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) 1991-2000, Larry Wall
  73  ****
  74  ****    You may distribute under the terms of either the GNU General Public
  75  ****    License or the Artistic License, as specified in the README file.
  76
  77  *
  78  * Beware that some of this code is subtly aware of the way operator
  79  * precedence is structured in regular expressions.  Serious changes in
  80  * regular-expression syntax might require a total rethink.
  81  */
  82 #include "EXTERN.h"
  83 #define PERL_IN_REGCOMP_C
  84 #include "perl.h"
  85
  86 #ifdef PERL_IN_XSUB_RE
  87 #  if defined(PERL_CAPI) || defined(PERL_OBJECT)
  88 #    include "XSUB.h"
  89 #  endif
  90 #else
  91 #  include "INTERN.h"
  92 #endif
  93
  94 #define REG_COMP_C
  95 #include "regcomp.h"
  96
  97 #ifdef op
  98 #undef op
  99 #endif /* op */
 100
 101 #ifdef MSDOS
 102 # if defined(BUGGY_MSC6)
 103  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
 104  # pragma optimize("a",off)
 105  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
 106  # pragma optimize("w",on )
 107 # endif /* BUGGY_MSC6 */
 108 #endif /* MSDOS */
 109
 110 #ifndef STATIC
 111 #define STATIC  static
 112 #endif
 113
 114 typedef struct RExC_state_t {
 115     U16         flags16;                /* are we folding, multilining? */
 116     char        *precomp;               /* uncompiled string. */
 117     regexp      *rx;
 118     char        *end;                   /* End of input for compile */
 119     char        *parse;                 /* Input-scan pointer. */
 120     I32         whilem_seen;            /* number of WHILEM in this expr */
 121     regnode     *emit;                  /* Code-emit pointer; &regdummy = don't */
 122     I32         naughty;                /* How bad is this pattern? */
 123     I32         sawback;                /* Did we see \1, ...? */
 124     U32         seen;
 125     I32         size;                   /* Code size. */
 126     I32         npar;                   /* () count. */
 127     I32         extralen;
 128     I32         seen_zerolen;
 129     I32         seen_evals;
 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_flags16    (pRExC_state->flags16)
 137 #define RExC_precomp    (pRExC_state->precomp)
 138 #define RExC_rx         (pRExC_state->rx)
 139 #define RExC_end        (pRExC_state->end)
 140 #define RExC_parse      (pRExC_state->parse)
 141 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
 142 #define RExC_emit       (pRExC_state->emit)
 143 #define RExC_naughty    (pRExC_state->naughty)
 144 #define RExC_sawback    (pRExC_state->sawback)
 145 #define RExC_seen       (pRExC_state->seen)
 146 #define RExC_size       (pRExC_state->size)
 147 #define RExC_npar       (pRExC_state->npar)
 148 #define RExC_extralen   (pRExC_state->extralen)
 149 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
 150 #define RExC_seen_evals (pRExC_state->seen_evals)
 151
 152 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 153 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
 154         ((*s) == '{' && regcurly(s)))
 155 #ifdef atarist
 156 #define PERL_META       "^$.[()|?+*\\"
 157 #else
 158 #define META    "^$.[()|?+*\\"
 159 #endif
 160
 161 #ifdef SPSTART
 162 #undef SPSTART          /* dratted cpp namespace... */
 163 #endif
 164 /*
 165  * Flags to be passed up and down.
 166  */
 167 #define WORST           0       /* Worst case. */
 168 #define HASWIDTH        0x1     /* Known to match non-null strings. */
 169 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
 170 #define SPSTART         0x4     /* Starts with * or +. */
 171 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
 172
 173 /* Length of a variant. */
 174
 175 typedef struct scan_data_t {
 176     I32 len_min;
 177     I32 len_delta;
 178     I32 pos_min;
 179     I32 pos_delta;
 180     SV *last_found;
 181     I32 last_end;                       /* min value, <0 unless valid. */
 182     I32 last_start_min;
 183     I32 last_start_max;
 184     SV **longest;                       /* Either &l_fixed, or &l_float. */
 185     SV *longest_fixed;
 186     I32 offset_fixed;
 187     SV *longest_float;
 188     I32 offset_float_min;
 189     I32 offset_float_max;
 190     I32 flags;
 191     I32 whilem_c;
 192     I32 *last_closep;
 193     struct regnode_charclass_class *start_class;
 194 } scan_data_t;
 195
 196 /*
 197  * Forward declarations for pregcomp()'s friends.
 198  */
 199
 200 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 201                                       0, 0, 0, 0, 0, 0};
 202
 203 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 204 #define SF_BEFORE_SEOL          0x1
 205 #define SF_BEFORE_MEOL          0x2
 206 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
 207 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
 208
 209 #ifdef NO_UNARY_PLUS
 210 #  define SF_FIX_SHIFT_EOL      (0+2)
 211 #  define SF_FL_SHIFT_EOL               (0+4)
 212 #else
 213 #  define SF_FIX_SHIFT_EOL      (+2)
 214 #  define SF_FL_SHIFT_EOL               (+4)
 215 #endif
 216
 217 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
 218 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
 219
 220 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
 221 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
 222 #define SF_IS_INF               0x40
 223 #define SF_HAS_PAR              0x80
 224 #define SF_IN_PAR               0x100
 225 #define SF_HAS_EVAL             0x200
 226 #define SCF_DO_SUBSTR           0x400
 227 #define SCF_DO_STCLASS_AND      0x0800
 228 #define SCF_DO_STCLASS_OR       0x1000
 229 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 230 #define SCF_WHILEM_VISITED_POS  0x2000
 231
 232 #define RF_utf8         8
 233 #define UTF (PL_reg_flags & RF_utf8)
 234 #define LOC (RExC_flags16 & PMf_LOCALE)
 235 #define FOLD (RExC_flags16 & PMf_FOLD)
 236
 237 #define OOB_CHAR8               1234
 238 #define OOB_UTF8                123456
 239 #define OOB_NAMEDCLASS          -1
 240
 241 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 242 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 243
 244
 245 /* length of regex to show in messages that don't mark a position within */
 246 #define RegexLengthToShowInErrorMessages 127
 247
 248 /*
 249  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
 250  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
 251  * op/pragma/warn/regcomp.
 252  */
 253 #define MARKER1 "HERE"      /* marker as it appears in the description */
 254 #define MARKER2 " << HERE "  /* marker as it appears within the regex */
 255
 256 #define REPORT_LOCATION " before " MARKER1 " mark in regex m/%.*s" MARKER2 "%s/"
 257
 258 /*
 259  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 260  * arg. Show regex, up to a maximum length. If it's too long, chop and add
 261  * "...".
 262  */
 263 #define FAIL(msg)                                                             \
 264     STMT_START {                                                             \
 265         char *ellipses = "";                                                 \
 266         unsigned len = strlen(RExC_precomp);                                \
 267                                                                              \
 268         if (!SIZE_ONLY)                                                      \
 269             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 270                                                                              \
 271         if (len > RegexLengthToShowInErrorMessages) {                        \
 272             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 273             len = RegexLengthToShowInErrorMessages - 10;                     \
 274             ellipses = "...";                                                \
 275         }                                                                    \
 276         Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                            \
 277                    msg, (int)len, RExC_precomp, ellipses);                  \
 278     } STMT_END
 279
 280 /*
 281  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 282  * args. Show regex, up to a maximum length. If it's too long, chop and add
 283  * "...".
 284  */
 285 #define FAIL2(pat,msg)                                                        \
 286     STMT_START {                                                             \
 287         char *ellipses = "";                                                 \
 288         unsigned len = strlen(RExC_precomp);                                \
 289                                                                              \
 290         if (!SIZE_ONLY)                                                      \
 291             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 292                                                                              \
 293         if (len > RegexLengthToShowInErrorMessages) {                        \
 294             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 295             len = RegexLengthToShowInErrorMessages - 10;                     \
 296             ellipses = "...";                                                \
 297         }                                                                    \
 298         S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                        \
 299                     msg, (int)len, RExC_precomp, ellipses);                \
 300     } STMT_END
 301
 302
 303 /*
 304  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
 305  */
 306 #define Simple_vFAIL(m)                                                      \
 307     STMT_START {                                                             \
 308       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 309                                                                              \
 310       Perl_croak(aTHX_ "%s" REPORT_LOCATION,               \
 311                  m, (int)offset, RExC_precomp, RExC_precomp + offset);     \
 312     } STMT_END
 313
 314 /*
 315  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
 316  */
 317 #define vFAIL(m)                                                             \
 318     STMT_START {                                                             \
 319       if (!SIZE_ONLY)                                                        \
 320             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 321       Simple_vFAIL(m);                                                       \
 322     } STMT_END
 323
 324 /*
 325  * Like Simple_vFAIL(), but accepts two arguments.
 326  */
 327 #define Simple_vFAIL2(m,a1)                                                  \
 328     STMT_START {                                                             \
 329       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 330                                                                              \
 331       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,       \
 332                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 333     } STMT_END
 334
 335 /*
 336  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
 337  */
 338 #define vFAIL2(m,a1)                                                         \
 339     STMT_START {                                                             \
 340       if (!SIZE_ONLY)                                                        \
 341             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 342       Simple_vFAIL2(m, a1);                                                  \
 343     } STMT_END
 344
 345
 346 /*
 347  * Like Simple_vFAIL(), but accepts three arguments.
 348  */
 349 #define Simple_vFAIL3(m, a1, a2)                                             \
 350     STMT_START {                                                             \
 351       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 352                                                                              \
 353       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,   \
 354                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 355     } STMT_END
 356
 357 /*
 358  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
 359  */
 360 #define vFAIL3(m,a1,a2)                                                      \
 361     STMT_START {                                                             \
 362       if (!SIZE_ONLY)                                                        \
 363             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 364       Simple_vFAIL3(m, a1, a2);                                              \
 365     } STMT_END
 366
 367 /*
 368  * Like Simple_vFAIL(), but accepts four arguments.
 369  */
 370 #define Simple_vFAIL4(m, a1, a2, a3)                                         \
 371     STMT_START {                                                             \
 372       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 373                                                                              \
 374       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,\
 375                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 376     } STMT_END
 377
 378 /*
 379  * Like Simple_vFAIL(), but accepts five arguments.
 380  */
 381 #define Simple_vFAIL5(m, a1, a2, a3, a4)                                     \
 382     STMT_START {                                                             \
 383       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 384       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,\
 385                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 386     } STMT_END
 387
 388
 389 #define vWARN(loc,m)                                                         \
 390     STMT_START {                                                             \
 391         unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));          \
 392         Perl_warner(aTHX_ WARN_REGEXP, "%s" REPORT_LOCATION,\
 393                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
 394     } STMT_END                                                               \
 395
 396
 397 #define vWARN2(loc, m, a1)                                                   \
 398     STMT_START {                                                             \
 399         unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));          \
 400         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 401                  a1,                                                         \
 402                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 403     } STMT_END
 404
 405 #define vWARN3(loc, m, a1, a2)                                               \
 406     STMT_START {                                                             \
 407       unsigned offset = strlen(RExC_precomp) - (RExC_end - (loc));        \
 408         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,                    \
 409                  a1, a2,                                                     \
 410                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 411     } STMT_END
 412
 413 #define vWARN4(loc, m, a1, a2, a3)                                           \
 414     STMT_START {                                                             \
 415       unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));            \
 416         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 417                  a1, a2, a3,                                                 \
 418                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 419     } STMT_END
 420
 421
 422 /* Allow for side effects in s */
 423 #define REGC(c,s) STMT_START { if (!SIZE_ONLY) *(s) = (c); else (s);} STMT_END
 424
 425 static void clear_re(pTHXo_ void *r);
 426
 427 /* Mark that we cannot extend a found fixed substring at this point.
 428    Updata the longest found anchored substring and the longest found
 429    floating substrings if needed. */
 430
 431 STATIC void
 432 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 433 {
 434     dTHR;
 435     STRLEN l = CHR_SVLEN(data->last_found);
 436     STRLEN old_l = CHR_SVLEN(*data->longest);
 437
 438     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
 439         sv_setsv(*data->longest, data->last_found);
 440         if (*data->longest == data->longest_fixed) {
 441             data->offset_fixed = l ? data->last_start_min : data->pos_min;
 442             if (data->flags & SF_BEFORE_EOL)
 443                 data->flags
 444                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
 445             else
 446                 data->flags &= ~SF_FIX_BEFORE_EOL;
 447         }
 448         else {
 449             data->offset_float_min = l ? data->last_start_min : data->pos_min;
 450             data->offset_float_max = (l
 451                                       ? data->last_start_max
 452                                       : data->pos_min + data->pos_delta);
 453             if (data->flags & SF_BEFORE_EOL)
 454                 data->flags
 455                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
 456             else
 457                 data->flags &= ~SF_FL_BEFORE_EOL;
 458         }
 459     }
 460     SvCUR_set(data->last_found, 0);
 461     data->last_end = -1;
 462     data->flags &= ~SF_BEFORE_EOL;
 463 }
 464
 465 /* Can match anything (initialization) */
 466 STATIC void
 467 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 468 {
 469     int value;
 470
 471     ANYOF_CLASS_ZERO(cl);
 472     for (value = 0; value < 256; ++value)
 473         ANYOF_BITMAP_SET(cl, value);
 474     cl->flags = ANYOF_EOS;
 475     if (LOC)
 476         cl->flags |= ANYOF_LOCALE;
 477 }
 478
 479 /* Can match anything (initialization) */
 480 STATIC int
 481 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
 482 {
 483     int value;
 484
 485     for (value = 0; value <= ANYOF_MAX; value += 2)
 486         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
 487             return 1;
 488     for (value = 0; value < 256; ++value)
 489         if (!ANYOF_BITMAP_TEST(cl, value))
 490             return 0;
 491     return 1;
 492 }
 493
 494 /* Can match anything (initialization) */
 495 STATIC void
 496 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 497 {
 498     Zero(cl, 1, struct regnode_charclass_class);
 499     cl->type = ANYOF;
 500     cl_anything(pRExC_state, cl);
 501 }
 502
 503 STATIC void
 504 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 505 {
 506     Zero(cl, 1, struct regnode_charclass_class);
 507     cl->type = ANYOF;
 508     cl_anything(pRExC_state, cl);
 509     if (LOC)
 510         cl->flags |= ANYOF_LOCALE;
 511 }
 512
 513 /* 'And' a given class with another one.  Can create false positives */
 514 /* We assume that cl is not inverted */
 515 STATIC void
 516 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 517          struct regnode_charclass_class *and_with)
 518 {
 519     if (!(and_with->flags & ANYOF_CLASS)
 520         && !(cl->flags & ANYOF_CLASS)
 521         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 522         && !(and_with->flags & ANYOF_FOLD)
 523         && !(cl->flags & ANYOF_FOLD)) {
 524         int i;
 525
 526         if (and_with->flags & ANYOF_INVERT)
 527             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 528                 cl->bitmap[i] &= ~and_with->bitmap[i];
 529         else
 530             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 531                 cl->bitmap[i] &= and_with->bitmap[i];
 532     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
 533     if (!(and_with->flags & ANYOF_EOS))
 534         cl->flags &= ~ANYOF_EOS;
 535 }
 536
 537 /* 'OR' a given class with another one.  Can create false positives */
 538 /* We assume that cl is not inverted */
 539 STATIC void
 540 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 541 {
 542     if (or_with->flags & ANYOF_INVERT) {
 543         /* We do not use
 544          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
 545          *   <= (B1 | !B2) | (CL1 | !CL2)
 546          * which is wasteful if CL2 is small, but we ignore CL2:
 547          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
 548          * XXXX Can we handle case-fold?  Unclear:
 549          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
 550          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
 551          */
 552         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 553              && !(or_with->flags & ANYOF_FOLD)
 554              && !(cl->flags & ANYOF_FOLD) ) {
 555             int i;
 556
 557             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 558                 cl->bitmap[i] |= ~or_with->bitmap[i];
 559         } /* XXXX: logic is complicated otherwise */
 560         else {
 561             cl_anything(pRExC_state, cl);
 562         }
 563     } else {
 564         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
 565         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 566              && (!(or_with->flags & ANYOF_FOLD)
 567                  || (cl->flags & ANYOF_FOLD)) ) {
 568             int i;
 569
 570             /* OR char bitmap and class bitmap separately */
 571             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 572                 cl->bitmap[i] |= or_with->bitmap[i];
 573             if (or_with->flags & ANYOF_CLASS) {
 574                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
 575                     cl->classflags[i] |= or_with->classflags[i];
 576                 cl->flags |= ANYOF_CLASS;
 577             }
 578         }
 579         else { /* XXXX: logic is complicated, leave it along for a moment. */
 580             cl_anything(pRExC_state, cl);
 581         }
 582     }
 583     if (or_with->flags & ANYOF_EOS)
 584         cl->flags |= ANYOF_EOS;
 585 }
 586
 587 /* REx optimizer.  Converts nodes into quickier variants "in place".
