regcomp.c

   1 /*    regcomp.c
   2  */
   3
   4 /*
   5  * "A fair jaw-cracker dwarf-language must be."  --Samwise Gamgee
   6  */
   7
   8 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
   9  * confused with the original package (see point 3 below).  Thanks, Henry!
  10  */
  11
  12 /* Additional note: this code is very heavily munged from Henry's version
  13  * in places.  In some spots I've traded clarity for efficiency, so don't
  14  * blame Henry for some of the lack of readability.
  15  */
  16
  17 /* The names of the functions have been changed from regcomp and
  18  * regexec to  pregcomp and pregexec in order to avoid conflicts
  19  * with the POSIX routines of the same names.
  20 */
  21
  22 #ifdef PERL_EXT_RE_BUILD
  23 /* need to replace pregcomp et al, so enable that */
  24 #  ifndef PERL_IN_XSUB_RE
  25 #    define PERL_IN_XSUB_RE
  26 #  endif
  27 /* need access to debugger hooks */
  28 #  if defined(PERL_EXT_RE_DEBUG) && !defined(DEBUGGING)
  29 #    define DEBUGGING
  30 #  endif
  31 #endif
  32
  33 #ifdef PERL_IN_XSUB_RE
  34 /* We *really* need to overwrite these symbols: */
  35 #  define Perl_pregcomp my_regcomp
  36 #  define Perl_regdump my_regdump
  37 #  define Perl_regprop my_regprop
  38 #  define Perl_pregfree my_regfree
  39 #  define Perl_re_intuit_string my_re_intuit_string
  40 /* *These* symbols are masked to allow static link. */
  41 #  define Perl_regnext my_regnext
  42 #  define Perl_save_re_context my_save_re_context
  43 #  define Perl_reginitcolors my_reginitcolors
  44
  45 #  define PERL_NO_GET_CONTEXT
  46 #endif
  47
  48 /*SUPPRESS 112*/
  49 /*
  50  * pregcomp and pregexec -- regsub and regerror are not used in perl
  51  *
  52  *      Copyright (c) 1986 by University of Toronto.
  53  *      Written by Henry Spencer.  Not derived from licensed software.
  54  *
  55  *      Permission is granted to anyone to use this software for any
  56  *      purpose on any computer system, and to redistribute it freely,
  57  *      subject to the following restrictions:
  58  *
  59  *      1. The author is not responsible for the consequences of use of
  60  *              this software, no matter how awful, even if they arise
  61  *              from defects in it.
  62  *
  63  *      2. The origin of this software must not be misrepresented, either
  64  *              by explicit claim or by omission.
  65  *
  66  *      3. Altered versions must be plainly marked as such, and must not
  67  *              be misrepresented as being the original software.
  68  *
  69  *
  70  ****    Alterations to Henry's code are...
  71  ****
  72  ****    Copyright (c) 1991-2001, Larry Wall
  73  ****
  74  ****    You may distribute under the terms of either the GNU General Public
  75  ****    License or the Artistic License, as specified in the README file.
  76
  77  *
  78  * Beware that some of this code is subtly aware of the way operator
  79  * precedence is structured in regular expressions.  Serious changes in
  80  * regular-expression syntax might require a total rethink.
  81  */
  82 #include "EXTERN.h"
  83 #define PERL_IN_REGCOMP_C
  84 #include "perl.h"
  85
  86 #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 = compiling */
 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     I32         utf8;
 131 #if ADD_TO_REGEXEC
 132     char        *starttry;              /* -Dr: where regtry was called. */
 133 #define RExC_starttry   (pRExC_state->starttry)
 134 #endif
 135 } RExC_state_t;
 136
 137 #define RExC_flags16    (pRExC_state->flags16)
 138 #define RExC_precomp    (pRExC_state->precomp)
 139 #define RExC_rx         (pRExC_state->rx)
 140 #define RExC_end        (pRExC_state->end)
 141 #define RExC_parse      (pRExC_state->parse)
 142 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
 143 #define RExC_emit       (pRExC_state->emit)
 144 #define RExC_naughty    (pRExC_state->naughty)
 145 #define RExC_sawback    (pRExC_state->sawback)
 146 #define RExC_seen       (pRExC_state->seen)
 147 #define RExC_size       (pRExC_state->size)
 148 #define RExC_npar       (pRExC_state->npar)
 149 #define RExC_extralen   (pRExC_state->extralen)
 150 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
 151 #define RExC_seen_evals (pRExC_state->seen_evals)
 152 #define RExC_utf8       (pRExC_state->utf8)
 153
 154 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 155 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
 156         ((*s) == '{' && regcurly(s)))
 157
 158 #ifdef SPSTART
 159 #undef SPSTART          /* dratted cpp namespace... */
 160 #endif
 161 /*
 162  * Flags to be passed up and down.
 163  */
 164 #define WORST           0       /* Worst case. */
 165 #define HASWIDTH        0x1     /* Known to match non-null strings. */
 166 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
 167 #define SPSTART         0x4     /* Starts with * or +. */
 168 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
 169
 170 /* Length of a variant. */
 171
 172 typedef struct scan_data_t {
 173     I32 len_min;
 174     I32 len_delta;
 175     I32 pos_min;
 176     I32 pos_delta;
 177     SV *last_found;
 178     I32 last_end;                       /* min value, <0 unless valid. */
 179     I32 last_start_min;
 180     I32 last_start_max;
 181     SV **longest;                       /* Either &l_fixed, or &l_float. */
 182     SV *longest_fixed;
 183     I32 offset_fixed;
 184     SV *longest_float;
 185     I32 offset_float_min;
 186     I32 offset_float_max;
 187     I32 flags;
 188     I32 whilem_c;
 189     I32 *last_closep;
 190     struct regnode_charclass_class *start_class;
 191 } scan_data_t;
 192
 193 /*
 194  * Forward declarations for pregcomp()'s friends.
 195  */
 196
 197 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 198                                       0, 0, 0, 0, 0, 0};
 199
 200 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 201 #define SF_BEFORE_SEOL          0x1
 202 #define SF_BEFORE_MEOL          0x2
 203 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
 204 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
 205
 206 #ifdef NO_UNARY_PLUS
 207 #  define SF_FIX_SHIFT_EOL      (0+2)
 208 #  define SF_FL_SHIFT_EOL               (0+4)
 209 #else
 210 #  define SF_FIX_SHIFT_EOL      (+2)
 211 #  define SF_FL_SHIFT_EOL               (+4)
 212 #endif
 213
 214 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
 215 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
 216
 217 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
 218 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
 219 #define SF_IS_INF               0x40
 220 #define SF_HAS_PAR              0x80
 221 #define SF_IN_PAR               0x100
 222 #define SF_HAS_EVAL             0x200
 223 #define SCF_DO_SUBSTR           0x400
 224 #define SCF_DO_STCLASS_AND      0x0800
 225 #define SCF_DO_STCLASS_OR       0x1000
 226 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 227 #define SCF_WHILEM_VISITED_POS  0x2000
 228
 229 #define UTF RExC_utf8
 230 #define LOC (RExC_flags16 & PMf_LOCALE)
 231 #define FOLD (RExC_flags16 & PMf_FOLD)
 232
 233 #define OOB_UNICODE             12345678
 234 #define OOB_NAMEDCLASS          -1
 235
 236 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 237 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 238
 239
 240 /* length of regex to show in messages that don't mark a position within */
 241 #define RegexLengthToShowInErrorMessages 127
 242
 243 /*
 244  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
 245  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
 246  * op/pragma/warn/regcomp.
 247  */
 248 #define MARKER1 "HERE"      /* marker as it appears in the description */
 249 #define MARKER2 " << HERE "  /* marker as it appears within the regex */
 250
 251 #define REPORT_LOCATION " before " MARKER1 " mark in regex m/%.*s" MARKER2 "%s/"
 252
 253 /*
 254  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 255  * arg. Show regex, up to a maximum length. If it's too long, chop and add
 256  * "...".
 257  */
 258 #define FAIL(msg)                                                             \
 259     STMT_START {                                                             \
 260         char *ellipses = "";                                                 \
 261         unsigned len = strlen(RExC_precomp);                                \
 262                                                                              \
 263         if (!SIZE_ONLY)                                                      \
 264             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 265                                                                              \
 266         if (len > RegexLengthToShowInErrorMessages) {                        \
 267             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 268             len = RegexLengthToShowInErrorMessages - 10;                     \
 269             ellipses = "...";                                                \
 270         }                                                                    \
 271         Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                            \
 272                    msg, (int)len, RExC_precomp, ellipses);                  \
 273     } STMT_END
 274
 275 /*
 276  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 277  * args. Show regex, up to a maximum length. If it's too long, chop and add
 278  * "...".
 279  */
 280 #define FAIL2(pat,msg)                                                        \
 281     STMT_START {                                                             \
 282         char *ellipses = "";                                                 \
 283         unsigned len = strlen(RExC_precomp);                                \
 284                                                                              \
 285         if (!SIZE_ONLY)                                                      \
 286             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 287                                                                              \
 288         if (len > RegexLengthToShowInErrorMessages) {                        \
 289             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 290             len = RegexLengthToShowInErrorMessages - 10;                     \
 291             ellipses = "...";                                                \
 292         }                                                                    \
 293         S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                        \
 294                     msg, (int)len, RExC_precomp, ellipses);                \
 295     } STMT_END
 296
 297
 298 /*
 299  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
 300  */
 301 #define Simple_vFAIL(m)                                                      \
 302     STMT_START {                                                             \
 303       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 304                                                                              \
 305       Perl_croak(aTHX_ "%s" REPORT_LOCATION,               \
 306                  m, (int)offset, RExC_precomp, RExC_precomp + offset);     \
 307     } STMT_END
 308
 309 /*
 310  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
 311  */
 312 #define vFAIL(m)                                                             \
 313     STMT_START {                                                             \
 314       if (!SIZE_ONLY)                                                        \
 315             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 316       Simple_vFAIL(m);                                                       \
 317     } STMT_END
 318
 319 /*
 320  * Like Simple_vFAIL(), but accepts two arguments.
 321  */
 322 #define Simple_vFAIL2(m,a1)                                                  \
 323     STMT_START {                                                             \
 324       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 325                                                                              \
 326       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,       \
 327                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 328     } STMT_END
 329
 330 /*
 331  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
 332  */
 333 #define vFAIL2(m,a1)                                                         \
 334     STMT_START {                                                             \
 335       if (!SIZE_ONLY)                                                        \
 336             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 337       Simple_vFAIL2(m, a1);                                                  \
 338     } STMT_END
 339
 340
 341 /*
 342  * Like Simple_vFAIL(), but accepts three arguments.
 343  */
 344 #define Simple_vFAIL3(m, a1, a2)                                             \
 345     STMT_START {                                                             \
 346       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 347                                                                              \
 348       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,   \
 349                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 350     } STMT_END
 351
 352 /*
 353  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
 354  */
 355 #define vFAIL3(m,a1,a2)                                                      \
 356     STMT_START {                                                             \
 357       if (!SIZE_ONLY)                                                        \
 358             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 359       Simple_vFAIL3(m, a1, a2);                                              \
 360     } STMT_END
 361
 362 /*
 363  * Like Simple_vFAIL(), but accepts four arguments.
 364  */
 365 #define Simple_vFAIL4(m, a1, a2, a3)                                         \
 366     STMT_START {                                                             \
 367       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 368                                                                              \
 369       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,\
 370                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 371     } STMT_END
 372
 373 /*
 374  * Like Simple_vFAIL(), but accepts five arguments.
 375  */
 376 #define Simple_vFAIL5(m, a1, a2, a3, a4)                                     \
 377     STMT_START {                                                             \
 378       unsigned offset = strlen(RExC_precomp)-(RExC_end-RExC_parse); \
 379       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,\
 380                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 381     } STMT_END
 382
 383
 384 #define vWARN(loc,m)                                                         \
 385     STMT_START {                                                             \
 386         unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));          \
 387         Perl_warner(aTHX_ WARN_REGEXP, "%s" REPORT_LOCATION,\
 388                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
 389     } STMT_END                                                               \
 390
 391
 392 #define vWARN2(loc, m, a1)                                                   \
 393     STMT_START {                                                             \
 394         unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));          \
 395         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 396                  a1,                                                         \
 397                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 398     } STMT_END
 399
 400 #define vWARN3(loc, m, a1, a2)                                               \
 401     STMT_START {                                                             \
 402       unsigned offset = strlen(RExC_precomp) - (RExC_end - (loc));        \
 403         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,                    \
 404                  a1, a2,                                                     \
 405                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 406     } STMT_END
 407
 408 #define vWARN4(loc, m, a1, a2, a3)                                           \
 409     STMT_START {                                                             \
 410       unsigned offset = strlen(RExC_precomp)-(RExC_end-(loc));            \
 411         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 412                  a1, a2, a3,                                                 \
 413                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 414     } STMT_END
 415
 416
 417 /* Allow for side effects in s */
 418 #define REGC(c,s) STMT_START { if (!SIZE_ONLY) *(s) = (c); else (s);} STMT_END
 419
 420 static void clear_re(pTHXo_ void *r);
 421
 422 /* Mark that we cannot extend a found fixed substring at this point.
 423    Updata the longest found anchored substring and the longest found
 424    floating substrings if needed. */
 425
 426 STATIC void
 427 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 428 {
 429     STRLEN l = CHR_SVLEN(data->last_found);
 430     STRLEN old_l = CHR_SVLEN(*data->longest);
 431
 432     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
 433         sv_setsv(*data->longest, data->last_found);
 434         if (*data->longest == data->longest_fixed) {
 435             data->offset_fixed = l ? data->last_start_min : data->pos_min;
 436             if (data->flags & SF_BEFORE_EOL)
 437                 data->flags
 438                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
 439             else
 440                 data->flags &= ~SF_FIX_BEFORE_EOL;
 441         }
 442         else {
 443             data->offset_float_min = l ? data->last_start_min : data->pos_min;
 444             data->offset_float_max = (l
 445                                       ? data->last_start_max
 446                                       : data->pos_min + data->pos_delta);
 447             if (data->flags & SF_BEFORE_EOL)
 448                 data->flags
 449                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
 450             else
 451                 data->flags &= ~SF_FL_BEFORE_EOL;
 452         }
 453     }
 454     SvCUR_set(data->last_found, 0);
 455     data->last_end = -1;
 456     data->flags &= ~SF_BEFORE_EOL;
 457 }
 458
 459 /* Can match anything (initialization) */
 460 STATIC void
 461 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 462 {
 463     int value;
 464
 465     ANYOF_CLASS_ZERO(cl);
 466     for (value = 0; value < 256; ++value)
 467         ANYOF_BITMAP_SET(cl, value);
 468     cl->flags = ANYOF_EOS|ANYOF_UNICODE_ALL;
 469     if (LOC)
 470         cl->flags |= ANYOF_LOCALE;
 471 }
 472
 473 /* Can match anything (initialization) */
 474 STATIC int
 475 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
 476 {
 477     int value;
 478
 479     for (value = 0; value <= ANYOF_MAX; value += 2)
 480         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
 481             return 1;
 482     if (!(cl->flags & ANYOF_UNICODE_ALL))
 483         return 0;
 484     for (value = 0; value < 256; ++value)
 485         if (!ANYOF_BITMAP_TEST(cl, value))
 486             return 0;
 487     return 1;
 488 }
 489
 490 /* Can match anything (initialization) */
 491 STATIC void
 492 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 493 {
 494     Zero(cl, 1, struct regnode_charclass_class);
 495     cl->type = ANYOF;
 496     cl_anything(pRExC_state, cl);
 497 }
 498
 499 STATIC void
 500 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 501 {
 502     Zero(cl, 1, struct regnode_charclass_class);
 503     cl->type = ANYOF;
 504     cl_anything(pRExC_state, cl);
 505     if (LOC)
 506         cl->flags |= ANYOF_LOCALE;
 507 }
 508
 509 /* 'And' a given class with another one.  Can create false positives */
 510 /* We assume that cl is not inverted */
 511 STATIC void
 512 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 513          struct regnode_charclass_class *and_with)
 514 {
 515     if (!(and_with->flags & ANYOF_CLASS)
 516         && !(cl->flags & ANYOF_CLASS)
 517         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 518         && !(and_with->flags & ANYOF_FOLD)
 519         && !(cl->flags & ANYOF_FOLD)) {
 520         int i;
 521
 522         if (and_with->flags & ANYOF_INVERT)
 523             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 524                 cl->bitmap[i] &= ~and_with->bitmap[i];
 525         else
 526             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 527                 cl->bitmap[i] &= and_with->bitmap[i];
 528     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
 529     if (!(and_with->flags & ANYOF_EOS))
 530         cl->flags &= ~ANYOF_EOS;
 531
 532     if (cl->flags & ANYOF_UNICODE_ALL && and_with->flags & ANYOF_UNICODE) {
 533         cl->flags &= ~ANYOF_UNICODE_ALL;
 534         cl->flags |= ANYOF_UNICODE;
 535         ARG_SET(cl, ARG(and_with));
 536     }
 537     if (!(and_with->flags & ANYOF_UNICODE_ALL))
 538         cl->flags &= ~ANYOF_UNICODE_ALL;
 539     if (!(and_with->flags & (ANYOF_UNICODE|ANYOF_UNICODE_ALL)))
 540         cl->flags &= ~ANYOF_UNICODE;
 541 }
 542
 543 /* 'OR' a given class with another one.  Can create false positives */
 544 /* We assume that cl is not inverted */
 545 STATIC void
 546 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 547 {
 548     if (or_with->flags & ANYOF_INVERT) {
 549         /* We do not use
 550          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
 551          *   <= (B1 | !B2) | (CL1 | !CL2)
 552          * which is wasteful if CL2 is small, but we ignore CL2:
 553          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
 554          * XXXX Can we handle case-fold?  Unclear:
 555          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
 556          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
 557          */
 558         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 559              && !(or_with->flags & ANYOF_FOLD)
 560              && !(cl->flags & ANYOF_FOLD) ) {
 561             int i;
 562
 563             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 564                 cl->bitmap[i] |= ~or_with->bitmap[i];
 565         } /* XXXX: logic is complicated otherwise */
 566         else {
 567             cl_anything(pRExC_state, cl);
 568         }
 569     } else {
 570         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
 571         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 572              && (!(or_with->flags & ANYOF_FOLD)
 573                  || (cl->flags & ANYOF_FOLD)) ) {
 574             int i;
 575
 576             /* OR char bitmap and class bitmap separately */
 577             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 578                 cl->bitmap[i] |= or_with->bitmap[i];
 579             if (or_with->flags & ANYOF_CLASS) {
 580                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
 581                     cl->classflags[i] |= or_with->classflags[i];
 582                 cl->flags |= ANYOF_CLASS;
 583             }
 584         }
 585         else { /* XXXX: logic is complicated, leave it along for a moment. */
 586             cl_anything(pRExC_state, cl);
 587         }
 588     }
 589     if (or_with->flags & ANYOF_EOS)
 590         cl->flags |= ANYOF_EOS;
 591
 592     if (cl->flags & ANYOF_UNICODE && or_with->flags & ANYOF_UNICODE &&
 593         ARG(cl) != ARG(or_with)) {
 594         cl->flags |= ANYOF_UNICODE_ALL;
 595         cl->flags &= ~ANYOF_UNICODE;
 596     }
 597     if (or_with->flags & ANYOF_UNICODE_ALL) {
 598         cl->flags |= ANYOF_UNICODE_ALL;
 599         cl->flags &= ~ANYOF_UNICODE;
 600     }
 601 }
 602
 603 /* REx optimizer.  Converts nodes into quickier variants "in place".
