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) 1991-2002, Larry Wall
  73  ****
  74  ****    You may distribute under the terms of either the GNU General Public
  75  ****    License or the Artistic License, as specified in the README file.
  76
  77  *
  78  * Beware that some of this code is subtly aware of the way operator
  79  * precedence is structured in regular expressions.  Serious changes in
  80  * regular-expression syntax might require a total rethink.
  81  */
  82 #include "EXTERN.h"
  83 #define PERL_IN_REGCOMP_C
  84 #include "perl.h"
  85
  86 #ifndef PERL_IN_XSUB_RE
  87 #  include "INTERN.h"
  88 #endif
  89
  90 #define REG_COMP_C
  91 #include "regcomp.h"
  92
  93 #ifdef op
  94 #undef op
  95 #endif /* op */
  96
  97 #ifdef MSDOS
  98 # if defined(BUGGY_MSC6)
  99  /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
 100  # pragma optimize("a",off)
 101  /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
 102  # pragma optimize("w",on )
 103 # endif /* BUGGY_MSC6 */
 104 #endif /* MSDOS */
 105
 106 #ifndef STATIC
 107 #define STATIC  static
 108 #endif
 109
 110 typedef struct RExC_state_t {
 111     U16         flags16;                /* are we folding, multilining? */
 112     char        *precomp;               /* uncompiled string. */
 113     regexp      *rx;
 114     char        *start;                 /* Start of input for compile */
 115     char        *end;                   /* End of input for compile */
 116     char        *parse;                 /* Input-scan pointer. */
 117     I32         whilem_seen;            /* number of WHILEM in this expr */
 118     regnode     *emit_start;            /* Start of emitted-code area */
 119     regnode     *emit;                  /* Code-emit pointer; &regdummy = don't = compiling */
 120     I32         naughty;                /* How bad is this pattern? */
 121     I32         sawback;                /* Did we see \1, ...? */
 122     U32         seen;
 123     I32         size;                   /* Code size. */
 124     I32         npar;                   /* () count. */
 125     I32         extralen;
 126     I32         seen_zerolen;
 127     I32         seen_evals;
 128     I32         utf8;
 129 #if ADD_TO_REGEXEC
 130     char        *starttry;              /* -Dr: where regtry was called. */
 131 #define RExC_starttry   (pRExC_state->starttry)
 132 #endif
 133 } RExC_state_t;
 134
 135 #define RExC_flags16    (pRExC_state->flags16)
 136 #define RExC_precomp    (pRExC_state->precomp)
 137 #define RExC_rx         (pRExC_state->rx)
 138 #define RExC_start      (pRExC_state->start)
 139 #define RExC_end        (pRExC_state->end)
 140 #define RExC_parse      (pRExC_state->parse)
 141 #define RExC_whilem_seen        (pRExC_state->whilem_seen)
 142 #define RExC_offsets    (pRExC_state->rx->offsets) /* I am not like the others */
 143 #define RExC_emit       (pRExC_state->emit)
 144 #define RExC_emit_start (pRExC_state->emit_start)
 145 #define RExC_naughty    (pRExC_state->naughty)
 146 #define RExC_sawback    (pRExC_state->sawback)
 147 #define RExC_seen       (pRExC_state->seen)
 148 #define RExC_size       (pRExC_state->size)
 149 #define RExC_npar       (pRExC_state->npar)
 150 #define RExC_extralen   (pRExC_state->extralen)
 151 #define RExC_seen_zerolen       (pRExC_state->seen_zerolen)
 152 #define RExC_seen_evals (pRExC_state->seen_evals)
 153 #define RExC_utf8       (pRExC_state->utf8)
 154
 155 #define ISMULT1(c)      ((c) == '*' || (c) == '+' || (c) == '?')
 156 #define ISMULT2(s)      ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
 157         ((*s) == '{' && regcurly(s)))
 158
 159 #ifdef SPSTART
 160 #undef SPSTART          /* dratted cpp namespace... */
 161 #endif
 162 /*
 163  * Flags to be passed up and down.
 164  */
 165 #define WORST           0       /* Worst case. */
 166 #define HASWIDTH        0x1     /* Known to match non-null strings. */
 167 #define SIMPLE          0x2     /* Simple enough to be STAR/PLUS operand. */
 168 #define SPSTART         0x4     /* Starts with * or +. */
 169 #define TRYAGAIN        0x8     /* Weeded out a declaration. */
 170
 171 /* Length of a variant. */
 172
 173 typedef struct scan_data_t {
 174     I32 len_min;
 175     I32 len_delta;
 176     I32 pos_min;
 177     I32 pos_delta;
 178     SV *last_found;
 179     I32 last_end;                       /* min value, <0 unless valid. */
 180     I32 last_start_min;
 181     I32 last_start_max;
 182     SV **longest;                       /* Either &l_fixed, or &l_float. */
 183     SV *longest_fixed;
 184     I32 offset_fixed;
 185     SV *longest_float;
 186     I32 offset_float_min;
 187     I32 offset_float_max;
 188     I32 flags;
 189     I32 whilem_c;
 190     I32 *last_closep;
 191     struct regnode_charclass_class *start_class;
 192 } scan_data_t;
 193
 194 /*
 195  * Forward declarations for pregcomp()'s friends.
 196  */
 197
 198 static scan_data_t zero_scan_data = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 199                                       0, 0, 0, 0, 0, 0};
 200
 201 #define SF_BEFORE_EOL           (SF_BEFORE_SEOL|SF_BEFORE_MEOL)
 202 #define SF_BEFORE_SEOL          0x1
 203 #define SF_BEFORE_MEOL          0x2
 204 #define SF_FIX_BEFORE_EOL       (SF_FIX_BEFORE_SEOL|SF_FIX_BEFORE_MEOL)
 205 #define SF_FL_BEFORE_EOL        (SF_FL_BEFORE_SEOL|SF_FL_BEFORE_MEOL)
 206
 207 #ifdef NO_UNARY_PLUS
 208 #  define SF_FIX_SHIFT_EOL      (0+2)
 209 #  define SF_FL_SHIFT_EOL               (0+4)
 210 #else
 211 #  define SF_FIX_SHIFT_EOL      (+2)
 212 #  define SF_FL_SHIFT_EOL               (+4)
 213 #endif
 214
 215 #define SF_FIX_BEFORE_SEOL      (SF_BEFORE_SEOL << SF_FIX_SHIFT_EOL)
 216 #define SF_FIX_BEFORE_MEOL      (SF_BEFORE_MEOL << SF_FIX_SHIFT_EOL)
 217
 218 #define SF_FL_BEFORE_SEOL       (SF_BEFORE_SEOL << SF_FL_SHIFT_EOL)
 219 #define SF_FL_BEFORE_MEOL       (SF_BEFORE_MEOL << SF_FL_SHIFT_EOL) /* 0x20 */
 220 #define SF_IS_INF               0x40
 221 #define SF_HAS_PAR              0x80
 222 #define SF_IN_PAR               0x100
 223 #define SF_HAS_EVAL             0x200
 224 #define SCF_DO_SUBSTR           0x400
 225 #define SCF_DO_STCLASS_AND      0x0800
 226 #define SCF_DO_STCLASS_OR       0x1000
 227 #define SCF_DO_STCLASS          (SCF_DO_STCLASS_AND|SCF_DO_STCLASS_OR)
 228 #define SCF_WHILEM_VISITED_POS  0x2000
 229
 230 #define UTF RExC_utf8
 231 #define LOC (RExC_flags16 & PMf_LOCALE)
 232 #define FOLD (RExC_flags16 & PMf_FOLD)
 233
 234 #define OOB_UNICODE             12345678
 235 #define OOB_NAMEDCLASS          -1
 236
 237 #define CHR_SVLEN(sv) (UTF ? sv_len_utf8(sv) : SvCUR(sv))
 238 #define CHR_DIST(a,b) (UTF ? utf8_distance(a,b) : a - b)
 239
 240
 241 /* length of regex to show in messages that don't mark a position within */
 242 #define RegexLengthToShowInErrorMessages 127
 243
 244 /*
 245  * If MARKER[12] are adjusted, be sure to adjust the constants at the top
 246  * of t/op/regmesg.t, the tests in t/op/re_tests, and those in
 247  * op/pragma/warn/regcomp.
 248  */
 249 #define MARKER1 "<-- HERE"    /* marker as it appears in the description */
 250 #define MARKER2 " <-- HERE "  /* marker as it appears within the regex */
 251
 252 #define REPORT_LOCATION " in regex; marked by " MARKER1 " in m/%.*s" MARKER2 "%s/"
 253
 254 /*
 255  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 256  * arg. Show regex, up to a maximum length. If it's too long, chop and add
 257  * "...".
 258  */
 259 #define FAIL(msg)                                                             \
 260     STMT_START {                                                             \
 261         char *ellipses = "";                                                 \
 262         IV len = RExC_end - RExC_precomp;                                \
 263                                                                              \
 264         if (!SIZE_ONLY)                                                      \
 265             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 266                                                                              \
 267         if (len > RegexLengthToShowInErrorMessages) {                        \
 268             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 269             len = RegexLengthToShowInErrorMessages - 10;                     \
 270             ellipses = "...";                                                \
 271         }                                                                    \
 272         Perl_croak(aTHX_ "%s in regex m/%.*s%s/",                            \
 273                    msg, (int)len, RExC_precomp, ellipses);                  \
 274     } STMT_END
 275
 276 /*
 277  * Calls SAVEDESTRUCTOR_X if needed, then calls Perl_croak with the given
 278  * args. Show regex, up to a maximum length. If it's too long, chop and add
 279  * "...".
 280  */
 281 #define FAIL2(pat,msg)                                                        \
 282     STMT_START {                                                             \
 283         char *ellipses = "";                                                 \
 284         IV len = RExC_end - RExC_precomp;                                \
 285                                                                              \
 286         if (!SIZE_ONLY)                                                      \
 287             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 288                                                                              \
 289         if (len > RegexLengthToShowInErrorMessages) {                        \
 290             /* chop 10 shorter than the max, to ensure meaning of "..." */   \
 291             len = RegexLengthToShowInErrorMessages - 10;                     \
 292             ellipses = "...";                                                \
 293         }                                                                    \
 294         S_re_croak2(aTHX_ pat, " in regex m/%.*s%s/",                        \
 295                     msg, (int)len, RExC_precomp, ellipses);                \
 296     } STMT_END
 297
 298
 299 /*
 300  * Simple_vFAIL -- like FAIL, but marks the current location in the scan
 301  */
 302 #define Simple_vFAIL(m)                                                      \
 303     STMT_START {                                                             \
 304       IV offset = RExC_parse - RExC_precomp; \
 305                                                                              \
 306       Perl_croak(aTHX_ "%s" REPORT_LOCATION,               \
 307                  m, (int)offset, RExC_precomp, RExC_precomp + offset);     \
 308     } STMT_END
 309
 310 /*
 311  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL()
 312  */
 313 #define vFAIL(m)                                                             \
 314     STMT_START {                                                             \
 315       if (!SIZE_ONLY)                                                        \
 316             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 317       Simple_vFAIL(m);                                                       \
 318     } STMT_END
 319
 320 /*
 321  * Like Simple_vFAIL(), but accepts two arguments.
 322  */
 323 #define Simple_vFAIL2(m,a1)                                                  \
 324     STMT_START {                                                             \
 325       IV offset = RExC_parse - RExC_precomp; \
 326                                                                              \
 327       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1,       \
 328                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 329     } STMT_END
 330
 331 /*
 332  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL2().
 333  */
 334 #define vFAIL2(m,a1)                                                         \
 335     STMT_START {                                                             \
 336       if (!SIZE_ONLY)                                                        \
 337             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 338       Simple_vFAIL2(m, a1);                                                  \
 339     } STMT_END
 340
 341
 342 /*
 343  * Like Simple_vFAIL(), but accepts three arguments.
 344  */
 345 #define Simple_vFAIL3(m, a1, a2)                                             \
 346     STMT_START {                                                             \
 347       IV offset = RExC_parse - RExC_precomp; \
 348                                                                              \
 349       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2,   \
 350                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 351     } STMT_END
 352
 353 /*
 354  * Calls SAVEDESTRUCTOR_X if needed, then Simple_vFAIL3().