 588    Finds fixed substrings.  */
 589
 590 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
 591    to the position after last scanned or to NULL. */
 592
 593 STATIC I32
 594 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
 595                         /* scanp: Start here (read-write). */
 596                         /* deltap: Write maxlen-minlen here. */
 597                         /* last: Stop before this one. */
 598 {
 599     dTHR;
 600     I32 min = 0, pars = 0, code;
 601     regnode *scan = *scanp, *next;
 602     I32 delta = 0;
 603     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
 604     int is_inf_internal = 0;            /* The studied chunk is infinite */
 605     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
 606     scan_data_t data_fake;
 607     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
 608
 609     while (scan && OP(scan) != END && scan < last) {
 610         /* Peephole optimizer: */
 611
 612         if (PL_regkind[(U8)OP(scan)] == EXACT) {
 613             /* Merge several consecutive EXACTish nodes into one. */
 614             regnode *n = regnext(scan);
 615             U32 stringok = 1;
 616 #ifdef DEBUGGING
 617             regnode *stop = scan;
 618 #endif
 619
 620             next = scan + NODE_SZ_STR(scan);
 621             /* Skip NOTHING, merge EXACT*. */
 622             while (n &&
 623                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
 624                      (stringok && (OP(n) == OP(scan))))
 625                    && NEXT_OFF(n)
 626                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
 627                 if (OP(n) == TAIL || n > next)
 628                     stringok = 0;
 629                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
 630                     NEXT_OFF(scan) += NEXT_OFF(n);
 631                     next = n + NODE_STEP_REGNODE;
 632 #ifdef DEBUGGING
 633                     if (stringok)
 634                         stop = n;
 635 #endif
 636                     n = regnext(n);
 637                 }
 638                 else {
 639                     int oldl = STR_LEN(scan);
 640                     regnode *nnext = regnext(n);
 641
 642                     if (oldl + STR_LEN(n) > U8_MAX)
 643                         break;
 644                     NEXT_OFF(scan) += NEXT_OFF(n);
 645                     STR_LEN(scan) += STR_LEN(n);
 646                     next = n + NODE_SZ_STR(n);
 647                     /* Now we can overwrite *n : */
 648                     Move(STRING(n), STRING(scan) + oldl,
 649                          STR_LEN(n), char);
 650 #ifdef DEBUGGING
 651                     if (stringok)
 652                         stop = next - 1;
 653 #endif
 654                     n = nnext;
 655                 }
 656             }
 657 #ifdef DEBUGGING
 658             /* Allow dumping */
 659             n = scan + NODE_SZ_STR(scan);
 660             while (n <= stop) {
 661                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
 662                     OP(n) = OPTIMIZED;
 663                     NEXT_OFF(n) = 0;
 664                 }
 665                 n++;
 666             }
 667 #endif
 668         }
 669         /* Follow the next-chain of the current node and optimize
 670            away all the NOTHINGs from it.  */
 671         if (OP(scan) != CURLYX) {
 672             int max = (reg_off_by_arg[OP(scan)]
 673                        ? I32_MAX
 674                        /* I32 may be smaller than U16 on CRAYs! */
 675                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
 676             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
 677             int noff;
 678             regnode *n = scan;
 679
 680             /* Skip NOTHING and LONGJMP. */
 681             while ((n = regnext(n))
 682                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
 683                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
 684                    && off + noff < max)
 685                 off += noff;
 686             if (reg_off_by_arg[OP(scan)])
 687                 ARG(scan) = off;
 688             else
 689                 NEXT_OFF(scan) = off;
 690         }
 691         /* The principal pseudo-switch.  Cannot be a switch, since we
 692            look into several different things.  */
 693         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
 694                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
 695             next = regnext(scan);
 696             code = OP(scan);
 697
 698             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
 699                 I32 max1 = 0, min1 = I32_MAX, num = 0;
 700                 struct regnode_charclass_class accum;
 701
 702                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
 703                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
 704                 if (flags & SCF_DO_STCLASS)
 705                     cl_init_zero(pRExC_state, &accum);
 706                 while (OP(scan) == code) {
 707                     I32 deltanext, minnext, f = 0, fake;
 708                     struct regnode_charclass_class this_class;
 709
 710                     num++;
 711                     data_fake.flags = 0;
 712                     if (data) {
 713                         data_fake.whilem_c = data->whilem_c;
 714                         data_fake.last_closep = data->last_closep;
 715                     }
 716                     else
 717                         data_fake.last_closep = &fake;
 718                     next = regnext(scan);
 719                     scan = NEXTOPER(scan);
 720                     if (code != BRANCH)
 721                         scan = NEXTOPER(scan);
 722                     if (flags & SCF_DO_STCLASS) {
 723                         cl_init(pRExC_state, &this_class);
 724                         data_fake.start_class = &this_class;
 725                         f = SCF_DO_STCLASS_AND;
 726                     }
 727                     if (flags & SCF_WHILEM_VISITED_POS)
 728                         f |= SCF_WHILEM_VISITED_POS;
 729                     /* we suppose the run is continuous, last=next...*/
 730                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
 731                                           next, &data_fake, f);
 732                     if (min1 > minnext)
 733                         min1 = minnext;
 734                     if (max1 < minnext + deltanext)
 735                         max1 = minnext + deltanext;
 736                     if (deltanext == I32_MAX)
 737                         is_inf = is_inf_internal = 1;
 738                     scan = next;
 739                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
 740                         pars++;
 741                     if (data && (data_fake.flags & SF_HAS_EVAL))
 742                         data->flags |= SF_HAS_EVAL;
 743                     if (data)
 744                         data->whilem_c = data_fake.whilem_c;
 745                     if (flags & SCF_DO_STCLASS)
 746                         cl_or(pRExC_state, &accum, &this_class);
 747                     if (code == SUSPEND)
 748                         break;
 749                 }
 750                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
 751                     min1 = 0;
 752                 if (flags & SCF_DO_SUBSTR) {
 753                     data->pos_min += min1;
 754                     data->pos_delta += max1 - min1;
 755                     if (max1 != min1 || is_inf)
 756                         data->longest = &(data->longest_float);
 757                 }
 758                 min += min1;
 759                 delta += max1 - min1;
 760                 if (flags & SCF_DO_STCLASS_OR) {
 761                     cl_or(pRExC_state, data->start_class, &accum);
 762                     if (min1) {
 763                         cl_and(data->start_class, &and_with);
 764                         flags &= ~SCF_DO_STCLASS;
 765                     }
 766                 }
 767                 else if (flags & SCF_DO_STCLASS_AND) {
 768                     if (min1) {
 769                         cl_and(data->start_class, &accum);
 770                         flags &= ~SCF_DO_STCLASS;
 771                     }
 772                     else {
 773                         /* Switch to OR mode: cache the old value of
 774                          * data->start_class */
 775                         StructCopy(data->start_class, &and_with,
 776                                    struct regnode_charclass_class);
 777                         flags &= ~SCF_DO_STCLASS_AND;
 778                         StructCopy(&accum, data->start_class,
 779                                    struct regnode_charclass_class);
 780                         flags |= SCF_DO_STCLASS_OR;
 781                         data->start_class->flags |= ANYOF_EOS;
 782                     }
 783                 }
 784             }
 785             else if (code == BRANCHJ)   /* single branch is optimized. */
 786                 scan = NEXTOPER(NEXTOPER(scan));
 787             else                        /* single branch is optimized. */
 788                 scan = NEXTOPER(scan);
 789             continue;
 790         }
 791         else if (OP(scan) == EXACT) {
 792             I32 l = STR_LEN(scan);
 793             if (UTF) {
 794                 unsigned char *s = (unsigned char *)STRING(scan);
 795                 unsigned char *e = s + l;
 796                 I32 newl = 0;
 797                 while (s < e) {
 798                     newl++;
 799                     s += UTF8SKIP(s);
 800                 }
 801                 l = newl;
 802             }
 803             min += l;
 804             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
 805                 /* The code below prefers earlier match for fixed
 806                    offset, later match for variable offset.  */
 807                 if (data->last_end == -1) { /* Update the start info. */
 808                     data->last_start_min = data->pos_min;
 809                     data->last_start_max = is_inf
 810                         ? I32_MAX : data->pos_min + data->pos_delta;
 811                 }
 812                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
 813                 data->last_end = data->pos_min + l;
 814                 data->pos_min += l; /* As in the first entry. */
 815                 data->flags &= ~SF_BEFORE_EOL;
 816             }
 817             if (flags & SCF_DO_STCLASS_AND) {
 818                 /* Check whether it is compatible with what we know already! */
 819                 int compat = 1;
 820
 821                 if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 822                     && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
 823                     && (!(data->start_class->flags & ANYOF_FOLD)
 824                         || !ANYOF_BITMAP_TEST(data->start_class,
 825                                               PL_fold[*(U8*)STRING(scan)])))
 826                     compat = 0;
 827                 ANYOF_CLASS_ZERO(data->start_class);
 828                 ANYOF_BITMAP_ZERO(data->start_class);
 829                 if (compat)
 830                     ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
 831                 data->start_class->flags &= ~ANYOF_EOS;
 832             }
 833             else if (flags & SCF_DO_STCLASS_OR) {
 834                 /* false positive possible if the class is case-folded */
 835                 ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
 836                 data->start_class->flags &= ~ANYOF_EOS;
 837                 cl_and(data->start_class, &and_with);
 838             }
 839             flags &= ~SCF_DO_STCLASS;
 840         }
 841         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
 842             I32 l = STR_LEN(scan);
 843
 844             /* Search for fixed substrings supports EXACT only. */
 845             if (flags & SCF_DO_SUBSTR)
 846                 scan_commit(pRExC_state, data);
 847             if (UTF) {
 848                 unsigned char *s = (unsigned char *)STRING(scan);
 849                 unsigned char *e = s + l;
 850                 I32 newl = 0;
 851                 while (s < e) {
 852                     newl++;
 853                     s += UTF8SKIP(s);
 854                 }
 855                 l = newl;
 856             }
 857             min += l;
 858             if (data && (flags & SCF_DO_SUBSTR))
 859                 data->pos_min += l;
 860             if (flags & SCF_DO_STCLASS_AND) {
 861                 /* Check whether it is compatible with what we know already! */
 862                 int compat = 1;
 863
 864                 if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 865                     && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
 866                     && !ANYOF_BITMAP_TEST(data->start_class,
 867                                           PL_fold[*(U8*)STRING(scan)]))
 868                     compat = 0;
 869                 ANYOF_CLASS_ZERO(data->start_class);
 870                 ANYOF_BITMAP_ZERO(data->start_class);
 871                 if (compat) {
 872                     ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
 873                     data->start_class->flags &= ~ANYOF_EOS;
 874                     data->start_class->flags |= ANYOF_FOLD;
 875                     if (OP(scan) == EXACTFL)
 876                         data->start_class->flags |= ANYOF_LOCALE;
 877                 }
 878             }
 879             else if (flags & SCF_DO_STCLASS_OR) {
 880                 if (data->start_class->flags & ANYOF_FOLD) {
 881                     /* false positive possible if the class is case-folded.
 882                        Assume that the locale settings are the same... */
 883                     ANYOF_BITMAP_SET(data->start_class, *STRING(scan));
 884                     data->start_class->flags &= ~ANYOF_EOS;
 885                 }
 886                 cl_and(data->start_class, &and_with);
 887             }
 888             flags &= ~SCF_DO_STCLASS;
 889         }
 890         else if (strchr((char*)PL_varies,OP(scan))) {
 891             I32 mincount, maxcount, minnext, deltanext, fl;
 892             I32 f = flags, pos_before = 0;
 893             regnode *oscan = scan;
 894             struct regnode_charclass_class this_class;
 895             struct regnode_charclass_class *oclass = NULL;
 896
 897             switch (PL_regkind[(U8)OP(scan)]) {
 898             case WHILEM:                /* End of (?:...)* . */
 899                 scan = NEXTOPER(scan);
 900                 goto finish;
 901             case PLUS:
 902                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
 903                     next = NEXTOPER(scan);
 904                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
 905                         mincount = 1;
 906                         maxcount = REG_INFTY;
 907                         next = regnext(scan);
 908                         scan = NEXTOPER(scan);
 909                         goto do_curly;
 910                     }
 911                 }
 912                 if (flags & SCF_DO_SUBSTR)
 913                     data->pos_min++;
 914                 min++;
 915                 /* Fall through. */
 916             case STAR:
 917                 if (flags & SCF_DO_STCLASS) {
 918                     mincount = 0;
 919                     maxcount = REG_INFTY;
 920                     next = regnext(scan);
 921                     scan = NEXTOPER(scan);
 922                     goto do_curly;
 923                 }
 924                 is_inf = is_inf_internal = 1;
 925                 scan = regnext(scan);
 926                 if (flags & SCF_DO_SUBSTR) {
 927                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
 928                     data->longest = &(data->longest_float);
 929                 }
 930                 goto optimize_curly_tail;
 931             case CURLY:
 932                 mincount = ARG1(scan);
 933                 maxcount = ARG2(scan);
 934                 next = regnext(scan);
 935                 if (OP(scan) == CURLYX) {
 936                     I32 lp = (data ? *(data->last_closep) : 0);
 937
 938                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
 939                 }
 940                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
 941               do_curly:
 942                 if (flags & SCF_DO_SUBSTR) {
 943                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
 944                     pos_before = data->pos_min;
 945                 }
 946                 if (data) {
 947                     fl = data->flags;
 948                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
 949                     if (is_inf)
 950                         data->flags |= SF_IS_INF;
 951                 }
 952                 if (flags & SCF_DO_STCLASS) {
 953                     cl_init(pRExC_state, &this_class);
 954                     oclass = data->start_class;
 955                     data->start_class = &this_class;
 956                     f |= SCF_DO_STCLASS_AND;
 957                     f &= ~SCF_DO_STCLASS_OR;
 958                 }
 959                 /* These are the cases when once a subexpression
 960                    fails at a particular position, it cannot succeed
 961                    even after backtracking at the enclosing scope.
 962
 963                    XXXX what if minimal match and we are at the
 964                         initial run of {n,m}? */
 965                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
 966                     f &= ~SCF_WHILEM_VISITED_POS;
 967
 968                 /* This will finish on WHILEM, setting scan, or on NULL: */
 969                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
 970                                       mincount == 0
 971                                         ? (f & ~SCF_DO_SUBSTR) : f);
 972
 973                 if (flags & SCF_DO_STCLASS)
 974                     data->start_class = oclass;
 975                 if (mincount == 0 || minnext == 0) {
 976                     if (flags & SCF_DO_STCLASS_OR) {
 977                         cl_or(pRExC_state, data->start_class, &this_class);
 978                     }
 979                     else if (flags & SCF_DO_STCLASS_AND) {
 980                         /* Switch to OR mode: cache the old value of
 981                          * data->start_class */
 982                         StructCopy(data->start_class, &and_with,
 983                                    struct regnode_charclass_class);
 984                         flags &= ~SCF_DO_STCLASS_AND;
 985                         StructCopy(&this_class, data->start_class,
 986                                    struct regnode_charclass_class);
 987                         flags |= SCF_DO_STCLASS_OR;
 988                         data->start_class->flags |= ANYOF_EOS;
 989                     }
 990                 } else {                /* Non-zero len */
 991                     if (flags & SCF_DO_STCLASS_OR) {
 992                         cl_or(pRExC_state, data->start_class, &this_class);
 993                         cl_and(data->start_class, &and_with);
 994                     }
 995                     else if (flags & SCF_DO_STCLASS_AND)
 996                         cl_and(data->start_class, &this_class);
 997                     flags &= ~SCF_DO_STCLASS;
 998                 }
 999                 if (!scan)              /* It was not CURLYX, but CURLY. */
1000                     scan = next;
1001                 if (ckWARN(WARN_REGEXP) && (minnext + deltanext == 0)
1002                     && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1003                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1004                 {
1005                     vWARN(RExC_parse,
1006                           "Quantifier unexpected on zero-length expression");
1007                 }
1008
1009                 min += minnext * mincount;
1010                 is_inf_internal |= ((maxcount == REG_INFTY
1011                                      && (minnext + deltanext) > 0)
1012                                     || deltanext == I32_MAX);
1013                 is_inf |= is_inf_internal;
1014                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1015
1016                 /* Try powerful optimization CURLYX => CURLYN. */
1017                 if (  OP(oscan) == CURLYX && data
1018                       && data->flags & SF_IN_PAR
1019                       && !(data->flags & SF_HAS_EVAL)
1020                       && !deltanext && minnext == 1 ) {
1021                     /* Try to optimize to CURLYN.  */
1022                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1023                     regnode *nxt1 = nxt, *nxt2;
1024
1025                     /* Skip open. */
1026                     nxt = regnext(nxt);
1027                     if (!strchr((char*)PL_simple,OP(nxt))
1028                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1029                              && STR_LEN(nxt) == 1))
1030                         goto nogo;
1031                     nxt2 = nxt;
1032                     nxt = regnext(nxt);
1033                     if (OP(nxt) != CLOSE)
1034                         goto nogo;
1035                     /* Now we know that nxt2 is the only contents: */
1036                     oscan->flags = ARG(nxt);
1037                     OP(oscan) = CURLYN;
1038                     OP(nxt1) = NOTHING; /* was OPEN. */
1039 #ifdef DEBUGGING
1040                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1041                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1042                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1043                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1044                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1045                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1046 #endif
1047                 }
1048               nogo:
1049
1050                 /* Try optimization CURLYX => CURLYM. */
1051                 if (  OP(oscan) == CURLYX && data
1052                       && !(data->flags & SF_HAS_PAR)
1053                       && !(data->flags & SF_HAS_EVAL)
1054                       && !deltanext  ) {
1055                     /* XXXX How to optimize if data == 0? */
1056                     /* Optimize to a simpler form.  */
1057                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1058                     regnode *nxt2;
1059
1060                     OP(oscan) = CURLYM;
1061                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1062                             && (OP(nxt2) != WHILEM))
1063                         nxt = nxt2;
1064                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1065                     /* Need to optimize away parenths. */
1066                     if (data->flags & SF_IN_PAR) {
1067                         /* Set the parenth number.  */
1068                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1069
1070                         if (OP(nxt) != CLOSE)
1071                             FAIL("Panic opt close");
1072                         oscan->flags = ARG(nxt);
1073                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1074                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1075 #ifdef DEBUGGING
1076                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1077                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1078                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1079                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1080 #endif
1081 #if 0
1082                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1083                             regnode *nnxt = regnext(nxt1);
1084
1085                             if (nnxt == nxt) {
1086                                 if (reg_off_by_arg[OP(nxt1)])
1087                                     ARG_SET(nxt1, nxt2 - nxt1);
1088                                 else if (nxt2 - nxt1 < U16_MAX)
1089                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1090                                 else
1091                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1092                             }
1093                             nxt1 = nnxt;
1094                         }
1095 #endif
1096                         /* Optimize again: */
1097                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1098                                     NULL, 0);
1099                     }
1100                     else
1101                         oscan->flags = 0;
1102                 }
1103                 else if ((OP(oscan) == CURLYX)
1104                          && (flags & SCF_WHILEM_VISITED_POS)
1105                          /* See the comment on a similar expression above.