 604    Finds fixed substrings.  */
 605
 606 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
 607    to the position after last scanned or to NULL. */
 608
 609 STATIC I32
 610 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
 611                         /* scanp: Start here (read-write). */
 612                         /* deltap: Write maxlen-minlen here. */
 613                         /* last: Stop before this one. */
 614 {
 615     I32 min = 0, pars = 0, code;
 616     regnode *scan = *scanp, *next;
 617     I32 delta = 0;
 618     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
 619     int is_inf_internal = 0;            /* The studied chunk is infinite */
 620     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
 621     scan_data_t data_fake;
 622     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
 623
 624     while (scan && OP(scan) != END && scan < last) {
 625         /* Peephole optimizer: */
 626
 627         if (PL_regkind[(U8)OP(scan)] == EXACT) {
 628             /* Merge several consecutive EXACTish nodes into one. */
 629             regnode *n = regnext(scan);
 630             U32 stringok = 1;
 631 #ifdef DEBUGGING
 632             regnode *stop = scan;
 633 #endif
 634
 635             next = scan + NODE_SZ_STR(scan);
 636             /* Skip NOTHING, merge EXACT*. */
 637             while (n &&
 638                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
 639                      (stringok && (OP(n) == OP(scan))))
 640                    && NEXT_OFF(n)
 641                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
 642                 if (OP(n) == TAIL || n > next)
 643                     stringok = 0;
 644                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
 645                     NEXT_OFF(scan) += NEXT_OFF(n);
 646                     next = n + NODE_STEP_REGNODE;
 647 #ifdef DEBUGGING
 648                     if (stringok)
 649                         stop = n;
 650 #endif
 651                     n = regnext(n);
 652                 }
 653                 else if (stringok) {
 654                     int oldl = STR_LEN(scan);
 655                     regnode *nnext = regnext(n);
 656
 657                     if (oldl + STR_LEN(n) > U8_MAX)
 658                         break;
 659                     NEXT_OFF(scan) += NEXT_OFF(n);
 660                     STR_LEN(scan) += STR_LEN(n);
 661                     next = n + NODE_SZ_STR(n);
 662                     /* Now we can overwrite *n : */
 663                     Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
 664 #ifdef DEBUGGING
 665                     stop = next - 1;
 666 #endif
 667                     n = nnext;
 668                 }
 669             }
 670 #ifdef DEBUGGING
 671             /* Allow dumping */
 672             n = scan + NODE_SZ_STR(scan);
 673             while (n <= stop) {
 674                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
 675                     OP(n) = OPTIMIZED;
 676                     NEXT_OFF(n) = 0;
 677                 }
 678                 n++;
 679             }
 680 #endif
 681         }
 682         /* Follow the next-chain of the current node and optimize
 683            away all the NOTHINGs from it.  */
 684         if (OP(scan) != CURLYX) {
 685             int max = (reg_off_by_arg[OP(scan)]
 686                        ? I32_MAX
 687                        /* I32 may be smaller than U16 on CRAYs! */
 688                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
 689             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
 690             int noff;
 691             regnode *n = scan;
 692
 693             /* Skip NOTHING and LONGJMP. */
 694             while ((n = regnext(n))
 695                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
 696                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
 697                    && off + noff < max)
 698                 off += noff;
 699             if (reg_off_by_arg[OP(scan)])
 700                 ARG(scan) = off;
 701             else
 702                 NEXT_OFF(scan) = off;
 703         }
 704         /* The principal pseudo-switch.  Cannot be a switch, since we
 705            look into several different things.  */
 706         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
 707                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
 708             next = regnext(scan);
 709             code = OP(scan);
 710
 711             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
 712                 I32 max1 = 0, min1 = I32_MAX, num = 0;
 713                 struct regnode_charclass_class accum;
 714
 715                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
 716                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
 717                 if (flags & SCF_DO_STCLASS)
 718                     cl_init_zero(pRExC_state, &accum);
 719                 while (OP(scan) == code) {
 720                     I32 deltanext, minnext, f = 0, fake;
 721                     struct regnode_charclass_class this_class;
 722
 723                     num++;
 724                     data_fake.flags = 0;
 725                     if (data) {
 726                         data_fake.whilem_c = data->whilem_c;
 727                         data_fake.last_closep = data->last_closep;
 728                     }
 729                     else
 730                         data_fake.last_closep = &fake;
 731                     next = regnext(scan);
 732                     scan = NEXTOPER(scan);
 733                     if (code != BRANCH)
 734                         scan = NEXTOPER(scan);
 735                     if (flags & SCF_DO_STCLASS) {
 736                         cl_init(pRExC_state, &this_class);
 737                         data_fake.start_class = &this_class;
 738                         f = SCF_DO_STCLASS_AND;
 739                     }
 740                     if (flags & SCF_WHILEM_VISITED_POS)
 741                         f |= SCF_WHILEM_VISITED_POS;
 742                     /* we suppose the run is continuous, last=next...*/
 743                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
 744                                           next, &data_fake, f);
 745                     if (min1 > minnext)
 746                         min1 = minnext;
 747                     if (max1 < minnext + deltanext)
 748                         max1 = minnext + deltanext;
 749                     if (deltanext == I32_MAX)
 750                         is_inf = is_inf_internal = 1;
 751                     scan = next;
 752                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
 753                         pars++;
 754                     if (data && (data_fake.flags & SF_HAS_EVAL))
 755                         data->flags |= SF_HAS_EVAL;
 756                     if (data)
 757                         data->whilem_c = data_fake.whilem_c;
 758                     if (flags & SCF_DO_STCLASS)
 759                         cl_or(pRExC_state, &accum, &this_class);
 760                     if (code == SUSPEND)
 761                         break;
 762                 }
 763                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
 764                     min1 = 0;
 765                 if (flags & SCF_DO_SUBSTR) {
 766                     data->pos_min += min1;
 767                     data->pos_delta += max1 - min1;
 768                     if (max1 != min1 || is_inf)
 769                         data->longest = &(data->longest_float);
 770                 }
 771                 min += min1;
 772                 delta += max1 - min1;
 773                 if (flags & SCF_DO_STCLASS_OR) {
 774                     cl_or(pRExC_state, data->start_class, &accum);
 775                     if (min1) {
 776                         cl_and(data->start_class, &and_with);
 777                         flags &= ~SCF_DO_STCLASS;
 778                     }
 779                 }
 780                 else if (flags & SCF_DO_STCLASS_AND) {
 781                     if (min1) {
 782                         cl_and(data->start_class, &accum);
 783                         flags &= ~SCF_DO_STCLASS;
 784                     }
 785                     else {
 786                         /* Switch to OR mode: cache the old value of
 787                          * data->start_class */
 788                         StructCopy(data->start_class, &and_with,
 789                                    struct regnode_charclass_class);
 790                         flags &= ~SCF_DO_STCLASS_AND;
 791                         StructCopy(&accum, data->start_class,
 792                                    struct regnode_charclass_class);
 793                         flags |= SCF_DO_STCLASS_OR;
 794                         data->start_class->flags |= ANYOF_EOS;
 795                     }
 796                 }
 797             }
 798             else if (code == BRANCHJ)   /* single branch is optimized. */
 799                 scan = NEXTOPER(NEXTOPER(scan));
 800             else                        /* single branch is optimized. */
 801                 scan = NEXTOPER(scan);
 802             continue;
 803         }
 804         else if (OP(scan) == EXACT) {
 805             I32 l = STR_LEN(scan);
 806             UV uc = *((U8*)STRING(scan));
 807             if (UTF) {
 808                 U8 *s = (U8*)STRING(scan);
 809                 l = utf8_length(s, s + l);
 810                 uc = utf8_to_uvchr(s, NULL);
 811             }
 812             min += l;
 813             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
 814                 /* The code below prefers earlier match for fixed
 815                    offset, later match for variable offset.  */
 816                 if (data->last_end == -1) { /* Update the start info. */
 817                     data->last_start_min = data->pos_min;
 818                     data->last_start_max = is_inf
 819                         ? I32_MAX : data->pos_min + data->pos_delta;
 820                 }
 821                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
 822                 data->last_end = data->pos_min + l;
 823                 data->pos_min += l; /* As in the first entry. */
 824                 data->flags &= ~SF_BEFORE_EOL;
 825             }
 826             if (flags & SCF_DO_STCLASS_AND) {
 827                 /* Check whether it is compatible with what we know already! */
 828                 int compat = 1;
 829
 830                 if (uc >= 0x100 ||
 831                     !(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 832                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 833                     && (!(data->start_class->flags & ANYOF_FOLD)
 834                         || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 835                     compat = 0;
 836                 ANYOF_CLASS_ZERO(data->start_class);
 837                 ANYOF_BITMAP_ZERO(data->start_class);
 838                 if (compat)
 839                     ANYOF_BITMAP_SET(data->start_class, uc);
 840                 data->start_class->flags &= ~ANYOF_EOS;
 841                 if (uc < 0x100)
 842                   data->start_class->flags &= ~ANYOF_UNICODE_ALL;
 843             }
 844             else if (flags & SCF_DO_STCLASS_OR) {
 845                 /* false positive possible if the class is case-folded */
 846                 if (uc < 0x100)
 847                     ANYOF_BITMAP_SET(data->start_class, uc);
 848                 else
 849                     data->start_class->flags |= ANYOF_UNICODE_ALL;
 850                 data->start_class->flags &= ~ANYOF_EOS;
 851                 cl_and(data->start_class, &and_with);
 852             }
 853             flags &= ~SCF_DO_STCLASS;
 854         }
 855         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
 856             I32 l = STR_LEN(scan);
 857             UV uc = *((U8*)STRING(scan));
 858
 859             /* Search for fixed substrings supports EXACT only. */
 860             if (flags & SCF_DO_SUBSTR)
 861                 scan_commit(pRExC_state, data);
 862             if (UTF) {
 863                 U8 *s = (U8 *)STRING(scan);
 864                 l = utf8_length(s, s + l);
 865                 uc = utf8_to_uvchr(s, NULL);
 866             }
 867             min += l;
 868             if (data && (flags & SCF_DO_SUBSTR))
 869                 data->pos_min += l;
 870             if (flags & SCF_DO_STCLASS_AND) {
 871                 /* Check whether it is compatible with what we know already! */
 872                 int compat = 1;
 873
 874                 if (uc >= 0x100 ||
 875                     !(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 876                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 877                     && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc]))
 878                     compat = 0;
 879                 ANYOF_CLASS_ZERO(data->start_class);
 880                 ANYOF_BITMAP_ZERO(data->start_class);
 881                 if (compat) {
 882                     ANYOF_BITMAP_SET(data->start_class, uc);
 883                     data->start_class->flags &= ~ANYOF_EOS;
 884                     data->start_class->flags |= ANYOF_FOLD;
 885                     if (OP(scan) == EXACTFL)
 886                         data->start_class->flags |= ANYOF_LOCALE;
 887                 }
 888             }
 889             else if (flags & SCF_DO_STCLASS_OR) {
 890                 if (data->start_class->flags & ANYOF_FOLD) {
 891                     /* false positive possible if the class is case-folded.
 892                        Assume that the locale settings are the same... */
 893                     if (uc < 0x100)
 894                         ANYOF_BITMAP_SET(data->start_class, uc);
 895                     data->start_class->flags &= ~ANYOF_EOS;
 896                 }
 897                 cl_and(data->start_class, &and_with);
 898             }
 899             flags &= ~SCF_DO_STCLASS;
 900         }
 901         else if (strchr((char*)PL_varies,OP(scan))) {
 902             I32 mincount, maxcount, minnext, deltanext, fl;
 903             I32 f = flags, pos_before = 0;
 904             regnode *oscan = scan;
 905             struct regnode_charclass_class this_class;
 906             struct regnode_charclass_class *oclass = NULL;
 907
 908             switch (PL_regkind[(U8)OP(scan)]) {
 909             case WHILEM:                /* End of (?:...)* . */
 910                 scan = NEXTOPER(scan);
 911                 goto finish;
 912             case PLUS:
 913                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
 914                     next = NEXTOPER(scan);
 915                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
 916                         mincount = 1;
 917                         maxcount = REG_INFTY;
 918                         next = regnext(scan);
 919                         scan = NEXTOPER(scan);
 920                         goto do_curly;
 921                     }
 922                 }
 923                 if (flags & SCF_DO_SUBSTR)
 924                     data->pos_min++;
 925                 min++;
 926                 /* Fall through. */
 927             case STAR:
 928                 if (flags & SCF_DO_STCLASS) {
 929                     mincount = 0;
 930                     maxcount = REG_INFTY;
 931                     next = regnext(scan);
 932                     scan = NEXTOPER(scan);
 933                     goto do_curly;
 934                 }
 935                 is_inf = is_inf_internal = 1;
 936                 scan = regnext(scan);
 937                 if (flags & SCF_DO_SUBSTR) {
 938                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
 939                     data->longest = &(data->longest_float);
 940                 }
 941                 goto optimize_curly_tail;
 942             case CURLY:
 943                 mincount = ARG1(scan);
 944                 maxcount = ARG2(scan);
 945                 next = regnext(scan);
 946                 if (OP(scan) == CURLYX) {
 947                     I32 lp = (data ? *(data->last_closep) : 0);
 948
 949                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
 950                 }
 951                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
 952               do_curly:
 953                 if (flags & SCF_DO_SUBSTR) {
 954                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
 955                     pos_before = data->pos_min;
 956                 }
 957                 if (data) {
 958                     fl = data->flags;
 959                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
 960                     if (is_inf)
 961                         data->flags |= SF_IS_INF;
 962                 }
 963                 if (flags & SCF_DO_STCLASS) {
 964                     cl_init(pRExC_state, &this_class);
 965                     oclass = data->start_class;
 966                     data->start_class = &this_class;
 967                     f |= SCF_DO_STCLASS_AND;
 968                     f &= ~SCF_DO_STCLASS_OR;
 969                 }
 970                 /* These are the cases when once a subexpression
 971                    fails at a particular position, it cannot succeed
 972                    even after backtracking at the enclosing scope.
 973
 974                    XXXX what if minimal match and we are at the
 975                         initial run of {n,m}? */
 976                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
 977                     f &= ~SCF_WHILEM_VISITED_POS;
 978
 979                 /* This will finish on WHILEM, setting scan, or on NULL: */
 980                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
 981                                       mincount == 0
 982                                         ? (f & ~SCF_DO_SUBSTR) : f);
 983
 984                 if (flags & SCF_DO_STCLASS)
 985                     data->start_class = oclass;
 986                 if (mincount == 0 || minnext == 0) {
 987                     if (flags & SCF_DO_STCLASS_OR) {
 988                         cl_or(pRExC_state, data->start_class, &this_class);
 989                     }
 990                     else if (flags & SCF_DO_STCLASS_AND) {
 991                         /* Switch to OR mode: cache the old value of
 992                          * data->start_class */
 993                         StructCopy(data->start_class, &and_with,
 994                                    struct regnode_charclass_class);
 995                         flags &= ~SCF_DO_STCLASS_AND;
 996                         StructCopy(&this_class, data->start_class,
 997                                    struct regnode_charclass_class);
 998                         flags |= SCF_DO_STCLASS_OR;
 999                         data->start_class->flags |= ANYOF_EOS;
1000                     }
1001                 } else {                /* Non-zero len */
1002                     if (flags & SCF_DO_STCLASS_OR) {
1003                         cl_or(pRExC_state, data->start_class, &this_class);
1004                         cl_and(data->start_class, &and_with);
1005                     }
1006                     else if (flags & SCF_DO_STCLASS_AND)
1007                         cl_and(data->start_class, &this_class);
1008                     flags &= ~SCF_DO_STCLASS;
1009                 }
1010                 if (!scan)              /* It was not CURLYX, but CURLY. */
1011                     scan = next;
1012                 if (ckWARN(WARN_REGEXP) && (minnext + deltanext == 0)
1013                     && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1014                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1015                 {
1016                     vWARN(RExC_parse,
1017                           "Quantifier unexpected on zero-length expression");
1018                 }
1019
1020                 min += minnext * mincount;
1021                 is_inf_internal |= ((maxcount == REG_INFTY
1022                                      && (minnext + deltanext) > 0)
1023                                     || deltanext == I32_MAX);
1024                 is_inf |= is_inf_internal;
1025                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1026
1027                 /* Try powerful optimization CURLYX => CURLYN. */
1028                 if (  OP(oscan) == CURLYX && data
1029                       && data->flags & SF_IN_PAR
1030                       && !(data->flags & SF_HAS_EVAL)
1031                       && !deltanext && minnext == 1 ) {
1032                     /* Try to optimize to CURLYN.  */
1033                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1034                     regnode *nxt1 = nxt, *nxt2;
1035
1036                     /* Skip open. */
1037                     nxt = regnext(nxt);
1038                     if (!strchr((char*)PL_simple,OP(nxt))
1039                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1040                              && STR_LEN(nxt) == 1))
1041                         goto nogo;
1042                     nxt2 = nxt;
1043                     nxt = regnext(nxt);
1044                     if (OP(nxt) != CLOSE)
1045                         goto nogo;
1046                     /* Now we know that nxt2 is the only contents: */
1047                     oscan->flags = ARG(nxt);
1048                     OP(oscan) = CURLYN;
1049                     OP(nxt1) = NOTHING; /* was OPEN. */
1050 #ifdef DEBUGGING
1051                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1052                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1053                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1054                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1055                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1056                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1057 #endif
1058                 }
1059               nogo:
1060
1061                 /* Try optimization CURLYX => CURLYM. */
1062                 if (  OP(oscan) == CURLYX && data
1063                       && !(data->flags & SF_HAS_PAR)
1064                       && !(data->flags & SF_HAS_EVAL)
1065                       && !deltanext  ) {
1066                     /* XXXX How to optimize if data == 0? */
1067                     /* Optimize to a simpler form.  */
1068                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1069                     regnode *nxt2;
1070
1071                     OP(oscan) = CURLYM;
1072                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1073                             && (OP(nxt2) != WHILEM))
1074                         nxt = nxt2;
1075                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1076                     /* Need to optimize away parenths. */
1077                     if (data->flags & SF_IN_PAR) {
1078                         /* Set the parenth number.  */
1079                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1080
1081                         if (OP(nxt) != CLOSE)
1082                             FAIL("Panic opt close");
1083                         oscan->flags = ARG(nxt);
1084                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1085                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1086 #ifdef DEBUGGING
1087                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1088                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1089                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1090                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1091 #endif
1092 #if 0
1093                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1094                             regnode *nnxt = regnext(nxt1);
1095
1096                             if (nnxt == nxt) {
1097                                 if (reg_off_by_arg[OP(nxt1)])
1098                                     ARG_SET(nxt1, nxt2 - nxt1);
1099                                 else if (nxt2 - nxt1 < U16_MAX)
1100                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1101                                 else
1102                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1103                             }
1104                             nxt1 = nnxt;
1105                         }
1106 #endif
1107                         /* Optimize again: */
1108                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1109                                     NULL, 0);
1110                     }
1111                     else
1112                         oscan->flags = 0;
1113                 }
1114                 else if ((OP(oscan) == CURLYX)
1115                          && (flags & SCF_WHILEM_VISITED_POS)
1116                          /* See the comment on a similar expression above.