 355  */
 356 #define vFAIL3(m,a1,a2)                                                      \
 357     STMT_START {                                                             \
 358       if (!SIZE_ONLY)                                                        \
 359             SAVEDESTRUCTOR_X(clear_re,(void*)RExC_rx);                 \
 360       Simple_vFAIL3(m, a1, a2);                                              \
 361     } STMT_END
 362
 363 /*
 364  * Like Simple_vFAIL(), but accepts four arguments.
 365  */
 366 #define Simple_vFAIL4(m, a1, a2, a3)                                         \
 367     STMT_START {                                                             \
 368       IV offset = RExC_parse - RExC_precomp; \
 369                                                                              \
 370       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3,\
 371                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 372     } STMT_END
 373
 374 /*
 375  * Like Simple_vFAIL(), but accepts five arguments.
 376  */
 377 #define Simple_vFAIL5(m, a1, a2, a3, a4)                                     \
 378     STMT_START {                                                             \
 379       IV offset = RExC_parse - RExC_precomp; \
 380       S_re_croak2(aTHX_ m, REPORT_LOCATION, a1, a2, a3, a4,\
 381                   (int)offset, RExC_precomp, RExC_precomp + offset);       \
 382     } STMT_END
 383
 384
 385 #define vWARN(loc,m)                                                         \
 386     STMT_START {                                                             \
 387         IV offset = loc - RExC_precomp;          \
 388         Perl_warner(aTHX_ WARN_REGEXP, "%s" REPORT_LOCATION,\
 389                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
 390     } STMT_END                                                               \
 391
 392 #define vWARNdep(loc,m)                                                         \
 393     STMT_START {                                                             \
 394         IV offset = loc - RExC_precomp;          \
 395         int warn_cat = ckWARN(WARN_REGEXP) ? WARN_REGEXP : WARN_DEPRECATED;  \
 396         Perl_warner(aTHX_ warn_cat, "%s" REPORT_LOCATION,\
 397                  m, (int)offset, RExC_precomp, RExC_precomp + offset);          \
 398     } STMT_END                                                               \
 399
 400
 401 #define vWARN2(loc, m, a1)                                                   \
 402     STMT_START {                                                             \
 403         IV offset = loc - RExC_precomp;          \
 404         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 405                  a1,                                                         \
 406                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 407     } STMT_END
 408
 409 #define vWARN3(loc, m, a1, a2)                                               \
 410     STMT_START {                                                             \
 411       IV offset = loc - RExC_precomp;        \
 412         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,                    \
 413                  a1, a2,                                                     \
 414                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 415     } STMT_END
 416
 417 #define vWARN4(loc, m, a1, a2, a3)                                           \
 418     STMT_START {                                                             \
 419       IV offset = loc - RExC_precomp;            \
 420         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,\
 421                  a1, a2, a3,                                                 \
 422                  (int)offset, RExC_precomp, RExC_precomp + offset);        \
 423     } STMT_END
 424
 425 /* used for the parse_flags section for (?c) -- japhy */
 426 #define vWARN5(loc, m, a1, a2, a3, a4)                                       \
 427   STMT_START {                                                   \
 428       IV offset = loc - RExC_precomp;   \
 429         Perl_warner(aTHX_ WARN_REGEXP, m REPORT_LOCATION,      \
 430                  a1, a2, a3, a4,                                 \
 431                  (int)offset, RExC_precomp, RExC_precomp + offset);  \
 432     } STMT_END
 433
 434
 435 /* Allow for side effects in s */
 436 #define REGC(c,s) STMT_START { if (!SIZE_ONLY) *(s) = (c); else (void)(s);} STMT_END
 437
 438 /* Macros for recording node offsets.   20001227 mjd@plover.com
 439  * Nodes are numbered 1, 2, 3, 4.  Node #n's position is recorded in
 440  * element 2*n-1 of the array.  Element #2n holds the byte length node #n.
 441  * Element 0 holds the number n.
 442  */
 443
 444 #define MJD_OFFSET_DEBUG(x)
 445 /* #define MJD_OFFSET_DEBUG(x) fprintf x */
 446
 447
 448 #  define Set_Node_Offset_To_R(node,byte)                           \
 449    STMT_START {                                        \
 450      if (! SIZE_ONLY) {                                  \
 451        if((node) < 0) {                   \
 452          Perl_croak(aTHX_ "value of node is %d in Offset macro", node); \
 453        } else {                                                        \
 454          RExC_offsets[2*(node)-1] = (byte);                               \
 455        }                                                               \
 456      }                                                                 \
 457    } STMT_END
 458
 459 #  define Set_Node_Offset(node,byte) Set_Node_Offset_To_R((node)-RExC_emit_start, (byte)-RExC_start)
 460 #  define Set_Cur_Node_Offset Set_Node_Offset(RExC_emit, RExC_parse)
 461
 462 #  define Set_Node_Length_To_R(node,len)                            \
 463    STMT_START {                                        \
 464      if (! SIZE_ONLY) {                                  \
 465        MJD_OFFSET_DEBUG((stderr, "** (%d) size of node %d is %d.\n", __LINE__, (node), (len))); \
 466        if((node) < 0) {                   \
 467          Perl_croak(aTHX_ "value of node is %d in Length macro", node); \
 468        } else {                                                        \
 469          RExC_offsets[2*(node)] = (len);                               \
 470        }                                                               \
 471      }                                                                 \
 472    } STMT_END
 473
 474 #  define Set_Node_Length(node,len) Set_Node_Length_To_R((node)-RExC_emit_start, len)
 475 #  define Set_Cur_Node_Length(len)  Set_Node_Length(RExC_emit, len)
 476 #  define Set_Node_Cur_Length(node)   Set_Node_Length(node, RExC_parse - parse_start)
 477
 478 /* Get offsets and lengths */
 479 #define Node_Offset(n) (RExC_offsets[2*((n)-RExC_emit_start)-1])
 480 #define Node_Length(n) (RExC_offsets[2*((n)-RExC_emit_start)])
 481
 482 static void clear_re(pTHX_ void *r);
 483
 484 /* Mark that we cannot extend a found fixed substring at this point.
 485    Updata the longest found anchored substring and the longest found
 486    floating substrings if needed. */
 487
 488 STATIC void
 489 S_scan_commit(pTHX_ RExC_state_t *pRExC_state, scan_data_t *data)
 490 {
 491     STRLEN l = CHR_SVLEN(data->last_found);
 492     STRLEN old_l = CHR_SVLEN(*data->longest);
 493
 494     if ((l >= old_l) && ((l > old_l) || (data->flags & SF_BEFORE_EOL))) {
 495         sv_setsv(*data->longest, data->last_found);
 496         if (*data->longest == data->longest_fixed) {
 497             data->offset_fixed = l ? data->last_start_min : data->pos_min;
 498             if (data->flags & SF_BEFORE_EOL)
 499                 data->flags
 500                     |= ((data->flags & SF_BEFORE_EOL) << SF_FIX_SHIFT_EOL);
 501             else
 502                 data->flags &= ~SF_FIX_BEFORE_EOL;
 503         }
 504         else {
 505             data->offset_float_min = l ? data->last_start_min : data->pos_min;
 506             data->offset_float_max = (l
 507                                       ? data->last_start_max
 508                                       : data->pos_min + data->pos_delta);
 509             if (data->flags & SF_BEFORE_EOL)
 510                 data->flags
 511                     |= ((data->flags & SF_BEFORE_EOL) << SF_FL_SHIFT_EOL);
 512             else
 513                 data->flags &= ~SF_FL_BEFORE_EOL;
 514         }
 515     }
 516     SvCUR_set(data->last_found, 0);
 517     data->last_end = -1;
 518     data->flags &= ~SF_BEFORE_EOL;
 519 }
 520
 521 /* Can match anything (initialization) */
 522 STATIC void
 523 S_cl_anything(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 524 {
 525     ANYOF_CLASS_ZERO(cl);
 526     ANYOF_BITMAP_SETALL(cl);
 527     cl->flags = ANYOF_EOS|ANYOF_UNICODE_ALL;
 528     if (LOC)
 529         cl->flags |= ANYOF_LOCALE;
 530 }
 531
 532 /* Can match anything (initialization) */
 533 STATIC int
 534 S_cl_is_anything(pTHX_ struct regnode_charclass_class *cl)
 535 {
 536     int value;
 537
 538     for (value = 0; value <= ANYOF_MAX; value += 2)
 539         if (ANYOF_CLASS_TEST(cl, value) && ANYOF_CLASS_TEST(cl, value + 1))
 540             return 1;
 541     if (!(cl->flags & ANYOF_UNICODE_ALL))
 542         return 0;
 543     if (!ANYOF_BITMAP_TESTALLSET(cl))
 544         return 0;
 545     return 1;
 546 }
 547
 548 /* Can match anything (initialization) */
 549 STATIC void
 550 S_cl_init(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 551 {
 552     Zero(cl, 1, struct regnode_charclass_class);
 553     cl->type = ANYOF;
 554     cl_anything(pRExC_state, cl);
 555 }
 556
 557 STATIC void
 558 S_cl_init_zero(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl)
 559 {
 560     Zero(cl, 1, struct regnode_charclass_class);
 561     cl->type = ANYOF;
 562     cl_anything(pRExC_state, cl);
 563     if (LOC)
 564         cl->flags |= ANYOF_LOCALE;
 565 }
 566
 567 /* 'And' a given class with another one.  Can create false positives */
 568 /* We assume that cl is not inverted */
 569 STATIC void
 570 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 571          struct regnode_charclass_class *and_with)
 572 {
 573     if (!(and_with->flags & ANYOF_CLASS)
 574         && !(cl->flags & ANYOF_CLASS)
 575         && (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 576         && !(and_with->flags & ANYOF_FOLD)
 577         && !(cl->flags & ANYOF_FOLD)) {
 578         int i;
 579
 580         if (and_with->flags & ANYOF_INVERT)
 581             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 582                 cl->bitmap[i] &= ~and_with->bitmap[i];
 583         else
 584             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 585                 cl->bitmap[i] &= and_with->bitmap[i];
 586     } /* XXXX: logic is complicated otherwise, leave it along for a moment. */
 587     if (!(and_with->flags & ANYOF_EOS))
 588         cl->flags &= ~ANYOF_EOS;
 589
 590     if (cl->flags & ANYOF_UNICODE_ALL && and_with->flags & ANYOF_UNICODE) {
 591         cl->flags &= ~ANYOF_UNICODE_ALL;
 592         cl->flags |= ANYOF_UNICODE;
 593         ARG_SET(cl, ARG(and_with));
 594     }
 595     if (!(and_with->flags & ANYOF_UNICODE_ALL))
 596         cl->flags &= ~ANYOF_UNICODE_ALL;
 597     if (!(and_with->flags & (ANYOF_UNICODE|ANYOF_UNICODE_ALL)))
 598         cl->flags &= ~ANYOF_UNICODE;
 599 }
 600
 601 /* 'OR' a given class with another one.  Can create false positives */
 602 /* We assume that cl is not inverted */
 603 STATIC void
 604 S_cl_or(pTHX_ RExC_state_t *pRExC_state, struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 605 {
 606     if (or_with->flags & ANYOF_INVERT) {
 607         /* We do not use
 608          * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
 609          *   <= (B1 | !B2) | (CL1 | !CL2)
 610          * which is wasteful if CL2 is small, but we ignore CL2:
 611          *   (B1 | CL1) | (!B2 & !CL2) <= (B1 | CL1) | !B2 = (B1 | !B2) | CL1
 612          * XXXX Can we handle case-fold?  Unclear:
 613          *   (OK1(i) | OK1(i')) | !(OK1(i) | OK1(i')) =
 614          *   (OK1(i) | OK1(i')) | (!OK1(i) & !OK1(i'))
 615          */
 616         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 617              && !(or_with->flags & ANYOF_FOLD)
 618              && !(cl->flags & ANYOF_FOLD) ) {
 619             int i;
 620
 621             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 622                 cl->bitmap[i] |= ~or_with->bitmap[i];
 623         } /* XXXX: logic is complicated otherwise */
 624         else {
 625             cl_anything(pRExC_state, cl);
 626         }
 627     } else {
 628         /* (B1 | CL1) | (B2 | CL2) = (B1 | B2) | (CL1 | CL2)) */
 629         if ( (or_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
 630              && (!(or_with->flags & ANYOF_FOLD)
 631                  || (cl->flags & ANYOF_FOLD)) ) {
 632             int i;
 633
 634             /* OR char bitmap and class bitmap separately */
 635             for (i = 0; i < ANYOF_BITMAP_SIZE; i++)
 636                 cl->bitmap[i] |= or_with->bitmap[i];
 637             if (or_with->flags & ANYOF_CLASS) {
 638                 for (i = 0; i < ANYOF_CLASSBITMAP_SIZE; i++)
 639                     cl->classflags[i] |= or_with->classflags[i];
 640                 cl->flags |= ANYOF_CLASS;
 641             }
 642         }
 643         else { /* XXXX: logic is complicated, leave it along for a moment. */
 644             cl_anything(pRExC_state, cl);
 645         }
 646     }
 647     if (or_with->flags & ANYOF_EOS)
 648         cl->flags |= ANYOF_EOS;
 649
 650     if (cl->flags & ANYOF_UNICODE && or_with->flags & ANYOF_UNICODE &&
 651         ARG(cl) != ARG(or_with)) {
 652         cl->flags |= ANYOF_UNICODE_ALL;
 653         cl->flags &= ~ANYOF_UNICODE;
 654     }
 655     if (or_with->flags & ANYOF_UNICODE_ALL) {
 656         cl->flags |= ANYOF_UNICODE_ALL;
 657         cl->flags &= ~ANYOF_UNICODE;
 658     }
 659 }
 660
 661 /*
 662  * There are strange code-generation bugs caused on sparc64 by gcc-2.95.2.