1106                             However, this time it not a subexpression
1107                             we care about, but the expression itself. */
1108                          && (maxcount == REG_INFTY)
1109                          && data && ++data->whilem_c < 16) {
1110                     /* This stays as CURLYX, we can put the count/of pair. */
1111                     /* Find WHILEM (as in regexec.c) */
1112                     regnode *nxt = oscan + NEXT_OFF(oscan);
1113
1114                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1115                         nxt += ARG(nxt);
1116                     PREVOPER(nxt)->flags = data->whilem_c
1117                         | (RExC_whilem_seen << 4); /* On WHILEM */
1118                 }
1119                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1120                     pars++;
1121                 if (flags & SCF_DO_SUBSTR) {
1122                     SV *last_str = Nullsv;
1123                     int counted = mincount != 0;
1124
1125                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1126                         I32 b = pos_before >= data->last_start_min
1127                             ? pos_before : data->last_start_min;
1128                         STRLEN l;
1129                         char *s = SvPV(data->last_found, l);
1130                         I32 old = b - data->last_start_min;
1131
1132                         if (UTF)
1133                             old = utf8_hop((U8*)s, old) - (U8*)s;
1134
1135                         l -= old;
1136                         /* Get the added string: */
1137                         last_str = newSVpvn(s  + old, l);
1138                         if (deltanext == 0 && pos_before == b) {
1139                             /* What was added is a constant string */
1140                             if (mincount > 1) {
1141                                 SvGROW(last_str, (mincount * l) + 1);
1142                                 repeatcpy(SvPVX(last_str) + l,
1143                                           SvPVX(last_str), l, mincount - 1);
1144                                 SvCUR(last_str) *= mincount;
1145                                 /* Add additional parts. */
1146                                 SvCUR_set(data->last_found,
1147                                           SvCUR(data->last_found) - l);
1148                                 sv_catsv(data->last_found, last_str);
1149                                 data->last_end += l * (mincount - 1);
1150                             }
1151                         } else {
1152                             /* start offset must point into the last copy */
1153                             data->last_start_min += minnext * (mincount - 1);
1154                             data->last_start_max += is_inf ? 0 : (maxcount - 1)
1155                                 * (minnext + data->pos_delta);
1156                         }
1157                     }
1158                     /* It is counted once already... */
1159                     data->pos_min += minnext * (mincount - counted);
1160                     data->pos_delta += - counted * deltanext +
1161                         (minnext + deltanext) * maxcount - minnext * mincount;
1162                     if (mincount != maxcount) {
1163                          /* Cannot extend fixed substrings found inside
1164                             the group.  */
1165                         scan_commit(pRExC_state,data);
1166                         if (mincount && last_str) {
1167                             sv_setsv(data->last_found, last_str);
1168                             data->last_end = data->pos_min;
1169                             data->last_start_min =
1170                                 data->pos_min - CHR_SVLEN(last_str);
1171                             data->last_start_max = is_inf
1172                                 ? I32_MAX
1173                                 : data->pos_min + data->pos_delta
1174                                 - CHR_SVLEN(last_str);
1175                         }
1176                         data->longest = &(data->longest_float);
1177                     }
1178                     SvREFCNT_dec(last_str);
1179                 }
1180                 if (data && (fl & SF_HAS_EVAL))
1181                     data->flags |= SF_HAS_EVAL;
1182               optimize_curly_tail:
1183                 if (OP(oscan) != CURLYX) {
1184                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1185                            && NEXT_OFF(next))
1186                         NEXT_OFF(oscan) += NEXT_OFF(next);
1187                 }
1188                 continue;
1189             default:                    /* REF and CLUMP only? */
1190                 if (flags & SCF_DO_SUBSTR) {
1191                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1192                     data->longest = &(data->longest_float);
1193                 }
1194                 is_inf = is_inf_internal = 1;
1195                 if (flags & SCF_DO_STCLASS_OR)
1196                     cl_anything(pRExC_state, data->start_class);
1197                 flags &= ~SCF_DO_STCLASS;
1198                 break;
1199             }
1200         }
1201         else if (strchr((char*)PL_simple,OP(scan)) || PL_regkind[(U8)OP(scan)] == ANYUTF8) {
1202             int value;
1203
1204             if (flags & SCF_DO_SUBSTR) {
1205                 scan_commit(pRExC_state,data);
1206                 data->pos_min++;
1207             }
1208             min++;
1209             if (flags & SCF_DO_STCLASS) {
1210                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1211
1212                 /* Some of the logic below assumes that switching
1213                    locale on will only add false positives. */
1214                 switch (PL_regkind[(U8)OP(scan)]) {
1215                 case ANYUTF8:
1216                 case SANY:
1217                 case SANYUTF8:
1218                 case ALNUMUTF8:
1219                 case ANYOFUTF8:
1220                 case ALNUMLUTF8:
1221                 case NALNUMUTF8:
1222                 case NALNUMLUTF8:
1223                 case SPACEUTF8:
1224                 case NSPACEUTF8:
1225                 case SPACELUTF8:
1226                 case NSPACELUTF8:
1227                 case DIGITUTF8:
1228                 case NDIGITUTF8:
1229                 default:
1230                   do_default:
1231                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1232                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1233                         cl_anything(pRExC_state, data->start_class);
1234                     break;
1235                 case REG_ANY:
1236                     if (OP(scan) == SANY)
1237                         goto do_default;
1238                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1239                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1240                                  || (data->start_class->flags & ANYOF_CLASS));
1241                         cl_anything(pRExC_state, data->start_class);
1242                     }
1243                     if (flags & SCF_DO_STCLASS_AND || !value)
1244                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1245                     break;
1246                 case ANYOF:
1247                     if (flags & SCF_DO_STCLASS_AND)
1248                         cl_and(data->start_class,
1249                                (struct regnode_charclass_class*)scan);
1250                     else
1251                         cl_or(pRExC_state, data->start_class,
1252                               (struct regnode_charclass_class*)scan);
1253                     break;
1254                 case ALNUM:
1255                     if (flags & SCF_DO_STCLASS_AND) {
1256                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1257                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1258                             for (value = 0; value < 256; value++)
1259                                 if (!isALNUM(value))
1260                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1261                         }
1262                     }
1263                     else {
1264                         if (data->start_class->flags & ANYOF_LOCALE)
1265                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1266                         else {
1267                             for (value = 0; value < 256; value++)
1268                                 if (isALNUM(value))
1269                                     ANYOF_BITMAP_SET(data->start_class, value);
1270                         }
1271                     }
1272                     break;
1273                 case ALNUML:
1274                     if (flags & SCF_DO_STCLASS_AND) {
1275                         if (data->start_class->flags & ANYOF_LOCALE)
1276                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1277                     }
1278                     else {
1279                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1280                         data->start_class->flags |= ANYOF_LOCALE;
1281                     }
1282                     break;
1283                 case NALNUM:
1284                     if (flags & SCF_DO_STCLASS_AND) {
1285                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1286                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1287                             for (value = 0; value < 256; value++)
1288                                 if (isALNUM(value))
1289                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1290                         }
1291                     }
1292                     else {
1293                         if (data->start_class->flags & ANYOF_LOCALE)
1294                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1295                         else {
1296                             for (value = 0; value < 256; value++)
1297                                 if (!isALNUM(value))
1298                                     ANYOF_BITMAP_SET(data->start_class, value);
1299                         }
1300                     }
1301                     break;
1302                 case NALNUML:
1303                     if (flags & SCF_DO_STCLASS_AND) {
1304                         if (data->start_class->flags & ANYOF_LOCALE)
1305                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1306                     }
1307                     else {
1308                         data->start_class->flags |= ANYOF_LOCALE;
1309                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1310                     }
1311                     break;
1312                 case SPACE:
1313                     if (flags & SCF_DO_STCLASS_AND) {
1314                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1315                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1316                             for (value = 0; value < 256; value++)
1317                                 if (!isSPACE(value))
1318                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1319                         }
1320                     }
1321                     else {
1322                         if (data->start_class->flags & ANYOF_LOCALE)
1323                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1324                         else {
1325                             for (value = 0; value < 256; value++)
1326                                 if (isSPACE(value))
1327                                     ANYOF_BITMAP_SET(data->start_class, value);
1328                         }
1329                     }
1330                     break;
1331                 case SPACEL:
1332                     if (flags & SCF_DO_STCLASS_AND) {
1333                         if (data->start_class->flags & ANYOF_LOCALE)
1334                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1335                     }
1336                     else {
1337                         data->start_class->flags |= ANYOF_LOCALE;
1338                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1339                     }
1340                     break;
1341                 case NSPACE:
1342                     if (flags & SCF_DO_STCLASS_AND) {
1343                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1344                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1345                             for (value = 0; value < 256; value++)
1346                                 if (isSPACE(value))
1347                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1348                         }
1349                     }
1350                     else {
1351                         if (data->start_class->flags & ANYOF_LOCALE)
1352                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1353                         else {
1354                             for (value = 0; value < 256; value++)
1355                                 if (!isSPACE(value))
1356                                     ANYOF_BITMAP_SET(data->start_class, value);
1357                         }
1358                     }
1359                     break;
1360                 case NSPACEL:
1361                     if (flags & SCF_DO_STCLASS_AND) {
1362                         if (data->start_class->flags & ANYOF_LOCALE) {
1363                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1364                             for (value = 0; value < 256; value++)
1365                                 if (!isSPACE(value))
1366                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1367                         }
1368                     }
1369                     else {
1370                         data->start_class->flags |= ANYOF_LOCALE;
1371                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1372                     }
1373                     break;
1374                 case DIGIT:
1375                     if (flags & SCF_DO_STCLASS_AND) {
1376                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1377                         for (value = 0; value < 256; value++)
1378                             if (!isDIGIT(value))
1379                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1380                     }
1381                     else {
1382                         if (data->start_class->flags & ANYOF_LOCALE)
1383                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1384                         else {
1385                             for (value = 0; value < 256; value++)
1386                                 if (isDIGIT(value))
1387                                     ANYOF_BITMAP_SET(data->start_class, value);
1388                         }
1389                     }
1390                     break;
1391                 case NDIGIT:
1392                     if (flags & SCF_DO_STCLASS_AND) {
1393                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1394                         for (value = 0; value < 256; value++)
1395                             if (isDIGIT(value))
1396                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1397                     }
1398                     else {
1399                         if (data->start_class->flags & ANYOF_LOCALE)
1400                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1401                         else {
1402                             for (value = 0; value < 256; value++)
1403                                 if (!isDIGIT(value))
1404                                     ANYOF_BITMAP_SET(data->start_class, value);
1405                         }
1406                     }
1407                     break;
1408                 }
1409                 if (flags & SCF_DO_STCLASS_OR)
1410                     cl_and(data->start_class, &and_with);
1411                 flags &= ~SCF_DO_STCLASS;
1412             }
1413         }
1414         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1415             data->flags |= (OP(scan) == MEOL
1416                             ? SF_BEFORE_MEOL
1417                             : SF_BEFORE_SEOL);
1418         }
1419         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1420                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1421                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1422                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1423             /* Lookahead/lookbehind */
1424             I32 deltanext, minnext, fake = 0;
1425             regnode *nscan;
1426             struct regnode_charclass_class intrnl;
1427             int f = 0;
1428
1429             data_fake.flags = 0;
1430             if (data) {
1431                 data_fake.whilem_c = data->whilem_c;
1432                 data_fake.last_closep = data->last_closep;
1433             }
1434             else
1435                 data_fake.last_closep = &fake;
1436             if ( flags & SCF_DO_STCLASS && !scan->flags
1437                  && OP(scan) == IFMATCH ) { /* Lookahead */
1438                 cl_init(pRExC_state, &intrnl);
1439                 data_fake.start_class = &intrnl;
1440                 f |= SCF_DO_STCLASS_AND;
1441             }
1442             if (flags & SCF_WHILEM_VISITED_POS)
1443                 f |= SCF_WHILEM_VISITED_POS;
1444             next = regnext(scan);
1445             nscan = NEXTOPER(NEXTOPER(scan));
1446             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1447             if (scan->flags) {
1448                 if (deltanext) {
1449                     vFAIL("Variable length lookbehind not implemented");
1450                 }
1451                 else if (minnext > U8_MAX) {
1452                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1453                 }
1454                 scan->flags = minnext;
1455             }
1456             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1457                 pars++;
1458             if (data && (data_fake.flags & SF_HAS_EVAL))
1459                 data->flags |= SF_HAS_EVAL;
1460             if (data)
1461                 data->whilem_c = data_fake.whilem_c;
1462             if (f & SCF_DO_STCLASS_AND) {
1463                 int was = (data->start_class->flags & ANYOF_EOS);
1464
1465                 cl_and(data->start_class, &intrnl);
1466                 if (was)
1467                     data->start_class->flags |= ANYOF_EOS;
1468             }
1469         }
1470         else if (OP(scan) == OPEN) {
1471             pars++;
1472         }
1473         else if (OP(scan) == CLOSE) {
1474             if (ARG(scan) == is_par) {
1475                 next = regnext(scan);
1476
1477                 if ( next && (OP(next) != WHILEM) && next < last)
1478                     is_par = 0;         /* Disable optimization */
1479             }
1480             if (data)
1481                 *(data->last_closep) = ARG(scan);
1482         }
1483         else if (OP(scan) == EVAL) {
1484                 if (data)
1485                     data->flags |= SF_HAS_EVAL;
1486         }
1487         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1488                 if (flags & SCF_DO_SUBSTR) {
1489                     scan_commit(pRExC_state,data);
1490                     data->longest = &(data->longest_float);
1491                 }
1492                 is_inf = is_inf_internal = 1;
1493                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1494                     cl_anything(pRExC_state, data->start_class);
1495                 flags &= ~SCF_DO_STCLASS;
1496         }
1497         /* Else: zero-length, ignore. */
1498         scan = regnext(scan);
1499     }
1500
1501   finish:
1502     *scanp = scan;
1503     *deltap = is_inf_internal ? I32_MAX : delta;
1504     if (flags & SCF_DO_SUBSTR && is_inf)
1505         data->pos_delta = I32_MAX - data->pos_min;
1506     if (is_par > U8_MAX)
1507         is_par = 0;
1508     if (is_par && pars==1 && data) {
1509         data->flags |= SF_IN_PAR;
1510         data->flags &= ~SF_HAS_PAR;
1511     }
1512     else if (pars && data) {
1513         data->flags |= SF_HAS_PAR;
1514         data->flags &= ~SF_IN_PAR;
1515     }
1516     if (flags & SCF_DO_STCLASS_OR)
1517         cl_and(data->start_class, &and_with);
1518     return min;
1519 }
1520
1521 STATIC I32
1522 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1523 {
1524     dTHR;
1525     if (RExC_rx->data) {
1526         Renewc(RExC_rx->data,
1527                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1528                char, struct reg_data);
1529         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1530         RExC_rx->data->count += n;
1531     }
1532     else {
1533         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1534              char, struct reg_data);
1535         New(1208, RExC_rx->data->what, n, U8);
1536         RExC_rx->data->count = n;
1537     }
1538     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1539     return RExC_rx->data->count - n;
1540 }
1541
1542 void
1543 Perl_reginitcolors(pTHX)
1544 {
1545     dTHR;
1546     int i = 0;
1547     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1548
1549     if (s) {
1550         PL_colors[0] = s = savepv(s);
1551         while (++i < 6) {
1552             s = strchr(s, '\t');
1553             if (s) {
1554                 *s = '\0';
1555                 PL_colors[i] = ++s;
1556             }
1557             else
1558                 PL_colors[i] = s = "";
1559         }
1560     } else {
1561         while (i < 6)
1562             PL_colors[i++] = "";
1563     }
1564     PL_colorset = 1;
1565 }
1566
1567
1568 /*
1569  - pregcomp - compile a regular expression into internal code
1570  *
1571  * We can't allocate space until we know how big the compiled form will be,
1572  * but we can't compile it (and thus know how big it is) until we've got a
1573  * place to put the code.  So we cheat:  we compile it twice, once with code
1574  * generation turned off and size counting turned on, and once "for real".
1575  * This also means that we don't allocate space until we are sure that the
1576  * thing really will compile successfully, and we never have to move the
1577  * code and thus invalidate pointers into it.  (Note that it has to be in
1578  * one piece because free() must be able to free it all.) [NB: not true in perl]
1579  *
1580  * Beware that the optimization-preparation code in here knows about some
1581  * of the structure of the compiled regexp.  [I'll say.]
1582  */
1583 regexp *
1584 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1585 {
1586     dTHR;
1587     register regexp *r;
1588     regnode *scan;
1589     regnode *first;
1590     I32 flags;
1591     I32 minlen = 0;
1592     I32 sawplus = 0;
1593     I32 sawopen = 0;
1594     scan_data_t data;
1595     RExC_state_t RExC_state;
1596     RExC_state_t *pRExC_state = &RExC_state;
1597
1598     if (exp == NULL)
1599         FAIL("NULL regexp argument");
1600
1601     /* XXXX This looks very suspicious... */
1602     if (pm->op_pmdynflags & PMdf_UTF8) {
1603         PL_reg_flags |= RF_utf8;
1604     }
1605     else
1606         PL_reg_flags = 0;
1607
1608     RExC_precomp = savepvn(exp, xend - exp);
1609     DEBUG_r(if (!PL_colorset) reginitcolors());
1610     DEBUG_r(PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1611                       PL_colors[4],PL_colors[5],PL_colors[0],
1612                       (int)(xend - exp), RExC_precomp, PL_colors[1]));
1613     RExC_flags16 = pm->op_pmflags;
1614     RExC_sawback = 0;
1615
1616     RExC_seen = 0;
1617     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1618     RExC_seen_evals = 0;
1619     RExC_extralen = 0;
1620
1621     /* First pass: determine size, legality. */
1622     RExC_parse = exp;
1623     RExC_end = xend;
1624     RExC_naughty = 0;
1625     RExC_npar = 1;
1626     RExC_size = 0L;
1627     RExC_emit = &PL_regdummy;
1628     RExC_whilem_seen = 0;
1629 #if 0 /* REGC() is (currently) a NOP at the first pass.
1630        * Clever compilers notice this and complain. --jhi */
1631     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1632 #endif
1633     if (reg(pRExC_state, 0, &flags) == NULL) {
1634         Safefree(RExC_precomp);
1635         RExC_precomp = Nullch;
1636         return(NULL);
1637     }
1638     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1639
1640     /* Small enough for pointer-storage convention?
1641        If extralen==0, this means that we will not need long jumps. */
1642     if (RExC_size >= 0x10000L && RExC_extralen)
1643         RExC_size += RExC_extralen;
1644     else
1645         RExC_extralen = 0;
1646     if (RExC_whilem_seen > 15)
1647         RExC_whilem_seen = 15;
1648
1649     /* Allocate space and initialize. */
1650     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1651          char, regexp);
1652     if (r == NULL)
1653         FAIL("Regexp out of space");
1654
1655 #ifdef DEBUGGING
1656     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1657     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1658 #endif
1659     r->refcnt = 1;
1660     r->prelen = xend - exp;
1661     r->precomp = RExC_precomp;
1662     r->subbeg = NULL;
1663     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1664     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1665
1666     r->substrs = 0;                     /* Useful during FAIL. */
1667     r->startp = 0;                      /* Useful during FAIL. */
1668     r->endp = 0;                        /* Useful during FAIL. */
1669
1670     RExC_rx = r;
1671
1672     /* Second pass: emit code. */
1673     RExC_parse = exp;
1674     RExC_end = xend;
1675     RExC_naughty = 0;
1676     RExC_npar = 1;
1677     RExC_emit = r->program;
1678     /* Store the count of eval-groups for security checks: */
1679     RExC_emit->next_off = ((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1680     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1681     r->data = 0;
1682     if (reg(pRExC_state, 0, &flags) == NULL)
1683         return(NULL);
1684
1685     /* Dig out information for optimizations. */
1686     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1687     pm->op_pmflags = RExC_flags16;
1688     if (UTF)
1689         r->reganch |= ROPT_UTF8;
1690     r->regstclass = NULL;
1691     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1692         r->reganch |= ROPT_NAUGHTY;
1693     scan = r->program + 1;              /* First BRANCH. */
1694
1695     /* XXXX To minimize changes to RE engine we always allocate
1696        3-units-long substrs field. */
1697     Newz(1004, r->substrs, 1, struct reg_substr_data);
1698
1699     StructCopy(&zero_scan_data, &data, scan_data_t);
1700     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1701     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1702         I32 fake;
1703         STRLEN longest_float_length, longest_fixed_length;
1704         struct regnode_charclass_class ch_class;
1705         int stclass_flag;
1706         I32 last_close = 0;
1707
1708         first = scan;
1709         /* Skip introductions and multiplicators >= 1. */
1710         while ((OP(first) == OPEN && (sawopen = 1)) ||
1711                /* An OR of *one* alternative - should not happen now. */
1712             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1713             (OP(first) == PLUS) ||
1714             (OP(first) == MINMOD) ||
1715                /* An {n,m} with n>0 */
1716             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1717                 if (OP(first) == PLUS)
1718                     sawplus = 1;
1719                 else
1720                     first += regarglen[(U8)OP(first)];
1721                 first = NEXTOPER(first);
1722         }
1723
1724         /* Starting-point info. */
1725       again:
1726         if (PL_regkind[(U8)OP(first)] == EXACT) {
1727             if (OP(first) == EXACT);    /* Empty, get anchored substr later. */
1728             else if ((OP(first) == EXACTF || OP(first) == EXACTFL)
1729                      && !UTF)
1730                 r->regstclass = first;
1731         }
1732         else if (strchr((char*)PL_simple,OP(first)))
1733             r->regstclass = first;
1734         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1735                  PL_regkind[(U8)OP(first)] == NBOUND)
1736             r->regstclass = first;
1737         else if (PL_regkind[(U8)OP(first)] == BOL) {
1738             r->reganch |= (OP(first) == MBOL
1739                            ? ROPT_ANCH_MBOL
1740                            : (OP(first) == SBOL
1741                               ? ROPT_ANCH_SBOL
1742                               : ROPT_ANCH_BOL));
1743             first = NEXTOPER(first);
1744             goto again;
1745         }
1746         else if (OP(first) == GPOS) {
1747             r->reganch |= ROPT_ANCH_GPOS;
1748             first = NEXTOPER(first);
1749             goto again;
1750         }
1751         else if ((OP(first) == STAR &&
1752             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1753             !(r->reganch & ROPT_ANCH) )
1754         {
1755             /* turn .* into ^.* with an implied $*=1 */
1756             int type = OP(NEXTOPER(first));
1757
1758             if (type == REG_ANY || type == ANYUTF8)
1759                 type = ROPT_ANCH_MBOL;
1760             else
1761                 type = ROPT_ANCH_SBOL;
1762
1763             r->reganch |= type | ROPT_IMPLICIT;
1764             first = NEXTOPER(first);
1765             goto again;
1766         }
1767         if (sawplus && (!sawopen || !RExC_sawback)
1768             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1769             /* x+ must match at the 1st pos of run of x's */
1770             r->reganch |= ROPT_SKIP;
1771
1772         /* Scan is after the zeroth branch, first is atomic matcher. */
1773         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1774                               (IV)(first - scan + 1)));
1775         /*
1776         * If there's something expensive in the r.e., find the
1777         * longest literal string that must appear and make it the
1778         * regmust.  Resolve ties in favor of later strings, since
1779         * the regstart check works with the beginning of the r.e.