1117                             However, this time it not a subexpression
1118                             we care about, but the expression itself. */
1119                          && (maxcount == REG_INFTY)
1120                          && data && ++data->whilem_c < 16) {
1121                     /* This stays as CURLYX, we can put the count/of pair. */
1122                     /* Find WHILEM (as in regexec.c) */
1123                     regnode *nxt = oscan + NEXT_OFF(oscan);
1124
1125                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1126                         nxt += ARG(nxt);
1127                     PREVOPER(nxt)->flags = data->whilem_c
1128                         | (RExC_whilem_seen << 4); /* On WHILEM */
1129                 }
1130                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1131                     pars++;
1132                 if (flags & SCF_DO_SUBSTR) {
1133                     SV *last_str = Nullsv;
1134                     int counted = mincount != 0;
1135
1136                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1137                         I32 b = pos_before >= data->last_start_min
1138                             ? pos_before : data->last_start_min;
1139                         STRLEN l;
1140                         char *s = SvPV(data->last_found, l);
1141                         I32 old = b - data->last_start_min;
1142
1143                         if (UTF)
1144                             old = utf8_hop((U8*)s, old) - (U8*)s;
1145
1146                         l -= old;
1147                         /* Get the added string: */
1148                         last_str = newSVpvn(s  + old, l);
1149                         if (deltanext == 0 && pos_before == b) {
1150                             /* What was added is a constant string */
1151                             if (mincount > 1) {
1152                                 SvGROW(last_str, (mincount * l) + 1);
1153                                 repeatcpy(SvPVX(last_str) + l,
1154                                           SvPVX(last_str), l, mincount - 1);
1155                                 SvCUR(last_str) *= mincount;
1156                                 /* Add additional parts. */
1157                                 SvCUR_set(data->last_found,
1158                                           SvCUR(data->last_found) - l);
1159                                 sv_catsv(data->last_found, last_str);
1160                                 data->last_end += l * (mincount - 1);
1161                             }
1162                         } else {
1163                             /* start offset must point into the last copy */
1164                             data->last_start_min += minnext * (mincount - 1);
1165                             data->last_start_max += is_inf ? 0 : (maxcount - 1)
1166                                 * (minnext + data->pos_delta);
1167                         }
1168                     }
1169                     /* It is counted once already... */
1170                     data->pos_min += minnext * (mincount - counted);
1171                     data->pos_delta += - counted * deltanext +
1172                         (minnext + deltanext) * maxcount - minnext * mincount;
1173                     if (mincount != maxcount) {
1174                          /* Cannot extend fixed substrings found inside
1175                             the group.  */
1176                         scan_commit(pRExC_state,data);
1177                         if (mincount && last_str) {
1178                             sv_setsv(data->last_found, last_str);
1179                             data->last_end = data->pos_min;
1180                             data->last_start_min =
1181                                 data->pos_min - CHR_SVLEN(last_str);
1182                             data->last_start_max = is_inf
1183                                 ? I32_MAX
1184                                 : data->pos_min + data->pos_delta
1185                                 - CHR_SVLEN(last_str);
1186                         }
1187                         data->longest = &(data->longest_float);
1188                     }
1189                     SvREFCNT_dec(last_str);
1190                 }
1191                 if (data && (fl & SF_HAS_EVAL))
1192                     data->flags |= SF_HAS_EVAL;
1193               optimize_curly_tail:
1194                 if (OP(oscan) != CURLYX) {
1195                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1196                            && NEXT_OFF(next))
1197                         NEXT_OFF(oscan) += NEXT_OFF(next);
1198                 }
1199                 continue;
1200             default:                    /* REF and CLUMP only? */
1201                 if (flags & SCF_DO_SUBSTR) {
1202                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1203                     data->longest = &(data->longest_float);
1204                 }
1205                 is_inf = is_inf_internal = 1;
1206                 if (flags & SCF_DO_STCLASS_OR)
1207                     cl_anything(pRExC_state, data->start_class);
1208                 flags &= ~SCF_DO_STCLASS;
1209                 break;
1210             }
1211         }
1212         else if (strchr((char*)PL_simple,OP(scan))) {
1213             int value;
1214
1215             if (flags & SCF_DO_SUBSTR) {
1216                 scan_commit(pRExC_state,data);
1217                 data->pos_min++;
1218             }
1219             min++;
1220             if (flags & SCF_DO_STCLASS) {
1221                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1222
1223                 /* Some of the logic below assumes that switching
1224                    locale on will only add false positives. */
1225                 switch (PL_regkind[(U8)OP(scan)]) {
1226                 case SANY:
1227                 default:
1228                   do_default:
1229                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1230                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1231                         cl_anything(pRExC_state, data->start_class);
1232                     break;
1233                 case REG_ANY:
1234                     if (OP(scan) == SANY)
1235                         goto do_default;
1236                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1237                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1238                                  || (data->start_class->flags & ANYOF_CLASS));
1239                         cl_anything(pRExC_state, data->start_class);
1240                     }
1241                     if (flags & SCF_DO_STCLASS_AND || !value)
1242                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1243                     break;
1244                 case ANYOF:
1245                     if (flags & SCF_DO_STCLASS_AND)
1246                         cl_and(data->start_class,
1247                                (struct regnode_charclass_class*)scan);
1248                     else
1249                         cl_or(pRExC_state, data->start_class,
1250                               (struct regnode_charclass_class*)scan);
1251                     break;
1252                 case ALNUM:
1253                     if (flags & SCF_DO_STCLASS_AND) {
1254                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1255                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1256                             for (value = 0; value < 256; value++)
1257                                 if (!isALNUM(value))
1258                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1259                         }
1260                     }
1261                     else {
1262                         if (data->start_class->flags & ANYOF_LOCALE)
1263                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1264                         else {
1265                             for (value = 0; value < 256; value++)
1266                                 if (isALNUM(value))
1267                                     ANYOF_BITMAP_SET(data->start_class, value);
1268                         }
1269                     }
1270                     break;
1271                 case ALNUML:
1272                     if (flags & SCF_DO_STCLASS_AND) {
1273                         if (data->start_class->flags & ANYOF_LOCALE)
1274                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1275                     }
1276                     else {
1277                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1278                         data->start_class->flags |= ANYOF_LOCALE;
1279                     }
1280                     break;
1281                 case NALNUM:
1282                     if (flags & SCF_DO_STCLASS_AND) {
1283                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1284                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1285                             for (value = 0; value < 256; value++)
1286                                 if (isALNUM(value))
1287                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1288                         }
1289                     }
1290                     else {
1291                         if (data->start_class->flags & ANYOF_LOCALE)
1292                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1293                         else {
1294                             for (value = 0; value < 256; value++)
1295                                 if (!isALNUM(value))
1296                                     ANYOF_BITMAP_SET(data->start_class, value);
1297                         }
1298                     }
1299                     break;
1300                 case NALNUML:
1301                     if (flags & SCF_DO_STCLASS_AND) {
1302                         if (data->start_class->flags & ANYOF_LOCALE)
1303                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1304                     }
1305                     else {
1306                         data->start_class->flags |= ANYOF_LOCALE;
1307                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1308                     }
1309                     break;
1310                 case SPACE:
1311                     if (flags & SCF_DO_STCLASS_AND) {
1312                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1313                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1314                             for (value = 0; value < 256; value++)
1315                                 if (!isSPACE(value))
1316                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1317                         }
1318                     }
1319                     else {
1320                         if (data->start_class->flags & ANYOF_LOCALE)
1321                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1322                         else {
1323                             for (value = 0; value < 256; value++)
1324                                 if (isSPACE(value))
1325                                     ANYOF_BITMAP_SET(data->start_class, value);
1326                         }
1327                     }
1328                     break;
1329                 case SPACEL:
1330                     if (flags & SCF_DO_STCLASS_AND) {
1331                         if (data->start_class->flags & ANYOF_LOCALE)
1332                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1333                     }
1334                     else {
1335                         data->start_class->flags |= ANYOF_LOCALE;
1336                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1337                     }
1338                     break;
1339                 case NSPACE:
1340                     if (flags & SCF_DO_STCLASS_AND) {
1341                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1342                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1343                             for (value = 0; value < 256; value++)
1344                                 if (isSPACE(value))
1345                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1346                         }
1347                     }
1348                     else {
1349                         if (data->start_class->flags & ANYOF_LOCALE)
1350                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1351                         else {
1352                             for (value = 0; value < 256; value++)
1353                                 if (!isSPACE(value))
1354                                     ANYOF_BITMAP_SET(data->start_class, value);
1355                         }
1356                     }
1357                     break;
1358                 case NSPACEL:
1359                     if (flags & SCF_DO_STCLASS_AND) {
1360                         if (data->start_class->flags & ANYOF_LOCALE) {
1361                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1362                             for (value = 0; value < 256; value++)
1363                                 if (!isSPACE(value))
1364                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1365                         }
1366                     }
1367                     else {
1368                         data->start_class->flags |= ANYOF_LOCALE;
1369                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1370                     }
1371                     break;
1372                 case DIGIT:
1373                     if (flags & SCF_DO_STCLASS_AND) {
1374                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1375                         for (value = 0; value < 256; value++)
1376                             if (!isDIGIT(value))
1377                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1378                     }
1379                     else {
1380                         if (data->start_class->flags & ANYOF_LOCALE)
1381                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1382                         else {
1383                             for (value = 0; value < 256; value++)
1384                                 if (isDIGIT(value))
1385                                     ANYOF_BITMAP_SET(data->start_class, value);
1386                         }
1387                     }
1388                     break;
1389                 case NDIGIT:
1390                     if (flags & SCF_DO_STCLASS_AND) {
1391                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1392                         for (value = 0; value < 256; value++)
1393                             if (isDIGIT(value))
1394                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1395                     }
1396                     else {
1397                         if (data->start_class->flags & ANYOF_LOCALE)
1398                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1399                         else {
1400                             for (value = 0; value < 256; value++)
1401                                 if (!isDIGIT(value))
1402                                     ANYOF_BITMAP_SET(data->start_class, value);
1403                         }
1404                     }
1405                     break;
1406                 }
1407                 if (flags & SCF_DO_STCLASS_OR)
1408                     cl_and(data->start_class, &and_with);
1409                 flags &= ~SCF_DO_STCLASS;
1410             }
1411         }
1412         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1413             data->flags |= (OP(scan) == MEOL
1414                             ? SF_BEFORE_MEOL
1415                             : SF_BEFORE_SEOL);
1416         }
1417         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1418                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1419                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1420                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1421             /* Lookahead/lookbehind */
1422             I32 deltanext, minnext, fake = 0;
1423             regnode *nscan;
1424             struct regnode_charclass_class intrnl;
1425             int f = 0;
1426
1427             data_fake.flags = 0;
1428             if (data) {
1429                 data_fake.whilem_c = data->whilem_c;
1430                 data_fake.last_closep = data->last_closep;
1431             }
1432             else
1433                 data_fake.last_closep = &fake;
1434             if ( flags & SCF_DO_STCLASS && !scan->flags
1435                  && OP(scan) == IFMATCH ) { /* Lookahead */
1436                 cl_init(pRExC_state, &intrnl);
1437                 data_fake.start_class = &intrnl;
1438                 f |= SCF_DO_STCLASS_AND;
1439             }
1440             if (flags & SCF_WHILEM_VISITED_POS)
1441                 f |= SCF_WHILEM_VISITED_POS;
1442             next = regnext(scan);
1443             nscan = NEXTOPER(NEXTOPER(scan));
1444             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1445             if (scan->flags) {
1446                 if (deltanext) {
1447                     vFAIL("Variable length lookbehind not implemented");
1448                 }
1449                 else if (minnext > U8_MAX) {
1450                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1451                 }
1452                 scan->flags = minnext;
1453             }
1454             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1455                 pars++;
1456             if (data && (data_fake.flags & SF_HAS_EVAL))
1457                 data->flags |= SF_HAS_EVAL;
1458             if (data)
1459                 data->whilem_c = data_fake.whilem_c;
1460             if (f & SCF_DO_STCLASS_AND) {
1461                 int was = (data->start_class->flags & ANYOF_EOS);
1462
1463                 cl_and(data->start_class, &intrnl);
1464                 if (was)
1465                     data->start_class->flags |= ANYOF_EOS;
1466             }
1467         }
1468         else if (OP(scan) == OPEN) {
1469             pars++;
1470         }
1471         else if (OP(scan) == CLOSE) {
1472             if (ARG(scan) == is_par) {
1473                 next = regnext(scan);
1474
1475                 if ( next && (OP(next) != WHILEM) && next < last)
1476                     is_par = 0;         /* Disable optimization */
1477             }
1478             if (data)
1479                 *(data->last_closep) = ARG(scan);
1480         }
1481         else if (OP(scan) == EVAL) {
1482                 if (data)
1483                     data->flags |= SF_HAS_EVAL;
1484         }
1485         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1486                 if (flags & SCF_DO_SUBSTR) {
1487                     scan_commit(pRExC_state,data);
1488                     data->longest = &(data->longest_float);
1489                 }
1490                 is_inf = is_inf_internal = 1;
1491                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1492                     cl_anything(pRExC_state, data->start_class);
1493                 flags &= ~SCF_DO_STCLASS;
1494         }
1495         /* Else: zero-length, ignore. */
1496         scan = regnext(scan);
1497     }
1498
1499   finish:
1500     *scanp = scan;
1501     *deltap = is_inf_internal ? I32_MAX : delta;
1502     if (flags & SCF_DO_SUBSTR && is_inf)
1503         data->pos_delta = I32_MAX - data->pos_min;
1504     if (is_par > U8_MAX)
1505         is_par = 0;
1506     if (is_par && pars==1 && data) {
1507         data->flags |= SF_IN_PAR;
1508         data->flags &= ~SF_HAS_PAR;
1509     }
1510     else if (pars && data) {
1511         data->flags |= SF_HAS_PAR;
1512         data->flags &= ~SF_IN_PAR;
1513     }
1514     if (flags & SCF_DO_STCLASS_OR)
1515         cl_and(data->start_class, &and_with);
1516     return min;
1517 }
1518
1519 STATIC I32
1520 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1521 {
1522     if (RExC_rx->data) {
1523         Renewc(RExC_rx->data,
1524                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1525                char, struct reg_data);
1526         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1527         RExC_rx->data->count += n;
1528     }
1529     else {
1530         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1531              char, struct reg_data);
1532         New(1208, RExC_rx->data->what, n, U8);
1533         RExC_rx->data->count = n;
1534     }
1535     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1536     return RExC_rx->data->count - n;
1537 }
1538
1539 void
1540 Perl_reginitcolors(pTHX)
1541 {
1542     int i = 0;
1543     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1544
1545     if (s) {
1546         PL_colors[0] = s = savepv(s);
1547         while (++i < 6) {
1548             s = strchr(s, '\t');
1549             if (s) {
1550                 *s = '\0';
1551                 PL_colors[i] = ++s;
1552             }
1553             else
1554                 PL_colors[i] = s = "";
1555         }
1556     } else {
1557         while (i < 6)
1558             PL_colors[i++] = "";
1559     }
1560     PL_colorset = 1;
1561 }
1562
1563
1564 /*
1565  - pregcomp - compile a regular expression into internal code
1566  *
1567  * We can't allocate space until we know how big the compiled form will be,
1568  * but we can't compile it (and thus know how big it is) until we've got a
1569  * place to put the code.  So we cheat:  we compile it twice, once with code
1570  * generation turned off and size counting turned on, and once "for real".
1571  * This also means that we don't allocate space until we are sure that the
1572  * thing really will compile successfully, and we never have to move the
1573  * code and thus invalidate pointers into it.  (Note that it has to be in
1574  * one piece because free() must be able to free it all.) [NB: not true in perl]
1575  *
1576  * Beware that the optimization-preparation code in here knows about some
1577  * of the structure of the compiled regexp.  [I'll say.]
1578  */
1579 regexp *
1580 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1581 {
1582     register regexp *r;
1583     regnode *scan;
1584     regnode *first;
1585     I32 flags;
1586     I32 minlen = 0;
1587     I32 sawplus = 0;
1588     I32 sawopen = 0;
1589     scan_data_t data;
1590     RExC_state_t RExC_state;
1591     RExC_state_t *pRExC_state = &RExC_state;
1592
1593     if (exp == NULL)
1594         FAIL("NULL regexp argument");
1595
1596     /* XXXX This looks very suspicious... */
1597     if (pm->op_pmdynflags & PMdf_CMP_UTF8)
1598         RExC_utf8 = 1;
1599     else
1600         RExC_utf8 = 0;
1601
1602     RExC_precomp = exp;
1603     DEBUG_r(if (!PL_colorset) reginitcolors());
1604     DEBUG_r(PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1605                       PL_colors[4],PL_colors[5],PL_colors[0],
1606                       (int)(xend - exp), RExC_precomp, PL_colors[1]));
1607     RExC_flags16 = pm->op_pmflags;
1608     RExC_sawback = 0;
1609
1610     RExC_seen = 0;
1611     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1612     RExC_seen_evals = 0;
1613     RExC_extralen = 0;
1614
1615     /* First pass: determine size, legality. */
1616     RExC_parse = exp;
1617     RExC_end = xend;
1618     RExC_naughty = 0;
1619     RExC_npar = 1;
1620     RExC_size = 0L;
1621     RExC_emit = &PL_regdummy;
1622     RExC_whilem_seen = 0;
1623 #if 0 /* REGC() is (currently) a NOP at the first pass.
1624        * Clever compilers notice this and complain. --jhi */
1625     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1626 #endif
1627     if (reg(pRExC_state, 0, &flags) == NULL) {
1628         RExC_precomp = Nullch;
1629         return(NULL);
1630     }
1631     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1632
1633     /* Small enough for pointer-storage convention?
