr(foldbuf, &numlen);
3236                                    if (numlen > 0) {
3237                                         reguni(pRExC_state, ender, s, &unilen);
3238                                         s       += unilen;
3239                                         len     += unilen;
3240                                         /* In EBCDIC the numlen
3241                                          * and unilen can differ. */
3242                                         foldbuf += numlen;
3243                                         if (numlen >= foldlen)
3244                                              break;
3245                                    }
3246                                    else
3247                                         break; /* "Can't happen." */
3248                               }
3249                          }
3250                          else {
3251                               reguni(pRExC_state, ender, s, &unilen);
3252                               if (unilen > 0) {
3253                                    s   += unilen;
3254                                    len += unilen;
3255                               }
3256                          }
3257                     }
3258                     else {
3259                         len++;
3260                         REGC((char)ender, s++);
3261                     }
3262                     break;
3263                 }
3264                 if (UTF) {
3265                      STRLEN unilen;
3266
3267                      if (FOLD) {
3268                           /* Emit all the Unicode characters. */
3269                           for (foldbuf = tmpbuf;
3270                                foldlen;
3271                                foldlen -= numlen) {
3272                                ender = utf8_to_uvchr(foldbuf, &numlen);
3273                                if (numlen > 0) {
3274                                     reguni(pRExC_state, ender, s, &unilen);
3275                                     len     += unilen;
3276                                     s       += unilen;
3277                                     /* In EBCDIC the numlen
3278                                      * and unilen can differ. */
3279                                     foldbuf += numlen;
3280                                     if (numlen >= foldlen)
3281                                          break;
3282                                }
3283                                else
3284                                     break;
3285                           }
3286                      }
3287                      else {
3288                           reguni(pRExC_state, ender, s, &unilen);
3289                           if (unilen > 0) {
3290                                s   += unilen;
3291                                len += unilen;
3292                           }
3293                      }
3294                      len--;
3295                 }
3296                 else
3297                     REGC((char)ender, s++);
3298             }
3299         loopdone:
3300             RExC_parse = p - 1;
3301             Set_Node_Cur_Length(ret); /* MJD */
3302             nextchar(pRExC_state);
3303             {
3304                 /* len is STRLEN which is unsigned, need to copy to signed */
3305                 IV iv = len;
3306                 if (iv < 0)
3307                     vFAIL("Internal disaster");
3308             }
3309             if (len > 0)
3310                 *flagp |= HASWIDTH;
3311             if (len == 1 && UNI_IS_INVARIANT(ender))
3312                 *flagp |= SIMPLE;
3313             if (!SIZE_ONLY)
3314                 STR_LEN(ret) = len;
3315             if (SIZE_ONLY)
3316                 RExC_size += STR_SZ(len);
3317             else
3318                 RExC_emit += STR_SZ(len);
3319         }
3320         break;
3321     }
3322
3323     /* If the encoding pragma is in effect recode the text of
3324      * any EXACT-kind nodes. */
3325     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3326         STRLEN oldlen = STR_LEN(ret);
3327         SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3328
3329         if (RExC_utf8)
3330             SvUTF8_on(sv);
3331         if (sv_utf8_downgrade(sv, TRUE)) {
3332             char *s       = sv_recode_to_utf8(sv, PL_encoding);
3333             STRLEN newlen = SvCUR(sv);
3334
3335             if (SvUTF8(sv))
3336                 RExC_utf8 = 1;
3337             if (!SIZE_ONLY) {
3338                 DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3339                                       (int)oldlen, STRING(ret),
3340                                       (int)newlen, s));
3341                 Copy(s, STRING(ret), newlen, char);
3342                 STR_LEN(ret) += newlen - oldlen;
3343                 RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3344             } else
3345                 RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3346         }
3347     }
3348
3349     return(ret);
3350 }
3351
3352 STATIC char *
3353 S_regwhite(pTHX_ char *p, char *e)
3354 {
3355     while (p < e) {
3356         if (isSPACE(*p))
3357             ++p;
3358         else if (*p == '#') {
3359             do {
3360                 p++;
3361             } while (p < e && *p != '\n');
3362         }
3363         else
3364             break;
3365     }
3366     return p;
3367 }
3368
3369 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3370    Character classes ([:foo:]) can also be negated ([:^foo:]).
3371    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3372    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3373    but trigger failures because they are currently unimplemented. */
3374
3375 #define POSIXCC_DONE(c)   ((c) == ':')
3376 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3377 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3378
3379 STATIC I32
3380 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3381 {
3382     char *posixcc = 0;
3383     I32 namedclass = OOB_NAMEDCLASS;
3384
3385     if (value == '[' && RExC_parse + 1 < RExC_end &&
3386         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3387         POSIXCC(UCHARAT(RExC_parse))) {
3388         char  c = UCHARAT(RExC_parse);
3389         char* s = RExC_parse++;
3390
3391         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3392             RExC_parse++;
3393         if (RExC_parse == RExC_end)
3394             /* Grandfather lone [:, [=, [. */
3395             RExC_parse = s;
3396         else {
3397             char* t = RExC_parse++; /* skip over the c */
3398
3399             if (UCHARAT(RExC_parse) == ']') {
3400                 RExC_parse++; /* skip over the ending ] */
3401                 posixcc = s + 1;
3402                 if (*s == ':') {
3403                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3404                     I32 skip = 5; /* the most common skip */
3405
3406                     switch (*posixcc) {
3407                     case 'a':
3408                         if (strnEQ(posixcc, "alnum", 5))
3409                             namedclass =
3410                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3411                         else if (strnEQ(posixcc, "alpha", 5))
3412                             namedclass =
3413                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3414                         else if (strnEQ(posixcc, "ascii", 5))
3415                             namedclass =
3416                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3417                         break;
3418                     case 'b':
3419                         if (strnEQ(posixcc, "blank", 5))
3420                             namedclass =
3421                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3422                         break;
3423                     case 'c':
3424                         if (strnEQ(posixcc, "cntrl", 5))
3425                             namedclass =
3426                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3427                         break;
3428                     case 'd':
3429                         if (strnEQ(posixcc, "digit", 5))
3430                             namedclass =
3431                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3432                         break;
3433                     case 'g':
3434                         if (strnEQ(posixcc, "graph", 5))
3435                             namedclass =
3436                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3437                         break;
3438                     case 'l':
3439                         if (strnEQ(posixcc, "lower", 5))
3440                             namedclass =
3441                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3442                         break;
3443                     case 'p':
3444                         if (strnEQ(posixcc, "print", 5))
3445                             namedclass =
3446                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3447                         else if (strnEQ(posixcc, "punct", 5))
3448                             namedclass =
3449                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3450                         break;
3451                     case 's':
3452                         if (strnEQ(posixcc, "space", 5))
3453                             namedclass =
3454                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3455                         break;
3456                     case 'u':
3457                         if (strnEQ(posixcc, "upper", 5))
3458                             namedclass =
3459                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3460                         break;
3461                     case 'w': /* this is not POSIX, this is the Perl \w */
3462                         if (strnEQ(posixcc, "word", 4)) {
3463                             namedclass =
3464                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3465                             skip = 4;
3466                         }
3467                         break;
3468                     case 'x':
3469                         if (strnEQ(posixcc, "xdigit", 6)) {
3470                             namedclass =
3471                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3472                             skip = 6;
3473                         }
3474                         break;
3475                     }
3476                     if (namedclass == OOB_NAMEDCLASS ||
3477                         posixcc[skip] != ':' ||
3478                         posixcc[skip+1] != ']')
3479                     {
3480                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3481                                       t - s - 1, s + 1);
3482                     }
3483                 } else if (!SIZE_ONLY) {