1780         * and avoiding duplication strengthens checking.  Not a
1781         * strong reason, but sufficient in the absence of others.
1782         * [Now we resolve ties in favor of the earlier string if
1783         * it happens that c_offset_min has been invalidated, since the
1784         * earlier string may buy us something the later one won't.]
1785         */
1786         minlen = 0;
1787
1788         data.longest_fixed = newSVpvn("",0);
1789         data.longest_float = newSVpvn("",0);
1790         data.last_found = newSVpvn("",0);
1791         data.longest = &(data.longest_fixed);
1792         first = scan;
1793         if (!r->regstclass) {
1794             cl_init(pRExC_state, &ch_class);
1795             data.start_class = &ch_class;
1796             stclass_flag = SCF_DO_STCLASS_AND;
1797         } else                          /* XXXX Check for BOUND? */
1798             stclass_flag = 0;
1799         data.last_closep = &last_close;
1800
1801         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1802                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1803         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1804              && data.last_start_min == 0 && data.last_end > 0
1805              && !RExC_seen_zerolen
1806              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1807             r->reganch |= ROPT_CHECK_ALL;
1808         scan_commit(pRExC_state, &data);
1809         SvREFCNT_dec(data.last_found);
1810
1811         longest_float_length = CHR_SVLEN(data.longest_float);
1812         if (longest_float_length
1813             || (data.flags & SF_FL_BEFORE_EOL
1814                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1815                     || (RExC_flags16 & PMf_MULTILINE)))) {
1816             int t;
1817
1818             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1819                 && data.offset_fixed == data.offset_float_min
1820                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1821                     goto remove_float;          /* As in (a)+. */
1822
1823             r->float_substr = data.longest_float;
1824             r->float_min_offset = data.offset_float_min;
1825             r->float_max_offset = data.offset_float_max;
1826             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1827                        && (!(data.flags & SF_FL_BEFORE_MEOL)
1828                            || (RExC_flags16 & PMf_MULTILINE)));
1829             fbm_compile(r->float_substr, t ? FBMcf_TAIL : 0);
1830         }
1831         else {
1832           remove_float:
1833             r->float_substr = Nullsv;
1834             SvREFCNT_dec(data.longest_float);
1835             longest_float_length = 0;
1836         }
1837
1838         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
1839         if (longest_fixed_length
1840             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
1841                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
1842                     || (RExC_flags16 & PMf_MULTILINE)))) {
1843             int t;
1844
1845             r->anchored_substr = data.longest_fixed;
1846             r->anchored_offset = data.offset_fixed;
1847             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
1848                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
1849                      || (RExC_flags16 & PMf_MULTILINE)));
1850             fbm_compile(r->anchored_substr, t ? FBMcf_TAIL : 0);
1851         }
1852         else {
1853             r->anchored_substr = Nullsv;
1854             SvREFCNT_dec(data.longest_fixed);
1855             longest_fixed_length = 0;
1856         }
1857         if (r->regstclass
1858             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == ANYUTF8
1859                 || OP(r->regstclass) == SANYUTF8 || OP(r->regstclass) == SANY))
1860             r->regstclass = NULL;
1861         if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
1862             && !(data.start_class->flags & ANYOF_EOS)
1863             && !cl_is_anything(data.start_class)) {
1864             SV *sv;
1865             I32 n = add_data(pRExC_state, 1, "f");
1866
1867             New(1006, RExC_rx->data->data[n], 1,
1868                 struct regnode_charclass_class);
1869             StructCopy(data.start_class,
1870                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
1871                        struct regnode_charclass_class);
1872             r->regstclass = (regnode*)RExC_rx->data->data[n];
1873             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
1874             DEBUG_r((sv = sv_newmortal(),
1875                      regprop(sv, (regnode*)data.start_class),
1876                      PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1877                                    SvPVX(sv))));
1878         }
1879
1880         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
1881         if (longest_fixed_length > longest_float_length) {
1882             r->check_substr = r->anchored_substr;
1883             r->check_offset_min = r->check_offset_max = r->anchored_offset;
1884             if (r->reganch & ROPT_ANCH_SINGLE)
1885                 r->reganch |= ROPT_NOSCAN;
1886         }
1887         else {
1888             r->check_substr = r->float_substr;
1889             r->check_offset_min = data.offset_float_min;
1890             r->check_offset_max = data.offset_float_max;
1891         }
1892         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
1893            This should be changed ASAP!  */
1894         if (r->check_substr && !(r->reganch & ROPT_ANCH_GPOS)) {
1895             r->reganch |= RE_USE_INTUIT;
1896             if (SvTAIL(r->check_substr))
1897                 r->reganch |= RE_INTUIT_TAIL;
1898         }
1899     }
1900     else {
1901         /* Several toplevels. Best we can is to set minlen. */
1902         I32 fake;
1903         struct regnode_charclass_class ch_class;
1904         I32 last_close = 0;
1905
1906         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
1907         scan = r->program + 1;
1908         cl_init(pRExC_state, &ch_class);
1909         data.start_class = &ch_class;
1910         data.last_closep = &last_close;
1911         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
1912         r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
1913         if (!(data.start_class->flags & ANYOF_EOS)
1914             && !cl_is_anything(data.start_class)) {
1915             SV *sv;
1916             I32 n = add_data(pRExC_state, 1, "f");
1917
1918             New(1006, RExC_rx->data->data[n], 1,
1919                 struct regnode_charclass_class);
1920             StructCopy(data.start_class,
1921                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
1922                        struct regnode_charclass_class);
1923             r->regstclass = (regnode*)RExC_rx->data->data[n];
1924             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
1925             DEBUG_r((sv = sv_newmortal(),
1926                      regprop(sv, (regnode*)data.start_class),
1927                      PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1928                                    SvPVX(sv))));
1929         }
1930     }
1931
1932     r->minlen = minlen;
1933     if (RExC_seen & REG_SEEN_GPOS)
1934         r->reganch |= ROPT_GPOS_SEEN;
1935     if (RExC_seen & REG_SEEN_LOOKBEHIND)
1936         r->reganch |= ROPT_LOOKBEHIND_SEEN;
1937     if (RExC_seen & REG_SEEN_EVAL)
1938         r->reganch |= ROPT_EVAL_SEEN;
1939     Newz(1002, r->startp, RExC_npar, I32);
1940     Newz(1002, r->endp, RExC_npar, I32);
1941     DEBUG_r(regdump(r));
1942     return(r);
1943 }
1944
1945 /*
1946  - reg - regular expression, i.e. main body or parenthesized thing
1947  *
1948  * Caller must absorb opening parenthesis.
1949  *
1950  * Combining parenthesis handling with the base level of regular expression
1951  * is a trifle forced, but the need to tie the tails of the branches to what
1952  * follows makes it hard to avoid.
1953  */
1954 STATIC regnode *
1955 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
1956     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
1957 {
1958     dTHR;
1959     register regnode *ret;              /* Will be the head of the group. */
1960     register regnode *br;
1961     register regnode *lastbr;
1962     register regnode *ender = 0;
1963     register I32 parno = 0;
1964     I32 flags, oregflags = RExC_flags16, have_branch = 0, open = 0;
1965     char *oregcomp_parse = RExC_parse;
1966     char c;
1967
1968     *flagp = 0;                         /* Tentatively. */
1969
1970     /* Make an OPEN node, if parenthesized. */
1971     if (paren) {
1972         if (*RExC_parse == '?') {
1973             U16 posflags = 0, negflags = 0;
1974             U16 *flagsp = &posflags;
1975             int logical = 0;
1976             char *seqstart = RExC_parse;
1977
1978             RExC_parse++;
1979             paren = *RExC_parse++;
1980             ret = NULL;                 /* For look-ahead/behind. */
1981             switch (paren) {
1982             case '<':
1983                 RExC_seen |= REG_SEEN_LOOKBEHIND;
1984                 if (*RExC_parse == '!')
1985                     paren = ',';
1986                 if (*RExC_parse != '=' && *RExC_parse != '!')
1987                     goto unknown;
1988                 RExC_parse++;
1989             case '=':
1990             case '!':
1991                 RExC_seen_zerolen++;
1992             case ':':
1993             case '>':
1994                 break;
1995             case '$':
1996             case '@':
1997                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
1998                 break;
1999             case '#':
2000                 while (*RExC_parse && *RExC_parse != ')')
2001                     RExC_parse++;
2002                 if (*RExC_parse != ')')
2003                     FAIL("Sequence (?#... not terminated");
2004                 nextchar(pRExC_state);
2005                 *flagp = TRYAGAIN;
2006                 return NULL;
2007             case 'p':
2008                 if (SIZE_ONLY)
2009                     vWARN(RExC_parse, "(?p{}) is deprecated - use (??{})");
2010                 /* FALL THROUGH*/
2011             case '?':
2012                 logical = 1;
2013                 paren = *RExC_parse++;
2014                 /* FALL THROUGH */
2015             case '{':
2016             {
2017                 dTHR;
2018                 I32 count = 1, n = 0;
2019                 char c;
2020                 char *s = RExC_parse;
2021                 SV *sv;
2022                 OP_4tree *sop, *rop;
2023
2024                 RExC_seen_zerolen++;
2025                 RExC_seen |= REG_SEEN_EVAL;
2026                 while (count && (c = *RExC_parse)) {
2027                     if (c == '\\' && RExC_parse[1])
2028                         RExC_parse++;
2029                     else if (c == '{')
2030                         count++;
2031                     else if (c == '}')
2032                         count--;
2033                     RExC_parse++;
2034                 }
2035                 if (*RExC_parse != ')')
2036                 {
2037                     RExC_parse = s;
2038                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2039                 }
2040                 if (!SIZE_ONLY) {
2041                     AV *av;
2042
2043                     if (RExC_parse - 1 - s)
2044                         sv = newSVpvn(s, RExC_parse - 1 - s);
2045                     else
2046                         sv = newSVpvn("", 0);
2047
2048                     ENTER;
2049                     Perl_save_re_context(aTHX);
2050                     rop = sv_compile_2op(sv, &sop, "re", &av);
2051                     LEAVE;
2052
2053                     n = add_data(pRExC_state, 3, "nop");
2054                     RExC_rx->data->data[n] = (void*)rop;
2055                     RExC_rx->data->data[n+1] = (void*)sop;
2056                     RExC_rx->data->data[n+2] = (void*)av;
2057                     SvREFCNT_dec(sv);
2058                 }
2059                 else {                                          /* First pass */
2060                     if (PL_reginterp_cnt < ++RExC_seen_evals
2061                         && PL_curcop != &PL_compiling)
2062                         /* No compiled RE interpolated, has runtime
2063                            components ===> unsafe.  */
2064                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2065                     if (PL_tainted)
2066                         FAIL("Eval-group in insecure regular expression");
2067                 }
2068
2069                 nextchar(pRExC_state);
2070                 if (logical) {
2071                     ret = reg_node(pRExC_state, LOGICAL);
2072                     if (!SIZE_ONLY)
2073                         ret->flags = 2;
2074                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2075                     return ret;
2076                 }
2077                 return reganode(pRExC_state, EVAL, n);
2078             }
2079             case '(':
2080             {
2081                 if (RExC_parse[0] == '?') {
2082                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2083                         || RExC_parse[1] == '<'
2084                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2085                         I32 flag;
2086
2087                         ret = reg_node(pRExC_state, LOGICAL);
2088                         if (!SIZE_ONLY)
2089                             ret->flags = 1;
2090                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2091                         goto insert_if;
2092                     }
2093                 }
2094                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2095                     parno = atoi(RExC_parse++);
2096
2097                     while (isDIGIT(*RExC_parse))
2098                         RExC_parse++;
2099                     ret = reganode(pRExC_state, GROUPP, parno);
2100                     if ((c = *nextchar(pRExC_state)) != ')')
2101                         vFAIL("Switch condition not recognized");
2102                   insert_if:
2103                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2104                     br = regbranch(pRExC_state, &flags, 1);
2105                     if (br == NULL)
2106                         br = reganode(pRExC_state, LONGJMP, 0);
2107                     else
2108                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2109                     c = *nextchar(pRExC_state);
2110                     if (flags&HASWIDTH)
2111                         *flagp |= HASWIDTH;
2112                     if (c == '|') {
2113                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2114                         regbranch(pRExC_state, &flags, 1);
2115                         regtail(pRExC_state, ret, lastbr);
2116                         if (flags&HASWIDTH)
2117                             *flagp |= HASWIDTH;
2118                         c = *nextchar(pRExC_state);
2119                     }
2120                     else
2121                         lastbr = NULL;
2122                     if (c != ')')
2123                         vFAIL("Switch (?(condition)... contains too many branches");
2124                     ender = reg_node(pRExC_state, TAIL);
2125                     regtail(pRExC_state, br, ender);
2126                     if (lastbr) {
2127                         regtail(pRExC_state, lastbr, ender);
2128                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2129                     }
2130                     else
2131                         regtail(pRExC_state, ret, ender);
2132                     return ret;
2133                 }
2134                 else {
2135                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2136                 }
2137             }
2138             case 0:
2139                 RExC_parse--; /* for vFAIL to print correctly */
2140                 vFAIL("Sequence (? incomplete");
2141                 break;
2142             default:
2143                 --RExC_parse;
2144               parse_flags:
2145                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2146                     if (*RExC_parse != 'o')
2147                         pmflag(flagsp, *RExC_parse);
2148                     ++RExC_parse;
2149                 }
2150                 if (*RExC_parse == '-') {
2151                     flagsp = &negflags;
2152                     ++RExC_parse;
2153                     goto parse_flags;
2154                 }
2155                 RExC_flags16 |= posflags;
2156                 RExC_flags16 &= ~negflags;
2157                 if (*RExC_parse == ':') {
2158                     RExC_parse++;
2159                     paren = ':';
2160                     break;
2161                 }
2162               unknown:
2163                 if (*RExC_parse != ')') {
2164                     RExC_parse++;
2165                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2166                 }
2167                 nextchar(pRExC_state);
2168                 *flagp = TRYAGAIN;
2169                 return NULL;
2170             }
2171         }
2172         else {
2173             parno = RExC_npar;
2174             RExC_npar++;
2175             ret = reganode(pRExC_state, OPEN, parno);
2176             open = 1;
2177         }
2178     }
2179     else
2180         ret = NULL;
2181
2182     /* Pick up the branches, linking them together. */
2183     br = regbranch(pRExC_state, &flags, 1);
2184     if (br == NULL)
2185         return(NULL);
2186     if (*RExC_parse == '|') {
2187         if (!SIZE_ONLY && RExC_extralen) {
2188             reginsert(pRExC_state, BRANCHJ, br);
2189         }
2190         else
2191             reginsert(pRExC_state, BRANCH, br);
2192         have_branch = 1;
2193         if (SIZE_ONLY)
2194             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2195     }
2196     else if (paren == ':') {
2197         *flagp |= flags&SIMPLE;
2198     }
2199     if (open) {                         /* Starts with OPEN. */
2200         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2201     }
2202     else if (paren != '?')              /* Not Conditional */
2203         ret = br;
2204     if (flags&HASWIDTH)
2205         *flagp |= HASWIDTH;
2206     *flagp |= flags&SPSTART;
2207     lastbr = br;
2208     while (*RExC_parse == '|') {
2209         if (!SIZE_ONLY && RExC_extralen) {
2210             ender = reganode(pRExC_state, LONGJMP,0);
2211             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2212         }
2213         if (SIZE_ONLY)
2214             RExC_extralen += 2;         /* Account for LONGJMP. */
2215         nextchar(pRExC_state);
2216         br = regbranch(pRExC_state, &flags, 0);
2217         if (br == NULL)
2218             return(NULL);
2219         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2220         lastbr = br;
2221         if (flags&HASWIDTH)
2222             *flagp |= HASWIDTH;
2223         *flagp |= flags&SPSTART;
2224     }
2225
2226     if (have_branch || paren != ':') {
2227         /* Make a closing node, and hook it on the end. */
2228         switch (paren) {
2229         case ':':
2230             ender = reg_node(pRExC_state, TAIL);
2231             break;
2232         case 1:
2233             ender = reganode(pRExC_state, CLOSE, parno);
2234             break;
2235         case '<':
2236         case ',':
2237         case '=':
2238         case '!':
2239             *flagp &= ~HASWIDTH;
2240             /* FALL THROUGH */
2241         case '>':
2242             ender = reg_node(pRExC_state, SUCCEED);
2243             break;
2244         case 0:
2245             ender = reg_node(pRExC_state, END);
2246             break;
2247         }
2248         regtail(pRExC_state, lastbr, ender);
2249
2250         if (have_branch) {
2251             /* Hook the tails of the branches to the closing node. */
2252             for (br = ret; br != NULL; br = regnext(br)) {
2253                 regoptail(pRExC_state, br, ender);
2254             }
2255         }
2256     }
2257
2258     {
2259         char *p;
2260         static char parens[] = "=!<,>";
2261
2262         if (paren && (p = strchr(parens, paren))) {
2263             int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2264             int flag = (p - parens) > 1;
2265
2266             if (paren == '>')
2267                 node = SUSPEND, flag = 0;
2268             reginsert(pRExC_state, node,ret);
2269             ret->flags = flag;
2270             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2271         }
2272     }
2273
2274     /* Check for proper termination. */
2275     if (paren) {
2276         RExC_flags16 = oregflags;
2277         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2278             RExC_parse = oregcomp_parse;
2279             vFAIL("Unmatched (");
2280         }
2281     }
2282     else if (!paren && RExC_parse < RExC_end) {
2283         if (*RExC_parse == ')') {
2284             RExC_parse++;
2285             vFAIL("Unmatched )");
2286         }
2287         else
2288             FAIL("Junk on end of regexp");      /* "Can't happen". */
2289         /* NOTREACHED */
2290     }
2291
2292     return(ret);
2293 }
2294
2295 /*
2296  - regbranch - one alternative of an | operator
2297  *
2298  * Implements the concatenation operator.