 663  * These need to be revisited when a newer toolchain becomes available.
 664  */
 665 #if defined(__sparc64__) && defined(__GNUC__)
 666 #   if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
 667 #       undef  SPARC64_GCC_WORKAROUND
 668 #       define SPARC64_GCC_WORKAROUND 1
 669 #   endif
 670 #endif
 671
 672 /* REx optimizer.  Converts nodes into quickier variants "in place".
 673    Finds fixed substrings.  */
 674
 675 /* Stops at toplevel WHILEM as well as at `last'. At end *scanp is set
 676    to the position after last scanned or to NULL. */
 677
 678 STATIC I32
 679 S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, I32 *deltap, regnode *last, scan_data_t *data, U32 flags)
 680                         /* scanp: Start here (read-write). */
 681                         /* deltap: Write maxlen-minlen here. */
 682                         /* last: Stop before this one. */
 683 {
 684     I32 min = 0, pars = 0, code;
 685     regnode *scan = *scanp, *next;
 686     I32 delta = 0;
 687     int is_inf = (flags & SCF_DO_SUBSTR) && (data->flags & SF_IS_INF);
 688     int is_inf_internal = 0;            /* The studied chunk is infinite */
 689     I32 is_par = OP(scan) == OPEN ? ARG(scan) : 0;
 690     scan_data_t data_fake;
 691     struct regnode_charclass_class and_with; /* Valid if flags & SCF_DO_STCLASS_OR */
 692
 693     while (scan && OP(scan) != END && scan < last) {
 694         /* Peephole optimizer: */
 695
 696         if (PL_regkind[(U8)OP(scan)] == EXACT) {
 697             /* Merge several consecutive EXACTish nodes into one. */
 698             regnode *n = regnext(scan);
 699             U32 stringok = 1;
 700 #ifdef DEBUGGING
 701             regnode *stop = scan;
 702 #endif
 703
 704             next = scan + NODE_SZ_STR(scan);
 705             /* Skip NOTHING, merge EXACT*. */
 706             while (n &&
 707                    ( PL_regkind[(U8)OP(n)] == NOTHING ||
 708                      (stringok && (OP(n) == OP(scan))))
 709                    && NEXT_OFF(n)
 710                    && NEXT_OFF(scan) + NEXT_OFF(n) < I16_MAX) {
 711                 if (OP(n) == TAIL || n > next)
 712                     stringok = 0;
 713                 if (PL_regkind[(U8)OP(n)] == NOTHING) {
 714                     NEXT_OFF(scan) += NEXT_OFF(n);
 715                     next = n + NODE_STEP_REGNODE;
 716 #ifdef DEBUGGING
 717                     if (stringok)
 718                         stop = n;
 719 #endif
 720                     n = regnext(n);
 721                 }
 722                 else if (stringok) {
 723                     int oldl = STR_LEN(scan);
 724                     regnode *nnext = regnext(n);
 725
 726                     if (oldl + STR_LEN(n) > U8_MAX)
 727                         break;
 728                     NEXT_OFF(scan) += NEXT_OFF(n);
 729                     STR_LEN(scan) += STR_LEN(n);
 730                     next = n + NODE_SZ_STR(n);
 731                     /* Now we can overwrite *n : */
 732                     Move(STRING(n), STRING(scan) + oldl, STR_LEN(n), char);
 733 #ifdef DEBUGGING
 734                     stop = next - 1;
 735 #endif
 736                     n = nnext;
 737                 }
 738             }
 739
 740             if (UTF && OP(scan) == EXACTF && STR_LEN(scan) >= 6) {
 741 /*
 742   Two problematic code points in Unicode casefolding of EXACT nodes:
 743
 744    U+0390 - GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
 745    U+03B0 - GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
 746
 747    which casefold to
 748
 749    Unicode                      UTF-8
 750
 751    U+03B9 U+0308 U+0301         0xCE 0xB9 0xCC 0x88 0xCC 0x81
 752    U+03C5 U+0308 U+0301         0xCF 0x85 0xCC 0x88 0xCC 0x81
 753
 754    This means that in case-insensitive matching (or "loose matching",
 755    as Unicode calls it), an EXACTF of length six (the UTF-8 encoded byte
 756    length of the above casefolded versions) can match a target string
 757    of length two (the byte length of UTF-8 encoded U+0390 or U+03B0).
 758    This would rather mess up the minimum length computation.
 759
 760    What we'll do is to look for the tail four bytes, and then peek
 761    at the preceding two bytes to see whether we need to decrease
 762    the minimum length by four (six minus two).
 763
 764    Thanks to the design of UTF-8, there cannot be false matches:
 765    A sequence of valid UTF-8 bytes cannot be a subsequence of
 766    another valid sequence of UTF-8 bytes.
 767
 768 */
 769                  char *s0 = STRING(scan), *s, *t;
 770                  char *s1 = s0 + STR_LEN(scan) - 1, *s2 = s1 - 4;
 771                  char *t0 = "\xcc\x88\xcc\x81";
 772                  char *t1 = t0 + 3;
 773
 774                  for (s = s0 + 2;
 775                       s < s2 && (t = ninstr(s, s1, t0, t1));
 776                       s = t + 4) {
 777                       if (((U8)t[-1] == 0xB9 && (U8)t[-2] == 0xCE) ||
 778                           ((U8)t[-1] == 0x85 && (U8)t[-2] == 0xCF))
 779                            min -= 4;
 780                  }
 781             }
 782
 783 #ifdef DEBUGGING
 784             /* Allow dumping */
 785             n = scan + NODE_SZ_STR(scan);
 786             while (n <= stop) {
 787                 if (PL_regkind[(U8)OP(n)] != NOTHING || OP(n) == NOTHING) {
 788                     OP(n) = OPTIMIZED;
 789                     NEXT_OFF(n) = 0;
 790                 }
 791                 n++;
 792             }
 793 #endif
 794         }
 795         /* Follow the next-chain of the current node and optimize
 796            away all the NOTHINGs from it.  */
 797         if (OP(scan) != CURLYX) {
 798             int max = (reg_off_by_arg[OP(scan)]
 799                        ? I32_MAX
 800                        /* I32 may be smaller than U16 on CRAYs! */
 801                        : (I32_MAX < U16_MAX ? I32_MAX : U16_MAX));
 802             int off = (reg_off_by_arg[OP(scan)] ? ARG(scan) : NEXT_OFF(scan));
 803             int noff;
 804             regnode *n = scan;
 805
 806             /* Skip NOTHING and LONGJMP. */
 807             while ((n = regnext(n))
 808                    && ((PL_regkind[(U8)OP(n)] == NOTHING && (noff = NEXT_OFF(n)))
 809                        || ((OP(n) == LONGJMP) && (noff = ARG(n))))
 810                    && off + noff < max)
 811                 off += noff;
 812             if (reg_off_by_arg[OP(scan)])
 813                 ARG(scan) = off;
 814             else
 815                 NEXT_OFF(scan) = off;
 816         }
 817         /* The principal pseudo-switch.  Cannot be a switch, since we
 818            look into several different things.  */
 819         if (OP(scan) == BRANCH || OP(scan) == BRANCHJ
 820                    || OP(scan) == IFTHEN || OP(scan) == SUSPEND) {
 821             next = regnext(scan);
 822             code = OP(scan);
 823
 824             if (OP(next) == code || code == IFTHEN || code == SUSPEND) {
 825                 I32 max1 = 0, min1 = I32_MAX, num = 0;
 826                 struct regnode_charclass_class accum;
 827
 828                 if (flags & SCF_DO_SUBSTR) /* XXXX Add !SUSPEND? */
 829                     scan_commit(pRExC_state, data); /* Cannot merge strings after this. */
 830                 if (flags & SCF_DO_STCLASS)
 831                     cl_init_zero(pRExC_state, &accum);
 832                 while (OP(scan) == code) {
 833                     I32 deltanext, minnext, f = 0, fake;
 834                     struct regnode_charclass_class this_class;
 835
 836                     num++;
 837                     data_fake.flags = 0;
 838                     if (data) {
 839                         data_fake.whilem_c = data->whilem_c;
 840                         data_fake.last_closep = data->last_closep;
 841                     }
 842                     else
 843                         data_fake.last_closep = &fake;
 844                     next = regnext(scan);
 845                     scan = NEXTOPER(scan);
 846                     if (code != BRANCH)
 847                         scan = NEXTOPER(scan);
 848                     if (flags & SCF_DO_STCLASS) {
 849                         cl_init(pRExC_state, &this_class);
 850                         data_fake.start_class = &this_class;
 851                         f = SCF_DO_STCLASS_AND;
 852                     }
 853                     if (flags & SCF_WHILEM_VISITED_POS)
 854                         f |= SCF_WHILEM_VISITED_POS;
 855                     /* we suppose the run is continuous, last=next...*/
 856                     minnext = study_chunk(pRExC_state, &scan, &deltanext,
 857                                           next, &data_fake, f);
 858                     if (min1 > minnext)
 859                         min1 = minnext;
 860                     if (max1 < minnext + deltanext)
 861                         max1 = minnext + deltanext;
 862                     if (deltanext == I32_MAX)
 863                         is_inf = is_inf_internal = 1;
 864                     scan = next;
 865                     if (data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
 866                         pars++;
 867                     if (data && (data_fake.flags & SF_HAS_EVAL))
 868                         data->flags |= SF_HAS_EVAL;
 869                     if (data)
 870                         data->whilem_c = data_fake.whilem_c;
 871                     if (flags & SCF_DO_STCLASS)
 872                         cl_or(pRExC_state, &accum, &this_class);
 873                     if (code == SUSPEND)
 874                         break;
 875                 }
 876                 if (code == IFTHEN && num < 2) /* Empty ELSE branch */
 877                     min1 = 0;
 878                 if (flags & SCF_DO_SUBSTR) {
 879                     data->pos_min += min1;
 880                     data->pos_delta += max1 - min1;
 881                     if (max1 != min1 || is_inf)
 882                         data->longest = &(data->longest_float);
 883                 }