3484                     /* [[=foo=]] and [[.foo.]] are still future. */
3485
3486                     /* adjust RExC_parse so the warning shows after
3487                        the class closes */
3488                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3489                         RExC_parse++;
3490                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3491                 }
3492             } else {
3493                 /* Maternal grandfather:
3494                  * "[:" ending in ":" but not in ":]" */
3495                 RExC_parse = s;
3496             }
3497         }
3498     }
3499
3500     return namedclass;
3501 }
3502
3503 STATIC void
3504 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3505 {
3506     if (!SIZE_ONLY && POSIXCC(UCHARAT(RExC_parse))) {
3507         char *s = RExC_parse;
3508         char  c = *s++;
3509
3510         while(*s && isALNUM(*s))
3511             s++;
3512         if (*s && c == *s && s[1] == ']') {
3513             if (ckWARN(WARN_REGEXP))
3514                 vWARN3(s+2,
3515                         "POSIX syntax [%c %c] belongs inside character classes",
3516                         c, c);
3517
3518             /* [[=foo=]] and [[.foo.]] are still future. */
3519             if (POSIXCC_NOTYET(c)) {
3520                 /* adjust RExC_parse so the error shows after
3521                    the class closes */
3522                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3523                     ;
3524                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3525             }
3526         }
3527     }
3528 }
3529
3530 STATIC regnode *
3531 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3532 {
3533     register UV value;
3534     register UV nextvalue;
3535     register IV prevvalue = OOB_UNICODE;
3536     register IV range = 0;
3537     register regnode *ret;
3538     STRLEN numlen;
3539     IV namedclass;
3540     char *rangebegin = 0;
3541     bool need_class = 0;
3542     SV *listsv = Nullsv;
3543     register char *e;
3544     UV n;
3545     bool optimize_invert   = TRUE;
3546     AV* unicode_alternate  = 0;
3547 #ifdef EBCDIC
3548     UV literal_endpoint = 0;
3549 #endif
3550
3551     ret = reganode(pRExC_state, ANYOF, 0);
3552
3553     if (!SIZE_ONLY)
3554         ANYOF_FLAGS(ret) = 0;
3555
3556     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3557         RExC_naughty++;
3558         RExC_parse++;
3559         if (!SIZE_ONLY)
3560             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3561     }
3562
3563     if (SIZE_ONLY)
3564         RExC_size += ANYOF_SKIP;
3565     else {
3566         RExC_emit += ANYOF_SKIP;
3567         if (FOLD)
3568             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3569         if (LOC)
3570             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3571         ANYOF_BITMAP_ZERO(ret);
3572         listsv = newSVpvn("# comment\n", 10);
3573     }
3574
3575     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3576
3577     if (!SIZE_ONLY && POSIXCC(nextvalue))
3578         checkposixcc(pRExC_state);
3579
3580     /* allow 1st char to be ] (allowing it to be - is dealt with later) */
3581     if (UCHARAT(RExC_parse) == ']')
3582         goto charclassloop;
3583
3584     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3585
3586     charclassloop:
3587
3588         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3589
3590         if (!range)
3591             rangebegin = RExC_parse;
3592         if (UTF) {
3593             value = utf8n_to_uvchr((U8*)RExC_parse,
3594                                    RExC_end - RExC_parse,
3595                                    &numlen, 0);
3596             RExC_parse += numlen;
3597         }
3598         else
3599             value = UCHARAT(RExC_parse++);
3600         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3601         if (value == '[' && POSIXCC(nextvalue))
3602             namedclass = regpposixcc(pRExC_state, value);
3603         else if (value == '\\') {
3604             if (UTF) {
3605                 value = utf8n_to_uvchr((U8*)RExC_parse,
3606                                    RExC_end - RExC_parse,
3607                                    &numlen, 0);
3608                 RExC_parse += numlen;
3609             }
3610             else
3611                 value = UCHARAT(RExC_parse++);
3612             /* Some compilers cannot handle switching on 64-bit integer
3613              * values, therefore value cannot be an UV.  Yes, this will
3614              * be a problem later if we want switch on Unicode.
3615              * A similar issue a little bit later when switching on
3616              * namedclass. --jhi */
3617             switch ((I32)value) {
3618             case 'w':   namedclass = ANYOF_ALNUM;       break;
3619             case 'W':   namedclass = ANYOF_NALNUM;      break;
3620             case 's':   namedclass = ANYOF_SPACE;       break;
3621             case 'S':   namedclass = ANYOF_NSPACE;      break;
3622             case 'd':   namedclass = ANYOF_DIGIT;       break;
3623             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3624             case 'p':
3625             case 'P':
3626                 if (RExC_parse >= RExC_end)
3627                     vFAIL2("Empty \\%c{}", (U8)value);
3628                 if (*RExC_parse == '{') {
3629                     U8 c = (U8)value;
3630                     e = strchr(RExC_parse++, '}');
3631                     if (!e)
3632                         vFAIL2("Missing right brace on \\%c{}", c);
3633                     while (isSPACE(UCHARAT(RExC_parse)))
3634                         RExC_parse++;
3635                     if (e == RExC_parse)
3636                         vFAIL2("Empty \\%c{}", c);
3637                     n = e - RExC_parse;
3638                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3639                         n--;
3640                 }
3641                 else {
3642                     e = RExC_parse;
3643                     n = 1;
3644                 }
3645                 if (!SIZE_ONLY) {
3646                     if (UCHARAT(RExC_parse) == '^') {
3647                          RExC_parse++;
3648                          n--;
3649                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3650                          while (isSPACE(UCHARAT(RExC_parse))) {
3651                               RExC_parse++;
3652                               n--;
3653                          }
3654                     }
3655                     if (value == 'p')
3656                          Perl_sv_catpvf(aTHX_ listsv,
3657                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3658                     else
3659                          Perl_sv_catpvf(aTHX_ listsv,
3660                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3661                 }
3662                 RExC_parse = e + 1;
3663                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3664                 continue;
3665             case 'n':   value = '\n';                   break;
3666             case 'r':   value = '\r';                   break;
3667             case 't':   value = '\t';                   break;
3668             case 'f':   value = '\f';                   break;
3669             case 'b':   value = '\b';                   break;
3670             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3671             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3672             case 'x':
3673                 if (*RExC_parse == '{') {
3674                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3675                         | PERL_SCAN_DISALLOW_PREFIX;
3676                     e = strchr(RExC_parse++, '}');
3677                     if (!e)
3678                         vFAIL("Missing right brace on \\x{}");
3679
3680                     numlen = e - RExC_parse;
3681                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3682                     RExC_parse = e + 1;
3683                 }
3684                 else {
3685                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3686                     numlen = 2;
3687                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3688                     RExC_parse += numlen;
3689                 }
3690                 break;
3691             case 'c':
3692                 value = UCHARAT(RExC_parse++);
3693                 value = toCTRL(value);
3694                 break;
3695             case '0': case '1': case '2': case '3': case '4':
3696             case '5': case '6': case '7': case '8': case '9':
3697             {
3698                 I32 flags = 0;
3699                 numlen = 3;
3700                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3701                 RExC_parse += numlen;
3702                 break;
3703             }
3704             default:
3705                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3706                     vWARN2(RExC_parse,
3707                            "Unrecognized escape \\%c in character class passed through",
3708                            (int)value);
3709                 break;
3710             }
3711         } /* end of \blah */
3712 #ifdef EBCDIC
3713         else
3714             literal_endpoint++;
3715 #endif
3716
3717         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3718
3719             if (!SIZE_ONLY && !need_class)
3720                 ANYOF_CLASS_ZERO(ret);
3721
3722             need_class = 1;
3723
3724             /* a bad range like a-\d, a-[:digit:] ? */
3725             if (range) {
3726                 if (!SIZE_ONLY) {
3727                     if (ckWARN(WARN_REGEXP))
3728                         vWARN4(RExC_parse,
3729                                "False [] range \"%*.*s\"",
3730                                RExC_parse - rangebegin,
3731                                RExC_parse - rangebegin,
3732                                rangebegin);
3733                     if (prevvalue < 256) {
3734                         ANYOF_BITMAP_SET(ret, prevvalue);
3735                         ANYOF_BITMAP_SET(ret, '-');
3736                     }
3737                     else {
3738                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3739                         Perl_sv_catpvf(aTHX_ listsv,
3740                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3741                     }
3742                 }
3743
3744                 range = 0; /* this was not a true range */
3745             }
3746
3747             if (!SIZE_ONLY) {
3748                 if (namedclass > OOB_NAMEDCLASS)
3749                     optimize_invert = FALSE;
3750                 /* Possible truncation here but in some 64-bit environments
3751                  * the compiler gets heartburn about switch on 64-bit values.