2299  */
2300 STATIC regnode *
2301 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2302 {
2303     dTHR;
2304     register regnode *ret;
2305     register regnode *chain = NULL;
2306     register regnode *latest;
2307     I32 flags = 0, c = 0;
2308
2309     if (first)
2310         ret = NULL;
2311     else {
2312         if (!SIZE_ONLY && RExC_extralen)
2313             ret = reganode(pRExC_state, BRANCHJ,0);
2314         else
2315             ret = reg_node(pRExC_state, BRANCH);
2316     }
2317
2318     if (!first && SIZE_ONLY)
2319         RExC_extralen += 1;                     /* BRANCHJ */
2320
2321     *flagp = WORST;                     /* Tentatively. */
2322
2323     RExC_parse--;
2324     nextchar(pRExC_state);
2325     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2326         flags &= ~TRYAGAIN;
2327         latest = regpiece(pRExC_state, &flags);
2328         if (latest == NULL) {
2329             if (flags & TRYAGAIN)
2330                 continue;
2331             return(NULL);
2332         }
2333         else if (ret == NULL)
2334             ret = latest;
2335         *flagp |= flags&HASWIDTH;
2336         if (chain == NULL)      /* First piece. */
2337             *flagp |= flags&SPSTART;
2338         else {
2339             RExC_naughty++;
2340             regtail(pRExC_state, chain, latest);
2341         }
2342         chain = latest;
2343         c++;
2344     }
2345     if (chain == NULL) {        /* Loop ran zero times. */
2346         chain = reg_node(pRExC_state, NOTHING);
2347         if (ret == NULL)
2348             ret = chain;
2349     }
2350     if (c == 1) {
2351         *flagp |= flags&SIMPLE;
2352     }
2353
2354     return(ret);
2355 }
2356
2357 /*
2358  - regpiece - something followed by possible [*+?]
2359  *
2360  * Note that the branching code sequences used for ? and the general cases
2361  * of * and + are somewhat optimized:  they use the same NOTHING node as
2362  * both the endmarker for their branch list and the body of the last branch.
2363  * It might seem that this node could be dispensed with entirely, but the
2364  * endmarker role is not redundant.
2365  */
2366 STATIC regnode *
2367 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2368 {
2369     dTHR;
2370     register regnode *ret;
2371     register char op;
2372     register char *next;
2373     I32 flags;
2374     char *origparse = RExC_parse;
2375     char *maxpos;
2376     I32 min;
2377     I32 max = REG_INFTY;
2378
2379     ret = regatom(pRExC_state, &flags);
2380     if (ret == NULL) {
2381         if (flags & TRYAGAIN)
2382             *flagp |= TRYAGAIN;
2383         return(NULL);
2384     }
2385
2386     op = *RExC_parse;
2387
2388     if (op == '{' && regcurly(RExC_parse)) {
2389         next = RExC_parse + 1;
2390         maxpos = Nullch;
2391         while (isDIGIT(*next) || *next == ',') {
2392             if (*next == ',') {
2393                 if (maxpos)
2394                     break;
2395                 else
2396                     maxpos = next;
2397             }
2398             next++;
2399         }
2400         if (*next == '}') {             /* got one */
2401             if (!maxpos)
2402                 maxpos = next;
2403             RExC_parse++;
2404             min = atoi(RExC_parse);
2405             if (*maxpos == ',')
2406                 maxpos++;
2407             else
2408                 maxpos = RExC_parse;
2409             max = atoi(maxpos);
2410             if (!max && *maxpos != '0')
2411                 max = REG_INFTY;                /* meaning "infinity" */
2412             else if (max >= REG_INFTY)
2413                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2414             RExC_parse = next;
2415             nextchar(pRExC_state);
2416
2417         do_curly:
2418             if ((flags&SIMPLE)) {
2419                 RExC_naughty += 2 + RExC_naughty / 2;
2420                 reginsert(pRExC_state, CURLY, ret);
2421             }
2422             else {
2423                 regnode *w = reg_node(pRExC_state, WHILEM);
2424
2425                 w->flags = 0;
2426                 regtail(pRExC_state, ret, w);
2427                 if (!SIZE_ONLY && RExC_extralen) {
2428                     reginsert(pRExC_state, LONGJMP,ret);
2429                     reginsert(pRExC_state, NOTHING,ret);
2430                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2431                 }
2432                 reginsert(pRExC_state, CURLYX,ret);
2433                 if (!SIZE_ONLY && RExC_extralen)
2434                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2435                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2436                 if (SIZE_ONLY)
2437                     RExC_whilem_seen++, RExC_extralen += 3;
2438                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2439             }
2440             ret->flags = 0;
2441
2442             if (min > 0)
2443                 *flagp = WORST;
2444             if (max > 0)
2445                 *flagp |= HASWIDTH;
2446             if (max && max < min)
2447                 vFAIL("Can't do {n,m} with n > m");
2448             if (!SIZE_ONLY) {
2449                 ARG1_SET(ret, min);
2450                 ARG2_SET(ret, max);
2451             }
2452
2453             goto nest_check;
2454         }
2455     }
2456
2457     if (!ISMULT1(op)) {
2458         *flagp = flags;
2459         return(ret);
2460     }
2461
2462 #if 0                           /* Now runtime fix should be reliable. */
2463
2464     /* if this is reinstated, don't forget to put this back into perldiag:
2465
2466             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2467
2468            (F) The part of the regexp subject to either the * or + quantifier
2469            could match an empty string. The {#} shows in the regular
2470            expression about where the problem was discovered.
2471
2472     */
2473
2474     if (!(flags&HASWIDTH) && op != '?')
2475       vFAIL("Regexp *+ operand could be empty");
2476 #endif
2477
2478     nextchar(pRExC_state);
2479
2480     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2481
2482     if (op == '*' && (flags&SIMPLE)) {
2483         reginsert(pRExC_state, STAR, ret);
2484         ret->flags = 0;
2485         RExC_naughty += 4;
2486     }
2487     else if (op == '*') {
2488         min = 0;
2489         goto do_curly;
2490     }
2491     else if (op == '+' && (flags&SIMPLE)) {
2492         reginsert(pRExC_state, PLUS, ret);
2493         ret->flags = 0;
2494         RExC_naughty += 3;
2495     }
2496     else if (op == '+') {
2497         min = 1;
2498         goto do_curly;
2499     }
2500     else if (op == '?') {
2501         min = 0; max = 1;
2502         goto do_curly;
2503     }
2504   nest_check:
2505     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2506         vWARN3(RExC_parse,
2507                "%.*s matches null string many times",
2508                RExC_parse - origparse,
2509                origparse);
2510     }
2511
2512     if (*RExC_parse == '?') {
2513         nextchar(pRExC_state);
2514         reginsert(pRExC_state, MINMOD, ret);
2515         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2516     }
2517     if (ISMULT2(RExC_parse)) {
2518         RExC_parse++;
2519         vFAIL("Nested quantifiers");
2520     }
2521
2522     return(ret);
2523 }
2524
2525 /*
2526  - regatom - the lowest level
2527  *
2528  * Optimization:  gobbles an entire sequence of ordinary characters so that
2529  * it can turn them into a single node, which is smaller to store and
2530  * faster to run.  Backslashed characters are exceptions, each becoming a
2531  * separate node; the code is simpler that way and it's not worth fixing.
2532  *
2533  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2534 STATIC regnode *
2535 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2536 {
2537     dTHR;
2538     register regnode *ret = 0;
2539     I32 flags;
2540
2541     *flagp = WORST;             /* Tentatively. */
2542
2543 tryagain:
2544     switch (*RExC_parse) {
2545     case '^':
2546         RExC_seen_zerolen++;
2547         nextchar(pRExC_state);
2548         if (RExC_flags16 & PMf_MULTILINE)
2549             ret = reg_node(pRExC_state, MBOL);
2550         else if (RExC_flags16 & PMf_SINGLELINE)
2551             ret = reg_node(pRExC_state, SBOL);
2552         else
2553             ret = reg_node(pRExC_state, BOL);
2554         break;
2555     case '$':
2556         nextchar(pRExC_state);
2557         if (*RExC_parse)
2558             RExC_seen_zerolen++;
2559         if (RExC_flags16 & PMf_MULTILINE)
2560             ret = reg_node(pRExC_state, MEOL);
2561         else if (RExC_flags16 & PMf_SINGLELINE)
2562             ret = reg_node(pRExC_state, SEOL);
2563         else
2564             ret = reg_node(pRExC_state, EOL);
2565         break;
2566     case '.':
2567         nextchar(pRExC_state);
2568         if (UTF) {
2569             if (RExC_flags16 & PMf_SINGLELINE)
2570                 ret = reg_node(pRExC_state, SANYUTF8);
2571             else
2572                 ret = reg_node(pRExC_state, ANYUTF8);
2573             *flagp |= HASWIDTH;
2574         }
2575         else {
2576             if (RExC_flags16 & PMf_SINGLELINE)
2577                 ret = reg_node(pRExC_state, SANY);
2578             else
2579                 ret = reg_node(pRExC_state, REG_ANY);
2580             *flagp |= HASWIDTH|SIMPLE;
2581         }
2582         RExC_naughty++;
2583         break;
2584     case '[':
2585     {
2586         char *oregcomp_parse = ++RExC_parse;
2587         ret = (UTF ? regclassutf8(pRExC_state) : regclass(pRExC_state));
2588         if (*RExC_parse != ']') {
2589             RExC_parse = oregcomp_parse;
2590             vFAIL("Unmatched [");
2591         }
2592         nextchar(pRExC_state);
2593         *flagp |= HASWIDTH|SIMPLE;
2594         break;
2595     }
2596     case '(':
2597         nextchar(pRExC_state);
2598         ret = reg(pRExC_state, 1, &flags);
2599         if (ret == NULL) {
2600                 if (flags & TRYAGAIN) {
2601                     if (RExC_parse == RExC_end) {
2602                          /* Make parent create an empty node if needed. */
2603                         *flagp |= TRYAGAIN;
2604                         return(NULL);
2605                     }
2606                     goto tryagain;
2607                 }
2608                 return(NULL);
2609         }
2610         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2611         break;
2612     case '|':
2613     case ')':
2614         if (flags & TRYAGAIN) {
2615             *flagp |= TRYAGAIN;
2616             return NULL;
2617         }
2618         vFAIL("Internal urp");
2619                                 /* Supposed to be caught earlier. */
2620         break;
2621     case '{':
2622         if (!regcurly(RExC_parse)) {
2623             RExC_parse++;
2624             goto defchar;
2625         }
2626         /* FALL THROUGH */
2627     case '?':
2628     case '+':
2629     case '*':
2630         RExC_parse++;
2631         vFAIL("Quantifier follows nothing");
2632         break;
2633     case '\\':
2634         switch (*++RExC_parse) {
2635         case 'A':
2636             RExC_seen_zerolen++;
2637             ret = reg_node(pRExC_state, SBOL);
2638             *flagp |= SIMPLE;
2639             nextchar(pRExC_state);
2640             break;
2641         case 'G':
2642             ret = reg_node(pRExC_state, GPOS);
2643             RExC_seen |= REG_SEEN_GPOS;
2644             *flagp |= SIMPLE;
2645             nextchar(pRExC_state);
2646             break;
2647         case 'Z':
2648             ret = reg_node(pRExC_state, SEOL);
2649             *flagp |= SIMPLE;
2650             nextchar(pRExC_state);
2651             break;
2652         case 'z':
2653             ret = reg_node(pRExC_state, EOS);
2654             *flagp |= SIMPLE;
2655             RExC_seen_zerolen++;                /* Do not optimize RE away */
2656             nextchar(pRExC_state);
2657             break;
2658         case 'C':
2659             ret = reg_node(pRExC_state, SANY);
2660             *flagp |= HASWIDTH|SIMPLE;
2661             nextchar(pRExC_state);
2662             break;
2663         case 'X':
2664             ret = reg_node(pRExC_state, CLUMP);
2665             *flagp |= HASWIDTH;
2666             nextchar(pRExC_state);
2667             if (UTF && !PL_utf8_mark)
2668                 is_utf8_mark((U8*)"~");         /* preload table */
2669             break;
2670         case 'w':
2671             ret = reg_node(pRExC_state,
2672                 UTF
2673                     ? (LOC ? ALNUMLUTF8 : ALNUMUTF8)
2674                     : (LOC ? ALNUML     : ALNUM));
2675             *flagp |= HASWIDTH|SIMPLE;
2676             nextchar(pRExC_state);
2677             if (UTF && !PL_utf8_alnum)
2678                 is_utf8_alnum((U8*)"a");        /* preload table */
2679             break;
2680         case 'W':
2681             ret = reg_node(pRExC_state,
2682                 UTF
2683                     ? (LOC ? NALNUMLUTF8 : NALNUMUTF8)
2684                     : (LOC ? NALNUML     : NALNUM));
2685             *flagp |= HASWIDTH|SIMPLE;
2686             nextchar(pRExC_state);
2687             if (UTF && !PL_utf8_alnum)
2688                 is_utf8_alnum((U8*)"a");        /* preload table */
2689             break;
2690         case 'b':
2691             RExC_seen_zerolen++;
2692             RExC_seen |= REG_SEEN_LOOKBEHIND;
2693             ret = reg_node(pRExC_state,
2694                 UTF
2695                     ? (LOC ? BOUNDLUTF8 : BOUNDUTF8)
2696                     : (LOC ? BOUNDL     : BOUND));
2697             *flagp |= SIMPLE;
2698             nextchar(pRExC_state);
2699             if (UTF && !PL_utf8_alnum)
2700                 is_utf8_alnum((U8*)"a");        /* preload table */
2701             break;
2702         case 'B':
2703             RExC_seen_zerolen++;
2704             RExC_seen |= REG_SEEN_LOOKBEHIND;
2705             ret = reg_node(pRExC_state,
2706                 UTF
2707                     ? (LOC ? NBOUNDLUTF8 : NBOUNDUTF8)
2708                     : (LOC ? NBOUNDL     : NBOUND));
2709             *flagp |= SIMPLE;
2710             nextchar(pRExC_state);
2711             if (UTF && !PL_utf8_alnum)
2712                 is_utf8_alnum((U8*)"a");        /* preload table */
2713             break;
2714         case 's':
2715             ret = reg_node(pRExC_state,
2716                 UTF
2717                     ? (LOC ? SPACELUTF8 : SPACEUTF8)
2718                     : (LOC ? SPACEL     : SPACE));
2719             *flagp |= HASWIDTH|SIMPLE;
2720             nextchar(pRExC_state);
2721             if (UTF && !PL_utf8_space)
2722                 is_utf8_space((U8*)" ");        /* preload table */
2723             break;
2724         case 'S':
2725             ret = reg_node(pRExC_state,
2726                 UTF
2727                     ? (LOC ? NSPACELUTF8 : NSPACEUTF8)
2728                     : (LOC ? NSPACEL     : NSPACE));
2729             *flagp |= HASWIDTH|SIMPLE;
2730             nextchar(pRExC_state);
2731             if (UTF && !PL_utf8_space)
2732                 is_utf8_space((U8*)" ");        /* preload table */
2733             break;
2734         case 'd':
2735             ret = reg_node(pRExC_state, UTF ? DIGITUTF8 : DIGIT);
2736             *flagp |= HASWIDTH|SIMPLE;
2737             nextchar(pRExC_state);
2738             if (UTF && !PL_utf8_digit)
2739                 is_utf8_digit((U8*)"1");        /* preload table */
2740             break;
2741         case 'D':
2742             ret = reg_node(pRExC_state, UTF ? NDIGITUTF8 : NDIGIT);
2743             *flagp |= HASWIDTH|SIMPLE;
2744             nextchar(pRExC_state);
2745             if (UTF && !PL_utf8_digit)
2746                 is_utf8_digit((U8*)"1");        /* preload table */
2747             break;
2748         case 'p':
2749         case 'P':
2750             {   /* a lovely hack--pretend we saw [\pX] instead */
2751                 char* oldregxend = RExC_end;
2752
2753                 if (RExC_parse[1] == '{') {
2754                     RExC_end = strchr(RExC_parse, '}');
2755                     if (!RExC_end) {
2756                         RExC_parse += 2;
2757                         RExC_end = oldregxend;
2758                         vFAIL("Missing right brace on \\p{}");
2759                     }
2760                     RExC_end++;
2761                 }
2762                 else
2763                     RExC_end = RExC_parse + 2;
2764                 RExC_parse--;
2765
2766                 ret = regclassutf8(pRExC_state);
2767
2768                 RExC_end = oldregxend;
2769                 RExC_parse--;
2770                 nextchar(pRExC_state);
2771                 *flagp |= HASWIDTH|SIMPLE;
2772             }
2773             break;
2774         case 'n':
2775         case 'r':
2776         case 't':
2777         case 'f':
2778         case 'e':
2779         case 'a':
2780         case 'x':
2781         case 'c':
2782         case '0':
2783             goto defchar;
2784         case '1': case '2': case '3': case '4':
2785         case '5': case '6': case '7': case '8': case '9':
2786             {
2787                 I32 num = atoi(RExC_parse);
2788
2789                 if (num > 9 && num >= RExC_npar)
2790                     goto defchar;
2791                 else {
2792                     while (isDIGIT(*RExC_parse))
2793                         RExC_parse++;
2794
2795                     if (!SIZE_ONLY && num > RExC_rx->nparens)
2796                         vFAIL("Reference to nonexistent group");
2797                     RExC_sawback = 1;
2798                     ret = reganode(pRExC_state, FOLD
2799                                    ? (LOC ? REFFL : REFF)
2800                                    : REF, num);
2801                     *flagp |= HASWIDTH;
2802                     RExC_parse--;
2803                     nextchar(pRExC_state);
2804                 }
2805             }
2806             break;
2807         case '\0':
2808             if (RExC_parse >= RExC_end)
2809                 FAIL("Trailing \\");
2810             /* FALL THROUGH */
2811         default:
2812             /* Do not generate `unrecognized' warnings here, we fall
2813                back into the quick-grab loop below */
2814             goto defchar;
2815         }
2816         break;
2817
2818     case '#':
2819         if (RExC_flags16 & PMf_EXTENDED) {
2820             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
2821             if (RExC_parse < RExC_end)
2822                 goto tryagain;
2823         }
2824         /* FALL THROUGH */
2825
2826     default: {
2827             register STRLEN len;
2828             register UV ender;
2829             register char *p;
2830             char *oldp, *s;
2831             STRLEN numlen;
2832
2833             RExC_parse++;
2834
2835         defchar:
2836             ret = reg_node(pRExC_state, FOLD
2837                           ? (LOC ? EXACTFL : EXACTF)
2838                           : EXACT);
2839             s = STRING(ret);
2840             for (len = 0, p = RExC_parse - 1;
2841               len < 127 && p < RExC_end;
2842               len++)
2843             {
2844                 oldp = p;
2845
2846                 if (RExC_flags16 & PMf_EXTENDED)
2847                     p = regwhite(p, RExC_end);
2848                 switch (*p) {
2849                 case '^':
2850                 case '$':
2851                 case '.':
2852                 case '[':
2853                 case '(':
2854                 case ')':
2855                 case '|':
2856                     goto loopdone;
2857                 case '\\':
2858                     switch (*++p) {
2859                     case 'A':
2860                     case 'G':
2861                     case 'Z':
2862                     case 'z':
2863                     case 'w':
2864                     case 'W':
2865                     case 'b':
2866                     case 'B':
2867                     case 's':
2868                     case 'S':
2869                     case 'd':
2870                     case 'D':
2871                     case 'p':
2872                     case 'P':
2873                         --p;
2874                         goto loopdone;
2875                     case 'n':
2876                         ender = '\n';
2877                         p++;
2878                         break;
2879                     case 'r':
2880                         ender = '\r';
2881                         p++;
2882                         break;
2883                     case 't':
2884                         ender = '\t';
2885                         p++;
2886                         break;
2887                     case 'f':
2888                         ender = '\f';
2889                         p++;
2890                         break;
2891                     case 'e':
2892 #ifdef ASCIIish
2893                           ender = '\033';
2894 #else
2895                           ender = '\047';
2896 #endif
2897                         p++;
2898                         break;
2899                     case 'a':
2900 #ifdef ASCIIish
2901                           ender = '\007';
2902 #else
2903                           ender = '\057';
2904 #endif
2905                         p++;
2906                         break;
2907                     case 'x':
2908                         if (*++p == '{') {
2909                             char* e = strchr(p, '}');
2910
2911                             if (!e) {
2912                                 RExC_parse = p + 1;
2913                                 vFAIL("Missing right brace on \\x{}");
2914                             }
2915                             else {
2916                                 numlen = 1;     /* allow underscores */
2917                                 ender = (UV)scan_hex(p + 1, e - p - 1, &numlen);
2918                                 /* numlen is generous */
2919                                 if (numlen + len >= 127) {
2920                                     p--;
2921                                     goto loopdone;
2922                                 }
2923                                 p = e + 1;
2924                             }
2925                         }
2926                         else {
2927                             numlen = 0;         /* disallow underscores */
2928                             ender = (UV)scan_hex(p, 2, &numlen);
2929                             p += numlen;
2930                         }
2931                         break;
2932                     case 'c':
2933                         p++;
2934                         ender = UCHARAT(p++);
2935                         ender = toCTRL(ender);
2936                         break;
2937                     case '0': case '1': case '2': case '3':case '4':
2938                     case '5': case '6': case '7': case '8':case '9':
2939                         if (*p == '0' ||
2940                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
2941                             numlen = 0;         /* disallow underscores */
2942                             ender = (UV)scan_oct(p, 3, &numlen);
2943                             p += numlen;
2944                         }
2945                         else {
2946                             --p;
2947                             goto loopdone;
2948                         }
2949                         break;
2950                     case '\0':
2951                         if (p >= RExC_end)
2952                             FAIL("Trailing \\");
2953                         /* FALL THROUGH */
2954                     default:
2955                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
2956                             vWARN2(p +1, "Unrecognized escape \\%c passed through", *p);
2957                         goto normal_default;
2958                     }
2959                     break;
2960                 default:
2961                   normal_default:
2962                     if ((*p & 0xc0) == 0xc0 && UTF) {
2963                         ender = utf8_to_uv((U8*)p, RExC_end - p,
2964                                                &numlen, 0);
2965                         p += numlen;
2966                     }
2967                     else
2968                         ender = *p++;
2969                     break;
2970                 }
2971                 if (RExC_flags16 & PMf_EXTENDED)
2972                     p = regwhite(p, RExC_end);
2973                 if (UTF && FOLD) {
2974                     if (LOC)
2975                         ender = toLOWER_LC_uni(ender);
2976                     else
2977                         ender = toLOWER_uni(ender);
2978                 }
2979                 if (ISMULT2(p)) { /* Back off on ?+*. */
2980                     if (len)
2981                         p = oldp;
2982                     else if (ender >= 0x80 && UTF) {
2983                         reguni(pRExC_state, ender, s, &numlen);
2984                         s += numlen;
2985                         len += numlen;
2986                     }
2987                     else {
2988                         len++;
2989                         REGC(ender, s++);
2990                     }
2991                     break;
2992                 }
2993                 if (ender >= 0x80 && UTF) {
2994                     reguni(pRExC_state, ender, s, &numlen);
2995                     s += numlen;
2996                     len += numlen - 1;
2997                 }
2998                 else
2999                     REGC(ender, s++);
3000             }
3001         loopdone:
3002             RExC_parse = p - 1;
3003             nextchar(pRExC_state);
3004             {
3005                 /* len is STRLEN which is unsigned, need to copy to signed */
3006                 IV iv = len;
3007                 if (iv < 0)
3008                     vFAIL("Internal disaster");
3009             }
3010             if (len > 0)
3011                 *flagp |= HASWIDTH;
3012             if (len == 1)
3013                 *flagp |= SIMPLE;
3014             if (!SIZE_ONLY)
3015                 STR_LEN(ret) = len;
3016             if (SIZE_ONLY)
3017                 RExC_size += STR_SZ(len);
3018             else
3019                 RExC_emit += STR_SZ(len);
3020         }
3021         break;
3022     }
3023
3024     return(ret);
3025 }
3026
3027 STATIC char *
3028 S_regwhite(pTHX_ char *p, char *e)
3029 {
3030     while (p < e) {
3031         if (isSPACE(*p))
3032             ++p;
3033         else if (*p == '#') {
3034             do {
3035                 p++;
3036             } while (p < e && *p != '\n');
3037         }
3038         else
3039             break;
3040     }
3041     return p;
3042 }
3043
3044 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3045    Character classes ([:foo:]) can also be negated ([:^foo:]).