 884                 min += min1;
 885                 delta += max1 - min1;
 886                 if (flags & SCF_DO_STCLASS_OR) {
 887                     cl_or(pRExC_state, data->start_class, &accum);
 888                     if (min1) {
 889                         cl_and(data->start_class, &and_with);
 890                         flags &= ~SCF_DO_STCLASS;
 891                     }
 892                 }
 893                 else if (flags & SCF_DO_STCLASS_AND) {
 894                     if (min1) {
 895                         cl_and(data->start_class, &accum);
 896                         flags &= ~SCF_DO_STCLASS;
 897                     }
 898                     else {
 899                         /* Switch to OR mode: cache the old value of
 900                          * data->start_class */
 901                         StructCopy(data->start_class, &and_with,
 902                                    struct regnode_charclass_class);
 903                         flags &= ~SCF_DO_STCLASS_AND;
 904                         StructCopy(&accum, data->start_class,
 905                                    struct regnode_charclass_class);
 906                         flags |= SCF_DO_STCLASS_OR;
 907                         data->start_class->flags |= ANYOF_EOS;
 908                     }
 909                 }
 910             }
 911             else if (code == BRANCHJ)   /* single branch is optimized. */
 912                 scan = NEXTOPER(NEXTOPER(scan));
 913             else                        /* single branch is optimized. */
 914                 scan = NEXTOPER(scan);
 915             continue;
 916         }
 917         else if (OP(scan) == EXACT) {
 918             I32 l = STR_LEN(scan);
 919             UV uc = *((U8*)STRING(scan));
 920             if (UTF) {
 921                 U8 *s = (U8*)STRING(scan);
 922                 l = utf8_length(s, s + l);
 923                 uc = utf8_to_uvchr(s, NULL);
 924             }
 925             min += l;
 926             if (flags & SCF_DO_SUBSTR) { /* Update longest substr. */
 927                 /* The code below prefers earlier match for fixed
 928                    offset, later match for variable offset.  */
 929                 if (data->last_end == -1) { /* Update the start info. */
 930                     data->last_start_min = data->pos_min;
 931                     data->last_start_max = is_inf
 932                         ? I32_MAX : data->pos_min + data->pos_delta;
 933                 }
 934                 sv_catpvn(data->last_found, STRING(scan), STR_LEN(scan));
 935                 data->last_end = data->pos_min + l;
 936                 data->pos_min += l; /* As in the first entry. */
 937                 data->flags &= ~SF_BEFORE_EOL;
 938             }
 939             if (flags & SCF_DO_STCLASS_AND) {
 940                 /* Check whether it is compatible with what we know already! */
 941                 int compat = 1;
 942
 943                 if (uc >= 0x100 ||
 944                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 945                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 946                     && (!(data->start_class->flags & ANYOF_FOLD)
 947                         || !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 948                     )
 949                     compat = 0;
 950                 ANYOF_CLASS_ZERO(data->start_class);
 951                 ANYOF_BITMAP_ZERO(data->start_class);
 952                 if (compat)
 953                     ANYOF_BITMAP_SET(data->start_class, uc);
 954                 data->start_class->flags &= ~ANYOF_EOS;
 955                 if (uc < 0x100)
 956                   data->start_class->flags &= ~ANYOF_UNICODE_ALL;
 957             }
 958             else if (flags & SCF_DO_STCLASS_OR) {
 959                 /* false positive possible if the class is case-folded */
 960                 if (uc < 0x100)
 961                     ANYOF_BITMAP_SET(data->start_class, uc);
 962                 else
 963                     data->start_class->flags |= ANYOF_UNICODE_ALL;
 964                 data->start_class->flags &= ~ANYOF_EOS;
 965                 cl_and(data->start_class, &and_with);
 966             }
 967             flags &= ~SCF_DO_STCLASS;
 968         }
 969         else if (PL_regkind[(U8)OP(scan)] == EXACT) { /* But OP != EXACT! */
 970             I32 l = STR_LEN(scan);
 971             UV uc = *((U8*)STRING(scan));
 972
 973             /* Search for fixed substrings supports EXACT only. */
 974             if (flags & SCF_DO_SUBSTR)
 975                 scan_commit(pRExC_state, data);
 976             if (UTF) {
 977                 U8 *s = (U8 *)STRING(scan);
 978                 l = utf8_length(s, s + l);
 979                 uc = utf8_to_uvchr(s, NULL);
 980             }
 981             min += l;
 982             if (data && (flags & SCF_DO_SUBSTR))
 983                 data->pos_min += l;
 984             if (flags & SCF_DO_STCLASS_AND) {
 985                 /* Check whether it is compatible with what we know already! */
 986                 int compat = 1;
 987
 988                 if (uc >= 0x100 ||
 989                     (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE))
 990                     && !ANYOF_BITMAP_TEST(data->start_class, uc)
 991                      && !ANYOF_BITMAP_TEST(data->start_class, PL_fold[uc])))
 992                     compat = 0;
 993                 ANYOF_CLASS_ZERO(data->start_class);
 994                 ANYOF_BITMAP_ZERO(data->start_class);
 995                 if (compat) {
 996                     ANYOF_BITMAP_SET(data->start_class, uc);
 997                     data->start_class->flags &= ~ANYOF_EOS;
 998                     data->start_class->flags |= ANYOF_FOLD;
 999                     if (OP(scan) == EXACTFL)
1000                         data->start_class->flags |= ANYOF_LOCALE;
1001                 }
1002             }
1003             else if (flags & SCF_DO_STCLASS_OR) {
1004                 if (data->start_class->flags & ANYOF_FOLD) {
1005                     /* false positive possible if the class is case-folded.
1006                        Assume that the locale settings are the same... */
1007                     if (uc < 0x100)
1008                         ANYOF_BITMAP_SET(data->start_class, uc);
1009                     data->start_class->flags &= ~ANYOF_EOS;
1010                 }
1011                 cl_and(data->start_class, &and_with);
1012             }
1013             flags &= ~SCF_DO_STCLASS;
1014         }
1015         else if (strchr((char*)PL_varies,OP(scan))) {
1016             I32 mincount, maxcount, minnext, deltanext, fl = 0;
1017             I32 f = flags, pos_before = 0;
1018             regnode *oscan = scan;
1019             struct regnode_charclass_class this_class;
1020             struct regnode_charclass_class *oclass = NULL;
1021             I32 next_is_eval = 0;
1022
1023             switch (PL_regkind[(U8)OP(scan)]) {
1024             case WHILEM:                /* End of (?:...)* . */
1025                 scan = NEXTOPER(scan);
1026                 goto finish;
1027             case PLUS:
1028                 if (flags & (SCF_DO_SUBSTR | SCF_DO_STCLASS)) {
1029                     next = NEXTOPER(scan);
1030                     if (OP(next) == EXACT || (flags & SCF_DO_STCLASS)) {
1031                         mincount = 1;
1032                         maxcount = REG_INFTY;
1033                         next = regnext(scan);
1034                         scan = NEXTOPER(scan);
1035                         goto do_curly;
1036                     }
1037                 }
1038                 if (flags & SCF_DO_SUBSTR)
1039                     data->pos_min++;
1040                 min++;
1041                 /* Fall through. */
1042             case STAR:
1043                 if (flags & SCF_DO_STCLASS) {
1044                     mincount = 0;
1045                     maxcount = REG_INFTY;
1046                     next = regnext(scan);
1047                     scan = NEXTOPER(scan);
1048                     goto do_curly;
1049                 }
1050                 is_inf = is_inf_internal = 1;
1051                 scan = regnext(scan);
1052                 if (flags & SCF_DO_SUBSTR) {
1053                     scan_commit(pRExC_state, data); /* Cannot extend fixed substrings */
1054                     data->longest = &(data->longest_float);
1055                 }
1056                 goto optimize_curly_tail;
1057             case CURLY:
1058                 mincount = ARG1(scan);
1059                 maxcount = ARG2(scan);
1060                 next = regnext(scan);
1061                 if (OP(scan) == CURLYX) {
1062                     I32 lp = (data ? *(data->last_closep) : 0);
1063
1064                     scan->flags = ((lp <= U8_MAX) ? lp : U8_MAX);
1065                 }
1066                 scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS;
1067                 next_is_eval = (OP(scan) == EVAL);
1068               do_curly:
1069                 if (flags & SCF_DO_SUBSTR) {
1070                     if (mincount == 0) scan_commit(pRExC_state,data); /* Cannot extend fixed substrings */
1071                     pos_before = data->pos_min;
1072                 }
1073                 if (data) {
1074                     fl = data->flags;
1075                     data->flags &= ~(SF_HAS_PAR|SF_IN_PAR|SF_HAS_EVAL);
1076                     if (is_inf)
1077                         data->flags |= SF_IS_INF;
1078                 }
1079                 if (flags & SCF_DO_STCLASS) {
1080                     cl_init(pRExC_state, &this_class);
1081                     oclass = data->start_class;
1082                     data->start_class = &this_class;
1083                     f |= SCF_DO_STCLASS_AND;
1084                     f &= ~SCF_DO_STCLASS_OR;
1085                 }
1086                 /* These are the cases when once a subexpression
1087                    fails at a particular position, it cannot succeed
1088                    even after backtracking at the enclosing scope.