3752                  * A similar issue a little earlier when switching on value.
3753                  * --jhi */
3754                 switch ((I32)namedclass) {
3755                 case ANYOF_ALNUM:
3756                     if (LOC)
3757                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3758                     else {
3759                         for (value = 0; value < 256; value++)
3760                             if (isALNUM(value))
3761                                 ANYOF_BITMAP_SET(ret, value);
3762                     }
3763                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");
3764                     break;
3765                 case ANYOF_NALNUM:
3766                     if (LOC)
3767                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3768                     else {
3769                         for (value = 0; value < 256; value++)
3770                             if (!isALNUM(value))
3771                                 ANYOF_BITMAP_SET(ret, value);
3772                     }
3773                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3774                     break;
3775                 case ANYOF_ALNUMC:
3776                     if (LOC)
3777                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3778                     else {
3779                         for (value = 0; value < 256; value++)
3780                             if (isALNUMC(value))
3781                                 ANYOF_BITMAP_SET(ret, value);
3782                     }
3783                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3784                     break;
3785                 case ANYOF_NALNUMC:
3786                     if (LOC)
3787                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3788                     else {
3789                         for (value = 0; value < 256; value++)
3790                             if (!isALNUMC(value))
3791                                 ANYOF_BITMAP_SET(ret, value);
3792                     }
3793                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3794                     break;
3795                 case ANYOF_ALPHA:
3796                     if (LOC)
3797                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3798                     else {
3799                         for (value = 0; value < 256; value++)
3800                             if (isALPHA(value))
3801                                 ANYOF_BITMAP_SET(ret, value);
3802                     }
3803                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3804                     break;
3805                 case ANYOF_NALPHA:
3806                     if (LOC)
3807                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3808                     else {
3809                         for (value = 0; value < 256; value++)
3810                             if (!isALPHA(value))
3811                                 ANYOF_BITMAP_SET(ret, value);
3812                     }
3813                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3814                     break;
3815                 case ANYOF_ASCII:
3816                     if (LOC)
3817                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3818                     else {
3819 #ifndef EBCDIC
3820                         for (value = 0; value < 128; value++)
3821                             ANYOF_BITMAP_SET(ret, value);
3822 #else  /* EBCDIC */
3823                         for (value = 0; value < 256; value++) {
3824                             if (isASCII(value))
3825                                 ANYOF_BITMAP_SET(ret, value);
3826                         }
3827 #endif /* EBCDIC */
3828                     }
3829                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3830                     break;
3831                 case ANYOF_NASCII:
3832                     if (LOC)
3833                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3834                     else {
3835 #ifndef EBCDIC
3836                         for (value = 128; value < 256; value++)
3837                             ANYOF_BITMAP_SET(ret, value);
3838 #else  /* EBCDIC */
3839                         for (value = 0; value < 256; value++) {
3840                             if (!isASCII(value))
3841                                 ANYOF_BITMAP_SET(ret, value);
3842                         }
3843 #endif /* EBCDIC */
3844                     }
3845                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3846                     break;
3847                 case ANYOF_BLANK:
3848                     if (LOC)
3849                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3850                     else {
3851                         for (value = 0; value < 256; value++)
3852                             if (isBLANK(value))
3853                                 ANYOF_BITMAP_SET(ret, value);
3854                     }
3855                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3856                     break;
3857                 case ANYOF_NBLANK:
3858                     if (LOC)
3859                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3860                     else {
3861                         for (value = 0; value < 256; value++)
3862                             if (!isBLANK(value))
3863                                 ANYOF_BITMAP_SET(ret, value);
3864                     }
3865                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3866                     break;
3867                 case ANYOF_CNTRL:
3868                     if (LOC)
3869                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3870                     else {
3871                         for (value = 0; value < 256; value++)
3872                             if (isCNTRL(value))
3873                                 ANYOF_BITMAP_SET(ret, value);
3874                     }
3875                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3876                     break;
3877                 case ANYOF_NCNTRL:
3878                     if (LOC)
3879                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3880                     else {
3881                         for (value = 0; value < 256; value++)
3882                             if (!isCNTRL(value))
3883                                 ANYOF_BITMAP_SET(ret, value);
3884                     }
3885                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3886                     break;
3887                 case ANYOF_DIGIT:
3888                     if (LOC)
3889                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3890                     else {
3891                         /* consecutive digits assumed */
3892                         for (value = '0'; value <= '9'; value++)
3893                             ANYOF_BITMAP_SET(ret, value);
3894                     }
3895                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3896                     break;
3897                 case ANYOF_NDIGIT:
3898                     if (LOC)
3899                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3900                     else {
3901                         /* consecutive digits assumed */
3902                         for (value = 0; value < '0'; value++)
3903                             ANYOF_BITMAP_SET(ret, value);
3904                         for (value = '9' + 1; value < 256; value++)
3905                             ANYOF_BITMAP_SET(ret, value);
3906                     }
3907                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3908                     break;
3909                 case ANYOF_GRAPH:
3910                     if (LOC)
3911                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3912                     else {
3913                         for (value = 0; value < 256; value++)
3914                             if (isGRAPH(value))
3915                                 ANYOF_BITMAP_SET(ret, value);
3916                     }
3917                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3918                     break;
3919                 case ANYOF_NGRAPH:
3920                     if (LOC)
3921                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3922                     else {
3923                         for (value = 0; value < 256; value++)
3924                             if (!isGRAPH(value))
3925                                 ANYOF_BITMAP_SET(ret, value);
3926                     }
3927                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3928                     break;
3929                 case ANYOF_LOWER:
3930                     if (LOC)
3931                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3932                     else {
3933                         for (value = 0; value < 256; value++)
3934                             if (isLOWER(value))
3935                                 ANYOF_BITMAP_SET(ret, value);
3936                     }
3937                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3938                     break;
3939                 case ANYOF_NLOWER:
3940                     if (LOC)
3941                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3942                     else {
3943                         for (value = 0; value < 256; value++)
3944                             if (!isLOWER(value))
3945                                 ANYOF_BITMAP_SET(ret, value);
3946                     }
3947                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3948                     break;
3949                 case ANYOF_PRINT:
3950                     if (LOC)
3951                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3952                     else {
3953                         for (value = 0; value < 256; value++)
3954                             if (isPRINT(value))
3955                                 ANYOF_BITMAP_SET(ret, value);
3956                     }
3957                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3958                     break;
3959                 case ANYOF_NPRINT:
3960                     if (LOC)
3961                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3962                     else {
3963                         for (value = 0; value < 256; value++)
3964                             if (!isPRINT(value))
3965                                 ANYOF_BITMAP_SET(ret, value);
3966                     }
3967                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3968                     break;