1634        If extralen==0, this means that we will not need long jumps. */
1635     if (RExC_size >= 0x10000L && RExC_extralen)
1636         RExC_size += RExC_extralen;
1637     else
1638         RExC_extralen = 0;
1639     if (RExC_whilem_seen > 15)
1640         RExC_whilem_seen = 15;
1641
1642     /* Allocate space and initialize. */
1643     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1644          char, regexp);
1645     if (r == NULL)
1646         FAIL("Regexp out of space");
1647
1648 #ifdef DEBUGGING
1649     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1650     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1651 #endif
1652     r->refcnt = 1;
1653     r->prelen = xend - exp;
1654     r->precomp = savepvn(RExC_precomp, r->prelen);
1655     r->subbeg = NULL;
1656     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1657     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1658
1659     r->substrs = 0;                     /* Useful during FAIL. */
1660     r->startp = 0;                      /* Useful during FAIL. */
1661     r->endp = 0;                        /* Useful during FAIL. */
1662
1663     RExC_rx = r;
1664
1665     /* Second pass: emit code. */
1666     RExC_parse = exp;
1667     RExC_end = xend;
1668     RExC_naughty = 0;
1669     RExC_npar = 1;
1670     RExC_emit = r->program;
1671     /* Store the count of eval-groups for security checks: */
1672     RExC_emit->next_off = ((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1673     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1674     r->data = 0;
1675     if (reg(pRExC_state, 0, &flags) == NULL)
1676         return(NULL);
1677
1678     /* Dig out information for optimizations. */
1679     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1680     pm->op_pmflags = RExC_flags16;
1681     if (UTF)
1682         r->reganch |= ROPT_UTF8;
1683     r->regstclass = NULL;
1684     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1685         r->reganch |= ROPT_NAUGHTY;
1686     scan = r->program + 1;              /* First BRANCH. */
1687
1688     /* XXXX To minimize changes to RE engine we always allocate
1689        3-units-long substrs field. */
1690     Newz(1004, r->substrs, 1, struct reg_substr_data);
1691
1692     StructCopy(&zero_scan_data, &data, scan_data_t);
1693     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1694     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1695         I32 fake;
1696         STRLEN longest_float_length, longest_fixed_length;
1697         struct regnode_charclass_class ch_class;
1698         int stclass_flag;
1699         I32 last_close = 0;
1700
1701         first = scan;
1702         /* Skip introductions and multiplicators >= 1. */
1703         while ((OP(first) == OPEN && (sawopen = 1)) ||
1704                /* An OR of *one* alternative - should not happen now. */
1705             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1706             (OP(first) == PLUS) ||
1707             (OP(first) == MINMOD) ||
1708                /* An {n,m} with n>0 */
1709             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1710                 if (OP(first) == PLUS)
1711                     sawplus = 1;
1712                 else
1713                     first += regarglen[(U8)OP(first)];
1714                 first = NEXTOPER(first);
1715         }
1716
1717         /* Starting-point info. */
1718       again:
1719         if (PL_regkind[(U8)OP(first)] == EXACT) {
1720             if (OP(first) == EXACT)
1721                 ;       /* Empty, get anchored substr later. */
1722             else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
1723                 r->regstclass = first;
1724         }
1725         else if (strchr((char*)PL_simple,OP(first)))
1726             r->regstclass = first;
1727         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1728                  PL_regkind[(U8)OP(first)] == NBOUND)
1729             r->regstclass = first;
1730         else if (PL_regkind[(U8)OP(first)] == BOL) {
1731             r->reganch |= (OP(first) == MBOL
1732                            ? ROPT_ANCH_MBOL
1733                            : (OP(first) == SBOL
1734                               ? ROPT_ANCH_SBOL
1735                               : ROPT_ANCH_BOL));
1736             first = NEXTOPER(first);
1737             goto again;
1738         }
1739         else if (OP(first) == GPOS) {
1740             r->reganch |= ROPT_ANCH_GPOS;
1741             first = NEXTOPER(first);
1742             goto again;
1743         }
1744         else if ((OP(first) == STAR &&
1745             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1746             !(r->reganch & ROPT_ANCH) )
1747         {
1748             /* turn .* into ^.* with an implied $*=1 */
1749             int type = OP(NEXTOPER(first));
1750
1751             if (type == REG_ANY)
1752                 type = ROPT_ANCH_MBOL;
1753             else
1754                 type = ROPT_ANCH_SBOL;
1755
1756             r->reganch |= type | ROPT_IMPLICIT;
1757             first = NEXTOPER(first);
1758             goto again;
1759         }
1760         if (sawplus && (!sawopen || !RExC_sawback)
1761             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1762             /* x+ must match at the 1st pos of run of x's */
1763             r->reganch |= ROPT_SKIP;
1764
1765         /* Scan is after the zeroth branch, first is atomic matcher. */
1766         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1767                               (IV)(first - scan + 1)));
1768         /*
1769         * If there's something expensive in the r.e., find the
1770         * longest literal string that must appear and make it the
1771         * regmust.  Resolve ties in favor of later strings, since
1772         * the regstart check works with the beginning of the r.e.
1773         * and avoiding duplication strengthens checking.  Not a
1774         * strong reason, but sufficient in the absence of others.
1775         * [Now we resolve ties in favor of the earlier string if
1776         * it happens that c_offset_min has been invalidated, since the
1777         * earlier string may buy us something the later one won't.]
1778         */
1779         minlen = 0;
1780
1781         data.longest_fixed = newSVpvn("",0);
1782         data.longest_float = newSVpvn("",0);
1783         data.last_found = newSVpvn("",0);
1784         data.longest = &(data.longest_fixed);
1785         first = scan;
1786         if (!r->regstclass) {
1787             cl_init(pRExC_state, &ch_class);
1788             data.start_class = &ch_class;
1789             stclass_flag = SCF_DO_STCLASS_AND;
1790         } else                          /* XXXX Check for BOUND? */
1791             stclass_flag = 0;
1792         data.last_closep = &last_close;
1793
1794         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1795                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1796         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1797              && data.last_start_min == 0 && data.last_end > 0
1798              && !RExC_seen_zerolen
1799              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1800             r->reganch |= ROPT_CHECK_ALL;
1801         scan_commit(pRExC_state, &data);
1802         SvREFCNT_dec(data.last_found);
1803
1804         longest_float_length = CHR_SVLEN(data.longest_float);
1805         if (longest_float_length
1806             || (data.flags & SF_FL_BEFORE_EOL
1807                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1808                     || (RExC_flags16 & PMf_MULTILINE)))) {
1809             int t;
1810
1811             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1812                 && data.offset_fixed == data.offset_float_min
1813                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1814                     goto remove_float;          /* As in (a)+. */
1815
1816             r->float_substr = data.longest_float;
1817             r->float_min_offset = data.offset_float_min;
1818             r->float_max_offset = data.offset_float_max;
1819             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1820                        && (!(data.flags & SF_FL_BEFORE_MEOL)
1821                            || (RExC_flags16 & PMf_MULTILINE)));
1822             fbm_compile(r->float_substr, t ? FBMcf_TAIL : 0);
1823         }
1824         else {
1825           remove_float:
1826             r->float_substr = Nullsv;
1827             SvREFCNT_dec(data.longest_float);
1828             longest_float_length = 0;
1829         }
1830
1831         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
1832         if (longest_fixed_length
1833             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
1834                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
1835                     || (RExC_flags16 & PMf_MULTILINE)))) {
1836             int t;
1837
1838             r->anchored_substr = data.longest_fixed;
1839             r->anchored_offset = data.offset_fixed;
1840             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
1841                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
1842                      || (RExC_flags16 & PMf_MULTILINE)));
1843             fbm_compile(r->anchored_substr, t ? FBMcf_TAIL : 0);
1844         }
1845         else {
1846             r->anchored_substr = Nullsv;
1847             SvREFCNT_dec(data.longest_fixed);
1848             longest_fixed_length = 0;
1849         }
1850         if (r->regstclass
1851             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == SANY))
1852             r->regstclass = NULL;
1853         if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
1854             && !(data.start_class->flags & ANYOF_EOS)
1855             && !cl_is_anything(data.start_class)) {
1856             SV *sv;
1857             I32 n = add_data(pRExC_state, 1, "f");
1858
1859             New(1006, RExC_rx->data->data[n], 1,
1860                 struct regnode_charclass_class);
1861             StructCopy(data.start_class,
1862                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
1863                        struct regnode_charclass_class);
1864             r->regstclass = (regnode*)RExC_rx->data->data[n];
1865             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
1866             PL_regdata = r->data; /* for regprop() */
1867             DEBUG_r((sv = sv_newmortal(),
1868                      regprop(sv, (regnode*)data.start_class),
1869                      PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1870                                    SvPVX(sv))));
1871         }
1872
1873         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
1874         if (longest_fixed_length > longest_float_length) {
1875             r->check_substr = r->anchored_substr;
1876             r->check_offset_min = r->check_offset_max = r->anchored_offset;
1877             if (r->reganch & ROPT_ANCH_SINGLE)
1878                 r->reganch |= ROPT_NOSCAN;
1879         }
1880         else {
1881             r->check_substr = r->float_substr;
1882             r->check_offset_min = data.offset_float_min;
1883             r->check_offset_max = data.offset_float_max;
1884         }
1885         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
1886            This should be changed ASAP!  */
1887         if (r->check_substr && !(r->reganch & ROPT_ANCH_GPOS)) {
1888             r->reganch |= RE_USE_INTUIT;
1889             if (SvTAIL(r->check_substr))
1890                 r->reganch |= RE_INTUIT_TAIL;
1891         }
1892     }
1893     else {
1894         /* Several toplevels. Best we can is to set minlen. */
1895         I32 fake;
1896         struct regnode_charclass_class ch_class;
1897         I32 last_close = 0;
1898
1899         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
1900         scan = r->program + 1;
1901         cl_init(pRExC_state, &ch_class);
1902         data.start_class = &ch_class;
1903         data.last_closep = &last_close;
1904         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
1905         r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
1906         if (!(data.start_class->flags & ANYOF_EOS)
1907             && !cl_is_anything(data.start_class)) {
1908             SV *sv;
1909             I32 n = add_data(pRExC_state, 1, "f");
1910
1911             New(1006, RExC_rx->data->data[n], 1,
1912                 struct regnode_charclass_class);
1913             StructCopy(data.start_class,
1914                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
1915                        struct regnode_charclass_class);
1916             r->regstclass = (regnode*)RExC_rx->data->data[n];
1917             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
1918             DEBUG_r((sv = sv_newmortal(),
1919                      regprop(sv, (regnode*)data.start_class),
1920                      PerlIO_printf(Perl_debug_log, "synthetic stclass `%s'.\n",
1921                                    SvPVX(sv))));
1922         }
1923     }
1924
1925     r->minlen = minlen;
1926     if (RExC_seen & REG_SEEN_GPOS)
1927         r->reganch |= ROPT_GPOS_SEEN;
1928     if (RExC_seen & REG_SEEN_LOOKBEHIND)
1929         r->reganch |= ROPT_LOOKBEHIND_SEEN;
1930     if (RExC_seen & REG_SEEN_EVAL)
1931         r->reganch |= ROPT_EVAL_SEEN;
1932     if (RExC_seen & REG_SEEN_SANY)
1933         r->reganch |= ROPT_SANY_SEEN;
1934     Newz(1002, r->startp, RExC_npar, I32);
1935     Newz(1002, r->endp, RExC_npar, I32);
1936     PL_regdata = r->data; /* for regprop() */
1937     DEBUG_r(regdump(r));
1938     return(r);
1939 }
1940
1941 /*
1942  - reg - regular expression, i.e. main body or parenthesized thing
1943  *
1944  * Caller must absorb opening parenthesis.
1945  *
1946  * Combining parenthesis handling with the base level of regular expression
1947  * is a trifle forced, but the need to tie the tails of the branches to what
1948  * follows makes it hard to avoid.
1949  */
1950 STATIC regnode *
1951 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
1952     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
1953 {
1954     register regnode *ret;              /* Will be the head of the group. */
1955     register regnode *br;
1956     register regnode *lastbr;
1957     register regnode *ender = 0;
1958     register I32 parno = 0;
1959     I32 flags, oregflags = RExC_flags16, have_branch = 0, open = 0;
1960     char *oregcomp_parse = RExC_parse;
1961     char c;
1962
1963     *flagp = 0;                         /* Tentatively. */
1964
1965     /* Make an OPEN node, if parenthesized. */
1966     if (paren) {
1967         if (*RExC_parse == '?') {
1968             U16 posflags = 0, negflags = 0;
1969             U16 *flagsp = &posflags;
1970             int logical = 0;
1971             char *seqstart = RExC_parse;
1972
1973             RExC_parse++;
1974             paren = *RExC_parse++;
1975             ret = NULL;                 /* For look-ahead/behind. */
1976             switch (paren) {
1977             case '<':
1978                 RExC_seen |= REG_SEEN_LOOKBEHIND;
1979                 if (*RExC_parse == '!')
1980                     paren = ',';
1981                 if (*RExC_parse != '=' && *RExC_parse != '!')
1982                     goto unknown;
1983                 RExC_parse++;
1984             case '=':
1985             case '!':
1986                 RExC_seen_zerolen++;
1987             case ':':
1988             case '>':
1989                 break;
1990             case '$':
1991             case '@':
1992                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
1993                 break;
1994             case '#':
1995                 while (*RExC_parse && *RExC_parse != ')')
1996                     RExC_parse++;
1997                 if (*RExC_parse != ')')
1998                     FAIL("Sequence (?#... not terminated");
1999                 nextchar(pRExC_state);
2000                 *flagp = TRYAGAIN;
2001                 return NULL;
2002             case 'p':
2003                 if (SIZE_ONLY)
2004                     vWARN(RExC_parse, "(?p{}) is deprecated - use (??{})");
2005                 /* FALL THROUGH*/
2006             case '?':
2007                 logical = 1;
2008                 paren = *RExC_parse++;
2009                 /* FALL THROUGH */
2010             case '{':
2011             {
2012                 I32 count = 1, n = 0;
2013                 char c;
2014                 char *s = RExC_parse;
2015                 SV *sv;
2016                 OP_4tree *sop, *rop;
2017
2018                 RExC_seen_zerolen++;
2019                 RExC_seen |= REG_SEEN_EVAL;
2020                 while (count && (c = *RExC_parse)) {
2021                     if (c == '\\' && RExC_parse[1])
2022                         RExC_parse++;
2023                     else if (c == '{')
2024                         count++;
2025                     else if (c == '}')
2026                         count--;
2027                     RExC_parse++;
2028                 }
2029                 if (*RExC_parse != ')')
2030                 {
2031                     RExC_parse = s;
2032                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2033                 }
2034                 if (!SIZE_ONLY) {
2035                     AV *av;
2036
2037                     if (RExC_parse - 1 - s)
2038                         sv = newSVpvn(s, RExC_parse - 1 - s);
2039                     else
2040                         sv = newSVpvn("", 0);
2041
2042                     ENTER;
2043                     Perl_save_re_context(aTHX);
2044                     rop = sv_compile_2op(sv, &sop, "re", &av);
2045                     LEAVE;
2046
2047                     n = add_data(pRExC_state, 3, "nop");
2048                     RExC_rx->data->data[n] = (void*)rop;
2049                     RExC_rx->data->data[n+1] = (void*)sop;
2050                     RExC_rx->data->data[n+2] = (void*)av;
2051                     SvREFCNT_dec(sv);
2052                 }
2053                 else {                                          /* First pass */
2054                     if (PL_reginterp_cnt < ++RExC_seen_evals
2055                         && PL_curcop != &PL_compiling)
2056                         /* No compiled RE interpolated, has runtime
2057                            components ===> unsafe.  */
2058                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2059                     if (PL_tainted)
2060                         FAIL("Eval-group in insecure regular expression");
2061                 }
2062
2063                 nextchar(pRExC_state);
2064                 if (logical) {
2065                     ret = reg_node(pRExC_state, LOGICAL);
2066                     if (!SIZE_ONLY)
2067                         ret->flags = 2;
2068                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2069                     return ret;
2070                 }
2071                 return reganode(pRExC_state, EVAL, n);
2072             }
2073             case '(':
2074             {
2075                 if (RExC_parse[0] == '?') {
2076                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2077                         || RExC_parse[1] == '<'
2078                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2079                         I32 flag;
2080
2081                         ret = reg_node(pRExC_state, LOGICAL);
2082                         if (!SIZE_ONLY)
2083                             ret->flags = 1;
2084                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2085                         goto insert_if;
2086                     }
2087                 }
2088                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2089                     parno = atoi(RExC_parse++);
2090
2091                     while (isDIGIT(*RExC_parse))
2092                         RExC_parse++;
2093                     ret = reganode(pRExC_state, GROUPP, parno);
2094                     if ((c = *nextchar(pRExC_state)) != ')')
2095                         vFAIL("Switch condition not recognized");
2096                   insert_if:
2097                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2098                     br = regbranch(pRExC_state, &flags, 1);
2099                     if (br == NULL)
2100                         br = reganode(pRExC_state, LONGJMP, 0);
2101                     else
2102                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2103                     c = *nextchar(pRExC_state);
2104                     if (flags&HASWIDTH)
2105                         *flagp |= HASWIDTH;
2106                     if (c == '|') {
2107                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2108                         regbranch(pRExC_state, &flags, 1);
2109                         regtail(pRExC_state, ret, lastbr);
2110                         if (flags&HASWIDTH)
2111                             *flagp |= HASWIDTH;
2112                         c = *nextchar(pRExC_state);
2113                     }
2114                     else
2115                         lastbr = NULL;
2116                     if (c != ')')
2117                         vFAIL("Switch (?(condition)... contains too many branches");
2118                     ender = reg_node(pRExC_state, TAIL);
2119                     regtail(pRExC_state, br, ender);
2120                     if (lastbr) {
2121                         regtail(pRExC_state, lastbr, ender);
2122                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2123                     }
2124                     else
2125                         regtail(pRExC_state, ret, ender);
2126                     return ret;
2127                 }
2128                 else {
2129                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2130                 }
2131             }
2132             case 0:
2133                 RExC_parse--; /* for vFAIL to print correctly */
2134                 vFAIL("Sequence (? incomplete");
2135                 break;
2136             default:
2137                 --RExC_parse;
2138               parse_flags:
2139                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2140                     if (*RExC_parse != 'o')
2141                         pmflag(flagsp, *RExC_parse);
2142                     ++RExC_parse;
2143                 }
2144                 if (*RExC_parse == '-') {
2145                     flagsp = &negflags;
2146                     ++RExC_parse;
2147                     goto parse_flags;
2148                 }
2149                 RExC_flags16 |= posflags;
2150                 RExC_flags16 &= ~negflags;
2151                 if (*RExC_parse == ':') {
2152                     RExC_parse++;
2153                     paren = ':';
2154                     break;
2155                 }
2156               unknown:
2157                 if (*RExC_parse != ')') {
2158                     RExC_parse++;
2159                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2160                 }
2161                 nextchar(pRExC_state);
2162                 *flagp = TRYAGAIN;
2163                 return NULL;
2164             }
2165         }
2166         else {
2167             parno = RExC_npar;
2168             RExC_npar++;
2169             ret = reganode(pRExC_state, OPEN, parno);
2170             open = 1;
2171         }
2172     }
2173     else
2174         ret = NULL;
2175
2176     /* Pick up the branches, linking them together. */
2177     br = regbranch(pRExC_state, &flags, 1);
2178     if (br == NULL)
2179         return(NULL);
2180     if (*RExC_parse == '|') {
2181         if (!SIZE_ONLY && RExC_extralen) {
2182             reginsert(pRExC_state, BRANCHJ, br);
2183         }
2184         else
2185             reginsert(pRExC_state, BRANCH, br);
2186         have_branch = 1;
2187         if (SIZE_ONLY)
2188             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2189     }
2190     else if (paren == ':') {
2191         *flagp |= flags&SIMPLE;
2192     }
2193     if (open) {                         /* Starts with OPEN. */
2194         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2195     }
2196     else if (paren != '?')              /* Not Conditional */
2197         ret = br;
2198     if (flags&HASWIDTH)
2199         *flagp |= HASWIDTH;
2200     *flagp |= flags&SPSTART;
2201     lastbr = br;
2202     while (*RExC_parse == '|') {
2203         if (!SIZE_ONLY && RExC_extralen) {
2204             ender = reganode(pRExC_state, LONGJMP,0);
2205             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2206         }
2207         if (SIZE_ONLY)
2208             RExC_extralen += 2;         /* Account for LONGJMP. */
2209         nextchar(pRExC_state);
2210         br = regbranch(pRExC_state, &flags, 0);
2211         if (br == NULL)
2212             return(NULL);
2213         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2214         lastbr = br;
2215         if (flags&HASWIDTH)
2216             *flagp |= HASWIDTH;
2217         *flagp |= flags&SPSTART;
2218     }
2219
2220     if (have_branch || paren != ':') {
2221         /* Make a closing node, and hook it on the end. */
2222         switch (paren) {
2223         case ':':
2224             ender = reg_node(pRExC_state, TAIL);
2225             break;
2226         case 1:
2227             ender = reganode(pRExC_state, CLOSE, parno);
2228             break;
2229         case '<':
2230         case ',':
2231         case '=':
2232         case '!':
2233             *flagp &= ~HASWIDTH;
2234             /* FALL THROUGH */
2235         case '>':
2236             ender = reg_node(pRExC_state, SUCCEED);
2237             break;
2238         case 0:
2239             ender = reg_node(pRExC_state, END);
2240             break;
2241         }
2242         regtail(pRExC_state, lastbr, ender);
2243
2244         if (have_branch) {
2245             /* Hook the tails of the branches to the closing node. */
2246             for (br = ret; br != NULL; br = regnext(br)) {
2247                 regoptail(pRExC_state, br, ender);
2248             }
2249         }
2250     }
2251
2252     {
2253         char *p;
2254         static char parens[] = "=!<,>";
2255
2256         if (paren && (p = strchr(parens, paren))) {
2257             int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2258             int flag = (p - parens) > 1;
2259
2260             if (paren == '>')
2261                 node = SUSPEND, flag = 0;
2262             reginsert(pRExC_state, node,ret);
2263             ret->flags = flag;
2264             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2265         }
2266     }
2267
2268     /* Check for proper termination. */
2269     if (paren) {
2270         RExC_flags16 = oregflags;
2271         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2272             RExC_parse = oregcomp_parse;
2273             vFAIL("Unmatched (");
2274         }
2275     }
2276     else if (!paren && RExC_parse < RExC_end) {
2277         if (*RExC_parse == ')') {
2278             RExC_parse++;
2279             vFAIL("Unmatched )");
2280         }
2281         else
2282             FAIL("Junk on end of regexp");      /* "Can't happen". */
2283         /* NOTREACHED */
2284     }
2285
2286     return(ret);
2287 }
2288
2289 /*
2290  - regbranch - one alternative of an | operator
2291  *
2292  * Implements the concatenation operator.