1089
1090                    XXXX what if minimal match and we are at the
1091                         initial run of {n,m}? */
1092                 if ((mincount != maxcount - 1) && (maxcount != REG_INFTY))
1093                     f &= ~SCF_WHILEM_VISITED_POS;
1094
1095                 /* This will finish on WHILEM, setting scan, or on NULL: */
1096                 minnext = study_chunk(pRExC_state, &scan, &deltanext, last, data,
1097                                       mincount == 0
1098                                         ? (f & ~SCF_DO_SUBSTR) : f);
1099
1100                 if (flags & SCF_DO_STCLASS)
1101                     data->start_class = oclass;
1102                 if (mincount == 0 || minnext == 0) {
1103                     if (flags & SCF_DO_STCLASS_OR) {
1104                         cl_or(pRExC_state, data->start_class, &this_class);
1105                     }
1106                     else if (flags & SCF_DO_STCLASS_AND) {
1107                         /* Switch to OR mode: cache the old value of
1108                          * data->start_class */
1109                         StructCopy(data->start_class, &and_with,
1110                                    struct regnode_charclass_class);
1111                         flags &= ~SCF_DO_STCLASS_AND;
1112                         StructCopy(&this_class, data->start_class,
1113                                    struct regnode_charclass_class);
1114                         flags |= SCF_DO_STCLASS_OR;
1115                         data->start_class->flags |= ANYOF_EOS;
1116                     }
1117                 } else {                /* Non-zero len */
1118                     if (flags & SCF_DO_STCLASS_OR) {
1119                         cl_or(pRExC_state, data->start_class, &this_class);
1120                         cl_and(data->start_class, &and_with);
1121                     }
1122                     else if (flags & SCF_DO_STCLASS_AND)
1123                         cl_and(data->start_class, &this_class);
1124                     flags &= ~SCF_DO_STCLASS;
1125                 }
1126                 if (!scan)              /* It was not CURLYX, but CURLY. */
1127                     scan = next;
1128                 if (ckWARN(WARN_REGEXP)
1129                        /* ? quantifier ok, except for (?{ ... }) */
1130                     && (next_is_eval || !(mincount == 0 && maxcount == 1))
1131                     && (minnext == 0) && (deltanext == 0)
1132                     && data && !(data->flags & (SF_HAS_PAR|SF_IN_PAR))
1133                     && maxcount <= REG_INFTY/3) /* Complement check for big count */
1134                 {
1135                     vWARN(RExC_parse,
1136                           "Quantifier unexpected on zero-length expression");
1137                 }
1138
1139                 min += minnext * mincount;
1140                 is_inf_internal |= ((maxcount == REG_INFTY
1141                                      && (minnext + deltanext) > 0)
1142                                     || deltanext == I32_MAX);
1143                 is_inf |= is_inf_internal;
1144                 delta += (minnext + deltanext) * maxcount - minnext * mincount;
1145
1146                 /* Try powerful optimization CURLYX => CURLYN. */
1147                 if (  OP(oscan) == CURLYX && data
1148                       && data->flags & SF_IN_PAR
1149                       && !(data->flags & SF_HAS_EVAL)
1150                       && !deltanext && minnext == 1 ) {
1151                     /* Try to optimize to CURLYN.  */
1152                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS;
1153                     regnode *nxt1 = nxt;
1154 #ifdef DEBUGGING
1155                     regnode *nxt2;
1156 #endif
1157
1158                     /* Skip open. */
1159                     nxt = regnext(nxt);
1160                     if (!strchr((char*)PL_simple,OP(nxt))
1161                         && !(PL_regkind[(U8)OP(nxt)] == EXACT
1162                              && STR_LEN(nxt) == 1))
1163                         goto nogo;
1164 #ifdef DEBUGGING
1165                     nxt2 = nxt;
1166 #endif
1167                     nxt = regnext(nxt);
1168                     if (OP(nxt) != CLOSE)
1169                         goto nogo;
1170                     /* Now we know that nxt2 is the only contents: */
1171                     oscan->flags = ARG(nxt);
1172                     OP(oscan) = CURLYN;
1173                     OP(nxt1) = NOTHING; /* was OPEN. */
1174 #ifdef DEBUGGING
1175                     OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1176                     NEXT_OFF(nxt1+ 1) = 0; /* just for consistancy. */
1177                     NEXT_OFF(nxt2) = 0; /* just for consistancy with CURLY. */
1178                     OP(nxt) = OPTIMIZED;        /* was CLOSE. */
1179                     OP(nxt + 1) = OPTIMIZED; /* was count. */
1180                     NEXT_OFF(nxt+ 1) = 0; /* just for consistancy. */
1181 #endif
1182                 }
1183               nogo:
1184
1185                 /* Try optimization CURLYX => CURLYM. */
1186                 if (  OP(oscan) == CURLYX && data
1187                       && !(data->flags & SF_HAS_PAR)
1188                       && !(data->flags & SF_HAS_EVAL)
1189                       && !deltanext  ) {
1190                     /* XXXX How to optimize if data == 0? */
1191                     /* Optimize to a simpler form.  */
1192                     regnode *nxt = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN */
1193                     regnode *nxt2;
1194
1195                     OP(oscan) = CURLYM;
1196                     while ( (nxt2 = regnext(nxt)) /* skip over embedded stuff*/
1197                             && (OP(nxt2) != WHILEM))
1198                         nxt = nxt2;
1199                     OP(nxt2)  = SUCCEED; /* Whas WHILEM */
1200                     /* Need to optimize away parenths. */
1201                     if (data->flags & SF_IN_PAR) {
1202                         /* Set the parenth number.  */
1203                         regnode *nxt1 = NEXTOPER(oscan) + EXTRA_STEP_2ARGS; /* OPEN*/
1204
1205                         if (OP(nxt) != CLOSE)
1206                             FAIL("Panic opt close");
1207                         oscan->flags = ARG(nxt);
1208                         OP(nxt1) = OPTIMIZED;   /* was OPEN. */
1209                         OP(nxt) = OPTIMIZED;    /* was CLOSE. */
1210 #ifdef DEBUGGING
1211                         OP(nxt1 + 1) = OPTIMIZED; /* was count. */
1212                         OP(nxt + 1) = OPTIMIZED; /* was count. */
1213                         NEXT_OFF(nxt1 + 1) = 0; /* just for consistancy. */
1214                         NEXT_OFF(nxt + 1) = 0; /* just for consistancy. */
1215 #endif
1216 #if 0
1217                         while ( nxt1 && (OP(nxt1) != WHILEM)) {
1218                             regnode *nnxt = regnext(nxt1);
1219
1220                             if (nnxt == nxt) {
1221                                 if (reg_off_by_arg[OP(nxt1)])
1222                                     ARG_SET(nxt1, nxt2 - nxt1);
1223                                 else if (nxt2 - nxt1 < U16_MAX)
1224                                     NEXT_OFF(nxt1) = nxt2 - nxt1;
1225                                 else
1226                                     OP(nxt) = NOTHING;  /* Cannot beautify */
1227                             }
1228                             nxt1 = nnxt;
1229                         }
1230 #endif
1231                         /* Optimize again: */
1232                         study_chunk(pRExC_state, &nxt1, &deltanext, nxt,
1233                                     NULL, 0);
1234                     }
1235                     else
1236                         oscan->flags = 0;
1237                 }
1238                 else if ((OP(oscan) == CURLYX)
1239                          && (flags & SCF_WHILEM_VISITED_POS)
1240                          /* See the comment on a similar expression above.
1241                             However, this time it not a subexpression
1242                             we care about, but the expression itself. */
1243                          && (maxcount == REG_INFTY)
1244                          && data && ++data->whilem_c < 16) {
1245                     /* This stays as CURLYX, we can put the count/of pair. */
1246                     /* Find WHILEM (as in regexec.c) */
1247                     regnode *nxt = oscan + NEXT_OFF(oscan);
1248
1249                     if (OP(PREVOPER(nxt)) == NOTHING) /* LONGJMP */
1250                         nxt += ARG(nxt);
1251                     PREVOPER(nxt)->flags = data->whilem_c
1252                         | (RExC_whilem_seen << 4); /* On WHILEM */
1253                 }
1254                 if (data && fl & (SF_HAS_PAR|SF_IN_PAR))
1255                     pars++;
1256                 if (flags & SCF_DO_SUBSTR) {
1257                     SV *last_str = Nullsv;
1258                     int counted = mincount != 0;
1259
1260                     if (data->last_end > 0 && mincount != 0) { /* Ends with a string. */
1261 #if defined(SPARC64_GCC_WORKAROUND)
1262                         I32 b = 0;
1263                         STRLEN l = 0;
1264                         char *s = NULL;
1265                         I32 old = 0;
1266
1267                         if (pos_before >= data->last_start_min)
1268                             b = pos_before;
1269                         else
1270                             b = data->last_start_min;
1271
1272                         l = 0;
1273                         s = SvPV(data->last_found, l);
1274                         old = b - data->last_start_min;
1275
1276 #else
1277                         I32 b = pos_before >= data->last_start_min
1278                             ? pos_before : data->last_start_min;
1279                         STRLEN l;
1280                         char *s = SvPV(data->last_found, l);
1281                         I32 old = b - data->last_start_min;
1282 #endif
1283
1284                         if (UTF)
1285                             old = utf8_hop((U8*)s, old) - (U8*)s;
1286
1287                         l -= old;
1288                         /* Get the added string: */
1289                         last_str = newSVpvn(s  + old, l);
1290                         if (deltanext == 0 && pos_before == b) {
1291                             /* What was added is a constant string */
1292                             if (mincount > 1) {
1293                                 SvGROW(last_str, (mincount * l) + 1);
1294                                 repeatcpy(SvPVX(last_str) + l,
1295                                           SvPVX(last_str), l, mincount - 1);
1296                                 SvCUR(last_str) *= mincount;
1297                                 /* Add additional parts. */
1298                                 SvCUR_set(data->last_found,
1299                                           SvCUR(data->last_found) - l);
1300                                 sv_catsv(data->last_found, last_str);
1301                                 data->last_end += l * (mincount - 1);
1302                             }
1303                         } else {
1304                             /* start offset must point into the last copy */
1305                             data->last_start_min += minnext * (mincount - 1);
1306                             data->last_start_max += is_inf ? 0 : (maxcount - 1)
1307                                 * (minnext + data->pos_delta);
1308                         }
1309                     }
1310                     /* It is counted once already... */
1311                     data->pos_min += minnext * (mincount - counted);
1312                     data->pos_delta += - counted * deltanext +
1313                         (minnext + deltanext) * maxcount - minnext * mincount;
1314                     if (mincount != maxcount) {
1315                          /* Cannot extend fixed substrings found inside
1316                             the group.  */
1317                         scan_commit(pRExC_state,data);
1318                         if (mincount && last_str) {
1319                             sv_setsv(data->last_found, last_str);
1320                             data->last_end = data->pos_min;
1321                             data->last_start_min =
1322                                 data->pos_min - CHR_SVLEN(last_str);
1323                             data->last_start_max = is_inf
1324                                 ? I32_MAX
1325                                 : data->pos_min + data->pos_delta
1326                                 - CHR_SVLEN(last_str);
1327                         }
1328                         data->longest = &(data->longest_float);
1329                     }
1330                     SvREFCNT_dec(last_str);
1331                 }
1332                 if (data && (fl & SF_HAS_EVAL))
1333                     data->flags |= SF_HAS_EVAL;
1334               optimize_curly_tail:
1335                 if (OP(oscan) != CURLYX) {
1336                     while (PL_regkind[(U8)OP(next = regnext(oscan))] == NOTHING
1337                            && NEXT_OFF(next))
1338                         NEXT_OFF(oscan) += NEXT_OFF(next);
1339                 }
1340                 continue;
1341             default:                    /* REF and CLUMP only? */
1342                 if (flags & SCF_DO_SUBSTR) {
1343                     scan_commit(pRExC_state,data);      /* Cannot expect anything... */
1344                     data->longest = &(data->longest_float);
1345                 }
1346                 is_inf = is_inf_internal = 1;
1347                 if (flags & SCF_DO_STCLASS_OR)
1348                     cl_anything(pRExC_state, data->start_class);
1349                 flags &= ~SCF_DO_STCLASS;
1350                 break;
1351             }
1352         }
1353         else if (strchr((char*)PL_simple,OP(scan))) {
1354             int value = 0;
1355
1356             if (flags & SCF_DO_SUBSTR) {
1357                 scan_commit(pRExC_state,data);
1358                 data->pos_min++;
1359             }
1360             min++;
1361             if (flags & SCF_DO_STCLASS) {
1362                 data->start_class->flags &= ~ANYOF_EOS; /* No match on empty */
1363
1364                 /* Some of the logic below assumes that switching
1365                    locale on will only add false positives. */
1366                 switch (PL_regkind[(U8)OP(scan)]) {
1367                 case SANY:
1368                 default:
1369                   do_default:
1370                     /* Perl_croak(aTHX_ "panic: unexpected simple REx opcode %d", OP(scan)); */
1371                     if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1372                         cl_anything(pRExC_state, data->start_class);
1373                     break;
1374                 case REG_ANY:
1375                     if (OP(scan) == SANY)
1376                         goto do_default;
1377                     if (flags & SCF_DO_STCLASS_OR) { /* Everything but \n */
1378                         value = (ANYOF_BITMAP_TEST(data->start_class,'\n')
1379                                  || (data->start_class->flags & ANYOF_CLASS));
1380                         cl_anything(pRExC_state, data->start_class);
1381                     }
1382                     if (flags & SCF_DO_STCLASS_AND || !value)
1383                         ANYOF_BITMAP_CLEAR(data->start_class,'\n');
1384                     break;
1385                 case ANYOF:
1386                     if (flags & SCF_DO_STCLASS_AND)
1387                         cl_and(data->start_class,
1388                                (struct regnode_charclass_class*)scan);
1389                     else
1390                         cl_or(pRExC_state, data->start_class,
1391                               (struct regnode_charclass_class*)scan);
1392                     break;
1393                 case ALNUM:
1394                     if (flags & SCF_DO_STCLASS_AND) {
1395                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1396                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1397                             for (value = 0; value < 256; value++)
1398                                 if (!isALNUM(value))
1399                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1400                         }
1401                     }
1402                     else {
1403                         if (data->start_class->flags & ANYOF_LOCALE)
1404                             ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1405                         else {
1406                             for (value = 0; value < 256; value++)
1407                                 if (isALNUM(value))
1408                                     ANYOF_BITMAP_SET(data->start_class, value);
1409                         }
1410                     }
1411                     break;
1412                 case ALNUML:
1413                     if (flags & SCF_DO_STCLASS_AND) {
1414                         if (data->start_class->flags & ANYOF_LOCALE)
1415                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NALNUM);
1416                     }
1417                     else {
1418                         ANYOF_CLASS_SET(data->start_class,ANYOF_ALNUM);
1419                         data->start_class->flags |= ANYOF_LOCALE;
1420                     }
1421                     break;
1422                 case NALNUM:
1423                     if (flags & SCF_DO_STCLASS_AND) {
1424                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1425                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1426                             for (value = 0; value < 256; value++)
1427                                 if (isALNUM(value))
1428                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1429                         }
1430                     }
1431                     else {
1432                         if (data->start_class->flags & ANYOF_LOCALE)
1433                             ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1434                         else {
1435                             for (value = 0; value < 256; value++)
1436                                 if (!isALNUM(value))
1437                                     ANYOF_BITMAP_SET(data->start_class, value);
1438                         }
1439                     }
1440                     break;
1441                 case NALNUML:
1442                     if (flags & SCF_DO_STCLASS_AND) {
1443                         if (data->start_class->flags & ANYOF_LOCALE)
1444                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_ALNUM);
1445                     }
1446                     else {
1447                         data->start_class->flags |= ANYOF_LOCALE;
1448                         ANYOF_CLASS_SET(data->start_class,ANYOF_NALNUM);
1449                     }
1450                     break;
1451                 case SPACE:
1452                     if (flags & SCF_DO_STCLASS_AND) {
1453                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1454                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1455                             for (value = 0; value < 256; value++)
1456                                 if (!isSPACE(value))
1457                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1458                         }
1459                     }
1460                     else {
1461                         if (data->start_class->flags & ANYOF_LOCALE)
1462                             ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1463                         else {
1464                             for (value = 0; value < 256; value++)
1465                                 if (isSPACE(value))
1466                                     ANYOF_BITMAP_SET(data->start_class, value);
1467                         }
1468                     }
1469                     break;
1470                 case SPACEL:
1471                     if (flags & SCF_DO_STCLASS_AND) {
1472                         if (data->start_class->flags & ANYOF_LOCALE)
1473                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NSPACE);
1474                     }
1475                     else {
1476                         data->start_class->flags |= ANYOF_LOCALE;
1477                         ANYOF_CLASS_SET(data->start_class,ANYOF_SPACE);
1478                     }
1479                     break;
1480                 case NSPACE:
1481                     if (flags & SCF_DO_STCLASS_AND) {
1482                         if (!(data->start_class->flags & ANYOF_LOCALE)) {
1483                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1484                             for (value = 0; value < 256; value++)
1485                                 if (isSPACE(value))
1486                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1487                         }
1488                     }
1489                     else {
1490                         if (data->start_class->flags & ANYOF_LOCALE)
1491                             ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1492                         else {
1493                             for (value = 0; value < 256; value++)
1494                                 if (!isSPACE(value))
1495                                     ANYOF_BITMAP_SET(data->start_class, value);
1496                         }
1497                     }
1498                     break;
1499                 case NSPACEL:
1500                     if (flags & SCF_DO_STCLASS_AND) {
1501                         if (data->start_class->flags & ANYOF_LOCALE) {
1502                             ANYOF_CLASS_CLEAR(data->start_class,ANYOF_SPACE);
1503                             for (value = 0; value < 256; value++)
1504                                 if (!isSPACE(value))
1505                                     ANYOF_BITMAP_CLEAR(data->start_class, value);
1506                         }
1507                     }
1508                     else {
1509                         data->start_class->flags |= ANYOF_LOCALE;
1510                         ANYOF_CLASS_SET(data->start_class,ANYOF_NSPACE);
1511                     }
1512                     break;
1513                 case DIGIT:
1514                     if (flags & SCF_DO_STCLASS_AND) {
1515                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_NDIGIT);
1516                         for (value = 0; value < 256; value++)
1517                             if (!isDIGIT(value))
1518                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1519                     }
1520                     else {
1521                         if (data->start_class->flags & ANYOF_LOCALE)
1522                             ANYOF_CLASS_SET(data->start_class,ANYOF_DIGIT);
1523                         else {
1524                             for (value = 0; value < 256; value++)
1525                                 if (isDIGIT(value))
1526                                     ANYOF_BITMAP_SET(data->start_class, value);
1527                         }
1528                     }
1529                     break;
1530                 case NDIGIT:
1531                     if (flags & SCF_DO_STCLASS_AND) {
1532                         ANYOF_CLASS_CLEAR(data->start_class,ANYOF_DIGIT);
1533                         for (value = 0; value < 256; value++)
1534                             if (isDIGIT(value))
1535                                 ANYOF_BITMAP_CLEAR(data->start_class, value);
1536                     }
1537                     else {
1538                         if (data->start_class->flags & ANYOF_LOCALE)
1539                             ANYOF_CLASS_SET(data->start_class,ANYOF_NDIGIT);
1540                         else {
1541                             for (value = 0; value < 256; value++)
1542                                 if (!isDIGIT(value))
1543                                     ANYOF_BITMAP_SET(data->start_class, value);
1544                         }
1545                     }
1546                     break;
1547                 }
1548                 if (flags & SCF_DO_STCLASS_OR)
1549                     cl_and(data->start_class, &and_with);
1550                 flags &= ~SCF_DO_STCLASS;
1551             }
1552         }
1553         else if (PL_regkind[(U8)OP(scan)] == EOL && flags & SCF_DO_SUBSTR) {
1554             data->flags |= (OP(scan) == MEOL
1555                             ? SF_BEFORE_MEOL
1556                             : SF_BEFORE_SEOL);
1557         }
1558         else if (  PL_regkind[(U8)OP(scan)] == BRANCHJ
1559                  /* Lookbehind, or need to calculate parens/evals/stclass: */
1560                    && (scan->flags || data || (flags & SCF_DO_STCLASS))
1561                    && (OP(scan) == IFMATCH || OP(scan) == UNLESSM)) {
1562             /* Lookahead/lookbehind */
1563             I32 deltanext, minnext, fake = 0;
1564             regnode *nscan;
1565             struct regnode_charclass_class intrnl;
1566             int f = 0;
1567
1568             data_fake.flags = 0;
1569             if (data) {
1570                 data_fake.whilem_c = data->whilem_c;
1571                 data_fake.last_closep = data->last_closep;
1572             }
1573             else
1574                 data_fake.last_closep = &fake;
1575             if ( flags & SCF_DO_STCLASS && !scan->flags
1576                  && OP(scan) == IFMATCH ) { /* Lookahead */
1577                 cl_init(pRExC_state, &intrnl);
1578                 data_fake.start_class = &intrnl;
1579                 f |= SCF_DO_STCLASS_AND;
1580             }
1581             if (flags & SCF_WHILEM_VISITED_POS)
1582                 f |= SCF_WHILEM_VISITED_POS;
1583             next = regnext(scan);
1584             nscan = NEXTOPER(NEXTOPER(scan));
1585             minnext = study_chunk(pRExC_state, &nscan, &deltanext, last, &data_fake, f);
1586             if (scan->flags) {
1587                 if (deltanext) {
1588                     vFAIL("Variable length lookbehind not implemented");
1589                 }
1590                 else if (minnext > U8_MAX) {
1591                     vFAIL2("Lookbehind longer than %"UVuf" not implemented", (UV)U8_MAX);
1592                 }
1593                 scan->flags = minnext;
1594             }
1595             if (data && data_fake.flags & (SF_HAS_PAR|SF_IN_PAR))
1596                 pars++;
1597             if (data && (data_fake.flags & SF_HAS_EVAL))
1598                 data->flags |= SF_HAS_EVAL;
1599             if (data)
1600                 data->whilem_c = data_fake.whilem_c;
1601             if (f & SCF_DO_STCLASS_AND) {
1602                 int was = (data->start_class->flags & ANYOF_EOS);
1603
1604                 cl_and(data->start_class, &intrnl);
1605                 if (was)
1606                     data->start_class->flags |= ANYOF_EOS;
1607             }
1608         }
1609         else if (OP(scan) == OPEN) {
1610             pars++;
1611         }
1612         else if (OP(scan) == CLOSE) {
1613             if (ARG(scan) == is_par) {
1614                 next = regnext(scan);
1615
1616                 if ( next && (OP(next) != WHILEM) && next < last)
1617                     is_par = 0;         /* Disable optimization */
1618             }
1619             if (data)
1620                 *(data->last_closep) = ARG(scan);
1621         }
1622         else if (OP(scan) == EVAL) {
1623                 if (data)
1624                     data->flags |= SF_HAS_EVAL;
1625         }
1626         else if (OP(scan) == LOGICAL && scan->flags == 2) { /* Embedded follows */
1627                 if (flags & SCF_DO_SUBSTR) {
1628                     scan_commit(pRExC_state,data);
1629                     data->longest = &(data->longest_float);
1630                 }
1631                 is_inf = is_inf_internal = 1;
1632                 if (flags & SCF_DO_STCLASS_OR) /* Allow everything */
1633                     cl_anything(pRExC_state, data->start_class);
1634                 flags &= ~SCF_DO_STCLASS;
1635         }
1636         /* Else: zero-length, ignore. */
1637         scan = regnext(scan);
1638     }
1639
1640   finish:
1641     *scanp = scan;
1642     *deltap = is_inf_internal ? I32_MAX : delta;
1643     if (flags & SCF_DO_SUBSTR && is_inf)
1644         data->pos_delta = I32_MAX - data->pos_min;
1645     if (is_par > U8_MAX)
1646         is_par = 0;
1647     if (is_par && pars==1 && data) {
1648         data->flags |= SF_IN_PAR;
1649         data->flags &= ~SF_HAS_PAR;
1650     }
1651     else if (pars && data) {
1652         data->flags |= SF_HAS_PAR;
1653         data->flags &= ~SF_IN_PAR;
1654     }
1655     if (flags & SCF_DO_STCLASS_OR)
1656         cl_and(data->start_class, &and_with);
1657     return min;
1658 }
1659
1660 STATIC I32
1661 S_add_data(pTHX_ RExC_state_t *pRExC_state, I32 n, char *s)
1662 {
1663     if (RExC_rx->data) {
1664         Renewc(RExC_rx->data,
1665                sizeof(*RExC_rx->data) + sizeof(void*) * (RExC_rx->data->count + n - 1),
1666                char, struct reg_data);
1667         Renew(RExC_rx->data->what, RExC_rx->data->count + n, U8);
1668         RExC_rx->data->count += n;
1669     }
1670     else {
1671         Newc(1207, RExC_rx->data, sizeof(*RExC_rx->data) + sizeof(void*) * (n - 1),
1672              char, struct reg_data);
1673         New(1208, RExC_rx->data->what, n, U8);
1674         RExC_rx->data->count = n;
1675     }
1676     Copy(s, RExC_rx->data->what + RExC_rx->data->count - n, n, U8);
1677     return RExC_rx->data->count - n;
1678 }
1679
1680 void
1681 Perl_reginitcolors(pTHX)
1682 {
1683     int i = 0;
1684     char *s = PerlEnv_getenv("PERL_RE_COLORS");
1685
1686     if (s) {
1687         PL_colors[0] = s = savepv(s);
1688         while (++i < 6) {
1689             s = strchr(s, '\t');
1690             if (s) {
1691                 *s = '\0';
1692                 PL_colors[i] = ++s;
1693             }
1694             else
1695                 PL_colors[i] = s = "";
1696         }
1697     } else {
1698         while (i < 6)
1699             PL_colors[i++] = "";
1700     }
1701     PL_colorset = 1;
1702 }
1703
1704
1705 /*
1706  - pregcomp - compile a regular expression into internal code
1707  *
1708  * We can't allocate space until we know how big the compiled form will be,
1709  * but we can't compile it (and thus know how big it is) until we've got a
1710  * place to put the code.  So we cheat:  we compile it twice, once with code
1711  * generation turned off and size counting turned on, and once "for real".
1712  * This also means that we don't allocate space until we are sure that the
1713  * thing really will compile successfully, and we never have to move the
1714  * code and thus invalidate pointers into it.  (Note that it has to be in
1715  * one piece because free() must be able to free it all.) [NB: not true in perl]
1716  *
1717  * Beware that the optimization-preparation code in here knows about some
1718  * of the structure of the compiled regexp.  [I'll say.]