3969                 case ANYOF_PSXSPC:
3970                     if (LOC)
3971                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3972                     else {
3973                         for (value = 0; value < 256; value++)
3974                             if (isPSXSPC(value))
3975                                 ANYOF_BITMAP_SET(ret, value);
3976                     }
3977                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3978                     break;
3979                 case ANYOF_NPSXSPC:
3980                     if (LOC)
3981                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3982                     else {
3983                         for (value = 0; value < 256; value++)
3984                             if (!isPSXSPC(value))
3985                                 ANYOF_BITMAP_SET(ret, value);
3986                     }
3987                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3988                     break;
3989                 case ANYOF_PUNCT:
3990                     if (LOC)
3991                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3992                     else {
3993                         for (value = 0; value < 256; value++)
3994                             if (isPUNCT(value))
3995                                 ANYOF_BITMAP_SET(ret, value);
3996                     }
3997                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3998                     break;
3999                 case ANYOF_NPUNCT:
4000                     if (LOC)
4001                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
4002                     else {
4003                         for (value = 0; value < 256; value++)
4004                             if (!isPUNCT(value))
4005                                 ANYOF_BITMAP_SET(ret, value);
4006                     }
4007                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
4008                     break;
4009                 case ANYOF_SPACE:
4010                     if (LOC)
4011                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
4012                     else {
4013                         for (value = 0; value < 256; value++)
4014                             if (isSPACE(value))
4015                                 ANYOF_BITMAP_SET(ret, value);
4016                     }
4017                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
4018                     break;
4019                 case ANYOF_NSPACE:
4020                     if (LOC)
4021                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
4022                     else {
4023                         for (value = 0; value < 256; value++)
4024                             if (!isSPACE(value))
4025                                 ANYOF_BITMAP_SET(ret, value);
4026                     }
4027                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
4028                     break;
4029                 case ANYOF_UPPER:
4030                     if (LOC)
4031                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
4032                     else {
4033                         for (value = 0; value < 256; value++)
4034                             if (isUPPER(value))
4035                                 ANYOF_BITMAP_SET(ret, value);
4036                     }
4037                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
4038                     break;
4039                 case ANYOF_NUPPER:
4040                     if (LOC)
4041                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
4042                     else {
4043                         for (value = 0; value < 256; value++)
4044                             if (!isUPPER(value))
4045                                 ANYOF_BITMAP_SET(ret, value);
4046                     }
4047                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
4048                     break;
4049                 case ANYOF_XDIGIT:
4050                     if (LOC)
4051                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
4052                     else {
4053                         for (value = 0; value < 256; value++)
4054                             if (isXDIGIT(value))
4055                                 ANYOF_BITMAP_SET(ret, value);
4056                     }
4057                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
4058                     break;
4059                 case ANYOF_NXDIGIT:
4060                     if (LOC)
4061                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
4062                     else {
4063                         for (value = 0; value < 256; value++)
4064                             if (!isXDIGIT(value))
4065                                 ANYOF_BITMAP_SET(ret, value);
4066                     }
4067                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
4068                     break;
4069                 default:
4070                     vFAIL("Invalid [::] class");
4071                     break;
4072                 }
4073                 if (LOC)
4074                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
4075                 continue;
4076             }
4077         } /* end of namedclass \blah */
4078
4079         if (range) {
4080             if (prevvalue > (IV)value) /* b-a */ {
4081                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
4082                               RExC_parse - rangebegin,
4083                               RExC_parse - rangebegin,
4084                               rangebegin);
4085                 range = 0; /* not a valid range */
4086             }
4087         }
4088         else {
4089             prevvalue = value; /* save the beginning of the range */
4090             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
4091                 RExC_parse[1] != ']') {
4092                 RExC_parse++;
4093
4094                 /* a bad range like \w-, [:word:]- ? */
4095                 if (namedclass > OOB_NAMEDCLASS) {
4096                     if (ckWARN(WARN_REGEXP))
4097                         vWARN4(RExC_parse,
4098                                "False [] range \"%*.*s\"",
4099                                RExC_parse - rangebegin,
4100                                RExC_parse - rangebegin,
4101                                rangebegin);
4102                     if (!SIZE_ONLY)
4103                         ANYOF_BITMAP_SET(ret, '-');
4104                 } else
4105                     range = 1;  /* yeah, it's a range! */
4106                 continue;       /* but do it the next time */
4107             }
4108         }
4109
4110         /* now is the next time */
4111         if (!SIZE_ONLY) {
4112             IV i;
4113
4114             if (prevvalue < 256) {
4115                 IV ceilvalue = value < 256 ? value : 255;
4116
4117 #ifdef EBCDIC
4118                 /* In EBCDIC [\x89-\x91] should include
4119                  * the \x8e but [i-j] should not. */
4120                 if (literal_endpoint == 2 &&
4121                     ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
4122                      (isUPPER(prevvalue) && isUPPER(ceilvalue))))
4123                 {
4124                     if (isLOWER(prevvalue)) {
4125                         for (i = prevvalue; i <= ceilvalue; i++)
4126                             if (isLOWER(i))
4127                                 ANYOF_BITMAP_SET(ret, i);
4128                     } else {
4129                         for (i = prevvalue; i <= ceilvalue; i++)
4130                             if (isUPPER(i))
4131                                 ANYOF_BITMAP_SET(ret, i);
4132                     }
4133                 }
4134                 else
4135 #endif
4136                       for (i = prevvalue; i <= ceilvalue; i++)
4137                           ANYOF_BITMAP_SET(ret, i);
4138           }
4139           if (value > 255 || UTF) {
4140                 UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
4141                 UV natvalue      = NATIVE_TO_UNI(value);
4142
4143                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
4144                 if (prevnatvalue < natvalue) { /* what about > ? */
4145                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
4146                                    prevnatvalue, natvalue);
4147                 }
4148                 else if (prevnatvalue == natvalue) {
4149                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", natvalue);
4150                     if (FOLD) {
4151                          U8 foldbuf[UTF8_MAXLEN_FOLD+1];
4152                          STRLEN foldlen;
4153                          UV f = to_uni_fold(natvalue, foldbuf, &foldlen);
4154
4155                          /* If folding and foldable and a single
4156                           * character, insert also the folded version
4157                           * to the charclass. */
4158                          if (f != value) {
4159                               if (foldlen == (STRLEN)UNISKIP(f))
4160                                   Perl_sv_catpvf(aTHX_ listsv,
4161                                                  "%04"UVxf"\n", f);
4162                               else {
4163                                   /* Any multicharacter foldings
4164                                    * require the following transform:
4165                                    * [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst)
4166                                    * where E folds into "pq" and F folds
4167                                    * into "rst", all other characters
4168                                    * fold to single characters.  We save
4169                                    * away these multicharacter foldings,
4170                                    * to be later saved as part of the
4171                                    * additional "s" data. */
4172                                   SV *sv;
4173
4174                                   if (!unicode_alternate)
4175                                       unicode_alternate = newAV();
4176                                   sv = newSVpvn((char*)foldbuf, foldlen);
4177                                   SvUTF8_on(sv);
4178                                   av_push(unicode_alternate, sv);
4179                               }
4180                          }
4181
4182                          /* If folding and the value is one of the Greek
4183                           * sigmas insert a few more sigmas to make the
4184                           * folding rules of the sigmas to work right.