2293  */
2294 STATIC regnode *
2295 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2296 {
2297     register regnode *ret;
2298     register regnode *chain = NULL;
2299     register regnode *latest;
2300     I32 flags = 0, c = 0;
2301
2302     if (first)
2303         ret = NULL;
2304     else {
2305         if (!SIZE_ONLY && RExC_extralen)
2306             ret = reganode(pRExC_state, BRANCHJ,0);
2307         else
2308             ret = reg_node(pRExC_state, BRANCH);
2309     }
2310
2311     if (!first && SIZE_ONLY)
2312         RExC_extralen += 1;                     /* BRANCHJ */
2313
2314     *flagp = WORST;                     /* Tentatively. */
2315
2316     RExC_parse--;
2317     nextchar(pRExC_state);
2318     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2319         flags &= ~TRYAGAIN;
2320         latest = regpiece(pRExC_state, &flags);
2321         if (latest == NULL) {
2322             if (flags & TRYAGAIN)
2323                 continue;
2324             return(NULL);
2325         }
2326         else if (ret == NULL)
2327             ret = latest;
2328         *flagp |= flags&HASWIDTH;
2329         if (chain == NULL)      /* First piece. */
2330             *flagp |= flags&SPSTART;
2331         else {
2332             RExC_naughty++;
2333             regtail(pRExC_state, chain, latest);
2334         }
2335         chain = latest;
2336         c++;
2337     }
2338     if (chain == NULL) {        /* Loop ran zero times. */
2339         chain = reg_node(pRExC_state, NOTHING);
2340         if (ret == NULL)
2341             ret = chain;
2342     }
2343     if (c == 1) {
2344         *flagp |= flags&SIMPLE;
2345     }
2346
2347     return(ret);
2348 }
2349
2350 /*
2351  - regpiece - something followed by possible [*+?]
2352  *
2353  * Note that the branching code sequences used for ? and the general cases
2354  * of * and + are somewhat optimized:  they use the same NOTHING node as
2355  * both the endmarker for their branch list and the body of the last branch.
2356  * It might seem that this node could be dispensed with entirely, but the
2357  * endmarker role is not redundant.
2358  */
2359 STATIC regnode *
2360 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2361 {
2362     register regnode *ret;
2363     register char op;
2364     register char *next;
2365     I32 flags;
2366     char *origparse = RExC_parse;
2367     char *maxpos;
2368     I32 min;
2369     I32 max = REG_INFTY;
2370
2371     ret = regatom(pRExC_state, &flags);
2372     if (ret == NULL) {
2373         if (flags & TRYAGAIN)
2374             *flagp |= TRYAGAIN;
2375         return(NULL);
2376     }
2377
2378     op = *RExC_parse;
2379
2380     if (op == '{' && regcurly(RExC_parse)) {
2381         next = RExC_parse + 1;
2382         maxpos = Nullch;
2383         while (isDIGIT(*next) || *next == ',') {
2384             if (*next == ',') {
2385                 if (maxpos)
2386                     break;
2387                 else
2388                     maxpos = next;
2389             }
2390             next++;
2391         }
2392         if (*next == '}') {             /* got one */
2393             if (!maxpos)
2394                 maxpos = next;
2395             RExC_parse++;
2396             min = atoi(RExC_parse);
2397             if (*maxpos == ',')
2398                 maxpos++;
2399             else
2400                 maxpos = RExC_parse;
2401             max = atoi(maxpos);
2402             if (!max && *maxpos != '0')
2403                 max = REG_INFTY;                /* meaning "infinity" */
2404             else if (max >= REG_INFTY)
2405                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2406             RExC_parse = next;
2407             nextchar(pRExC_state);
2408
2409         do_curly:
2410             if ((flags&SIMPLE)) {
2411                 RExC_naughty += 2 + RExC_naughty / 2;
2412                 reginsert(pRExC_state, CURLY, ret);
2413             }
2414             else {
2415                 regnode *w = reg_node(pRExC_state, WHILEM);
2416
2417                 w->flags = 0;
2418                 regtail(pRExC_state, ret, w);
2419                 if (!SIZE_ONLY && RExC_extralen) {
2420                     reginsert(pRExC_state, LONGJMP,ret);
2421                     reginsert(pRExC_state, NOTHING,ret);
2422                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2423                 }
2424                 reginsert(pRExC_state, CURLYX,ret);
2425                 if (!SIZE_ONLY && RExC_extralen)
2426                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2427                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2428                 if (SIZE_ONLY)
2429                     RExC_whilem_seen++, RExC_extralen += 3;
2430                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2431             }
2432             ret->flags = 0;
2433
2434             if (min > 0)
2435                 *flagp = WORST;
2436             if (max > 0)
2437                 *flagp |= HASWIDTH;
2438             if (max && max < min)
2439                 vFAIL("Can't do {n,m} with n > m");
2440             if (!SIZE_ONLY) {
2441                 ARG1_SET(ret, min);
2442                 ARG2_SET(ret, max);
2443             }
2444
2445             goto nest_check;
2446         }
2447     }
2448
2449     if (!ISMULT1(op)) {
2450         *flagp = flags;
2451         return(ret);
2452     }
2453
2454 #if 0                           /* Now runtime fix should be reliable. */
2455
2456     /* if this is reinstated, don't forget to put this back into perldiag:
2457
2458             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2459
2460            (F) The part of the regexp subject to either the * or + quantifier
2461            could match an empty string. The {#} shows in the regular
2462            expression about where the problem was discovered.
2463
2464     */
2465
2466     if (!(flags&HASWIDTH) && op != '?')
2467       vFAIL("Regexp *+ operand could be empty");
2468 #endif
2469
2470     nextchar(pRExC_state);
2471
2472     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2473
2474     if (op == '*' && (flags&SIMPLE)) {
2475         reginsert(pRExC_state, STAR, ret);
2476         ret->flags = 0;
2477         RExC_naughty += 4;
2478     }
2479     else if (op == '*') {
2480         min = 0;
2481         goto do_curly;
2482     }
2483     else if (op == '+' && (flags&SIMPLE)) {
2484         reginsert(pRExC_state, PLUS, ret);
2485         ret->flags = 0;
2486         RExC_naughty += 3;
2487     }
2488     else if (op == '+') {
2489         min = 1;
2490         goto do_curly;
2491     }
2492     else if (op == '?') {
2493         min = 0; max = 1;
2494         goto do_curly;
2495     }
2496   nest_check:
2497     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2498         vWARN3(RExC_parse,
2499                "%.*s matches null string many times",
2500                RExC_parse - origparse,
2501                origparse);
2502     }
2503
2504     if (*RExC_parse == '?') {
2505         nextchar(pRExC_state);
2506         reginsert(pRExC_state, MINMOD, ret);
2507         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2508     }
2509     if (ISMULT2(RExC_parse)) {
2510         RExC_parse++;
2511         vFAIL("Nested quantifiers");
2512     }
2513
2514     return(ret);
2515 }
2516
2517 /*
2518  - regatom - the lowest level
2519  *
2520  * Optimization:  gobbles an entire sequence of ordinary characters so that
2521  * it can turn them into a single node, which is smaller to store and
2522  * faster to run.  Backslashed characters are exceptions, each becoming a
2523  * separate node; the code is simpler that way and it's not worth fixing.
2524  *
2525  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2526 STATIC regnode *
2527 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2528 {
2529     register regnode *ret = 0;
2530     I32 flags;
2531
2532     *flagp = WORST;             /* Tentatively. */
2533
2534 tryagain:
2535     switch (*RExC_parse) {
2536     case '^':
2537         RExC_seen_zerolen++;
2538         nextchar(pRExC_state);
2539         if (RExC_flags16 & PMf_MULTILINE)
2540             ret = reg_node(pRExC_state, MBOL);
2541         else if (RExC_flags16 & PMf_SINGLELINE)
2542             ret = reg_node(pRExC_state, SBOL);
2543         else
2544             ret = reg_node(pRExC_state, BOL);
2545         break;
2546     case '$':
2547         nextchar(pRExC_state);
2548         if (*RExC_parse)
2549             RExC_seen_zerolen++;
2550         if (RExC_flags16 & PMf_MULTILINE)
2551             ret = reg_node(pRExC_state, MEOL);
2552         else if (RExC_flags16 & PMf_SINGLELINE)
2553             ret = reg_node(pRExC_state, SEOL);
2554         else
2555             ret = reg_node(pRExC_state, EOL);
2556         break;
2557     case '.':
2558         nextchar(pRExC_state);
2559         if (RExC_flags16 & PMf_SINGLELINE)
2560             ret = reg_node(pRExC_state, SANY);
2561         else
2562             ret = reg_node(pRExC_state, REG_ANY);
2563         *flagp |= HASWIDTH|SIMPLE;
2564         RExC_naughty++;
2565         break;
2566     case '[':
2567     {
2568         char *oregcomp_parse = ++RExC_parse;
2569         ret = regclass(pRExC_state);
2570         if (*RExC_parse != ']') {
2571             RExC_parse = oregcomp_parse;
2572             vFAIL("Unmatched [");
2573         }
2574         nextchar(pRExC_state);
2575         *flagp |= HASWIDTH|SIMPLE;
2576         break;
2577     }
2578     case '(':
2579         nextchar(pRExC_state);
2580         ret = reg(pRExC_state, 1, &flags);
2581         if (ret == NULL) {
2582                 if (flags & TRYAGAIN) {
2583                     if (RExC_parse == RExC_end) {
2584                          /* Make parent create an empty node if needed. */
2585                         *flagp |= TRYAGAIN;
2586                         return(NULL);
2587                     }
2588                     goto tryagain;
2589                 }
2590                 return(NULL);
2591         }
2592         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2593         break;
2594     case '|':
2595     case ')':
2596         if (flags & TRYAGAIN) {
2597             *flagp |= TRYAGAIN;
2598             return NULL;
2599         }
2600         vFAIL("Internal urp");
2601                                 /* Supposed to be caught earlier. */
2602         break;
2603     case '{':
2604         if (!regcurly(RExC_parse)) {
2605             RExC_parse++;
2606             goto defchar;
2607         }
2608         /* FALL THROUGH */
2609     case '?':
2610     case '+':
2611     case '*':
2612         RExC_parse++;
2613         vFAIL("Quantifier follows nothing");
2614         break;
2615     case '\\':
2616         switch (*++RExC_parse) {
2617         case 'A':
2618             RExC_seen_zerolen++;
2619             ret = reg_node(pRExC_state, SBOL);
2620             *flagp |= SIMPLE;
2621             nextchar(pRExC_state);
2622             break;
2623         case 'G':
2624             ret = reg_node(pRExC_state, GPOS);
2625             RExC_seen |= REG_SEEN_GPOS;
2626             *flagp |= SIMPLE;
2627             nextchar(pRExC_state);
2628             break;
2629         case 'Z':
2630             ret = reg_node(pRExC_state, SEOL);
2631             *flagp |= SIMPLE;
2632             nextchar(pRExC_state);
2633             break;
2634         case 'z':
2635             ret = reg_node(pRExC_state, EOS);
2636             *flagp |= SIMPLE;
2637             RExC_seen_zerolen++;                /* Do not optimize RE away */
2638             nextchar(pRExC_state);
2639             break;
2640         case 'C':
2641             ret = reg_node(pRExC_state, SANY);
2642             RExC_seen |= REG_SEEN_SANY;
2643             *flagp |= HASWIDTH|SIMPLE;
2644             nextchar(pRExC_state);
2645             break;
2646         case 'X':
2647             ret = reg_node(pRExC_state, CLUMP);
2648             *flagp |= HASWIDTH;
2649             nextchar(pRExC_state);
2650             break;
2651         case 'w':
2652             ret = reg_node(pRExC_state, LOC ? ALNUML     : ALNUM);
2653             *flagp |= HASWIDTH|SIMPLE;
2654             nextchar(pRExC_state);
2655             break;
2656         case 'W':
2657             ret = reg_node(pRExC_state, LOC ? NALNUML     : NALNUM);
2658             *flagp |= HASWIDTH|SIMPLE;
2659             nextchar(pRExC_state);
2660             break;
2661         case 'b':
2662             RExC_seen_zerolen++;
2663             RExC_seen |= REG_SEEN_LOOKBEHIND;
2664             ret = reg_node(pRExC_state, LOC ? BOUNDL     : BOUND);
2665             *flagp |= SIMPLE;
2666             nextchar(pRExC_state);
2667             break;
2668         case 'B':
2669             RExC_seen_zerolen++;
2670             RExC_seen |= REG_SEEN_LOOKBEHIND;
2671             ret = reg_node(pRExC_state, LOC ? NBOUNDL     : NBOUND);
2672             *flagp |= SIMPLE;
2673             nextchar(pRExC_state);
2674             break;
2675         case 's':
2676             ret = reg_node(pRExC_state, LOC ? SPACEL     : SPACE);
2677             *flagp |= HASWIDTH|SIMPLE;
2678             nextchar(pRExC_state);
2679             break;
2680         case 'S':
2681             ret = reg_node(pRExC_state, LOC ? NSPACEL     : NSPACE);
2682             *flagp |= HASWIDTH|SIMPLE;
2683             nextchar(pRExC_state);
2684             break;
2685         case 'd':
2686             ret = reg_node(pRExC_state, DIGIT);
2687             *flagp |= HASWIDTH|SIMPLE;
2688             nextchar(pRExC_state);
2689             break;
2690         case 'D':
2691             ret = reg_node(pRExC_state, NDIGIT);
2692             *flagp |= HASWIDTH|SIMPLE;
2693             nextchar(pRExC_state);
2694             break;
2695         case 'p':
2696         case 'P':
2697             {   /* a lovely hack--pretend we saw [\pX] instead */
2698                 char* oldregxend = RExC_end;
2699
2700                 if (RExC_parse[1] == '{') {
2701                     RExC_end = strchr(RExC_parse, '}');
2702                     if (!RExC_end) {
2703                         RExC_parse += 2;
2704                         RExC_end = oldregxend;
2705                         vFAIL("Missing right brace on \\p{}");
2706                     }
2707                     RExC_end++;
2708                 }
2709                 else
2710                     RExC_end = RExC_parse + 2;
2711                 RExC_parse--;
2712
2713                 ret = regclass(pRExC_state);
2714
2715                 RExC_end = oldregxend;
2716                 RExC_parse--;
2717                 nextchar(pRExC_state);
2718                 *flagp |= HASWIDTH|SIMPLE;
2719             }
2720             break;
2721         case 'n':
2722         case 'r':
2723         case 't':
2724         case 'f':
2725         case 'e':
2726         case 'a':
2727         case 'x':
2728         case 'c':
2729         case '0':
2730             goto defchar;
2731         case '1': case '2': case '3': case '4':
2732         case '5': case '6': case '7': case '8': case '9':
2733             {
2734                 I32 num = atoi(RExC_parse);
2735
2736                 if (num > 9 && num >= RExC_npar)
2737                     goto defchar;
2738                 else {
2739                     while (isDIGIT(*RExC_parse))
2740                         RExC_parse++;
2741
2742                     if (!SIZE_ONLY && num > RExC_rx->nparens)
2743                         vFAIL("Reference to nonexistent group");
2744                     RExC_sawback = 1;
2745                     ret = reganode(pRExC_state, FOLD
2746                                    ? (LOC ? REFFL : REFF)
2747                                    : REF, num);
2748                     *flagp |= HASWIDTH;
2749                     RExC_parse--;
2750                     nextchar(pRExC_state);
2751                 }
2752             }
2753             break;
2754         case '\0':
2755             if (RExC_parse >= RExC_end)
2756                 FAIL("Trailing \\");
2757             /* FALL THROUGH */
2758         default:
2759             /* Do not generate `unrecognized' warnings here, we fall
2760                back into the quick-grab loop below */
2761             goto defchar;
2762         }
2763         break;
2764
2765     case '#':
2766         if (RExC_flags16 & PMf_EXTENDED) {
2767             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
2768             if (RExC_parse < RExC_end)
2769                 goto tryagain;
2770         }
2771         /* FALL THROUGH */
2772
2773     default: {
2774             register STRLEN len;
2775             register UV ender;
2776             register char *p;
2777             char *oldp, *s;
2778             STRLEN numlen;
2779
2780             RExC_parse++;
2781
2782         defchar:
2783             ret = reg_node(pRExC_state, FOLD
2784                           ? (LOC ? EXACTFL : EXACTF)
2785                           : EXACT);
2786             s = STRING(ret);
2787             for (len = 0, p = RExC_parse - 1;
2788               len < 127 && p < RExC_end;
2789               len++)
2790             {
2791                 oldp = p;
2792
2793                 if (RExC_flags16 & PMf_EXTENDED)
2794                     p = regwhite(p, RExC_end);
2795                 switch (*p) {
2796                 case '^':
2797                 case '$':
2798                 case '.':
2799                 case '[':
2800                 case '(':
2801                 case ')':
2802                 case '|':
2803                     goto loopdone;
2804                 case '\\':
2805                     switch (*++p) {
2806                     case 'A':
2807                     case 'G':
2808                     case 'Z':
2809                     case 'z':
2810                     case 'w':
2811                     case 'W':
2812                     case 'b':
2813                     case 'B':
2814                     case 's':
2815                     case 'S':
2816                     case 'd':
2817                     case 'D':
2818                     case 'p':
2819                     case 'P':
2820                         --p;
2821                         goto loopdone;
2822                     case 'n':
2823                         ender = '\n';
2824                         p++;
2825                         break;
2826                     case 'r':
2827                         ender = '\r';
2828                         p++;
2829                         break;
2830                     case 't':
2831                         ender = '\t';
2832                         p++;
2833                         break;
2834                     case 'f':
2835                         ender = '\f';
2836                         p++;
2837                         break;
2838                     case 'e':
2839                           ender = ASCII_TO_NATIVE('\033');
2840                         p++;
2841                         break;
2842                     case 'a':
2843                           ender = ASCII_TO_NATIVE('\007');
2844                         p++;
2845                         break;
2846                     case 'x':
2847                         if (*++p == '{') {
2848                             char* e = strchr(p, '}');
2849
2850                             if (!e) {
2851                                 RExC_parse = p + 1;
2852                                 vFAIL("Missing right brace on \\x{}");
2853                             }
2854                             else {
2855                                 numlen = 1;     /* allow underscores */
2856                                 ender = (UV)scan_hex(p + 1, e - p - 1, &numlen);
2857                                 if (ender > 0xff)
2858                                     RExC_utf8 = 1;
2859                                 /* numlen is generous */