1719  */
1720 regexp *
1721 Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
1722 {
1723     register regexp *r;
1724     regnode *scan;
1725     regnode *first;
1726     I32 flags;
1727     I32 minlen = 0;
1728     I32 sawplus = 0;
1729     I32 sawopen = 0;
1730     scan_data_t data;
1731     RExC_state_t RExC_state;
1732     RExC_state_t *pRExC_state = &RExC_state;
1733
1734     if (exp == NULL)
1735         FAIL("NULL regexp argument");
1736
1737     RExC_utf8 = pm->op_pmdynflags & PMdf_CMP_UTF8;
1738
1739     RExC_precomp = exp;
1740     DEBUG_r({
1741          if (!PL_colorset) reginitcolors();
1742          PerlIO_printf(Perl_debug_log, "%sCompiling REx%s `%s%*s%s'\n",
1743                        PL_colors[4],PL_colors[5],PL_colors[0],
1744                        (int)(xend - exp), RExC_precomp, PL_colors[1]);
1745     });
1746     RExC_flags16 = pm->op_pmflags;
1747     RExC_sawback = 0;
1748
1749     RExC_seen = 0;
1750     RExC_seen_zerolen = *exp == '^' ? -1 : 0;
1751     RExC_seen_evals = 0;
1752     RExC_extralen = 0;
1753
1754     /* First pass: determine size, legality. */
1755     RExC_parse = exp;
1756     RExC_start = exp;
1757     RExC_end = xend;
1758     RExC_naughty = 0;
1759     RExC_npar = 1;
1760     RExC_size = 0L;
1761     RExC_emit = &PL_regdummy;
1762     RExC_whilem_seen = 0;
1763 #if 0 /* REGC() is (currently) a NOP at the first pass.
1764        * Clever compilers notice this and complain. --jhi */
1765     REGC((U8)REG_MAGIC, (char*)RExC_emit);
1766 #endif
1767     if (reg(pRExC_state, 0, &flags) == NULL) {
1768         RExC_precomp = Nullch;
1769         return(NULL);
1770     }
1771     DEBUG_r(PerlIO_printf(Perl_debug_log, "size %"IVdf" ", (IV)RExC_size));
1772
1773     /* Small enough for pointer-storage convention?
1774        If extralen==0, this means that we will not need long jumps. */
1775     if (RExC_size >= 0x10000L && RExC_extralen)
1776         RExC_size += RExC_extralen;
1777     else
1778         RExC_extralen = 0;
1779     if (RExC_whilem_seen > 15)
1780         RExC_whilem_seen = 15;
1781
1782     /* Allocate space and initialize. */
1783     Newc(1001, r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode),
1784          char, regexp);
1785     if (r == NULL)
1786         FAIL("Regexp out of space");
1787
1788 #ifdef DEBUGGING
1789     /* avoid reading uninitialized memory in DEBUGGING code in study_chunk() */
1790     Zero(r, sizeof(regexp) + (unsigned)RExC_size * sizeof(regnode), char);
1791 #endif
1792     r->refcnt = 1;
1793     r->prelen = xend - exp;
1794     r->precomp = savepvn(RExC_precomp, r->prelen);
1795     r->subbeg = NULL;
1796     r->reganch = pm->op_pmflags & PMf_COMPILETIME;
1797     r->nparens = RExC_npar - 1; /* set early to validate backrefs */
1798
1799     r->substrs = 0;                     /* Useful during FAIL. */
1800     r->startp = 0;                      /* Useful during FAIL. */
1801     r->endp = 0;                        /* Useful during FAIL. */
1802
1803     Newz(1304, r->offsets, 2*RExC_size+1, U32); /* MJD 20001228 */
1804     if (r->offsets) {
1805       r->offsets[0] = RExC_size;
1806     }
1807     DEBUG_r(PerlIO_printf(Perl_debug_log,
1808                           "%s %"UVuf" bytes for offset annotations.\n",
1809                           r->offsets ? "Got" : "Couldn't get",
1810                           (UV)((2*RExC_size+1) * sizeof(U32))));
1811
1812     RExC_rx = r;
1813
1814     /* Second pass: emit code. */
1815     RExC_flags16 = pm->op_pmflags;      /* don't let top level (?i) bleed */
1816     RExC_parse = exp;
1817     RExC_end = xend;
1818     RExC_naughty = 0;
1819     RExC_npar = 1;
1820     RExC_emit_start = r->program;
1821     RExC_emit = r->program;
1822     /* Store the count of eval-groups for security checks: */
1823     RExC_emit->next_off = ((RExC_seen_evals > U16_MAX) ? U16_MAX : RExC_seen_evals);
1824     REGC((U8)REG_MAGIC, (char*) RExC_emit++);
1825     r->data = 0;
1826     if (reg(pRExC_state, 0, &flags) == NULL)
1827         return(NULL);
1828
1829     /* Dig out information for optimizations. */
1830     r->reganch = pm->op_pmflags & PMf_COMPILETIME; /* Again? */
1831     pm->op_pmflags = RExC_flags16;
1832     if (UTF)
1833         r->reganch |= ROPT_UTF8;        /* Unicode in it? */
1834     r->regstclass = NULL;
1835     if (RExC_naughty >= 10)     /* Probably an expensive pattern. */
1836         r->reganch |= ROPT_NAUGHTY;
1837     scan = r->program + 1;              /* First BRANCH. */
1838
1839     /* XXXX To minimize changes to RE engine we always allocate
1840        3-units-long substrs field. */
1841     Newz(1004, r->substrs, 1, struct reg_substr_data);
1842
1843     StructCopy(&zero_scan_data, &data, scan_data_t);
1844     /* XXXX Should not we check for something else?  Usually it is OPEN1... */
1845     if (OP(scan) != BRANCH) {   /* Only one top-level choice. */
1846         I32 fake;
1847         STRLEN longest_float_length, longest_fixed_length;
1848         struct regnode_charclass_class ch_class;
1849         int stclass_flag;
1850         I32 last_close = 0;
1851
1852         first = scan;
1853         /* Skip introductions and multiplicators >= 1. */
1854         while ((OP(first) == OPEN && (sawopen = 1)) ||
1855                /* An OR of *one* alternative - should not happen now. */
1856             (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
1857             (OP(first) == PLUS) ||
1858             (OP(first) == MINMOD) ||
1859                /* An {n,m} with n>0 */
1860             (PL_regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
1861                 if (OP(first) == PLUS)
1862                     sawplus = 1;
1863                 else
1864                     first += regarglen[(U8)OP(first)];
1865                 first = NEXTOPER(first);
1866         }
1867
1868         /* Starting-point info. */
1869       again:
1870         if (PL_regkind[(U8)OP(first)] == EXACT) {
1871             if (OP(first) == EXACT)
1872                 ;       /* Empty, get anchored substr later. */
1873             else if ((OP(first) == EXACTF || OP(first) == EXACTFL))
1874                 r->regstclass = first;
1875         }
1876         else if (strchr((char*)PL_simple,OP(first)))
1877             r->regstclass = first;
1878         else if (PL_regkind[(U8)OP(first)] == BOUND ||
1879                  PL_regkind[(U8)OP(first)] == NBOUND)
1880             r->regstclass = first;
1881         else if (PL_regkind[(U8)OP(first)] == BOL) {
1882             r->reganch |= (OP(first) == MBOL
1883                            ? ROPT_ANCH_MBOL
1884                            : (OP(first) == SBOL
1885                               ? ROPT_ANCH_SBOL
1886                               : ROPT_ANCH_BOL));
1887             first = NEXTOPER(first);
1888             goto again;
1889         }
1890         else if (OP(first) == GPOS) {
1891             r->reganch |= ROPT_ANCH_GPOS;
1892             first = NEXTOPER(first);
1893             goto again;
1894         }
1895         else if (!sawopen && (OP(first) == STAR &&
1896             PL_regkind[(U8)OP(NEXTOPER(first))] == REG_ANY) &&
1897             !(r->reganch & ROPT_ANCH) )
1898         {
1899             /* turn .* into ^.* with an implied $*=1 */
1900             int type = OP(NEXTOPER(first));
1901
1902             if (type == REG_ANY)
1903                 type = ROPT_ANCH_MBOL;
1904             else
1905                 type = ROPT_ANCH_SBOL;
1906
1907             r->reganch |= type | ROPT_IMPLICIT;
1908             first = NEXTOPER(first);
1909             goto again;
1910         }
1911         if (sawplus && (!sawopen || !RExC_sawback)
1912             && !(RExC_seen & REG_SEEN_EVAL)) /* May examine pos and $& */
1913             /* x+ must match at the 1st pos of run of x's */
1914             r->reganch |= ROPT_SKIP;
1915
1916         /* Scan is after the zeroth branch, first is atomic matcher. */
1917         DEBUG_r(PerlIO_printf(Perl_debug_log, "first at %"IVdf"\n",
1918                               (IV)(first - scan + 1)));
1919         /*
1920         * If there's something expensive in the r.e., find the
1921         * longest literal string that must appear and make it the
1922         * regmust.  Resolve ties in favor of later strings, since
1923         * the regstart check works with the beginning of the r.e.
1924         * and avoiding duplication strengthens checking.  Not a
1925         * strong reason, but sufficient in the absence of others.
1926         * [Now we resolve ties in favor of the earlier string if
1927         * it happens that c_offset_min has been invalidated, since the
1928         * earlier string may buy us something the later one won't.]
1929         */
1930         minlen = 0;
1931
1932         data.longest_fixed = newSVpvn("",0);
1933         data.longest_float = newSVpvn("",0);
1934         data.last_found = newSVpvn("",0);
1935         data.longest = &(data.longest_fixed);
1936         first = scan;
1937         if (!r->regstclass) {
1938             cl_init(pRExC_state, &ch_class);
1939             data.start_class = &ch_class;
1940             stclass_flag = SCF_DO_STCLASS_AND;
1941         } else                          /* XXXX Check for BOUND? */
1942             stclass_flag = 0;
1943         data.last_closep = &last_close;
1944
1945         minlen = study_chunk(pRExC_state, &first, &fake, scan + RExC_size, /* Up to end */
1946                              &data, SCF_DO_SUBSTR | SCF_WHILEM_VISITED_POS | stclass_flag);
1947         if ( RExC_npar == 1 && data.longest == &(data.longest_fixed)
1948              && data.last_start_min == 0 && data.last_end > 0
1949              && !RExC_seen_zerolen
1950              && (!(RExC_seen & REG_SEEN_GPOS) || (r->reganch & ROPT_ANCH_GPOS)))
1951             r->reganch |= ROPT_CHECK_ALL;
1952         scan_commit(pRExC_state, &data);
1953         SvREFCNT_dec(data.last_found);
1954
1955         longest_float_length = CHR_SVLEN(data.longest_float);
1956         if (longest_float_length
1957             || (data.flags & SF_FL_BEFORE_EOL
1958                 && (!(data.flags & SF_FL_BEFORE_MEOL)
1959                     || (RExC_flags16 & PMf_MULTILINE)))) {
1960             int t;
1961
1962             if (SvCUR(data.longest_fixed)                       /* ok to leave SvCUR */
1963                 && data.offset_fixed == data.offset_float_min
1964                 && SvCUR(data.longest_fixed) == SvCUR(data.longest_float))
1965                     goto remove_float;          /* As in (a)+. */
1966
1967             r->float_substr = data.longest_float;
1968             r->float_min_offset = data.offset_float_min;
1969             r->float_max_offset = data.offset_float_max;
1970             t = (data.flags & SF_FL_BEFORE_EOL /* Can't have SEOL and MULTI */
1971                        && (!(data.flags & SF_FL_BEFORE_MEOL)
1972                            || (RExC_flags16 & PMf_MULTILINE)));
1973             fbm_compile(r->float_substr, t ? FBMcf_TAIL : 0);
1974         }
1975         else {
1976           remove_float:
1977             r->float_substr = Nullsv;
1978             SvREFCNT_dec(data.longest_float);
1979             longest_float_length = 0;
1980         }
1981
1982         longest_fixed_length = CHR_SVLEN(data.longest_fixed);
1983         if (longest_fixed_length
1984             || (data.flags & SF_FIX_BEFORE_EOL /* Cannot have SEOL and MULTI */
1985                 && (!(data.flags & SF_FIX_BEFORE_MEOL)
1986                     || (RExC_flags16 & PMf_MULTILINE)))) {
1987             int t;
1988
1989             r->anchored_substr = data.longest_fixed;
1990             r->anchored_offset = data.offset_fixed;
1991             t = (data.flags & SF_FIX_BEFORE_EOL /* Can't have SEOL and MULTI */
1992                  && (!(data.flags & SF_FIX_BEFORE_MEOL)
1993                      || (RExC_flags16 & PMf_MULTILINE)));
1994             fbm_compile(r->anchored_substr, t ? FBMcf_TAIL : 0);
1995         }
1996         else {
1997             r->anchored_substr = Nullsv;
1998             SvREFCNT_dec(data.longest_fixed);
1999             longest_fixed_length = 0;
2000         }
2001         if (r->regstclass
2002             && (OP(r->regstclass) == REG_ANY || OP(r->regstclass) == SANY))
2003             r->regstclass = NULL;
2004         if ((!r->anchored_substr || r->anchored_offset) && stclass_flag
2005             && !(data.start_class->flags & ANYOF_EOS)
2006             && !cl_is_anything(data.start_class)) {
2007             I32 n = add_data(pRExC_state, 1, "f");
2008
2009             New(1006, RExC_rx->data->data[n], 1,
2010                 struct regnode_charclass_class);
2011             StructCopy(data.start_class,
2012                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2013                        struct regnode_charclass_class);
2014             r->regstclass = (regnode*)RExC_rx->data->data[n];
2015             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2016             PL_regdata = r->data; /* for regprop() */
2017             DEBUG_r({ SV *sv = sv_newmortal();
2018                       regprop(sv, (regnode*)data.start_class);
2019                       PerlIO_printf(Perl_debug_log,
2020                                     "synthetic stclass `%s'.\n",
2021                                     SvPVX(sv));});
2022         }
2023
2024         /* A temporary algorithm prefers floated substr to fixed one to dig more info. */
2025         if (longest_fixed_length > longest_float_length) {
2026             r->check_substr = r->anchored_substr;
2027             r->check_offset_min = r->check_offset_max = r->anchored_offset;
2028             if (r->reganch & ROPT_ANCH_SINGLE)
2029                 r->reganch |= ROPT_NOSCAN;
2030         }
2031         else {
2032             r->check_substr = r->float_substr;
2033             r->check_offset_min = data.offset_float_min;
2034             r->check_offset_max = data.offset_float_max;
2035         }
2036         /* XXXX Currently intuiting is not compatible with ANCH_GPOS.