4185                           * Note that not all the possible combinations
4186                           * are handled here: some of them are handled
4187                           * by the standard folding rules, and some of
4188                           * them (literal or EXACTF cases) are handled
4189                           * during runtime in regexec.c:S_find_byclass(). */
4190                          if (value == UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA) {
4191                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4192                                              (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA);
4193                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4194                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4195                          }
4196                          else if (value == UNICODE_GREEK_CAPITAL_LETTER_SIGMA)
4197                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4198                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4199                     }
4200                 }
4201             }
4202 #ifdef EBCDIC
4203             literal_endpoint = 0;
4204 #endif
4205         }
4206
4207         range = 0; /* this range (if it was one) is done now */
4208     }
4209
4210     if (need_class) {
4211         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
4212         if (SIZE_ONLY)
4213             RExC_size += ANYOF_CLASS_ADD_SKIP;
4214         else
4215             RExC_emit += ANYOF_CLASS_ADD_SKIP;
4216     }
4217
4218     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4219     if (!SIZE_ONLY &&
4220          /* If the only flag is folding (plus possibly inversion). */
4221         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4222        ) {
4223         for (value = 0; value < 256; ++value) {
4224             if (ANYOF_BITMAP_TEST(ret, value)) {
4225                 UV fold = PL_fold[value];
4226
4227                 if (fold != value)
4228                     ANYOF_BITMAP_SET(ret, fold);
4229             }
4230         }
4231         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4232     }
4233
4234     /* optimize inverted simple patterns (e.g. [^a-z]) */
4235     if (!SIZE_ONLY && optimize_invert &&
4236         /* If the only flag is inversion. */
4237         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4238         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4239             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4240         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4241     }
4242
4243     if (!SIZE_ONLY) {
4244         AV *av = newAV();
4245         SV *rv;
4246
4247         /* The 0th element stores the character class description
4248          * in its textual form: used later (regexec.c:Perl_regclass_swash())
4249          * to initialize the appropriate swash (which gets stored in
4250          * the 1st element), and also useful for dumping the regnode.
4251          * The 2nd element stores the multicharacter foldings,
4252          * used later (regexec.c:S_reginclass()). */
4253         av_store(av, 0, listsv);
4254         av_store(av, 1, NULL);
4255         av_store(av, 2, (SV*)unicode_alternate);
4256         rv = newRV_noinc((SV*)av);
4257         n = add_data(pRExC_state, 1, "s");
4258         RExC_rx->data->data[n] = (void*)rv;
4259         ARG_SET(ret, n);
4260     }
4261
4262     return ret;
4263 }
4264
4265 STATIC char*
4266 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4267 {
4268     char* retval = RExC_parse++;
4269
4270     for (;;) {
4271         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4272                 RExC_parse[2] == '#') {
4273             while (*RExC_parse != ')') {
4274                 if (RExC_parse == RExC_end)
4275                     FAIL("Sequence (?#... not terminated");
4276                 RExC_parse++;
4277             }
4278             RExC_parse++;
4279             continue;
4280         }
4281         if (RExC_flags & PMf_EXTENDED) {
4282             if (isSPACE(*RExC_parse)) {
4283                 RExC_parse++;
4284                 continue;
4285             }
4286             else if (*RExC_parse == '#') {
4287                 while (RExC_parse < RExC_end)
4288                     if (*RExC_parse++ == '\n') break;
4289                 continue;
4290             }
4291         }
4292         return retval;
4293     }
4294 }
4295
4296 /*
4297 - reg_node - emit a node
4298 */
4299 STATIC regnode *                        /* Location. */
4300 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4301 {
4302     register regnode *ret;
4303     register regnode *ptr;
4304
4305     ret = RExC_emit;
4306     if (SIZE_ONLY) {
4307         SIZE_ALIGN(RExC_size);
4308         RExC_size += 1;
4309         return(ret);
4310     }
4311
4312     NODE_ALIGN_FILL(ret);
4313     ptr = ret;
4314     FILL_ADVANCE_NODE(ptr, op);
4315     if (RExC_offsets) {         /* MJD */
4316         MJD_OFFSET_DEBUG(("%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n",
4317               "reg_node", __LINE__,
4318               reg_name[op],
4319               RExC_emit - RExC_emit_start > RExC_offsets[0]
4320               ? "Overwriting end of array!\n" : "OK",
4321               RExC_emit - RExC_emit_start,
4322               RExC_parse - RExC_start,
4323               RExC_offsets[0]));
4324         Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4325     }
4326
4327     RExC_emit = ptr;
4328
4329     return(ret);
4330 }
4331
4332 /*
4333 - reganode - emit a node with an argument
4334 */
4335 STATIC regnode *                        /* Location. */
4336 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4337 {
4338     register regnode *ret;
4339     register regnode *ptr;
4340
4341     ret = RExC_emit;
4342     if (SIZE_ONLY) {
4343         SIZE_ALIGN(RExC_size);
4344         RExC_size += 2;
4345         return(ret);
4346     }
4347
4348     NODE_ALIGN_FILL(ret);
4349     ptr = ret;
4350     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4351     if (RExC_offsets) {         /* MJD */
4352         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4353               "reganode",
4354               __LINE__,
4355               reg_name[op],
4356               RExC_emit - RExC_emit_start > RExC_offsets[0] ?
4357               "Overwriting end of array!\n" : "OK",
4358               RExC_emit - RExC_emit_start,
4359               RExC_parse - RExC_start,
4360               RExC_offsets[0]));
4361         Set_Cur_Node_Offset;
4362     }
4363
4364     RExC_emit = ptr;
4365
4366     return(ret);
4367 }
4368
4369 /*
4370 - reguni - emit (if appropriate) a Unicode character
4371 */
4372 STATIC void
4373 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4374 {
4375     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4376 }
4377
4378 /*
4379 - reginsert - insert an operator in front of already-emitted operand
4380 *
4381 * Means relocating the operand.
4382 */
4383 STATIC void
4384 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4385 {
4386     register regnode *src;
4387     register regnode *dst;
4388     register regnode *place;
4389     register int offset = regarglen[(U8)op];
4390
4391 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4392
4393     if (SIZE_ONLY) {
4394         RExC_size += NODE_STEP_REGNODE + offset;
4395         return;
4396     }
4397
4398     src = RExC_emit;
4399     RExC_emit += NODE_STEP_REGNODE + offset;
4400     dst = RExC_emit;
4401     while (src > opnd) {
4402         StructCopy(--src, --dst, regnode);
4403         if (RExC_offsets) {     /* MJD 20010112 */
4404             MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s copy %u -> %u (max %u).\n",
4405                   "reg_insert",
4406                   __LINE__,
4407                   reg_name[op],
4408                   dst - RExC_emit_start > RExC_offsets[0]
4409                   ? "Overwriting end of array!\n" : "OK",
4410                   src - RExC_emit_start,
4411                   dst - RExC_emit_start,
4412                   RExC_offsets[0]));
4413             Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4414             Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4415         }
4416     }
4417
4418
4419     place = opnd;               /* Op node, where operand used to be. */
4420     if (RExC_offsets) {         /* MJD */
4421         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4422               "reginsert",
4423               __LINE__,
4424               reg_name[op],
4425               place - RExC_emit_start > RExC_offsets[0]
4426               ? "Overwriting end of array!\n" : "OK",
4427               place - RExC_emit_start,
4428               RExC_parse - RExC_start,
4429               RExC_offsets[0]));
4430         Set_Node_Offset(place, RExC_parse);
4431         Set_Node_Length(place, 1);
4432     }
4433     src = NEXTOPER(place);
4434     FILL_ADVANCE_NODE(place, op);
4435     Zero(src, offset, regnode);
4436 }
4437
4438 /*
4439 - regtail - set the next-pointer at the end of a node chain of p to val.