3046    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3047    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3048    but trigger warnings because they are currently unimplemented. */
3049 STATIC I32
3050 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3051 {
3052     dTHR;
3053     char *posixcc = 0;
3054     I32 namedclass = OOB_NAMEDCLASS;
3055
3056     if (value == '[' && RExC_parse + 1 < RExC_end &&
3057         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3058         (*RExC_parse == ':' ||
3059          *RExC_parse == '=' ||
3060          *RExC_parse == '.')) {
3061         char  c = *RExC_parse;
3062         char* s = RExC_parse++;
3063
3064         while (RExC_parse < RExC_end && *RExC_parse != c)
3065             RExC_parse++;
3066         if (RExC_parse == RExC_end)
3067             /* Grandfather lone [:, [=, [. */
3068             RExC_parse = s;
3069         else {
3070             char* t = RExC_parse++; /* skip over the c */
3071
3072             if (*RExC_parse == ']') {
3073                 RExC_parse++; /* skip over the ending ] */
3074                 posixcc = s + 1;
3075                 if (*s == ':') {
3076                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3077                     I32 skip = 5; /* the most common skip */
3078
3079                     switch (*posixcc) {
3080                     case 'a':
3081                         if (strnEQ(posixcc, "alnum", 5))
3082                             namedclass =
3083                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3084                         else if (strnEQ(posixcc, "alpha", 5))
3085                             namedclass =
3086                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3087                         else if (strnEQ(posixcc, "ascii", 5))
3088                             namedclass =
3089                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3090                         break;
3091                     case 'b':
3092                         if (strnEQ(posixcc, "blank", 5))
3093                             namedclass =
3094                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3095                         break;
3096                     case 'c':
3097                         if (strnEQ(posixcc, "cntrl", 5))
3098                             namedclass =
3099                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3100                         break;
3101                     case 'd':
3102                         if (strnEQ(posixcc, "digit", 5))
3103                             namedclass =
3104                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3105                         break;
3106                     case 'g':
3107                         if (strnEQ(posixcc, "graph", 5))
3108                             namedclass =
3109                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3110                         break;
3111                     case 'l':
3112                         if (strnEQ(posixcc, "lower", 5))
3113                             namedclass =
3114                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3115                         break;
3116                     case 'p':
3117                         if (strnEQ(posixcc, "print", 5))
3118                             namedclass =
3119                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3120                         else if (strnEQ(posixcc, "punct", 5))
3121                             namedclass =
3122                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3123                         break;
3124                     case 's':
3125                         if (strnEQ(posixcc, "space", 5))
3126                             namedclass =
3127                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3128                         break;
3129                     case 'u':
3130                         if (strnEQ(posixcc, "upper", 5))
3131                             namedclass =
3132                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3133                         break;
3134                     case 'w': /* this is not POSIX, this is the Perl \w */
3135                         if (strnEQ(posixcc, "word", 4)) {
3136                             namedclass =
3137                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3138                             skip = 4;
3139                         }
3140                         break;
3141                     case 'x':
3142                         if (strnEQ(posixcc, "xdigit", 6)) {
3143                             namedclass =
3144                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3145                             skip = 6;
3146                         }
3147                         break;
3148                     }
3149                     if (namedclass == OOB_NAMEDCLASS ||
3150                         posixcc[skip] != ':' ||
3151                         posixcc[skip+1] != ']')
3152                     {
3153                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3154                                       t - s - 1, s + 1);
3155                     }
3156                 } else if (!SIZE_ONLY) {
3157                     /* [[=foo=]] and [[.foo.]] are still future. */
3158
3159                     /* adjust RExC_parse so the warning shows after
3160                        the class closes */
3161                     while (*RExC_parse && *RExC_parse != ']')
3162                         RExC_parse++;
3163                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3164                 }
3165             } else {
3166                 /* Maternal grandfather:
3167                  * "[:" ending in ":" but not in ":]" */
3168                 RExC_parse = s;
3169             }
3170         }
3171     }
3172
3173     return namedclass;
3174 }
3175
3176 STATIC void
3177 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3178 {
3179     if (!SIZE_ONLY && ckWARN(WARN_REGEXP) &&
3180         (*RExC_parse == ':' ||
3181          *RExC_parse == '=' ||
3182          *RExC_parse == '.')) {
3183         char *s = RExC_parse;
3184         char  c = *s++;
3185
3186         while(*s && isALNUM(*s))
3187             s++;
3188         if (*s && c == *s && s[1] == ']') {
3189             vWARN3(s+2, "POSIX syntax [%c %c] belongs inside character classes", c, c);
3190
3191             /* [[=foo=]] and [[.foo.]] are still future. */
3192             if (c == '=' || c == '.')
3193             {
3194                 /* adjust RExC_parse so the error shows after
3195                    the class closes */
3196                 while (*RExC_parse && *RExC_parse++ != ']')
3197                     ;
3198                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3199             }
3200         }
3201     }
3202 }
3203
3204 STATIC regnode *
3205 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3206 {
3207     dTHR;
3208     register U32 value;
3209     register I32 lastvalue = OOB_CHAR8;
3210     register I32 range = 0;
3211     register regnode *ret;
3212     STRLEN numlen;
3213     I32 namedclass;
3214     char *rangebegin;
3215     bool need_class = 0;
3216
3217     ret = reg_node(pRExC_state, ANYOF);
3218     if (SIZE_ONLY)
3219         RExC_size += ANYOF_SKIP;
3220     else {
3221         ret->flags = 0;
3222         ANYOF_BITMAP_ZERO(ret);
3223         RExC_emit += ANYOF_SKIP;
3224         if (FOLD)
3225             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3226         if (LOC)
3227             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3228     }
3229     if (*RExC_parse == '^') {   /* Complement of range. */
3230         RExC_naughty++;
3231         RExC_parse++;
3232         if (!SIZE_ONLY)
3233             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3234     }
3235
3236     if (!SIZE_ONLY && ckWARN(WARN_REGEXP))
3237         checkposixcc(pRExC_state);
3238
3239     if (*RExC_parse == ']' || *RExC_parse == '-')
3240         goto skipcond;          /* allow 1st char to be ] or - */
3241     while (RExC_parse < RExC_end && *RExC_parse != ']') {
3242        skipcond:
3243         namedclass = OOB_NAMEDCLASS;
3244         if (!range)
3245             rangebegin = RExC_parse;
3246         value = UCHARAT(RExC_parse++);
3247         if (value == '[')
3248             namedclass = regpposixcc(pRExC_state, value);
3249         else if (value == '\\') {
3250             value = UCHARAT(RExC_parse++);
3251             /* Some compilers cannot handle switching on 64-bit integer
3252              * values, therefore the 'value' cannot be an UV. --jhi */
3253             switch (value) {
3254             case 'w':   namedclass = ANYOF_ALNUM;       break;
3255             case 'W':   namedclass = ANYOF_NALNUM;      break;
3256             case 's':   namedclass = ANYOF_SPACE;       break;
3257             case 'S':   namedclass = ANYOF_NSPACE;      break;
3258             case 'd':   namedclass = ANYOF_DIGIT;       break;
3259             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3260             case 'n':   value = '\n';                   break;
3261             case 'r':   value = '\r';                   break;
3262             case 't':   value = '\t';                   break;
3263             case 'f':   value = '\f';                   break;
3264             case 'b':   value = '\b';                   break;
3265 #ifdef ASCIIish
3266             case 'e':   value = '\033';                 break;
3267             case 'a':   value = '\007';                 break;
3268 #else
3269             case 'e':   value = '\047';                 break;
3270             case 'a':   value = '\057';                 break;
3271 #endif
3272             case 'x':
3273                 numlen = 0;             /* disallow underscores */
3274                 value = (UV)scan_hex(RExC_parse, 2, &numlen);
3275                 RExC_parse += numlen;
3276                 break;
3277             case 'c':
3278                 value = UCHARAT(RExC_parse++);
3279                 value = toCTRL(value);
3280                 break;
3281             case '0': case '1': case '2': case '3': case '4':
3282             case '5': case '6': case '7': case '8': case '9':
3283                 numlen = 0;             /* disallow underscores */
3284                 value = (UV)scan_oct(--RExC_parse, 3, &numlen);
3285                 RExC_parse += numlen;
3286                 break;
3287             default:
3288                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3289
3290                     vWARN2(RExC_parse, "Unrecognized escape \\%c in character class passed through", (int)value);
3291                 break;
3292             }
3293         }
3294         if (namedclass > OOB_NAMEDCLASS) {
3295             if (!need_class && !SIZE_ONLY)
3296                 ANYOF_CLASS_ZERO(ret);
3297             need_class = 1;
3298             if (range) { /* a-\d, a-[:digit:] */
3299                 if (!SIZE_ONLY) {
3300                     if (ckWARN(WARN_REGEXP))
3301                         vWARN4(RExC_parse,
3302                                "False [] range \"%*.*s\"",
3303                                RExC_parse - rangebegin,
3304                                RExC_parse - rangebegin,
3305                                rangebegin);
3306                     ANYOF_BITMAP_SET(ret, lastvalue);
3307                     ANYOF_BITMAP_SET(ret, '-');
3308                 }
3309                 range = 0; /* this is not a true range */
3310             }
3311             if (!SIZE_ONLY) {
3312                 switch (namedclass) {
3313                 case ANYOF_ALNUM:
3314                     if (LOC)
3315                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3316                     else {
3317                         for (value = 0; value < 256; value++)
3318                             if (isALNUM(value))
3319                                 ANYOF_BITMAP_SET(ret, value);
3320                     }
3321                     break;
3322                 case ANYOF_NALNUM:
3323                     if (LOC)
3324                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3325                     else {
3326                         for (value = 0; value < 256; value++)
3327                             if (!isALNUM(value))
3328                                 ANYOF_BITMAP_SET(ret, value);
3329                     }
3330                     break;
3331                 case ANYOF_SPACE:
3332                     if (LOC)
3333                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
3334                     else {
3335                         for (value = 0; value < 256; value++)
3336                             if (isSPACE(value))
3337                                 ANYOF_BITMAP_SET(ret, value);
3338                     }
3339                     break;
3340                 case ANYOF_NSPACE:
3341                     if (LOC)
3342                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
3343                     else {
3344                         for (value = 0; value < 256; value++)
3345                             if (!isSPACE(value))
3346                                 ANYOF_BITMAP_SET(ret, value);
3347                     }
3348                     break;
3349                 case ANYOF_DIGIT:
3350                     if (LOC)
3351                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3352                     else {
3353                         for (value = '0'; value <= '9'; value++)
3354                             ANYOF_BITMAP_SET(ret, value);
3355                     }
3356                     break;
3357                 case ANYOF_NDIGIT:
3358                     if (LOC)
3359                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3360                     else {
3361                         for (value = 0; value < '0'; value++)
3362                             ANYOF_BITMAP_SET(ret, value);
3363                         for (value = '9' + 1; value < 256; value++)
3364                             ANYOF_BITMAP_SET(ret, value);
3365                     }
3366                     break;
3367                 case ANYOF_NALNUMC:
3368                     if (LOC)
3369                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3370                     else {
3371                         for (value = 0; value < 256; value++)
3372                             if (!isALNUMC(value))
3373                                 ANYOF_BITMAP_SET(ret, value);
3374                     }
3375                     break;
3376                 case ANYOF_ALNUMC:
3377                     if (LOC)
3378                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3379                     else {
3380                         for (value = 0; value < 256; value++)
3381                             if (isALNUMC(value))
3382                                 ANYOF_BITMAP_SET(ret, value);
3383                     }
3384                     break;
3385                 case ANYOF_ALPHA:
3386                     if (LOC)
3387                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3388                     else {
3389                         for (value = 0; value < 256; value++)
3390                             if (isALPHA(value))
3391                                 ANYOF_BITMAP_SET(ret, value);
3392                     }
3393                     break;
3394                 case ANYOF_NALPHA:
3395                     if (LOC)
3396                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3397                     else {
3398                         for (value = 0; value < 256; value++)
3399                             if (!isALPHA(value))
3400                                 ANYOF_BITMAP_SET(ret, value);
3401                     }
3402                     break;
3403                 case ANYOF_ASCII:
3404                     if (LOC)
3405                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3406                     else {
3407 #ifdef ASCIIish
3408                         for (value = 0; value < 128; value++)
3409                             ANYOF_BITMAP_SET(ret, value);
3410 #else  /* EBCDIC */
3411                         for (value = 0; value < 256; value++)
3412                             if (isASCII(value))
3413                                 ANYOF_BITMAP_SET(ret, value);
3414 #endif /* EBCDIC */
3415                     }
3416                     break;
3417                 case ANYOF_NASCII:
3418                     if (LOC)
3419                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3420                     else {
3421 #ifdef ASCIIish
3422                         for (value = 128; value < 256; value++)
3423                             ANYOF_BITMAP_SET(ret, value);
3424 #else  /* EBCDIC */
3425                         for (value = 0; value < 256; value++)
3426                             if (!isASCII(value))
3427                                 ANYOF_BITMAP_SET(ret, value);
3428 #endif /* EBCDIC */
3429                     }
3430                     break;
3431                 case ANYOF_BLANK:
3432                     if (LOC)
3433                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3434                     else {
3435                         for (value = 0; value < 256; value++)
3436                             if (isBLANK(value))
3437                                 ANYOF_BITMAP_SET(ret, value);
3438                     }
3439                     break;
3440                 case ANYOF_NBLANK:
3441                     if (LOC)
3442                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3443                     else {
3444                         for (value = 0; value < 256; value++)
3445                             if (!isBLANK(value))
3446                                 ANYOF_BITMAP_SET(ret, value);
3447                     }
3448                     break;
3449                 case ANYOF_CNTRL:
3450                     if (LOC)
3451                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3452                     else {
3453                         for (value = 0; value < 256; value++)
3454                             if (isCNTRL(value))
3455                                 ANYOF_BITMAP_SET(ret, value);
3456                     }
3457                     lastvalue = OOB_CHAR8;
3458                     break;
3459                 case ANYOF_NCNTRL:
3460                     if (LOC)
3461                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3462                     else {
3463                         for (value = 0; value < 256; value++)
3464                             if (!isCNTRL(value))
3465                                 ANYOF_BITMAP_SET(ret, value);
3466                     }
3467                     break;
3468                 case ANYOF_GRAPH:
3469                     if (LOC)
3470                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3471                     else {
3472                         for (value = 0; value < 256; value++)
3473                             if (isGRAPH(value))
3474                                 ANYOF_BITMAP_SET(ret, value);
3475                     }
3476                     break;
3477                 case ANYOF_NGRAPH:
3478                     if (LOC)
3479                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3480                     else {
3481                         for (value = 0; value < 256; value++)
3482                             if (!isGRAPH(value))
3483                                 ANYOF_BITMAP_SET(ret, value);
3484                     }
3485                     break;
3486                 case ANYOF_LOWER:
3487                     if (LOC)
3488                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3489                     else {
3490                         for (value = 0; value < 256; value++)
3491                             if (isLOWER(value))
3492                                 ANYOF_BITMAP_SET(ret, value);
3493                     }
3494                     break;
3495                 case ANYOF_NLOWER:
3496                     if (LOC)
3497                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3498                     else {
3499                         for (value = 0; value < 256; value++)
3500                             if (!isLOWER(value))
3501                                 ANYOF_BITMAP_SET(ret, value);
3502                     }
3503                     break;
3504                 case ANYOF_PRINT:
3505                     if (LOC)
3506                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3507                     else {
3508                         for (value = 0; value < 256; value++)
3509                             if (isPRINT(value))
3510                                 ANYOF_BITMAP_SET(ret, value);
3511                     }
3512                     break;
3513                 case ANYOF_NPRINT:
3514                     if (LOC)
3515                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3516                     else {
3517                         for (value = 0; value < 256; value++)
3518                             if (!isPRINT(value))
3519                                 ANYOF_BITMAP_SET(ret, value);
3520                     }
3521                     break;
3522                 case ANYOF_PSXSPC:
3523                     if (LOC)
3524                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3525                     else {