2860                                 if (numlen + len >= 127) {
2861                                     p--;
2862                                     goto loopdone;
2863                                 }
2864                                 p = e + 1;
2865                             }
2866                         }
2867                         else {
2868                             numlen = 0;         /* disallow underscores */
2869                             ender = (UV)scan_hex(p, 2, &numlen);
2870                             p += numlen;
2871                         }
2872                         break;
2873                     case 'c':
2874                         p++;
2875                         ender = UCHARAT(p++);
2876                         ender = toCTRL(ender);
2877                         break;
2878                     case '0': case '1': case '2': case '3':case '4':
2879                     case '5': case '6': case '7': case '8':case '9':
2880                         if (*p == '0' ||
2881                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
2882                             numlen = 0;         /* disallow underscores */
2883                             ender = (UV)scan_oct(p, 3, &numlen);
2884                             p += numlen;
2885                         }
2886                         else {
2887                             --p;
2888                             goto loopdone;
2889                         }
2890                         break;
2891                     case '\0':
2892                         if (p >= RExC_end)
2893                             FAIL("Trailing \\");
2894                         /* FALL THROUGH */
2895                     default:
2896                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
2897                             vWARN2(p +1, "Unrecognized escape \\%c passed through", *p);
2898                         goto normal_default;
2899                     }
2900                     break;
2901                 default:
2902                   normal_default:
2903                     if (UTF8_IS_START(*p) && UTF) {
2904                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
2905                                                &numlen, 0);
2906                         p += numlen;
2907                     }
2908                     else
2909                         ender = *p++;
2910                     break;
2911                 }
2912                 if (RExC_flags16 & PMf_EXTENDED)
2913                     p = regwhite(p, RExC_end);
2914                 if (UTF && FOLD) {
2915                     if (LOC)
2916                         ender = toLOWER_LC_uvchr(ender);
2917                     else
2918                         ender = toLOWER_uni(ender);
2919                 }
2920                 if (ISMULT2(p)) { /* Back off on ?+*. */
2921                     if (len)
2922                         p = oldp;
2923                     else if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(ender)) && UTF) {
2924                         reguni(pRExC_state, ender, s, &numlen);
2925                         s += numlen;
2926                         len += numlen;
2927                     }
2928                     else {
2929                         len++;
2930                         REGC(ender, s++);
2931                     }
2932                     break;
2933                 }
2934                 if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(ender)) && UTF) {
2935                     reguni(pRExC_state, ender, s, &numlen);
2936                     s += numlen;
2937                     len += numlen - 1;
2938                 }
2939                 else
2940                     REGC(ender, s++);
2941             }
2942         loopdone:
2943             RExC_parse = p - 1;
2944             nextchar(pRExC_state);
2945             {
2946                 /* len is STRLEN which is unsigned, need to copy to signed */
2947                 IV iv = len;
2948                 if (iv < 0)
2949                     vFAIL("Internal disaster");
2950             }
2951             if (len > 0)
2952                 *flagp |= HASWIDTH;
2953             if (len == 1)
2954                 *flagp |= SIMPLE;
2955             if (!SIZE_ONLY)
2956                 STR_LEN(ret) = len;
2957             if (SIZE_ONLY)
2958                 RExC_size += STR_SZ(len);
2959             else
2960                 RExC_emit += STR_SZ(len);
2961         }
2962         break;
2963     }
2964
2965     return(ret);
2966 }
2967
2968 STATIC char *
2969 S_regwhite(pTHX_ char *p, char *e)
2970 {
2971     while (p < e) {
2972         if (isSPACE(*p))
2973             ++p;
2974         else if (*p == '#') {
2975             do {
2976                 p++;
2977             } while (p < e && *p != '\n');
2978         }
2979         else
2980             break;
2981     }
2982     return p;
2983 }
2984
2985 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
2986    Character classes ([:foo:]) can also be negated ([:^foo:]).
2987    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
2988    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
2989    but trigger warnings because they are currently unimplemented. */
2990 STATIC I32
2991 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
2992 {
2993     char *posixcc = 0;
2994     I32 namedclass = OOB_NAMEDCLASS;
2995
2996     if (value == '[' && RExC_parse + 1 < RExC_end &&
2997         /* I smell either [: or [= or [. -- POSIX has been here, right? */
2998         (*RExC_parse == ':' ||
2999          *RExC_parse == '=' ||
3000          *RExC_parse == '.')) {
3001         char  c = *RExC_parse;
3002         char* s = RExC_parse++;
3003
3004         while (RExC_parse < RExC_end && *RExC_parse != c)
3005             RExC_parse++;
3006         if (RExC_parse == RExC_end)
3007             /* Grandfather lone [:, [=, [. */
3008             RExC_parse = s;
3009         else {
3010             char* t = RExC_parse++; /* skip over the c */
3011
3012             if (*RExC_parse == ']') {
3013                 RExC_parse++; /* skip over the ending ] */
3014                 posixcc = s + 1;
3015                 if (*s == ':') {
3016                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3017                     I32 skip = 5; /* the most common skip */
3018
3019                     switch (*posixcc) {
3020                     case 'a':
3021                         if (strnEQ(posixcc, "alnum", 5))
3022                             namedclass =
3023                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3024                         else if (strnEQ(posixcc, "alpha", 5))
3025                             namedclass =
3026                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3027                         else if (strnEQ(posixcc, "ascii", 5))
3028                             namedclass =
3029                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3030                         break;
3031                     case 'b':
3032                         if (strnEQ(posixcc, "blank", 5))
3033                             namedclass =
3034                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3035                         break;
3036                     case 'c':
3037                         if (strnEQ(posixcc, "cntrl", 5))
3038                             namedclass =
3039                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3040                         break;
3041                     case 'd':
3042                         if (strnEQ(posixcc, "digit", 5))
3043                             namedclass =
3044                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3045                         break;
3046                     case 'g':
3047                         if (strnEQ(posixcc, "graph", 5))
3048                             namedclass =
3049                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3050                         break;
3051                     case 'l':
3052                         if (strnEQ(posixcc, "lower", 5))
3053                             namedclass =
3054                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3055                         break;
3056                     case 'p':
3057                         if (strnEQ(posixcc, "print", 5))
3058                             namedclass =
3059                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3060                         else if (strnEQ(posixcc, "punct", 5))
3061                             namedclass =
3062                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3063                         break;
3064                     case 's':
3065                         if (strnEQ(posixcc, "space", 5))
3066                             namedclass =
3067                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3068                         break;
3069                     case 'u':
3070                         if (strnEQ(posixcc, "upper", 5))
3071                             namedclass =
3072                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3073                         break;
3074                     case 'w': /* this is not POSIX, this is the Perl \w */
3075                         if (strnEQ(posixcc, "word", 4)) {
3076                             namedclass =
3077                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3078                             skip = 4;
3079                         }
3080                         break;
3081                     case 'x':
3082                         if (strnEQ(posixcc, "xdigit", 6)) {
3083                             namedclass =
3084                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3085                             skip = 6;
3086                         }
3087                         break;
3088                     }
3089                     if (namedclass == OOB_NAMEDCLASS ||
3090                         posixcc[skip] != ':' ||
3091                         posixcc[skip+1] != ']')
3092                     {
3093                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3094                                       t - s - 1, s + 1);
3095                     }
3096                 } else if (!SIZE_ONLY) {
3097                     /* [[=foo=]] and [[.foo.]] are still future. */
3098
3099                     /* adjust RExC_parse so the warning shows after
3100                        the class closes */
3101                     while (*RExC_parse && *RExC_parse != ']')
3102                         RExC_parse++;
3103                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3104                 }
3105             } else {
3106                 /* Maternal grandfather:
3107                  * "[:" ending in ":" but not in ":]" */
3108                 RExC_parse = s;
3109             }
3110         }
3111     }
3112
3113     return namedclass;
3114 }
3115
3116 STATIC void
3117 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3118 {
3119     if (!SIZE_ONLY && ckWARN(WARN_REGEXP) &&
3120         (*RExC_parse == ':' ||
3121          *RExC_parse == '=' ||
3122          *RExC_parse == '.')) {
3123         char *s = RExC_parse;
3124         char  c = *s++;
3125
3126         while(*s && isALNUM(*s))
3127             s++;
3128         if (*s && c == *s && s[1] == ']') {
3129             vWARN3(s+2, "POSIX syntax [%c %c] belongs inside character classes", c, c);
3130
3131             /* [[=foo=]] and [[.foo.]] are still future. */
3132             if (c == '=' || c == '.')
3133             {
3134                 /* adjust RExC_parse so the error shows after
3135                    the class closes */
3136                 while (*RExC_parse && *RExC_parse++ != ']')
3137                     ;
3138                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3139             }
3140         }
3141     }
3142 }
3143
3144 STATIC regnode *
3145 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3146 {
3147     register UV value;
3148     register IV lastvalue = OOB_UNICODE;
3149     register IV range = 0;
3150     register regnode *ret;
3151     STRLEN numlen;
3152     IV namedclass;
3153     char *rangebegin;
3154     bool need_class = 0;
3155     SV *listsv;
3156     register char *e;
3157     UV n;
3158     bool dont_optimize_invert = FALSE;
3159
3160     ret = reganode(pRExC_state, ANYOF, 0);
3161
3162     if (!SIZE_ONLY)
3163         ANYOF_FLAGS(ret) = 0;
3164
3165     if (*RExC_parse == '^') {   /* Complement of range. */
3166         RExC_naughty++;
3167         RExC_parse++;
3168         if (!SIZE_ONLY)
3169             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3170     }
3171
3172     if (SIZE_ONLY)
3173         RExC_size += ANYOF_SKIP;
3174     else {
3175         RExC_emit += ANYOF_SKIP;
3176         if (FOLD)
3177             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3178         if (LOC)
3179             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3180         ANYOF_BITMAP_ZERO(ret);
3181         listsv = newSVpvn("# comment\n", 10);
3182     }
3183
3184     if (!SIZE_ONLY && ckWARN(WARN_REGEXP))
3185         checkposixcc(pRExC_state);
3186
3187     if (*RExC_parse == ']' || *RExC_parse == '-')
3188         goto charclassloop;             /* allow 1st char to be ] or - */
3189
3190     while (RExC_parse < RExC_end && *RExC_parse != ']') {
3191
3192     charclassloop:
3193
3194         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3195
3196         if (!range)
3197             rangebegin = RExC_parse;
3198         if (UTF) {
3199             value = utf8n_to_uvchr((U8*)RExC_parse,
3200                                RExC_end - RExC_parse,
3201                                &numlen, 0);
3202             RExC_parse += numlen;
3203         }
3204         else
3205             value = UCHARAT(RExC_parse++);
3206         if (value == '[')
3207             namedclass = regpposixcc(pRExC_state, value);
3208         else if (value == '\\') {
3209             if (UTF) {
3210                 value = utf8n_to_uvchr((U8*)RExC_parse,
3211                                    RExC_end - RExC_parse,
3212                                    &numlen, 0);
3213                 RExC_parse += numlen;
3214             }
3215             else
3216                 value = UCHARAT(RExC_parse++);
3217             /* Some compilers cannot handle switching on 64-bit integer
3218              * values, therefore value cannot be an UV.  Yes, this will
3219              * be a problem later if we want switch on Unicode.
3220              * A similar issue a little bit later when switching on
3221              * namedclass. --jhi */
3222             switch ((I32)value) {
3223             case 'w':   namedclass = ANYOF_ALNUM;       break;
3224             case 'W':   namedclass = ANYOF_NALNUM;      break;
3225             case 's':   namedclass = ANYOF_SPACE;       break;
3226             case 'S':   namedclass = ANYOF_NSPACE;      break;
3227             case 'd':   namedclass = ANYOF_DIGIT;       break;
3228             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3229             case 'p':
3230             case 'P':
3231                 if (*RExC_parse == '{') {
3232                     e = strchr(RExC_parse++, '}');
3233                     if (!e)
3234                         vFAIL("Missing right brace on \\p{}");
3235                     n = e - RExC_parse;
3236                 }
3237                 else {
3238                     e = RExC_parse;
3239                     n = 1;
3240                 }
3241                 if (!SIZE_ONLY) {
3242                     if (value == 'p')
3243                         Perl_sv_catpvf(aTHX_ listsv,
3244                                        "+utf8::%.*s\n", (int)n, RExC_parse);
3245                     else
3246                         Perl_sv_catpvf(aTHX_ listsv,
3247                                        "!utf8::%.*s\n", (int)n, RExC_parse);
3248                 }
3249                 RExC_parse = e + 1;
3250                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3251                 continue;
3252             case 'n':   value = '\n';                   break;
3253             case 'r':   value = '\r';                   break;
3254             case 't':   value = '\t';                   break;
3255             case 'f':   value = '\f';                   break;
3256             case 'b':   value = '\b';                   break;
3257             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3258             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3259             case 'x':
3260                 if (*RExC_parse == '{') {
3261                     e = strchr(RExC_parse++, '}');
3262                     if (!e)
3263                         vFAIL("Missing right brace on \\x{}");
3264                     numlen = 1;         /* allow underscores */
3265                     value = (UV)scan_hex(RExC_parse,
3266                                          e - RExC_parse,
3267                                          &numlen);
3268                     RExC_parse = e + 1;
3269                 }
3270                 else {
3271                     numlen = 0;         /* disallow underscores */
3272                     value = (UV)scan_hex(RExC_parse, 2, &numlen);
3273                     RExC_parse += numlen;
3274                 }
3275                 break;
3276             case 'c':
3277                 value = UCHARAT(RExC_parse++);
3278                 value = toCTRL(value);
3279                 break;
3280             case '0': case '1': case '2': case '3': case '4':
3281             case '5': case '6': case '7': case '8': case '9':
3282                 numlen = 0;             /* disallow underscores */
3283                 value = (UV)scan_oct(--RExC_parse, 3, &numlen);
3284                 RExC_parse += numlen;
3285                 break;
3286             default:
3287                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3288                     vWARN2(RExC_parse,
3289                            "Unrecognized escape \\%c in character class passed through",
3290                            (int)value);
3291                 break;
3292             }
3293         } /* end of \blah */
3294
3295         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3296
3297             if (!SIZE_ONLY && !need_class)
3298                 ANYOF_CLASS_ZERO(ret);
3299
3300             need_class = 1;
3301
3302             /* a bad range like a-\d, a-[:digit:] ? */
3303             if (range) {
3304                 if (!SIZE_ONLY) {
3305                     if (ckWARN(WARN_REGEXP))
3306                         vWARN4(RExC_parse,
3307                                "False [] range \"%*.*s\"",
3308                                RExC_parse - rangebegin,
3309                                RExC_parse - rangebegin,
3310                                rangebegin);
3311                     if (lastvalue < 256) {
3312                         ANYOF_BITMAP_SET(ret, lastvalue);
3313                         ANYOF_BITMAP_SET(ret, '-');
3314                     }
3315                     else {
3316                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3317                         Perl_sv_catpvf(aTHX_ listsv,
3318                                        "%04"UVxf"\n%04"UVxf"\n", (UV)lastvalue, (UV) '-');
3319                     }
3320                 }
3321
3322                 range = 0; /* this was not a true range */
3323             }
3324
3325             if (!SIZE_ONLY) {
3326                 /* Possible truncation here but in some 64-bit environments
3327                  * the compiler gets heartburn about switch on 64-bit values.
3328                  * A similar issue a little earlier when switching on value.