4440 */
4441 STATIC void
4442 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4443 {
4444     register regnode *scan;
4445     register regnode *temp;
4446
4447     if (SIZE_ONLY)
4448         return;
4449
4450     /* Find last node. */
4451     scan = p;
4452     for (;;) {
4453         temp = regnext(scan);
4454         if (temp == NULL)
4455             break;
4456         scan = temp;
4457     }
4458
4459     if (reg_off_by_arg[OP(scan)]) {
4460         ARG_SET(scan, val - scan);
4461     }
4462     else {
4463         NEXT_OFF(scan) = val - scan;
4464     }
4465 }
4466
4467 /*
4468 - regoptail - regtail on operand of first argument; nop if operandless
4469 */
4470 STATIC void
4471 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4472 {
4473     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4474     if (p == NULL || SIZE_ONLY)
4475         return;
4476     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4477         regtail(pRExC_state, NEXTOPER(p), val);
4478     }
4479     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4480         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4481     }
4482     else
4483         return;
4484 }
4485
4486 /*
4487  - regcurly - a little FSA that accepts {\d+,?\d*}
4488  */
4489 STATIC I32
4490 S_regcurly(pTHX_ register char *s)
4491 {
4492     if (*s++ != '{')
4493         return FALSE;
4494     if (!isDIGIT(*s))
4495         return FALSE;
4496     while (isDIGIT(*s))
4497         s++;
4498     if (*s == ',')
4499         s++;
4500     while (isDIGIT(*s))
4501         s++;
4502     if (*s != '}')
4503         return FALSE;
4504     return TRUE;
4505 }
4506
4507
4508 #ifdef DEBUGGING
4509
4510 STATIC regnode *
4511 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4512 {
4513     register U8 op = EXACT;     /* Arbitrary non-END op. */
4514     register regnode *next;
4515
4516     while (op != END && (!last || node < last)) {
4517         /* While that wasn't END last time... */
4518
4519         NODE_ALIGN(node);
4520         op = OP(node);
4521         if (op == CLOSE)
4522             l--;
4523         next = regnext(node);
4524         /* Where, what. */
4525         if (OP(node) == OPTIMIZED)
4526             goto after_print;
4527         regprop(sv, node);
4528         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4529                       (int)(2*l + 1), "", SvPVX(sv));
4530         if (next == NULL)               /* Next ptr. */
4531             PerlIO_printf(Perl_debug_log, "(0)");
4532         else
4533             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4534         (void)PerlIO_putc(Perl_debug_log, '\n');
4535       after_print:
4536         if (PL_regkind[(U8)op] == BRANCHJ) {
4537             register regnode *nnode = (OP(next) == LONGJMP
4538                                        ? regnext(next)
4539                                        : next);
4540             if (last && nnode > last)
4541                 nnode = last;
4542             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4543         }
4544         else if (PL_regkind[(U8)op] == BRANCH) {
4545             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4546         }
4547         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4548             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4549                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4550         }
4551         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4552             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4553                              next, sv, l + 1);
4554         }
4555         else if ( op == PLUS || op == STAR) {
4556             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4557         }
4558         else if (op == ANYOF) {
4559             /* arglen 1 + class block */
4560             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4561                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4562             node = NEXTOPER(node);
4563         }
4564         else if (PL_regkind[(U8)op] == EXACT) {
4565             /* Literal string, where present. */
4566             node += NODE_SZ_STR(node) - 1;
4567             node = NEXTOPER(node);
4568         }
4569         else {
4570             node = NEXTOPER(node);
4571             node += regarglen[(U8)op];
4572         }
4573         if (op == CURLYX || op == OPEN)
4574             l++;
4575         else if (op == WHILEM)
4576             l--;
4577     }
4578     return node;
4579 }
4580
4581 #endif  /* DEBUGGING */
4582
4583 /*
4584  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4585  */
4586 void
4587 Perl_regdump(pTHX_ regexp *r)
4588 {
4589 #ifdef DEBUGGING
4590     SV *sv = sv_newmortal();
4591
4592     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4593
4594     /* Header fields of interest. */
4595     if (r->anchored_substr)
4596         PerlIO_printf(Perl_debug_log,
4597                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4598                       PL_colors[0],
4599                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4600                       SvPVX(r->anchored_substr),
4601                       PL_colors[1],
4602                       SvTAIL(r->anchored_substr) ? "$" : "",
4603                       (IV)r->anchored_offset);
4604     else if (r->anchored_utf8)
4605         PerlIO_printf(Perl_debug_log,
4606                       "anchored utf8 `%s%.*s%s'%s at %"IVdf" ",
4607                       PL_colors[0],
4608                       (int)(SvCUR(r->anchored_utf8) - (SvTAIL(r->anchored_utf8)!=0)),
4609                       SvPVX(r->anchored_utf8),
4610                       PL_colors[1],
4611                       SvTAIL(r->anchored_utf8) ? "$" : "",
4612                       (IV)r->anchored_offset);
4613     if (r->float_substr)
4614         PerlIO_printf(Perl_debug_log,
4615                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4616                       PL_colors[0],
4617                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4618                       SvPVX(r->float_substr),
4619                       PL_colors[1],
4620                       SvTAIL(r->float_substr) ? "$" : "",
4621                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4622     else if (r->float_utf8)
4623         PerlIO_printf(Perl_debug_log,
4624                       "floating utf8 `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4625                       PL_colors[0],
4626                       (int)(SvCUR(r->float_utf8) - (SvTAIL(r->float_utf8)!=0)),
4627                       SvPVX(r->float_utf8),
4628                       PL_colors[1],
4629                       SvTAIL(r->float_utf8) ? "$" : "",
4630                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4631     if (r->check_substr || r->check_utf8)
4632         PerlIO_printf(Perl_debug_log,
4633                       r->check_substr == r->float_substr
4634                       && r->check_utf8 == r->float_utf8
4635                       ? "(checking floating" : "(checking anchored");
4636     if (r->reganch & ROPT_NOSCAN)
4637         PerlIO_printf(Perl_debug_log, " noscan");
4638     if (r->reganch & ROPT_CHECK_ALL)
4639         PerlIO_printf(Perl_debug_log, " isall");
4640     if (r->check_substr || r->check_utf8)
4641         PerlIO_printf(Perl_debug_log, ") ");
4642
4643     if (r->regstclass) {
4644         regprop(sv, r->regstclass);
4645         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4646     }
4647     if (r->reganch & ROPT_ANCH) {
4648         PerlIO_printf(Perl_debug_log, "anchored");
4649         if (r->reganch & ROPT_ANCH_BOL)
4650             PerlIO_printf(Perl_debug_log, "(BOL)");
4651         if (r->reganch & ROPT_ANCH_MBOL)
4652             PerlIO_printf(Perl_debug_log, "(MBOL)");
4653         if (r->reganch & ROPT_ANCH_SBOL)
4654             PerlIO_printf(Perl_debug_log, "(SBOL)");
4655         if (r->reganch & ROPT_ANCH_GPOS)
4656             PerlIO_printf(Perl_debug_log, "(GPOS)");
4657         PerlIO_putc(Perl_debug_log, ' ');
4658     }
4659     if (r->reganch & ROPT_GPOS_SEEN)
4660         PerlIO_printf(Perl_debug_log, "GPOS ");
4661     if (r->reganch & ROPT_SKIP)
4662         PerlIO_printf(Perl_debug_log, "plus ");
4663     if (r->reganch & ROPT_IMPLICIT)
4664         PerlIO_printf(Perl_debug_log, "implicit ");
4665     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4666     if (r->reganch & ROPT_EVAL_SEEN)
4667         PerlIO_printf(Perl_debug_log, "with eval ");
4668     PerlIO_printf(Perl_debug_log, "\n");
4669     if (r->offsets) {
4670       U32 i;
4671       U32 len = r->offsets[0];
4672       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4673       for (i = 1; i <= len; i++)
4674         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ",
4675                       (UV)r->offsets[i*2-1],
4676                       (UV)r->offsets[i*2]);
4677       PerlIO_printf(Perl_debug_log, "\n");
4678     }
4679 #endif  /* DEBUGGING */
4680 }
4681
4682 #ifdef DEBUGGING
4683
4684 STATIC void
4685 S_put_byte(pTHX_ SV *sv, int c)
4686 {
4687     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4688         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4689     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4690         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4691     else
4692         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4693 }
4694
4695 #endif  /* DEBUGGING */
4696
4697 /*
4698 - regprop - printable representation of opcode
4699 */
4700 void
4701 Perl_regprop(pTHX_ SV *sv, regnode *o)
4702 {
4703 #ifdef DEBUGGING
4704     register int k;
4705
4706     sv_setpvn(sv, "", 0);
4707     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4708         /* It would be nice to FAIL() here, but this may be called from
4709            regexec.c, and it would be hard to supply pRExC_state. */
4710         Perl_croak(aTHX_ "Corrupted regexp opcode");
4711     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4712
4713     k = PL_regkind[(U8)OP(o)];
4714
4715     if (k == EXACT) {
4716         SV *dsv = sv_2mortal(newSVpvn("", 0));
4717         /* Using is_utf8_string() is a crude hack but it may
4718          * be the best for now since we have no flag "this EXACTish
4719          * node was UTF-8" --jhi */
4720         bool do_utf8 = is_utf8_string((U8*)STRING(o), STR_LEN(o));
4721         char *s    = do_utf8 ?