3526                         for (value = 0; value < 256; value++)
3527                             if (isPSXSPC(value))
3528                                 ANYOF_BITMAP_SET(ret, value);
3529                     }
3530                     break;
3531                 case ANYOF_NPSXSPC:
3532                     if (LOC)
3533                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3534                     else {
3535                         for (value = 0; value < 256; value++)
3536                             if (!isPSXSPC(value))
3537                                 ANYOF_BITMAP_SET(ret, value);
3538                     }
3539                     break;
3540                 case ANYOF_PUNCT:
3541                     if (LOC)
3542                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3543                     else {
3544                         for (value = 0; value < 256; value++)
3545                             if (isPUNCT(value))
3546                                 ANYOF_BITMAP_SET(ret, value);
3547                     }
3548                     break;
3549                 case ANYOF_NPUNCT:
3550                     if (LOC)
3551                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3552                     else {
3553                         for (value = 0; value < 256; value++)
3554                             if (!isPUNCT(value))
3555                                 ANYOF_BITMAP_SET(ret, value);
3556                     }
3557                     break;
3558                 case ANYOF_UPPER:
3559                     if (LOC)
3560                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
3561                     else {
3562                         for (value = 0; value < 256; value++)
3563                             if (isUPPER(value))
3564                                 ANYOF_BITMAP_SET(ret, value);
3565                     }
3566                     break;
3567                 case ANYOF_NUPPER:
3568                     if (LOC)
3569                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
3570                     else {
3571                         for (value = 0; value < 256; value++)
3572                             if (!isUPPER(value))
3573                                 ANYOF_BITMAP_SET(ret, value);
3574                     }
3575                     break;
3576                 case ANYOF_XDIGIT:
3577                     if (LOC)
3578                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
3579                     else {
3580                         for (value = 0; value < 256; value++)
3581                             if (isXDIGIT(value))
3582                                 ANYOF_BITMAP_SET(ret, value);
3583                     }
3584                     break;
3585                 case ANYOF_NXDIGIT:
3586                     if (LOC)
3587                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
3588                     else {
3589                         for (value = 0; value < 256; value++)
3590                             if (!isXDIGIT(value))
3591                                 ANYOF_BITMAP_SET(ret, value);
3592                     }
3593                     break;
3594                 default:
3595                     vFAIL("Invalid [::] class");
3596                     break;
3597                 }
3598                 if (LOC)
3599                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
3600                 continue;
3601             }
3602         }
3603         if (range) {
3604             if (lastvalue > value) /* b-a */ {
3605                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3606                               RExC_parse - rangebegin,
3607                               RExC_parse - rangebegin,
3608                               rangebegin);
3609             }
3610             range = 0;
3611         }
3612         else {
3613             lastvalue = value;
3614             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
3615                 RExC_parse[1] != ']') {
3616                 RExC_parse++;
3617                 if (namedclass > OOB_NAMEDCLASS) { /* \w-, [:word:]- */
3618                     if (ckWARN(WARN_REGEXP))
3619                         vWARN4(RExC_parse,
3620                                "False [] range \"%*.*s\"",
3621                                RExC_parse - rangebegin,
3622                                RExC_parse - rangebegin,
3623                                rangebegin);
3624                     if (!SIZE_ONLY)
3625                         ANYOF_BITMAP_SET(ret, '-');
3626                 } else
3627                     range = 1;
3628                 continue;       /* do it next time */
3629             }
3630         }
3631         /* now is the next time */
3632         if (!SIZE_ONLY) {
3633 #ifndef ASCIIish /* EBCDIC, for example. */
3634             if ((isLOWER(lastvalue) && isLOWER(value)) ||
3635                 (isUPPER(lastvalue) && isUPPER(value)))
3636             {
3637                 I32 i;
3638                 if (isLOWER(lastvalue)) {
3639                     for (i = lastvalue; i <= value; i++)
3640                         if (isLOWER(i))
3641                             ANYOF_BITMAP_SET(ret, i);
3642                 } else {
3643                     for (i = lastvalue; i <= value; i++)
3644                         if (isUPPER(i))
3645                             ANYOF_BITMAP_SET(ret, i);
3646                 }
3647             }
3648             else
3649 #endif
3650                 for ( ; lastvalue <= value; lastvalue++)
3651                     ANYOF_BITMAP_SET(ret, lastvalue);
3652         }
3653         range = 0;
3654     }
3655     if (need_class) {
3656         if (SIZE_ONLY)
3657             RExC_size += ANYOF_CLASS_ADD_SKIP;
3658         else
3659             RExC_emit += ANYOF_CLASS_ADD_SKIP;
3660     }
3661     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
3662     if (!SIZE_ONLY &&
3663         (ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD) {
3664         for (value = 0; value < 256; ++value) {
3665             if (ANYOF_BITMAP_TEST(ret, value)) {
3666                 I32 cf = PL_fold[value];
3667                 ANYOF_BITMAP_SET(ret, cf);
3668             }
3669         }
3670         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
3671     }
3672     /* optimize inverted simple patterns (e.g. [^a-z]) */
3673     if (!SIZE_ONLY && (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
3674         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
3675             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
3676         ANYOF_FLAGS(ret) = 0;
3677     }
3678     return ret;
3679 }
3680
3681 STATIC regnode *
3682 S_regclassutf8(pTHX_ RExC_state_t *pRExC_state)
3683 {
3684     dTHR;
3685     register char *e;
3686     register U32 value;
3687     register U32 lastvalue = OOB_UTF8;
3688     register I32 range = 0;
3689     register regnode *ret;
3690     STRLEN numlen;
3691     I32 n;
3692     SV *listsv;
3693     U8 flags = 0;
3694     I32 namedclass;
3695     char *rangebegin;
3696
3697     if (*RExC_parse == '^') {   /* Complement of range. */
3698         RExC_naughty++;
3699         RExC_parse++;
3700         if (!SIZE_ONLY)
3701             flags |= ANYOF_INVERT;
3702     }
3703     if (!SIZE_ONLY) {
3704         if (FOLD)
3705             flags |= ANYOF_FOLD;
3706         if (LOC)
3707             flags |= ANYOF_LOCALE;
3708         listsv = newSVpvn("# comment\n",10);
3709     }
3710
3711     if (!SIZE_ONLY && ckWARN(WARN_REGEXP))
3712         checkposixcc(pRExC_state);
3713
3714     if (*RExC_parse == ']' || *RExC_parse == '-')
3715         goto skipcond;          /* allow 1st char to be ] or - */
3716
3717     while (RExC_parse < RExC_end && *RExC_parse != ']') {
3718        skipcond:
3719         namedclass = OOB_NAMEDCLASS;
3720         if (!range)
3721             rangebegin = RExC_parse;
3722         value = utf8_to_uv((U8*)RExC_parse,
3723                                RExC_end - RExC_parse,
3724                                &numlen, 0);
3725         RExC_parse += numlen;
3726         if (value == '[')
3727             namedclass = regpposixcc(pRExC_state, value);
3728         else if (value == '\\') {
3729             value = (U32)utf8_to_uv((U8*)RExC_parse,
3730                                         RExC_end - RExC_parse,
3731                                         &numlen, 0);
3732             RExC_parse += numlen;
3733             /* Some compilers cannot handle switching on 64-bit integer
3734              * values, therefore value cannot be an UV.  Yes, this will
3735              * be a problem later if we want switch on Unicode.  --jhi */
3736             switch (value) {
3737             case 'w':           namedclass = ANYOF_ALNUM;               break;
3738             case 'W':           namedclass = ANYOF_NALNUM;              break;
3739             case 's':           namedclass = ANYOF_SPACE;               break;
3740             case 'S':           namedclass = ANYOF_NSPACE;              break;
3741             case 'd':           namedclass = ANYOF_DIGIT;               break;
3742             case 'D':           namedclass = ANYOF_NDIGIT;              break;
3743             case 'p':
3744             case 'P':
3745                 if (*RExC_parse == '{') {
3746                     e = strchr(RExC_parse++, '}');
3747                     if (!e)
3748                         vFAIL("Missing right brace on \\p{}");
3749                     n = e - RExC_parse;
3750                 }
3751                 else {
3752                     e = RExC_parse;
3753                     n = 1;
3754                 }
3755                 if (!SIZE_ONLY) {
3756                     if (value == 'p')
3757                         Perl_sv_catpvf(aTHX_ listsv,
3758                                        "+utf8::%.*s\n", (int)n, RExC_parse);
3759                     else
3760                         Perl_sv_catpvf(aTHX_ listsv,
3761                                        "!utf8::%.*s\n", (int)n, RExC_parse);
3762                 }
3763                 RExC_parse = e + 1;
3764                 lastvalue = OOB_UTF8;
3765                 continue;
3766             case 'n':           value = '\n';           break;
3767             case 'r':           value = '\r';           break;
3768             case 't':           value = '\t';           break;
3769             case 'f':           value = '\f';           break;
3770             case 'b':           value = '\b';           break;
3771 #ifdef ASCIIish
3772             case 'e':           value = '\033';         break;
3773             case 'a':           value = '\007';         break;
3774 #else
3775             case 'e':           value = '\047';         break;
3776             case 'a':           value = '\057';         break;
3777 #endif
3778             case 'x':
3779                 if (*RExC_parse == '{') {
3780                     e = strchr(RExC_parse++, '}');
3781                     if (!e)
3782                         vFAIL("Missing right brace on \\x{}");
3783                     numlen = 1;         /* allow underscores */
3784                     value = (UV)scan_hex(RExC_parse,
3785                                      e - RExC_parse,
3786                                      &numlen);
3787                     RExC_parse = e + 1;
3788                 }
3789                 else {
3790                     numlen = 0;         /* disallow underscores */
3791                     value = (UV)scan_hex(RExC_parse, 2, &numlen);
3792                     RExC_parse += numlen;
3793                 }
3794                 break;
3795             case 'c':
3796                 value = UCHARAT(RExC_parse++);
3797                 value = toCTRL(value);
3798                 break;
3799             case '0': case '1': case '2': case '3': case '4':
3800             case '5': case '6': case '7': case '8': case '9':
3801                 numlen = 0;             /* disallow underscores */
3802                 value = (UV)scan_oct(--RExC_parse, 3, &numlen);
3803                 RExC_parse += numlen;
3804                 break;
3805             default:
3806                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3807                     vWARN2(RExC_parse,
3808                            "Unrecognized escape \\%c in character class passed through",
3809                            (int)value);
3810                 break;
3811             }
3812         }
3813         if (namedclass > OOB_NAMEDCLASS) {
3814             if (range) { /* a-\d, a-[:digit:] */
3815                 if (!SIZE_ONLY) {
3816                     if (ckWARN(WARN_REGEXP))
3817                         vWARN4(RExC_parse,
3818                                "False [] range \"%*.*s\"",
3819                                RExC_parse - rangebegin,
3820                                RExC_parse - rangebegin,
3821                                rangebegin);
3822                     Perl_sv_catpvf(aTHX_ listsv,
3823                                    /* 0x002D is Unicode for '-' */
3824                                    "%04"UVxf"\n002D\n", (UV)lastvalue);
3825                 }
3826                 range = 0;
3827             }
3828             if (!SIZE_ONLY) {
3829                 switch (namedclass) {
3830                 case ANYOF_ALNUM:
3831                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");    break;
3832                 case ANYOF_NALNUM:
3833                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");    break;
3834                 case ANYOF_ALNUMC:
3835                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");   break;
3836                 case ANYOF_NALNUMC:
3837                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");   break;
3838                 case ANYOF_ALPHA:
3839                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");   break;
3840                 case ANYOF_NALPHA:
3841                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");   break;
3842                 case ANYOF_ASCII:
3843                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");   break;
3844                 case ANYOF_NASCII:
3845                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");   break;
3846                 case ANYOF_CNTRL:
3847                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");   break;
3848                 case ANYOF_NCNTRL:
3849                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");   break;
3850                 case ANYOF_GRAPH:
3851                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");   break;
3852                 case ANYOF_NGRAPH:
3853                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");   break;
3854                 case ANYOF_DIGIT:
3855                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");   break;
3856                 case ANYOF_NDIGIT:
3857                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");   break;
3858                 case ANYOF_LOWER:
3859                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");   break;
3860                 case ANYOF_NLOWER:
3861                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");   break;
3862                 case ANYOF_PRINT:
3863                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");   break;
3864                 case ANYOF_NPRINT:
3865                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");   break;
3866                 case ANYOF_PUNCT:
3867                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");   break;
3868                 case ANYOF_NPUNCT:
3869                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");   break;
3870                 case ANYOF_SPACE:
3871                 case ANYOF_PSXSPC:
3872                 case ANYOF_BLANK:
3873                     /* Not very true for PSXSPC and BLANK
3874                      * but not feeling like creating IsPOSIXSpace and
3875                      * IsBlank right now. --jhi */
3876                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");   break;
3877                 case ANYOF_NSPACE:
3878                 case ANYOF_NPSXSPC:
3879                 case ANYOF_NBLANK:
3880                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");   break;
3881                 case ANYOF_UPPER:
3882                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");   break;
3883                 case ANYOF_NUPPER:
3884                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");   break;
3885                 case ANYOF_XDIGIT:
3886                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");  break;
3887                 case ANYOF_NXDIGIT:
3888                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");  break;
3889                 }
3890                 continue;
3891             }
3892         }
3893         if (range) {
3894             if (lastvalue > value) { /* b-a */
3895                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3896                               RExC_parse - rangebegin,
3897                               RExC_parse - rangebegin,
3898                               rangebegin);
3899             }
3900             range = 0;
3901         }
3902         else {
3903             lastvalue = value;
3904             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
3905                 RExC_parse[1] != ']') {
3906                 RExC_parse++;
3907                 if (namedclass > OOB_NAMEDCLASS) { /* \w-, [:word:]- */
3908                     if (ckWARN(WARN_REGEXP))
3909                         vWARN4(RExC_parse,
3910                                "False [] range \"%*.*s\"",
3911                                RExC_parse - rangebegin,
3912                                RExC_parse - rangebegin,
3913                                rangebegin);
3914                     if (!SIZE_ONLY)
3915                         Perl_sv_catpvf(aTHX_ listsv,
3916                                        /* 0x002D is Unicode for '-' */
3917                                        "002D\n");
3918                 } else
3919                     range = 1;
3920                 continue;       /* do it next time */
3921             }
3922         }
3923         /* now is the next time */
3924         if (!SIZE_ONLY)
3925             Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
3926                            (UV)lastvalue, (UV)value);
3927         range = 0;
3928     }
3929
3930     ret = reganode(pRExC_state, ANYOFUTF8, 0);
3931
3932     if (!SIZE_ONLY) {
3933         SV *rv = swash_init("utf8", "", listsv, 1, 0);
3934         SvREFCNT_dec(listsv);
3935         n = add_data(pRExC_state, 1,"s");
3936         RExC_rx->data->data[n] = (void*)rv;
3937         ARG1_SET(ret, flags);
3938         ARG2_SET(ret, n);
3939     }
3940
3941     return ret;
3942 }
3943
3944 STATIC char*
3945 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
3946 {
3947     dTHR;
3948     char* retval = RExC_parse++;
3949
3950     for (;;) {
3951         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
3952                 RExC_parse[2] == '#') {
3953             while (*RExC_parse && *RExC_parse != ')')
3954                 RExC_parse++;
3955             RExC_parse++;
3956             continue;
3957         }
3958         if (RExC_flags16 & PMf_EXTENDED) {
3959             if (isSPACE(*RExC_parse)) {
3960                 RExC_parse++;
3961                 continue;
3962             }
3963             else if (*RExC_parse == '#') {
3964                 while (*RExC_parse && *RExC_parse != '\n')
3965                     RExC_parse++;
3966                 RExC_parse++;
3967                 continue;
3968             }
3969         }
3970         return retval;
3971     }
3972 }
3973
3974 /*
3975 - reg_node - emit a node
3976 */
3977 STATIC regnode *                        /* Location. */
3978 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
3979 {
3980     dTHR;
3981     register regnode *ret;
3982     register regnode *ptr;
3983
3984     ret = RExC_emit;
3985     if (SIZE_ONLY) {
3986         SIZE_ALIGN(RExC_size);
3987         RExC_size += 1;
3988         return(ret);
3989     }
3990
3991     NODE_ALIGN_FILL(ret);
3992     ptr = ret;
3993     FILL_ADVANCE_NODE(ptr, op);
3994     RExC_emit = ptr;
3995
3996     return(ret);
3997 }
3998
3999 /*
4000 - reganode - emit a node with an argument
4001 */
4002 STATIC regnode *                        /* Location. */
4003 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4004 {
4005     dTHR;
4006     register regnode *ret;
4007     register regnode *ptr;
4008
4009     ret = RExC_emit;
4010     if (SIZE_ONLY) {
4011         SIZE_ALIGN(RExC_size);
4012         RExC_size += 2;
4013         return(ret);
4014     }
4015
4016     NODE_ALIGN_FILL(ret);
4017     ptr = ret;
4018     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4019     RExC_emit = ptr;
4020
4021     return(ret);
4022 }
4023
4024 /*
4025 - reguni - emit (if appropriate) a Unicode character
4026 */
4027 STATIC void
4028 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4029 {
4030     dTHR;
4031     if (SIZE_ONLY) {
4032         U8 tmpbuf[UTF8_MAXLEN];
4033         *lenp = uv_to_utf8(tmpbuf, uv) - tmpbuf;
4034     }
4035     else
4036         *lenp = uv_to_utf8((U8*)s, uv) - (U8*)s;
4037
4038 }
4039
4040 /*
4041 - reginsert - insert an operator in front of already-emitted operand
4042 *
4043 * Means relocating the operand.