3329                  * --jhi */
3330                 switch ((I32)namedclass) {
3331                 case ANYOF_ALNUM:
3332                     if (LOC)
3333                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3334                     else {
3335                         for (value = 0; value < 256; value++)
3336                             if (isALNUM(value))
3337                                 ANYOF_BITMAP_SET(ret, value);
3338                     }
3339                     dont_optimize_invert = TRUE;
3340                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");
3341                     break;
3342                 case ANYOF_NALNUM:
3343                     if (LOC)
3344                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3345                     else {
3346                         for (value = 0; value < 256; value++)
3347                             if (!isALNUM(value))
3348                                 ANYOF_BITMAP_SET(ret, value);
3349                     }
3350                     dont_optimize_invert = TRUE;
3351                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3352                     break;
3353                 case ANYOF_ALNUMC:
3354                     if (LOC)
3355                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3356                     else {
3357                         for (value = 0; value < 256; value++)
3358                             if (isALNUMC(value))
3359                                 ANYOF_BITMAP_SET(ret, value);
3360                     }
3361                     dont_optimize_invert = TRUE;
3362                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3363                     break;
3364                 case ANYOF_NALNUMC:
3365                     if (LOC)
3366                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3367                     else {
3368                         for (value = 0; value < 256; value++)
3369                             if (!isALNUMC(value))
3370                                 ANYOF_BITMAP_SET(ret, value);
3371                     }
3372                     dont_optimize_invert = TRUE;
3373                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3374                     break;
3375                 case ANYOF_ALPHA:
3376                     if (LOC)
3377                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3378                     else {
3379                         for (value = 0; value < 256; value++)
3380                             if (isALPHA(value))
3381                                 ANYOF_BITMAP_SET(ret, value);
3382                     }
3383                     dont_optimize_invert = TRUE;
3384                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3385                     break;
3386                 case ANYOF_NALPHA:
3387                     if (LOC)
3388                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3389                     else {
3390                         for (value = 0; value < 256; value++)
3391                             if (!isALPHA(value))
3392                                 ANYOF_BITMAP_SET(ret, value);
3393                     }
3394                     dont_optimize_invert = TRUE;
3395                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3396                     break;
3397                 case ANYOF_ASCII:
3398                     if (LOC)
3399                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3400                     else {
3401 #ifndef EBCDIC
3402                         for (value = 0; value < 128; value++)
3403                             ANYOF_BITMAP_SET(ret, value);
3404 #else  /* EBCDIC */
3405                         for (value = 0; value < 256; value++) {
3406                             if (PL_hints & HINT_RE_ASCIIR) {
3407                                 if (NATIVE_TO_ASCII(value) < 128)
3408                                     ANYOF_BITMAP_SET(ret, value);
3409                             }
3410                             else {
3411                                 if (isASCII(value))
3412                                     ANYOF_BITMAP_SET(ret, value);
3413                             }
3414                         }
3415 #endif /* EBCDIC */
3416                     }
3417                     dont_optimize_invert = TRUE;
3418                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3419                     break;
3420                 case ANYOF_NASCII:
3421                     if (LOC)
3422                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3423                     else {
3424 #ifndef EBCDIC
3425                         for (value = 128; value < 256; value++)
3426                             ANYOF_BITMAP_SET(ret, value);
3427 #else  /* EBCDIC */
3428                         for (value = 0; value < 256; value++) {
3429                             if (PL_hints & HINT_RE_ASCIIR) {
3430                                 if (NATIVE_TO_ASCII(value) >= 128)
3431                                     ANYOF_BITMAP_SET(ret, value);
3432                             }
3433                             else {
3434                                 if (!isASCII(value))
3435                                     ANYOF_BITMAP_SET(ret, value);
3436                             }
3437                         }
3438 #endif /* EBCDIC */
3439                     }
3440                     dont_optimize_invert = TRUE;
3441                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3442                     break;
3443                 case ANYOF_BLANK:
3444                     if (LOC)
3445                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3446                     else {
3447                         for (value = 0; value < 256; value++)
3448                             if (isBLANK(value))
3449                                 ANYOF_BITMAP_SET(ret, value);
3450                     }
3451                     dont_optimize_invert = TRUE;
3452                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3453                     break;
3454                 case ANYOF_NBLANK:
3455                     if (LOC)
3456                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3457                     else {
3458                         for (value = 0; value < 256; value++)
3459                             if (!isBLANK(value))
3460                                 ANYOF_BITMAP_SET(ret, value);
3461                     }
3462                     dont_optimize_invert = TRUE;
3463                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3464                     break;
3465                 case ANYOF_CNTRL:
3466                     if (LOC)
3467                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3468                     else {
3469                         for (value = 0; value < 256; value++)
3470                             if (isCNTRL(value))
3471                                 ANYOF_BITMAP_SET(ret, value);
3472                     }
3473                     dont_optimize_invert = TRUE;
3474                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3475                     break;
3476                 case ANYOF_NCNTRL:
3477                     if (LOC)
3478                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3479                     else {
3480                         for (value = 0; value < 256; value++)
3481                             if (!isCNTRL(value))
3482                                 ANYOF_BITMAP_SET(ret, value);
3483                     }
3484                     dont_optimize_invert = TRUE;
3485                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3486                     break;
3487                 case ANYOF_DIGIT:
3488                     if (LOC)
3489                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3490                     else {
3491                         /* consecutive digits assumed */
3492                         for (value = '0'; value <= '9'; value++)
3493                             ANYOF_BITMAP_SET(ret, value);
3494                     }
3495                     dont_optimize_invert = TRUE;
3496                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3497                     break;
3498                 case ANYOF_NDIGIT:
3499                     if (LOC)
3500                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3501                     else {
3502                         /* consecutive digits assumed */
3503                         for (value = 0; value < '0'; value++)
3504                             ANYOF_BITMAP_SET(ret, value);
3505                         for (value = '9' + 1; value < 256; value++)
3506                             ANYOF_BITMAP_SET(ret, value);
3507                     }
3508                     dont_optimize_invert = TRUE;
3509                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3510                     break;
3511                 case ANYOF_GRAPH:
3512                     if (LOC)
3513                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3514                     else {
3515                         for (value = 0; value < 256; value++)
3516                             if (isGRAPH(value))
3517                                 ANYOF_BITMAP_SET(ret, value);
3518                     }
3519                     dont_optimize_invert = TRUE;
3520                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3521                     break;
3522                 case ANYOF_NGRAPH:
3523                     if (LOC)
3524                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3525                     else {
3526                         for (value = 0; value < 256; value++)
3527                             if (!isGRAPH(value))
3528                                 ANYOF_BITMAP_SET(ret, value);
3529                     }
3530                     dont_optimize_invert = TRUE;
3531                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3532                     break;
3533                 case ANYOF_LOWER:
3534                     if (LOC)
3535                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3536                     else {
3537                         for (value = 0; value < 256; value++)
3538                             if (isLOWER(value))
3539                                 ANYOF_BITMAP_SET(ret, value);
3540                     }
3541                     dont_optimize_invert = TRUE;
3542                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3543                     break;
3544                 case ANYOF_NLOWER:
3545                     if (LOC)
3546                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3547                     else {
3548                         for (value = 0; value < 256; value++)
3549                             if (!isLOWER(value))
3550                                 ANYOF_BITMAP_SET(ret, value);
3551                     }
3552                     dont_optimize_invert = TRUE;
3553                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3554                     break;
3555                 case ANYOF_PRINT:
3556                     if (LOC)
3557                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3558                     else {
3559                         for (value = 0; value < 256; value++)
3560                             if (isPRINT(value))
3561                                 ANYOF_BITMAP_SET(ret, value);
3562                     }
3563                     dont_optimize_invert = TRUE;
3564                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3565                     break;
3566                 case ANYOF_NPRINT:
3567                     if (LOC)
3568                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3569                     else {
3570                         for (value = 0; value < 256; value++)
3571                             if (!isPRINT(value))
3572                                 ANYOF_BITMAP_SET(ret, value);
3573                     }
3574                     dont_optimize_invert = TRUE;
3575                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3576                     break;
3577                 case ANYOF_PSXSPC:
3578                     if (LOC)
3579                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3580                     else {
3581                         for (value = 0; value < 256; value++)
3582                             if (isPSXSPC(value))
3583                                 ANYOF_BITMAP_SET(ret, value);
3584                     }
3585                     dont_optimize_invert = TRUE;
3586                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3587                     break;
3588                 case ANYOF_NPSXSPC:
3589                     if (LOC)
3590                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3591                     else {
3592                         for (value = 0; value < 256; value++)
3593                             if (!isPSXSPC(value))
3594                                 ANYOF_BITMAP_SET(ret, value);
3595                     }
3596                     dont_optimize_invert = TRUE;
3597                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3598                     break;
3599                 case ANYOF_PUNCT:
3600                     if (LOC)
3601                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3602                     else {
3603                         for (value = 0; value < 256; value++)
3604                             if (isPUNCT(value))
3605                                 ANYOF_BITMAP_SET(ret, value);
3606                     }
3607                     dont_optimize_invert = TRUE;
3608                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3609                     break;
3610                 case ANYOF_NPUNCT:
3611                     if (LOC)
3612                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3613                     else {
3614                         for (value = 0; value < 256; value++)
3615                             if (!isPUNCT(value))
3616                                 ANYOF_BITMAP_SET(ret, value);
3617                     }
3618                     dont_optimize_invert = TRUE;
3619                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
3620                     break;
3621                 case ANYOF_SPACE:
3622                     if (LOC)
3623                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
3624                     else {
3625                         for (value = 0; value < 256; value++)
3626                             if (isSPACE(value))
3627                                 ANYOF_BITMAP_SET(ret, value);
3628                     }
3629                     dont_optimize_invert = TRUE;
3630                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
3631                     break;
3632                 case ANYOF_NSPACE:
3633                     if (LOC)
3634                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
3635                     else {
3636                         for (value = 0; value < 256; value++)
3637                             if (!isSPACE(value))
3638                                 ANYOF_BITMAP_SET(ret, value);
3639                     }
3640                     dont_optimize_invert = TRUE;
3641                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
3642                     break;
3643                 case ANYOF_UPPER:
3644                     if (LOC)
3645                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
3646                     else {
3647                         for (value = 0; value < 256; value++)
3648                             if (isUPPER(value))
3649                                 ANYOF_BITMAP_SET(ret, value);
3650                     }
3651                     dont_optimize_invert = TRUE;
3652                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
3653                     break;
3654                 case ANYOF_NUPPER:
3655                     if (LOC)
3656                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
3657                     else {
3658                         for (value = 0; value < 256; value++)
3659                             if (!isUPPER(value))
3660                                 ANYOF_BITMAP_SET(ret, value);
3661                     }
3662                     dont_optimize_invert = TRUE;
3663                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
3664                     break;
3665                 case ANYOF_XDIGIT:
3666                     if (LOC)
3667                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
3668                     else {
3669                         for (value = 0; value < 256; value++)
3670                             if (isXDIGIT(value))
3671                                 ANYOF_BITMAP_SET(ret, value);
3672                     }
3673                     dont_optimize_invert = TRUE;
3674                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
3675                     break;
3676                 case ANYOF_NXDIGIT:
3677                     if (LOC)
3678                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
3679                     else {
3680                         for (value = 0; value < 256; value++)
3681                             if (!isXDIGIT(value))
3682                                 ANYOF_BITMAP_SET(ret, value);
3683                     }
3684                     dont_optimize_invert = TRUE;
3685                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
3686                     break;
3687                 default:
3688                     vFAIL("Invalid [::] class");
3689                     break;
3690                 }
3691                 if (LOC)
3692                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
3693                 continue;
3694             }
3695         } /* end of namedclass \blah */
3696
3697         if (range) {
3698             if (((lastvalue > value) && !(PL_hints & HINT_RE_ASCIIR)) ||
3699                 ((NATIVE_TO_UNI(lastvalue) > NATIVE_TO_UNI(value)) && (PL_hints & HINT_RE_ASCIIR))) /* b-a */ {
3700                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
3701                               RExC_parse - rangebegin,
3702                               RExC_parse - rangebegin,
3703                               rangebegin);
3704             }
3705             range = 0; /* not a true range */
3706         }
3707         else {
3708             lastvalue = value; /* save the beginning of the range */
3709             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
3710                 RExC_parse[1] != ']') {
3711                 RExC_parse++;
3712
3713                 /* a bad range like \w-, [:word:]- ? */
3714                 if (namedclass > OOB_NAMEDCLASS) {
3715                     if (ckWARN(WARN_REGEXP))
3716                         vWARN4(RExC_parse,
3717                                "False [] range \"%*.*s\"",
3718                                RExC_parse - rangebegin,
3719                                RExC_parse - rangebegin,
3720                                rangebegin);
3721                     if (!SIZE_ONLY)
3722                         ANYOF_BITMAP_SET(ret, '-');
3723                 } else
3724                     range = 1;  /* yeah, it's a range! */
3725                 continue;       /* but do it the next time */
3726             }
3727         }
3728
3729         /* now is the next time */
3730         if (!SIZE_ONLY) {
3731             if (lastvalue < 256 && value < 256) {
3732 #ifdef EBCDIC /* EBCDIC, for example. */
3733                 if (PL_hints & HINT_RE_ASCIIR) {
3734                     IV i;
3735                     /* New style scheme for ranges:
3736                      * after :
3737                      * use re 'asciir';
3738                      * do ranges in ASCII/Unicode space
3739                      */
3740                     for (i = NATIVE_TO_ASCII(lastvalue) ; i <= NATIVE_TO_ASCII(value); i++)
3741                         ANYOF_BITMAP_SET(ret, ASCII_TO_NATIVE(i));
3742                 }
3743                 else if ((isLOWER(lastvalue) && isLOWER(value)) ||
3744                     (isUPPER(lastvalue) && isUPPER(value)))
3745                 {
3746                     IV i;
3747                     if (isLOWER(lastvalue)) {
3748                         for (i = lastvalue; i <= value; i++)
3749                             if (isLOWER(i))
3750                                 ANYOF_BITMAP_SET(ret, i);
3751                     } else {
3752                         for (i = lastvalue; i <= value; i++)
3753                             if (isUPPER(i))
3754                                 ANYOF_BITMAP_SET(ret, i);
3755                     }
3756                 }
3757                 else
3758 #endif
3759                     for ( ; lastvalue <= value; lastvalue++)
3760                         ANYOF_BITMAP_SET(ret, lastvalue);
3761             } else {
3762                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3763                 if (lastvalue < value)
3764                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
3765                                    (UV)lastvalue, (UV)value);
3766                 else
3767                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
3768                                    (UV)value);
3769             }
3770         }
3771
3772         range = 0; /* this range (if it was one) is done now */
3773     }
3774
3775     if (need_class) {
3776         if (SIZE_ONLY)
3777             RExC_size += ANYOF_CLASS_ADD_SKIP;
3778         else
3779             RExC_emit += ANYOF_CLASS_ADD_SKIP;
3780     }
3781
3782     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
3783     if (!SIZE_ONLY &&
3784         (ANYOF_FLAGS(ret) &
3785          /* If the only flag is folding (plus possibly inversion). */
3786          (ANYOF_FLAGS_ALL ^ ANYOF_INVERT) == ANYOF_FOLD)) {
3787         for (value = 0; value < 256; ++value) {
3788             if (ANYOF_BITMAP_TEST(ret, value)) {
3789                 IV fold = PL_fold[value];
3790
3791                 if (fold != value)
3792                     ANYOF_BITMAP_SET(ret, fold);
3793             }
3794         }
3795         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
3796     }
3797
3798     /* optimize inverted simple patterns (e.g. [^a-z]) */
3799     if (!SIZE_ONLY && !dont_optimize_invert &&
3800         /* If the only flag is inversion. */
3801         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
3802         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
3803             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
3804         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
3805     }
3806
3807     if (!SIZE_ONLY) {
3808         AV *av = newAV();
3809         SV *rv;
3810
3811         av_store(av, 0, listsv);
3812         av_store(av, 1, NULL);
3813         rv = newRV_noinc((SV*)av);
3814         n = add_data(pRExC_state, 1, "s");
3815         RExC_rx->data->data[n] = (void*)rv;
3816         ARG_SET(ret, n);
3817     }
3818
3819     return ret;
3820 }
3821
3822 STATIC char*
3823 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
3824 {
3825     char* retval = RExC_parse++;
3826
3827     for (;;) {
3828         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
3829                 RExC_parse[2] == '#') {
3830             while (*RExC_parse && *RExC_parse != ')')
3831                 RExC_parse++;
3832             RExC_parse++;
3833             continue;
3834         }
3835         if (RExC_flags16 & PMf_EXTENDED) {
3836             if (isSPACE(*RExC_parse)) {
3837                 RExC_parse++;
3838                 continue;
3839             }
3840             else if (*RExC_parse == '#') {
3841                 while (*RExC_parse && *RExC_parse != '\n')
3842                     RExC_parse++;
3843                 RExC_parse++;
3844                 continue;
3845             }
3846         }
3847         return retval;
3848     }
3849 }
3850
3851 /*
3852 - reg_node - emit a node
3853 */
3854 STATIC regnode *                        /* Location. */
3855 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
3856 {
3857     register regnode *ret;
3858     register regnode *ptr;
3859
3860     ret = RExC_emit;
3861     if (SIZE_ONLY) {
3862         SIZE_ALIGN(RExC_size);
3863         RExC_size += 1;
3864         return(ret);
3865     }
3866
3867     NODE_ALIGN_FILL(ret);
3868     ptr = ret;
3869     FILL_ADVANCE_NODE(ptr, op);
3870     RExC_emit = ptr;
3871
3872     return(ret);
3873 }
3874
3875 /*
3876 - reganode - emit a node with an argument
3877 */
3878 STATIC regnode *                        /* Location. */
3879 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
3880 {
3881     register regnode *ret;
3882     register regnode *ptr;
3883
3884     ret = RExC_emit;
3885     if (SIZE_ONLY) {
3886         SIZE_ALIGN(RExC_size);
3887         RExC_size += 2;
3888         return(ret);
3889     }
3890
3891     NODE_ALIGN_FILL(ret);
3892     ptr = ret;
3893     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
3894     RExC_emit = ptr;
3895
3896     return(ret);
3897 }
3898
3899 /*
3900 - reguni - emit (if appropriate) a Unicode character
3901 */
3902 STATIC void
3903 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
3904 {
3905     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
3906 }
3907
3908 /*
3909 - reginsert - insert an operator in front of already-emitted operand
3910 *
3911 * Means relocating the operand.
3912 */
3913 STATIC void
3914 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
3915 {
3916     register regnode *src;
3917     register regnode *dst;
3918     register regnode *place;
3919     register int offset = regarglen[(U8)op];
3920
3921 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
3922
3923     if (SIZE_ONLY) {
3924         RExC_size += NODE_STEP_REGNODE + offset;
3925         return;
3926     }
3927
3928     src = RExC_emit;
3929     RExC_emit += NODE_STEP_REGNODE + offset;
3930     dst = RExC_emit;
3931     while (src > opnd)
3932         StructCopy(--src, --dst, regnode);
3933
3934     place = opnd;               /* Op node, where operand used to be. */
3935     src = NEXTOPER(place);
3936     FILL_ADVANCE_NODE(place, op);
3937     Zero(src, offset, regnode);
3938 }
3939
3940 /*
3941 - regtail - set the next-pointer at the end of a node chain of p to val.