4722           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60,
4723                          UNI_DISPLAY_REGEX) :
4724           STRING(o);
4725         int len = do_utf8 ?
4726           strlen(s) :
4727           STR_LEN(o);
4728         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4729                        PL_colors[0],
4730                        len, s,
4731                        PL_colors[1]);
4732     }
4733     else if (k == CURLY) {
4734         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4735             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4736         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4737     }
4738     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4739         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4740     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4741         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4742     else if (k == LOGICAL)
4743         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4744     else if (k == ANYOF) {
4745         int i, rangestart = -1;
4746         U8 flags = ANYOF_FLAGS(o);
4747         const char * const anyofs[] = { /* Should be synchronized with
4748                                          * ANYOF_ #xdefines in regcomp.h */
4749             "\\w",
4750             "\\W",
4751             "\\s",
4752             "\\S",
4753             "\\d",
4754             "\\D",
4755             "[:alnum:]",
4756             "[:^alnum:]",
4757             "[:alpha:]",
4758             "[:^alpha:]",
4759             "[:ascii:]",
4760             "[:^ascii:]",
4761             "[:ctrl:]",
4762             "[:^ctrl:]",
4763             "[:graph:]",
4764             "[:^graph:]",
4765             "[:lower:]",
4766             "[:^lower:]",
4767             "[:print:]",
4768             "[:^print:]",
4769             "[:punct:]",
4770             "[:^punct:]",
4771             "[:upper:]",
4772             "[:^upper:]",
4773             "[:xdigit:]",
4774             "[:^xdigit:]",
4775             "[:space:]",
4776             "[:^space:]",
4777             "[:blank:]",
4778             "[:^blank:]"
4779         };
4780
4781         if (flags & ANYOF_LOCALE)
4782             sv_catpv(sv, "{loc}");
4783         if (flags & ANYOF_FOLD)
4784             sv_catpv(sv, "{i}");
4785         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4786         if (flags & ANYOF_INVERT)
4787             sv_catpv(sv, "^");
4788         for (i = 0; i <= 256; i++) {
4789             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4790                 if (rangestart == -1)
4791                     rangestart = i;
4792             } else if (rangestart != -1) {
4793                 if (i <= rangestart + 3)
4794                     for (; rangestart < i; rangestart++)
4795                         put_byte(sv, rangestart);
4796                 else {
4797                     put_byte(sv, rangestart);
4798                     sv_catpv(sv, "-");
4799                     put_byte(sv, i - 1);
4800                 }
4801                 rangestart = -1;
4802             }
4803         }
4804
4805         if (o->flags & ANYOF_CLASS)
4806             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4807                 if (ANYOF_CLASS_TEST(o,i))
4808                     sv_catpv(sv, anyofs[i]);
4809
4810         if (flags & ANYOF_UNICODE)
4811             sv_catpv(sv, "{unicode}");
4812         else if (flags & ANYOF_UNICODE_ALL)
4813             sv_catpv(sv, "{unicode_all}");
4814
4815         {
4816             SV *lv;
4817             SV *sw = regclass_swash(o, FALSE, &lv, 0);
4818
4819             if (lv) {
4820                 if (sw) {
4821                     U8 s[UTF8_MAXLEN+1];
4822
4823                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4824                         U8 *e = uvchr_to_utf8(s, i);
4825
4826                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4827                             if (rangestart == -1)
4828                                 rangestart = i;
4829                         } else if (rangestart != -1) {
4830                             U8 *p;
4831
4832                             if (i <= rangestart + 3)
4833                                 for (; rangestart < i; rangestart++) {
4834                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4835                                         put_byte(sv, *p);
4836                                 }
4837                             else {
4838                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4839                                     put_byte(sv, *p);
4840                                 sv_catpv(sv, "-");
4841                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4842                                         put_byte(sv, *p);
4843                                 }
4844                                 rangestart = -1;
4845                             }
4846                         }
4847
4848                     sv_catpv(sv, "..."); /* et cetera */
4849                 }
4850
4851                 {
4852                     char *s = savepv(SvPVX(lv));
4853                     char *origs = s;
4854
4855                     while(*s && *s != '\n') s++;
4856
4857                     if (*s == '\n') {
4858                         char *t = ++s;
4859
4860                         while (*s) {
4861                             if (*s == '\n')
4862                                 *s = ' ';
4863                             s++;
4864                         }
4865                         if (s[-1] == ' ')
4866                             s[-1] = 0;
4867
4868                         sv_catpv(sv, t);
4869                     }
4870
4871                     Safefree(origs);
4872                 }
4873             }
4874         }
4875
4876         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4877     }
4878     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4879         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4880 #endif  /* DEBUGGING */
4881 }
4882
4883 SV *
4884 Perl_re_intuit_string(pTHX_ regexp *prog)
4885 {                               /* Assume that RE_INTUIT is set */
4886     DEBUG_r(
4887         {   STRLEN n_a;
4888             char *s = SvPV(prog->check_substr
4889                       ? prog->check_substr : prog->check_utf8, n_a);
4890
4891             if (!PL_colorset) reginitcolors();
4892             PerlIO_printf(Perl_debug_log,
4893                       "%sUsing REx %ssubstr:%s `%s%.60s%s%s'\n",
4894                       PL_colors[4],
4895                       prog->check_substr ? "" : "utf8 ",
4896                       PL_colors[5],PL_colors[0],
4897                       s,
4898                       PL_colors[1],
4899                       (strlen(s) > 60 ? "..." : ""));
4900         } );
4901
4902     return prog->check_substr ? prog->check_substr : prog->check_utf8;
4903 }
4904
4905 void
4906 Perl_pregfree(pTHX_ struct regexp *r)
4907 {
4908 #ifdef DEBUGGING
4909     SV *dsv = PERL_DEBUG_PAD_ZERO(0);
4910 #endif
4911
4912     if (!r || (--r->refcnt > 0))
4913         return;
4914     DEBUG_r({
4915          int len;
4916          char *s;
4917
4918          s = (r->reganch & ROPT_UTF8) ? pv_uni_display(dsv, (U8*)r->precomp,
4919                 r->prelen, 60, UNI_DISPLAY_REGEX)
4920             : pv_display(dsv, r->precomp, r->prelen, 0, 60);
4921          len = SvCUR(dsv);
4922          if (!PL_colorset)
4923               reginitcolors();
4924          PerlIO_printf(Perl_debug_log,
4925                        "%sFreeing REx:%s `%s%*.*s%s%s'\n",
4926                        PL_colors[4],PL_colors[5],PL_colors[0],
4927                        len, len, s,
4928                        PL_colors[1],
4929                        len > 60 ? "..." : "");
4930     });
4931
4932     if (r->precomp)
4933         Safefree(r->precomp);
4934     if (r->offsets)             /* 20010421 MJD */
4935         Safefree(r->offsets);
4936     RX_MATCH_COPY_FREE(r);
4937 #ifdef PERL_COPY_ON_WRITE
4938     if (r->saved_copy)
4939         SvREFCNT_dec(r->saved_copy);
4940 #endif
4941     if (r->substrs) {
4942         if (r->anchored_substr)
4943             SvREFCNT_dec(r->anchored_substr);
4944         if (r->anchored_utf8)
4945             SvREFCNT_dec(r->anchored_utf8);
4946         if (r->float_substr)
4947             SvREFCNT_dec(r->float_substr);
4948         if (r->float_utf8)
4949             SvREFCNT_dec(r->float_utf8);
4950         Safefree(r->substrs);
4951     }
4952     if (r->data) {
4953         int n = r->data->count;
4954         PAD* new_comppad = NULL;
4955         PAD* old_comppad;
4956
4957         while (--n >= 0) {
4958           /* If you add a ->what type here, update the comment in regcomp.h */
4959             switch (r->data->what[n]) {
4960             case 's':
4961                 SvREFCNT_dec((SV*)r->data->data[n]);
4962                 break;
4963             case 'f':
4964                 Safefree(r->data->data[n]);
4965                 break;
4966             case 'p':
4967                 new_comppad = (AV*)r->data->data[n];
4968                 break;
4969             case 'o':
4970                 if (new_comppad == NULL)
4971                     Perl_croak(aTHX_ "panic: pregfree comppad");
4972                 PAD_SAVE_LOCAL(old_comppad,
4973                     /* Watch out for global destruction's random ordering. */
4974                     (SvTYPE(new_comppad) == SVt_PVAV) ?