4044 */
4045 STATIC void
4046 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4047 {
4048     dTHR;
4049     register regnode *src;
4050     register regnode *dst;
4051     register regnode *place;
4052     register int offset = regarglen[(U8)op];
4053
4054 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4055
4056     if (SIZE_ONLY) {
4057         RExC_size += NODE_STEP_REGNODE + offset;
4058         return;
4059     }
4060
4061     src = RExC_emit;
4062     RExC_emit += NODE_STEP_REGNODE + offset;
4063     dst = RExC_emit;
4064     while (src > opnd)
4065         StructCopy(--src, --dst, regnode);
4066
4067     place = opnd;               /* Op node, where operand used to be. */
4068     src = NEXTOPER(place);
4069     FILL_ADVANCE_NODE(place, op);
4070     Zero(src, offset, regnode);
4071 }
4072
4073 /*
4074 - regtail - set the next-pointer at the end of a node chain of p to val.
4075 */
4076 STATIC void
4077 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4078 {
4079     dTHR;
4080     register regnode *scan;
4081     register regnode *temp;
4082
4083     if (SIZE_ONLY)
4084         return;
4085
4086     /* Find last node. */
4087     scan = p;
4088     for (;;) {
4089         temp = regnext(scan);
4090         if (temp == NULL)
4091             break;
4092         scan = temp;
4093     }
4094
4095     if (reg_off_by_arg[OP(scan)]) {
4096         ARG_SET(scan, val - scan);
4097     }
4098     else {
4099         NEXT_OFF(scan) = val - scan;
4100     }
4101 }
4102
4103 /*
4104 - regoptail - regtail on operand of first argument; nop if operandless
4105 */
4106 STATIC void
4107 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4108 {
4109     dTHR;
4110     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4111     if (p == NULL || SIZE_ONLY)
4112         return;
4113     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4114         regtail(pRExC_state, NEXTOPER(p), val);
4115     }
4116     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4117         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4118     }
4119     else
4120         return;
4121 }
4122
4123 /*
4124  - regcurly - a little FSA that accepts {\d+,?\d*}
4125  */
4126 STATIC I32
4127 S_regcurly(pTHX_ register char *s)
4128 {
4129     if (*s++ != '{')
4130         return FALSE;
4131     if (!isDIGIT(*s))
4132         return FALSE;
4133     while (isDIGIT(*s))
4134         s++;
4135     if (*s == ',')
4136         s++;
4137     while (isDIGIT(*s))
4138         s++;
4139     if (*s != '}')
4140         return FALSE;
4141     return TRUE;
4142 }
4143
4144
4145 STATIC regnode *
4146 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4147 {
4148 #ifdef DEBUGGING
4149     register U8 op = EXACT;     /* Arbitrary non-END op. */
4150     register regnode *next;
4151
4152     while (op != END && (!last || node < last)) {
4153         /* While that wasn't END last time... */
4154
4155         NODE_ALIGN(node);
4156         op = OP(node);
4157         if (op == CLOSE)
4158             l--;
4159         next = regnext(node);
4160         /* Where, what. */
4161         if (OP(node) == OPTIMIZED)
4162             goto after_print;
4163         regprop(sv, node);
4164         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4165                       (int)(2*l + 1), "", SvPVX(sv));
4166         if (next == NULL)               /* Next ptr. */
4167             PerlIO_printf(Perl_debug_log, "(0)");
4168         else
4169             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4170         (void)PerlIO_putc(Perl_debug_log, '\n');
4171       after_print:
4172         if (PL_regkind[(U8)op] == BRANCHJ) {
4173             register regnode *nnode = (OP(next) == LONGJMP
4174                                        ? regnext(next)
4175                                        : next);
4176             if (last && nnode > last)
4177                 nnode = last;
4178             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4179         }
4180         else if (PL_regkind[(U8)op] == BRANCH) {
4181             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4182         }
4183         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4184             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4185                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4186         }
4187         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4188             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4189                              next, sv, l + 1);
4190         }
4191         else if ( op == PLUS || op == STAR) {
4192             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4193         }
4194         else if (op == ANYOF) {
4195             node = NEXTOPER(node);
4196             node += ANYOF_SKIP;
4197         }
4198         else if (PL_regkind[(U8)op] == EXACT) {
4199             /* Literal string, where present. */
4200             node += NODE_SZ_STR(node) - 1;
4201             node = NEXTOPER(node);
4202         }
4203         else {
4204             node = NEXTOPER(node);
4205             node += regarglen[(U8)op];
4206         }
4207         if (op == CURLYX || op == OPEN)
4208             l++;
4209         else if (op == WHILEM)
4210             l--;
4211     }
4212 #endif  /* DEBUGGING */
4213     return node;
4214 }
4215
4216 /*
4217  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4218  */
4219 void
4220 Perl_regdump(pTHX_ regexp *r)
4221 {
4222 #ifdef DEBUGGING
4223     dTHR;
4224     SV *sv = sv_newmortal();
4225
4226     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4227
4228     /* Header fields of interest. */
4229     if (r->anchored_substr)
4230         PerlIO_printf(Perl_debug_log,
4231                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4232                       PL_colors[0],
4233                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4234                       SvPVX(r->anchored_substr),
4235                       PL_colors[1],
4236                       SvTAIL(r->anchored_substr) ? "$" : "",
4237                       (IV)r->anchored_offset);
4238     if (r->float_substr)
4239         PerlIO_printf(Perl_debug_log,
4240                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4241                       PL_colors[0],
4242                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4243                       SvPVX(r->float_substr),
4244                       PL_colors[1],
4245                       SvTAIL(r->float_substr) ? "$" : "",
4246                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4247     if (r->check_substr)
4248         PerlIO_printf(Perl_debug_log,
4249                       r->check_substr == r->float_substr
4250                       ? "(checking floating" : "(checking anchored");
4251     if (r->reganch & ROPT_NOSCAN)
4252         PerlIO_printf(Perl_debug_log, " noscan");
4253     if (r->reganch & ROPT_CHECK_ALL)
4254         PerlIO_printf(Perl_debug_log, " isall");
4255     if (r->check_substr)
4256         PerlIO_printf(Perl_debug_log, ") ");
4257
4258     if (r->regstclass) {
4259         regprop(sv, r->regstclass);
4260         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4261     }
4262     if (r->reganch & ROPT_ANCH) {
4263         PerlIO_printf(Perl_debug_log, "anchored");
4264         if (r->reganch & ROPT_ANCH_BOL)
4265             PerlIO_printf(Perl_debug_log, "(BOL)");
4266         if (r->reganch & ROPT_ANCH_MBOL)
4267             PerlIO_printf(Perl_debug_log, "(MBOL)");
4268         if (r->reganch & ROPT_ANCH_SBOL)
4269             PerlIO_printf(Perl_debug_log, "(SBOL)");
4270         if (r->reganch & ROPT_ANCH_GPOS)
4271             PerlIO_printf(Perl_debug_log, "(GPOS)");
4272         PerlIO_putc(Perl_debug_log, ' ');
4273     }
4274     if (r->reganch & ROPT_GPOS_SEEN)
4275         PerlIO_printf(Perl_debug_log, "GPOS ");
4276     if (r->reganch & ROPT_SKIP)
4277         PerlIO_printf(Perl_debug_log, "plus ");
4278     if (r->reganch & ROPT_IMPLICIT)
4279         PerlIO_printf(Perl_debug_log, "implicit ");
4280     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4281     if (r->reganch & ROPT_EVAL_SEEN)
4282         PerlIO_printf(Perl_debug_log, "with eval ");
4283     PerlIO_printf(Perl_debug_log, "\n");
4284 #endif  /* DEBUGGING */
4285 }
4286
4287 STATIC void
4288 S_put_byte(pTHX_ SV *sv, int c)
4289 {
4290     if (c <= ' ' || c == 127 || c == 255)
4291         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4292     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4293         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4294     else
4295         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4296 }
4297
4298 /*
4299 - regprop - printable representation of opcode
4300 */
4301 void
4302 Perl_regprop(pTHX_ SV *sv, regnode *o)
4303 {
4304 #ifdef DEBUGGING
4305     dTHR;
4306     register int k;
4307
4308     sv_setpvn(sv, "", 0);
4309     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4310         /* It would be nice to FAIL() here, but this may be called from
4311            regexec.c, and it would be hard to supply pRExC_state. */
4312         Perl_croak(aTHX_ "Corrupted regexp opcode");
4313     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4314
4315     k = PL_regkind[(U8)OP(o)];
4316
4317     if (k == EXACT)
4318         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>", PL_colors[0],
4319                        STR_LEN(o), STRING(o), PL_colors[1]);
4320     else if (k == CURLY) {
4321         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4322             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4323         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4324     }
4325     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4326         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4327     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4328         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4329     else if (k == LOGICAL)
4330         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4331     else if (k == ANYOF) {
4332         int i, rangestart = -1;
4333         const char * const out[] = {    /* Should be syncronized with
4334                                            ANYOF_ #xdefines in regcomp.h */
4335             "\\w",
4336             "\\W",
4337             "\\s",
4338             "\\S",
4339             "\\d",
4340             "\\D",
4341             "[:alnum:]",
4342             "[:^alnum:]",
4343             "[:alpha:]",
4344             "[:^alpha:]",
4345             "[:ascii:]",
4346             "[:^ascii:]",
4347             "[:ctrl:]",
4348             "[:^ctrl:]",
4349             "[:graph:]",
4350             "[:^graph:]",
4351             "[:lower:]",
4352             "[:^lower:]",
4353             "[:print:]",
4354             "[:^print:]",
4355             "[:punct:]",
4356             "[:^punct:]",
4357             "[:upper:]",
4358             "[:^upper:]",
4359             "[:xdigit:]",
4360             "[:^xdigit:]",
4361             "[:space:]",
4362             "[:^space:]",
4363             "[:blank:]",
4364             "[:^blank:]"
4365         };
4366
4367         if (o->flags & ANYOF_LOCALE)
4368             sv_catpv(sv, "{loc}");
4369         if (o->flags & ANYOF_FOLD)
4370             sv_catpv(sv, "{i}");
4371         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4372         if (o->flags & ANYOF_INVERT)
4373             sv_catpv(sv, "^");
4374         if (OP(o) == ANYOF) {
4375             for (i = 0; i <= 256; i++) {
4376                 if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4377                     if (rangestart == -1)
4378                         rangestart = i;
4379                 } else if (rangestart != -1) {
4380                     if (i <= rangestart + 3)
4381                         for (; rangestart < i; rangestart++)
4382                             put_byte(sv, rangestart);
4383                     else {
4384                         put_byte(sv, rangestart);
4385                         sv_catpv(sv, "-");
4386                         put_byte(sv, i - 1);
4387                     }
4388                     rangestart = -1;
4389                 }
4390             }
4391             if (o->flags & ANYOF_CLASS)
4392                 for (i = 0; i < sizeof(out)/sizeof(char*); i++)
4393                     if (ANYOF_CLASS_TEST(o,i))
4394                         sv_catpv(sv, out[i]);
4395         }
4396         else {
4397             sv_catpv(sv, "{ANYOFUTF8}"); /* TODO: full decode */
4398         }
4399         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4400     }
4401     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4402         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4403 #endif  /* DEBUGGING */
4404 }
4405
4406 SV *
4407 Perl_re_intuit_string(pTHX_ regexp *prog)
4408 {                               /* Assume that RE_INTUIT is set */
4409     DEBUG_r(
4410         {   STRLEN n_a;
4411             char *s = SvPV(prog->check_substr,n_a);
4412
4413             if (!PL_colorset) reginitcolors();
4414             PerlIO_printf(Perl_debug_log,
4415                       "%sUsing REx substr:%s `%s%.60s%s%s'\n",
4416                       PL_colors[4],PL_colors[5],PL_colors[0],
4417                       s,
4418                       PL_colors[1],
4419                       (strlen(s) > 60 ? "..." : ""));
4420         } );
4421
4422     return prog->check_substr;
4423 }
4424
4425 void
4426 Perl_pregfree(pTHX_ struct regexp *r)
4427 {
4428     dTHR;
4429     DEBUG_r(if (!PL_colorset) reginitcolors());
4430
4431     if (!r || (--r->refcnt > 0))
4432         return;
4433     DEBUG_r(PerlIO_printf(Perl_debug_log,
4434                       "%sFreeing REx:%s `%s%.60s%s%s'\n",
4435                       PL_colors[4],PL_colors[5],PL_colors[0],
4436                       r->precomp,
4437                       PL_colors[1],
4438                       (strlen(r->precomp) > 60 ? "..." : "")));
4439
4440     if (r->precomp)
4441         Safefree(r->precomp);
4442     if (RX_MATCH_COPIED(r))
4443         Safefree(r->subbeg);
4444     if (r->substrs) {
4445         if (r->anchored_substr)
4446             SvREFCNT_dec(r->anchored_substr);
4447         if (r->float_substr)
4448             SvREFCNT_dec(r->float_substr);
4449         Safefree(r->substrs);
4450     }
4451     if (r->data) {
4452         int n = r->data->count;
4453         AV* new_comppad = NULL;
4454         AV* old_comppad;
4455         SV** old_curpad;
4456
4457         while (--n >= 0) {
4458             switch (r->data->what[n]) {
4459             case 's':
4460                 SvREFCNT_dec((SV*)r->data->data[n]);
4461                 break;
4462             case 'f':
4463                 Safefree(r->data->data[n]);
4464                 break;
4465             case 'p':
4466                 new_comppad = (AV*)r->data->data[n];
4467                 break;
4468             case 'o':
4469                 if (new_comppad == NULL)
4470                     Perl_croak(aTHX_ "panic: pregfree comppad");
4471                 old_comppad = PL_comppad;
4472                 old_curpad = PL_curpad;
4473                 /* Watch out for global destruction's random ordering. */
4474                 if (SvTYPE(new_comppad) == SVt_PVAV) {
4475                     PL_comppad = new_comppad;
4476                     PL_curpad = AvARRAY(new_comppad);
4477                 }
4478                 else
4479                     PL_curpad = NULL;
4480                 op_free((OP_4tree*)r->data->data[n]);
4481                 PL_comppad = old_comppad;
4482                 PL_curpad = old_curpad;
4483                 SvREFCNT_dec((SV*)new_comppad);
4484                 new_comppad = NULL;
4485                 break;
4486             case 'n':
4487                 break;
4488             default:
4489                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4490             }
4491         }
4492         Safefree(r->data->what);
4493         Safefree(r->data);
4494     }
4495     Safefree(r->startp);
4496     Safefree(r->endp);
4497     Safefree(r);
4498 }
4499
4500 /*
4501  - regnext - dig the "next" pointer out of a node
4502  *
4503  * [Note, when REGALIGN is defined there are two places in regmatch()
4504  * that bypass this code for speed.]
4505  */
4506 regnode *
4507 Perl_regnext(pTHX_ register regnode *p)
4508 {
4509     dTHR;
4510     register I32 offset;
4511
4512     if (p == &PL_regdummy)
4513         return(NULL);
4514
4515     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
4516     if (offset == 0)
4517         return(NULL);
4518
4519     return(p+offset);
4520 }
4521
4522 STATIC void
4523 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
4524 {
4525     va_list args;
4526     STRLEN l1 = strlen(pat1);
4527     STRLEN l2 = strlen(pat2);
4528     char buf[512];
4529     SV *msv;
4530     char *message;
4531
4532     if (l1 > 510)
4533         l1 = 510;
4534     if (l1 + l2 > 510)
4535         l2 = 510 - l1;
4536     Copy(pat1, buf, l1 , char);
4537     Copy(pat2, buf + l1, l2 , char);
4538     buf[l1 + l2] = '\n';
4539     buf[l1 + l2 + 1] = '\0';
4540 #ifdef I_STDARG
4541     /* ANSI variant takes additional second argument */
4542     va_start(args, pat2);
4543 #else
4544     va_start(args);
4545 #endif
4546     msv = vmess(buf, &args);
4547     va_end(args);
4548     message = SvPV(msv,l1);
4549     if (l1 > 512)
4550         l1 = 512;
4551     Copy(message, buf, l1 , char);
4552     buf[l1] = '\0';                     /* Overwrite \n */
4553     Perl_croak(aTHX_ "%s", buf);
4554 }
4555
4556 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
4557
4558 void
4559 Perl_save_re_context(pTHX)
4560 {
4561     dTHR;
4562
4563 #if 0
4564     SAVEPPTR(RExC_precomp);             /* uncompiled string. */
4565     SAVEI32(RExC_npar);         /* () count. */
4566     SAVEI32(RExC_size);         /* Code size. */
4567     SAVEI16(RExC_flags16);              /* are we folding, multilining? */
4568     SAVEVPTR(RExC_rx);          /* from regcomp.c */
4569     SAVEI32(RExC_seen);         /* from regcomp.c */
4570     SAVEI32(RExC_sawback);              /* Did we see \1, ...? */
4571     SAVEI32(RExC_naughty);              /* How bad is this pattern? */
4572     SAVEVPTR(RExC_emit);                /* Code-emit pointer; &regdummy = don't */
4573     SAVEPPTR(RExC_end);         /* End of input for compile */
4574     SAVEPPTR(RExC_parse);               /* Input-scan pointer. */
4575 #endif
4576
4577     SAVEI32(PL_reg_flags);              /* from regexec.c */
4578     SAVEPPTR(PL_bostr);
4579     SAVEPPTR(PL_reginput);              /* String-input pointer. */
4580     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
4581     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
4582     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
4583     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
4584     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
4585     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
4586     SAVEI8(PL_regprev);                 /* char before regbol, \n if none */
4587     SAVEVPTR(PL_reg_start_tmp);         /* from regexec.c */
4588     PL_reg_start_tmp = 0;
4589     SAVEFREEPV(PL_reg_start_tmp);
4590     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
4591     PL_reg_start_tmpl = 0;
4592     SAVEVPTR(PL_regdata);
4593     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
4594     SAVEI32(PL_regnarrate);             /* from regexec.c */
4595     SAVEVPTR(PL_regprogram);            /* from regexec.c */
4596     SAVEINT(PL_regindent);              /* from regexec.c */
4597     SAVEVPTR(PL_regcc);                 /* from regexec.c */
4598     SAVEVPTR(PL_curcop);
4599     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
4600     SAVEVPTR(PL_reg_re);                /* from regexec.c */
4601     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
4602     SAVESPTR(PL_reg_sv);                /* from regexec.c */
4603     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
4604     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
4605     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
4606     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
4607     SAVEI32(PL_regnpar);                /* () count. */
4608 #ifdef DEBUGGING
4609     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
4610 #endif
4611 }
4612
4613 #ifdef PERL_OBJECT
4614 #include "XSUB.h"
4615 #undef this
4616 #define this pPerl
4617 #endif
4618
4619 static void
4620 clear_re(pTHXo_ void *r)
4621 {
4622     ReREFCNT_dec((regexp *)r);
4623 }
4624