3942 */
3943 STATIC void
3944 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
3945 {
3946     register regnode *scan;
3947     register regnode *temp;
3948
3949     if (SIZE_ONLY)
3950         return;
3951
3952     /* Find last node. */
3953     scan = p;
3954     for (;;) {
3955         temp = regnext(scan);
3956         if (temp == NULL)
3957             break;
3958         scan = temp;
3959     }
3960
3961     if (reg_off_by_arg[OP(scan)]) {
3962         ARG_SET(scan, val - scan);
3963     }
3964     else {
3965         NEXT_OFF(scan) = val - scan;
3966     }
3967 }
3968
3969 /*
3970 - regoptail - regtail on operand of first argument; nop if operandless
3971 */
3972 STATIC void
3973 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
3974 {
3975     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
3976     if (p == NULL || SIZE_ONLY)
3977         return;
3978     if (PL_regkind[(U8)OP(p)] == BRANCH) {
3979         regtail(pRExC_state, NEXTOPER(p), val);
3980     }
3981     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
3982         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
3983     }
3984     else
3985         return;
3986 }
3987
3988 /*
3989  - regcurly - a little FSA that accepts {\d+,?\d*}
3990  */
3991 STATIC I32
3992 S_regcurly(pTHX_ register char *s)
3993 {
3994     if (*s++ != '{')
3995         return FALSE;
3996     if (!isDIGIT(*s))
3997         return FALSE;
3998     while (isDIGIT(*s))
3999         s++;
4000     if (*s == ',')
4001         s++;
4002     while (isDIGIT(*s))
4003         s++;
4004     if (*s != '}')
4005         return FALSE;
4006     return TRUE;
4007 }
4008
4009
4010 STATIC regnode *
4011 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4012 {
4013 #ifdef DEBUGGING
4014     register U8 op = EXACT;     /* Arbitrary non-END op. */
4015     register regnode *next;
4016
4017     while (op != END && (!last || node < last)) {
4018         /* While that wasn't END last time... */
4019
4020         NODE_ALIGN(node);
4021         op = OP(node);
4022         if (op == CLOSE)
4023             l--;
4024         next = regnext(node);
4025         /* Where, what. */
4026         if (OP(node) == OPTIMIZED)
4027             goto after_print;
4028         regprop(sv, node);
4029         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4030                       (int)(2*l + 1), "", SvPVX(sv));
4031         if (next == NULL)               /* Next ptr. */
4032             PerlIO_printf(Perl_debug_log, "(0)");
4033         else
4034             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4035         (void)PerlIO_putc(Perl_debug_log, '\n');
4036       after_print:
4037         if (PL_regkind[(U8)op] == BRANCHJ) {
4038             register regnode *nnode = (OP(next) == LONGJMP
4039                                        ? regnext(next)
4040                                        : next);
4041             if (last && nnode > last)
4042                 nnode = last;
4043             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4044         }
4045         else if (PL_regkind[(U8)op] == BRANCH) {
4046             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4047         }
4048         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4049             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4050                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4051         }
4052         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4053             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4054                              next, sv, l + 1);
4055         }
4056         else if ( op == PLUS || op == STAR) {
4057             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4058         }
4059         else if (op == ANYOF) {
4060             node = NEXTOPER(node);
4061             node += ANYOF_SKIP;
4062         }
4063         else if (PL_regkind[(U8)op] == EXACT) {
4064             /* Literal string, where present. */
4065             node += NODE_SZ_STR(node) - 1;
4066             node = NEXTOPER(node);
4067         }
4068         else {
4069             node = NEXTOPER(node);
4070             node += regarglen[(U8)op];
4071         }
4072         if (op == CURLYX || op == OPEN)
4073             l++;
4074         else if (op == WHILEM)
4075             l--;
4076     }
4077 #endif  /* DEBUGGING */
4078     return node;
4079 }
4080
4081 /*
4082  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4083  */
4084 void
4085 Perl_regdump(pTHX_ regexp *r)
4086 {
4087 #ifdef DEBUGGING
4088     SV *sv = sv_newmortal();
4089
4090     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4091
4092     /* Header fields of interest. */
4093     if (r->anchored_substr)
4094         PerlIO_printf(Perl_debug_log,
4095                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4096                       PL_colors[0],
4097                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4098                       SvPVX(r->anchored_substr),
4099                       PL_colors[1],
4100                       SvTAIL(r->anchored_substr) ? "$" : "",
4101                       (IV)r->anchored_offset);
4102     if (r->float_substr)
4103         PerlIO_printf(Perl_debug_log,
4104                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4105                       PL_colors[0],
4106                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4107                       SvPVX(r->float_substr),
4108                       PL_colors[1],
4109                       SvTAIL(r->float_substr) ? "$" : "",
4110                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4111     if (r->check_substr)
4112         PerlIO_printf(Perl_debug_log,
4113                       r->check_substr == r->float_substr
4114                       ? "(checking floating" : "(checking anchored");
4115     if (r->reganch & ROPT_NOSCAN)
4116         PerlIO_printf(Perl_debug_log, " noscan");
4117     if (r->reganch & ROPT_CHECK_ALL)
4118         PerlIO_printf(Perl_debug_log, " isall");
4119     if (r->check_substr)
4120         PerlIO_printf(Perl_debug_log, ") ");
4121
4122     if (r->regstclass) {
4123         regprop(sv, r->regstclass);
4124         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4125     }
4126     if (r->reganch & ROPT_ANCH) {
4127         PerlIO_printf(Perl_debug_log, "anchored");
4128         if (r->reganch & ROPT_ANCH_BOL)
4129             PerlIO_printf(Perl_debug_log, "(BOL)");
4130         if (r->reganch & ROPT_ANCH_MBOL)
4131             PerlIO_printf(Perl_debug_log, "(MBOL)");
4132         if (r->reganch & ROPT_ANCH_SBOL)
4133             PerlIO_printf(Perl_debug_log, "(SBOL)");
4134         if (r->reganch & ROPT_ANCH_GPOS)
4135             PerlIO_printf(Perl_debug_log, "(GPOS)");
4136         PerlIO_putc(Perl_debug_log, ' ');
4137     }
4138     if (r->reganch & ROPT_GPOS_SEEN)
4139         PerlIO_printf(Perl_debug_log, "GPOS ");
4140     if (r->reganch & ROPT_SKIP)
4141         PerlIO_printf(Perl_debug_log, "plus ");
4142     if (r->reganch & ROPT_IMPLICIT)
4143         PerlIO_printf(Perl_debug_log, "implicit ");
4144     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4145     if (r->reganch & ROPT_EVAL_SEEN)
4146         PerlIO_printf(Perl_debug_log, "with eval ");
4147     PerlIO_printf(Perl_debug_log, "\n");
4148 #endif  /* DEBUGGING */
4149 }
4150
4151 STATIC void
4152 S_put_byte(pTHX_ SV *sv, int c)
4153 {
4154     if (isCNTRL(c) || c == 127 || c == 255 || !isPRINT(c))
4155         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4156     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4157         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4158     else
4159         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4160 }
4161
4162 /*
4163 - regprop - printable representation of opcode
4164 */
4165 void
4166 Perl_regprop(pTHX_ SV *sv, regnode *o)
4167 {
4168 #ifdef DEBUGGING
4169     register int k;
4170
4171     sv_setpvn(sv, "", 0);
4172     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4173         /* It would be nice to FAIL() here, but this may be called from
4174            regexec.c, and it would be hard to supply pRExC_state. */
4175         Perl_croak(aTHX_ "Corrupted regexp opcode");
4176     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4177
4178     k = PL_regkind[(U8)OP(o)];
4179
4180     if (k == EXACT)
4181         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>", PL_colors[0],
4182                        STR_LEN(o), STRING(o), PL_colors[1]);
4183     else if (k == CURLY) {
4184         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4185             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4186         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4187     }
4188     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4189         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4190     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4191         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4192     else if (k == LOGICAL)
4193         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4194     else if (k == ANYOF) {
4195         int i, rangestart = -1;
4196         U8 flags = ANYOF_FLAGS(o);
4197         const char * const anyofs[] = { /* Should be syncronized with
4198                                          * ANYOF_ #xdefines in regcomp.h */
4199             "\\w",
4200             "\\W",
4201             "\\s",
4202             "\\S",
4203             "\\d",
4204             "\\D",
4205             "[:alnum:]",
4206             "[:^alnum:]",
4207             "[:alpha:]",
4208             "[:^alpha:]",
4209             "[:ascii:]",
4210             "[:^ascii:]",
4211             "[:ctrl:]",
4212             "[:^ctrl:]",
4213             "[:graph:]",
4214             "[:^graph:]",
4215             "[:lower:]",
4216             "[:^lower:]",
4217             "[:print:]",
4218             "[:^print:]",
4219             "[:punct:]",
4220             "[:^punct:]",
4221             "[:upper:]",
4222             "[:^upper:]",
4223             "[:xdigit:]",
4224             "[:^xdigit:]",
4225             "[:space:]",
4226             "[:^space:]",
4227             "[:blank:]",
4228             "[:^blank:]"
4229         };
4230
4231         if (flags & ANYOF_LOCALE)
4232             sv_catpv(sv, "{loc}");
4233         if (flags & ANYOF_FOLD)
4234             sv_catpv(sv, "{i}");
4235         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4236         if (flags & ANYOF_INVERT)
4237             sv_catpv(sv, "^");
4238         for (i = 0; i <= 256; i++) {
4239             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4240                 if (rangestart == -1)
4241                     rangestart = i;
4242             } else if (rangestart != -1) {
4243                 if (i <= rangestart + 3)
4244                     for (; rangestart < i; rangestart++)
4245                         put_byte(sv, rangestart);
4246                 else {
4247                     put_byte(sv, rangestart);
4248                     sv_catpv(sv, "-");
4249                     put_byte(sv, i - 1);
4250                 }
4251                 rangestart = -1;
4252             }
4253         }
4254
4255         if (o->flags & ANYOF_CLASS)
4256             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4257                 if (ANYOF_CLASS_TEST(o,i))
4258                     sv_catpv(sv, anyofs[i]);
4259
4260         if (flags & ANYOF_UNICODE)
4261             sv_catpv(sv, "{unicode}");
4262         else if (flags & ANYOF_UNICODE_ALL)
4263             sv_catpv(sv, "{all-unicode}");
4264
4265         {
4266             SV *lv;
4267             SV *sw = regclass_swash(o, FALSE, &lv);
4268
4269             if (lv) {
4270                 if (sw) {
4271                     UV i;
4272                     U8 s[UTF8_MAXLEN+1];
4273
4274                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4275                         U8 *e = uvchr_to_utf8(s, i);
4276
4277                         if (i < 256 && swash_fetch(sw, s)) {
4278                             if (rangestart == -1)
4279                                 rangestart = i;
4280                         } else if (rangestart != -1) {
4281                             U8 *p;
4282
4283                             if (i <= rangestart + 3)
4284                                 for (; rangestart < i; rangestart++) {
4285                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4286                                         put_byte(sv, *p);
4287                                 }
4288                             else {
4289                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4290                                     put_byte(sv, *p);
4291                                 sv_catpv(sv, "-");
4292                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4293                                         put_byte(sv, *p);
4294                                 }
4295                                 rangestart = -1;
4296                             }
4297                         }
4298
4299                     sv_catpv(sv, "..."); /* et cetera */
4300                 }
4301
4302                 {
4303                     char *s = savepv(SvPVX(lv));
4304                     char *origs = s;
4305
4306                     while(*s && *s != '\n') s++;
4307
4308                     if (*s == '\n') {
4309                         char *t = ++s;
4310
4311                         while (*s) {
4312                             if (*s == '\n')
4313                                 *s = ' ';
4314                             s++;
4315                         }
4316                         if (s[-1] == ' ')
4317                             s[-1] = 0;
4318
4319                         sv_catpv(sv, t);
4320                     }
4321
4322                     Safefree(origs);
4323                 }
4324             }
4325         }
4326
4327         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4328     }
4329     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4330         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4331 #endif  /* DEBUGGING */
4332 }
4333
4334 SV *
4335 Perl_re_intuit_string(pTHX_ regexp *prog)
4336 {                               /* Assume that RE_INTUIT is set */
4337     DEBUG_r(
4338         {   STRLEN n_a;
4339             char *s = SvPV(prog->check_substr,n_a);
4340
4341             if (!PL_colorset) reginitcolors();
4342             PerlIO_printf(Perl_debug_log,
4343                       "%sUsing REx substr:%s `%s%.60s%s%s'\n",
4344                       PL_colors[4],PL_colors[5],PL_colors[0],
4345                       s,
4346                       PL_colors[1],
4347                       (strlen(s) > 60 ? "..." : ""));
4348         } );
4349
4350     return prog->check_substr;
4351 }
4352
4353 void
4354 Perl_pregfree(pTHX_ struct regexp *r)
4355 {
4356     DEBUG_r(if (!PL_colorset) reginitcolors());
4357
4358     if (!r || (--r->refcnt > 0))
4359         return;
4360     DEBUG_r(PerlIO_printf(Perl_debug_log,
4361                       "%sFreeing REx:%s `%s%.60s%s%s'\n",
4362                       PL_colors[4],PL_colors[5],PL_colors[0],
4363                       r->precomp,
4364                       PL_colors[1],
4365                       (strlen(r->precomp) > 60 ? "..." : "")));
4366
4367     if (r->precomp)
4368         Safefree(r->precomp);
4369     if (RX_MATCH_COPIED(r))
4370         Safefree(r->subbeg);
4371     if (r->substrs) {
4372         if (r->anchored_substr)
4373             SvREFCNT_dec(r->anchored_substr);
4374         if (r->float_substr)
4375             SvREFCNT_dec(r->float_substr);
4376         Safefree(r->substrs);
4377     }
4378     if (r->data) {
4379         int n = r->data->count;
4380         AV* new_comppad = NULL;
4381         AV* old_comppad;
4382         SV** old_curpad;
4383
4384         while (--n >= 0) {
4385             switch (r->data->what[n]) {
4386             case 's':
4387                 SvREFCNT_dec((SV*)r->data->data[n]);
4388                 break;
4389             case 'f':
4390                 Safefree(r->data->data[n]);
4391                 break;
4392             case 'p':
4393                 new_comppad = (AV*)r->data->data[n];
4394                 break;
4395             case 'o':
4396                 if (new_comppad == NULL)
4397                     Perl_croak(aTHX_ "panic: pregfree comppad");
4398                 old_comppad = PL_comppad;
4399                 old_curpad = PL_curpad;
4400                 /* Watch out for global destruction's random ordering. */
4401                 if (SvTYPE(new_comppad) == SVt_PVAV) {
4402                     PL_comppad = new_comppad;
4403                     PL_curpad = AvARRAY(new_comppad);
4404                 }
4405                 else
4406                     PL_curpad = NULL;
4407                 op_free((OP_4tree*)r->data->data[n]);
4408                 PL_comppad = old_comppad;
4409                 PL_curpad = old_curpad;
4410                 SvREFCNT_dec((SV*)new_comppad);
4411                 new_comppad = NULL;
4412                 break;
4413             case 'n':
4414                 break;
4415             default:
4416                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4417             }
4418         }
4419         Safefree(r->data->what);
4420         Safefree(r->data);
4421     }
4422     Safefree(r->startp);
4423     Safefree(r->endp);
4424     Safefree(r);
4425 }
4426
4427 /*
4428  - regnext - dig the "next" pointer out of a node
4429  *
4430  * [Note, when REGALIGN is defined there are two places in regmatch()
4431  * that bypass this code for speed.]
4432  */
4433 regnode *
4434 Perl_regnext(pTHX_ register regnode *p)
4435 {
4436     register I32 offset;
4437
4438     if (p == &PL_regdummy)
4439         return(NULL);
4440
4441     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
4442     if (offset == 0)
4443         return(NULL);
4444
4445     return(p+offset);
4446 }
4447
4448 STATIC void
4449 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
4450 {
4451     va_list args;
4452     STRLEN l1 = strlen(pat1);
4453     STRLEN l2 = strlen(pat2);
4454     char buf[512];
4455     SV *msv;
4456     char *message;
4457
4458     if (l1 > 510)
4459         l1 = 510;
4460     if (l1 + l2 > 510)
4461         l2 = 510 - l1;
4462     Copy(pat1, buf, l1 , char);
4463     Copy(pat2, buf + l1, l2 , char);
4464     buf[l1 + l2] = '\n';
4465     buf[l1 + l2 + 1] = '\0';
4466 #ifdef I_STDARG
4467     /* ANSI variant takes additional second argument */
4468     va_start(args, pat2);
4469 #else
4470     va_start(args);
4471 #endif
4472     msv = vmess(buf, &args);
4473     va_end(args);
4474     message = SvPV(msv,l1);
4475     if (l1 > 512)
4476         l1 = 512;
4477     Copy(message, buf, l1 , char);
4478     buf[l1] = '\0';                     /* Overwrite \n */
4479     Perl_croak(aTHX_ "%s", buf);
4480 }
4481
4482 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
4483
4484 void
4485 Perl_save_re_context(pTHX)
4486 {
4487 #if 0
4488     SAVEPPTR(RExC_precomp);             /* uncompiled string. */
4489     SAVEI32(RExC_npar);         /* () count. */
4490     SAVEI32(RExC_size);         /* Code size. */
4491     SAVEI16(RExC_flags16);              /* are we folding, multilining? */
4492     SAVEVPTR(RExC_rx);          /* from regcomp.c */
4493     SAVEI32(RExC_seen);         /* from regcomp.c */
4494     SAVEI32(RExC_sawback);              /* Did we see \1, ...? */
4495     SAVEI32(RExC_naughty);              /* How bad is this pattern? */
4496     SAVEVPTR(RExC_emit);                /* Code-emit pointer; &regdummy = don't */
4497     SAVEPPTR(RExC_end);         /* End of input for compile */
4498     SAVEPPTR(RExC_parse);               /* Input-scan pointer. */
4499 #endif
4500
4501     SAVEI32(PL_reg_flags);              /* from regexec.c */
4502     SAVEPPTR(PL_bostr);
4503     SAVEPPTR(PL_reginput);              /* String-input pointer. */
4504     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
4505     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
4506     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
4507     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
4508     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
4509     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
4510     SAVEI8(PL_regprev);                 /* char before regbol, \n if none */
4511     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
4512     PL_reg_start_tmp = 0;
4513     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
4514     PL_reg_start_tmpl = 0;
4515     SAVEVPTR(PL_regdata);
4516     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
4517     SAVEI32(PL_regnarrate);             /* from regexec.c */
4518     SAVEVPTR(PL_regprogram);            /* from regexec.c */
4519     SAVEINT(PL_regindent);              /* from regexec.c */
4520     SAVEVPTR(PL_regcc);                 /* from regexec.c */
4521     SAVEVPTR(PL_curcop);
4522     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
4523     SAVEVPTR(PL_reg_re);                /* from regexec.c */
4524     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
4525     SAVESPTR(PL_reg_sv);                /* from regexec.c */
4526     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
4527     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
4528     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
4529     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
4530     SAVEI32(PL_regnpar);                /* () count. */
4531 #ifdef DEBUGGING
4532     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
4533 #endif
4534 }
4535
4536 #ifdef PERL_OBJECT
4537 #include "XSUB.h"
4538 #undef this
4539 #define this pPerl
4540 #endif
4541
4542 static void
4543 clear_re(pTHXo_ void *r)
4544 {
4545     ReREFCNT_dec((regexp *)r);
4546 }
4547