4975                                 new_comppad : Null(PAD *)
4976                 );
4977                 if (!OpREFCNT_dec((OP_4tree*)r->data->data[n])) {
4978                     op_free((OP_4tree*)r->data->data[n]);
4979                 }
4980
4981                 PAD_RESTORE_LOCAL(old_comppad);
4982                 SvREFCNT_dec((SV*)new_comppad);
4983                 new_comppad = NULL;
4984                 break;
4985             case 'n':
4986                 break;
4987             default:
4988                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4989             }
4990         }
4991         Safefree(r->data->what);
4992         Safefree(r->data);
4993     }
4994     Safefree(r->startp);
4995     Safefree(r->endp);
4996     Safefree(r);
4997 }
4998
4999 /*
5000  - regnext - dig the "next" pointer out of a node
5001  *
5002  * [Note, when REGALIGN is defined there are two places in regmatch()
5003  * that bypass this code for speed.]
5004  */
5005 regnode *
5006 Perl_regnext(pTHX_ register regnode *p)
5007 {
5008     register I32 offset;
5009
5010     if (p == &PL_regdummy)
5011         return(NULL);
5012
5013     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
5014     if (offset == 0)
5015         return(NULL);
5016
5017     return(p+offset);
5018 }
5019
5020 STATIC void
5021 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
5022 {
5023     va_list args;
5024     STRLEN l1 = strlen(pat1);
5025     STRLEN l2 = strlen(pat2);
5026     char buf[512];
5027     SV *msv;
5028     char *message;
5029
5030     if (l1 > 510)
5031         l1 = 510;
5032     if (l1 + l2 > 510)
5033         l2 = 510 - l1;
5034     Copy(pat1, buf, l1 , char);
5035     Copy(pat2, buf + l1, l2 , char);
5036     buf[l1 + l2] = '\n';
5037     buf[l1 + l2 + 1] = '\0';
5038 #ifdef I_STDARG
5039     /* ANSI variant takes additional second argument */
5040     va_start(args, pat2);
5041 #else
5042     va_start(args);
5043 #endif
5044     msv = vmess(buf, &args);
5045     va_end(args);
5046     message = SvPV(msv,l1);
5047     if (l1 > 512)
5048         l1 = 512;
5049     Copy(message, buf, l1 , char);
5050     buf[l1-1] = '\0';                   /* Overwrite \n */
5051     Perl_croak(aTHX_ "%s", buf);
5052 }
5053
5054 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
5055
5056 void
5057 Perl_save_re_context(pTHX)
5058 {
5059     SAVEI32(PL_reg_flags);              /* from regexec.c */
5060     SAVEPPTR(PL_bostr);
5061     SAVEPPTR(PL_reginput);              /* String-input pointer. */
5062     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
5063     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
5064     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
5065     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
5066     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
5067     SAVEVPTR(PL_reglastcloseparen);     /* Similarly for lastcloseparen. */
5068     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
5069     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
5070     PL_reg_start_tmp = 0;
5071     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
5072     PL_reg_start_tmpl = 0;
5073     SAVEVPTR(PL_regdata);
5074     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
5075     SAVEI32(PL_regnarrate);             /* from regexec.c */
5076     SAVEVPTR(PL_regprogram);            /* from regexec.c */
5077     SAVEINT(PL_regindent);              /* from regexec.c */
5078     SAVEVPTR(PL_regcc);                 /* from regexec.c */
5079     SAVEVPTR(PL_curcop);
5080     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
5081     SAVEVPTR(PL_reg_re);                /* from regexec.c */
5082     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
5083     SAVESPTR(PL_reg_sv);                /* from regexec.c */
5084     SAVEBOOL(PL_reg_match_utf8);        /* from regexec.c */
5085     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
5086     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
5087     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
5088     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
5089     SAVEPPTR(PL_reg_oldsaved);          /* old saved substr during match */
5090     PL_reg_oldsaved = Nullch;
5091     SAVEI32(PL_reg_oldsavedlen);        /* old length of saved substr during match */
5092     PL_reg_oldsavedlen = 0;
5093 #ifdef PERL_COPY_ON_WRITE
5094     SAVESPTR(PL_nrs);
5095     PL_nrs = Nullsv;
5096 #endif
5097     SAVEI32(PL_reg_maxiter);            /* max wait until caching pos */
5098     PL_reg_maxiter = 0;
5099     SAVEI32(PL_reg_leftiter);           /* wait until caching pos */
5100     PL_reg_leftiter = 0;
5101     SAVEGENERICPV(PL_reg_poscache);     /* cache of pos of WHILEM */
5102     PL_reg_poscache = Nullch;
5103     SAVEI32(PL_reg_poscache_size);      /* size of pos cache of WHILEM */
5104     PL_reg_poscache_size = 0;
5105     SAVEPPTR(PL_regprecomp);            /* uncompiled string. */
5106     SAVEI32(PL_regnpar);                /* () count. */
5107     SAVEI32(PL_regsize);                /* from regexec.c */
5108
5109     {
5110         /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
5111         U32 i;
5112         GV *mgv;
5113         REGEXP *rx;
5114         char digits[16];
5115
5116         if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
5117             for (i = 1; i <= rx->nparens; i++) {
5118                 sprintf(digits, "%lu", (long)i);
5119                 if ((mgv = gv_fetchpv(digits, FALSE, SVt_PV)))
5120                     save_scalar(mgv);
5121             }
5122         }
5123     }
5124
5125 #ifdef DEBUGGING
5126     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
5127 #endif
5128 }
5129
5130 static void
5131 clear_re(pTHX_ void *r)
5132 {
5133     ReREFCNT_dec((regexp *)r);
5134 }
5135