2037            This should be changed ASAP!  */
2038         if (r->check_substr && !(r->reganch & ROPT_ANCH_GPOS)) {
2039             r->reganch |= RE_USE_INTUIT;
2040             if (SvTAIL(r->check_substr))
2041                 r->reganch |= RE_INTUIT_TAIL;
2042         }
2043     }
2044     else {
2045         /* Several toplevels. Best we can is to set minlen. */
2046         I32 fake;
2047         struct regnode_charclass_class ch_class;
2048         I32 last_close = 0;
2049
2050         DEBUG_r(PerlIO_printf(Perl_debug_log, "\n"));
2051         scan = r->program + 1;
2052         cl_init(pRExC_state, &ch_class);
2053         data.start_class = &ch_class;
2054         data.last_closep = &last_close;
2055         minlen = study_chunk(pRExC_state, &scan, &fake, scan + RExC_size, &data, SCF_DO_STCLASS_AND|SCF_WHILEM_VISITED_POS);
2056         r->check_substr = r->anchored_substr = r->float_substr = Nullsv;
2057         if (!(data.start_class->flags & ANYOF_EOS)
2058             && !cl_is_anything(data.start_class)) {
2059             I32 n = add_data(pRExC_state, 1, "f");
2060
2061             New(1006, RExC_rx->data->data[n], 1,
2062                 struct regnode_charclass_class);
2063             StructCopy(data.start_class,
2064                        (struct regnode_charclass_class*)RExC_rx->data->data[n],
2065                        struct regnode_charclass_class);
2066             r->regstclass = (regnode*)RExC_rx->data->data[n];
2067             r->reganch &= ~ROPT_SKIP;   /* Used in find_byclass(). */
2068             DEBUG_r({ SV* sv = sv_newmortal();
2069                       regprop(sv, (regnode*)data.start_class);
2070                       PerlIO_printf(Perl_debug_log,
2071                                     "synthetic stclass `%s'.\n",
2072                                     SvPVX(sv));});
2073         }
2074     }
2075
2076     r->minlen = minlen;
2077     if (RExC_seen & REG_SEEN_GPOS)
2078         r->reganch |= ROPT_GPOS_SEEN;
2079     if (RExC_seen & REG_SEEN_LOOKBEHIND)
2080         r->reganch |= ROPT_LOOKBEHIND_SEEN;
2081     if (RExC_seen & REG_SEEN_EVAL)
2082         r->reganch |= ROPT_EVAL_SEEN;
2083     if (RExC_seen & REG_SEEN_CANY)
2084         r->reganch |= ROPT_CANY_SEEN;
2085     Newz(1002, r->startp, RExC_npar, I32);
2086     Newz(1002, r->endp, RExC_npar, I32);
2087     PL_regdata = r->data; /* for regprop() */
2088     DEBUG_r(regdump(r));
2089     return(r);
2090 }
2091
2092 /*
2093  - reg - regular expression, i.e. main body or parenthesized thing
2094  *
2095  * Caller must absorb opening parenthesis.
2096  *
2097  * Combining parenthesis handling with the base level of regular expression
2098  * is a trifle forced, but the need to tie the tails of the branches to what
2099  * follows makes it hard to avoid.
2100  */
2101 STATIC regnode *
2102 S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
2103     /* paren: Parenthesized? 0=top, 1=(, inside: changed to letter. */
2104 {
2105     register regnode *ret;              /* Will be the head of the group. */
2106     register regnode *br;
2107     register regnode *lastbr;
2108     register regnode *ender = 0;
2109     register I32 parno = 0;
2110     I32 flags, oregflags = RExC_flags16, have_branch = 0, open = 0;
2111
2112     /* for (?g), (?gc), and (?o) warnings; warning
2113        about (?c) will warn about (?g) -- japhy    */
2114
2115     I32 wastedflags = 0x00,
2116         wasted_o    = 0x01,
2117         wasted_g    = 0x02,
2118         wasted_gc   = 0x02 | 0x04,
2119         wasted_c    = 0x04;
2120
2121     char * parse_start = RExC_parse; /* MJD */
2122     char *oregcomp_parse = RExC_parse;
2123     char c;
2124
2125     *flagp = 0;                         /* Tentatively. */
2126
2127
2128     /* Make an OPEN node, if parenthesized. */
2129     if (paren) {
2130         if (*RExC_parse == '?') { /* (?...) */
2131             U16 posflags = 0, negflags = 0;
2132             U16 *flagsp = &posflags;
2133             int logical = 0;
2134             char *seqstart = RExC_parse;
2135
2136             RExC_parse++;
2137             paren = *RExC_parse++;
2138             ret = NULL;                 /* For look-ahead/behind. */
2139             switch (paren) {
2140             case '<':           /* (?<...) */
2141                 RExC_seen |= REG_SEEN_LOOKBEHIND;
2142                 if (*RExC_parse == '!')
2143                     paren = ',';
2144                 if (*RExC_parse != '=' && *RExC_parse != '!')
2145                     goto unknown;
2146                 RExC_parse++;
2147             case '=':           /* (?=...) */
2148             case '!':           /* (?!...) */
2149                 RExC_seen_zerolen++;
2150             case ':':           /* (?:...) */
2151             case '>':           /* (?>...) */
2152                 break;
2153             case '$':           /* (?$...) */
2154             case '@':           /* (?@...) */
2155                 vFAIL2("Sequence (?%c...) not implemented", (int)paren);
2156                 break;
2157             case '#':           /* (?#...) */
2158                 while (*RExC_parse && *RExC_parse != ')')
2159                     RExC_parse++;
2160                 if (*RExC_parse != ')')
2161                     FAIL("Sequence (?#... not terminated");
2162                 nextchar(pRExC_state);
2163                 *flagp = TRYAGAIN;
2164                 return NULL;
2165             case 'p':           /* (?p...) */
2166                 if (SIZE_ONLY && ckWARN2(WARN_DEPRECATED, WARN_REGEXP))
2167                     vWARNdep(RExC_parse, "(?p{}) is deprecated - use (??{})");
2168                 /* FALL THROUGH*/
2169             case '?':           /* (??...) */
2170                 logical = 1;
2171                 if (*RExC_parse != '{')
2172                     goto unknown;
2173                 paren = *RExC_parse++;
2174                 /* FALL THROUGH */
2175             case '{':           /* (?{...}) */
2176             {
2177                 I32 count = 1, n = 0;
2178                 char c;
2179                 char *s = RExC_parse;
2180                 SV *sv;
2181                 OP_4tree *sop, *rop;
2182
2183                 RExC_seen_zerolen++;
2184                 RExC_seen |= REG_SEEN_EVAL;
2185                 while (count && (c = *RExC_parse)) {
2186                     if (c == '\\' && RExC_parse[1])
2187                         RExC_parse++;
2188                     else if (c == '{')
2189                         count++;
2190                     else if (c == '}')
2191                         count--;
2192                     RExC_parse++;
2193                 }
2194                 if (*RExC_parse != ')')
2195                 {
2196                     RExC_parse = s;
2197                     vFAIL("Sequence (?{...}) not terminated or not {}-balanced");
2198                 }
2199                 if (!SIZE_ONLY) {
2200                     AV *av;
2201
2202                     if (RExC_parse - 1 - s)
2203                         sv = newSVpvn(s, RExC_parse - 1 - s);
2204                     else
2205                         sv = newSVpvn("", 0);
2206
2207                     ENTER;
2208                     Perl_save_re_context(aTHX);
2209                     rop = sv_compile_2op(sv, &sop, "re", &av);
2210                     sop->op_private |= OPpREFCOUNTED;
2211                     /* re_dup will OpREFCNT_inc */
2212                     OpREFCNT_set(sop, 1);
2213                     LEAVE;
2214
2215                     n = add_data(pRExC_state, 3, "nop");
2216                     RExC_rx->data->data[n] = (void*)rop;
2217                     RExC_rx->data->data[n+1] = (void*)sop;
2218                     RExC_rx->data->data[n+2] = (void*)av;
2219                     SvREFCNT_dec(sv);
2220                 }
2221                 else {                                          /* First pass */
2222                     if (PL_reginterp_cnt < ++RExC_seen_evals
2223                         && PL_curcop != &PL_compiling)
2224                         /* No compiled RE interpolated, has runtime
2225                            components ===> unsafe.  */
2226                         FAIL("Eval-group not allowed at runtime, use re 'eval'");
2227                     if (PL_tainting && PL_tainted)
2228                         FAIL("Eval-group in insecure regular expression");
2229                 }
2230
2231                 nextchar(pRExC_state);
2232                 if (logical) {
2233                     ret = reg_node(pRExC_state, LOGICAL);
2234                     if (!SIZE_ONLY)
2235                         ret->flags = 2;
2236                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2237                     /* deal with the length of this later - MJD */
2238                     return ret;
2239                 }
2240                 return reganode(pRExC_state, EVAL, n);
2241             }
2242             case '(':           /* (?(?{...})...) and (?(?=...)...) */
2243             {
2244                 if (RExC_parse[0] == '?') {        /* (?(?...)) */
2245                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2246                         || RExC_parse[1] == '<'
2247                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2248                         I32 flag;
2249
2250                         ret = reg_node(pRExC_state, LOGICAL);
2251                         if (!SIZE_ONLY)
2252                             ret->flags = 1;
2253                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2254                         goto insert_if;
2255                     }
2256                 }
2257                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2258                     /* (?(1)...) */
2259                     parno = atoi(RExC_parse++);
2260
2261                     while (isDIGIT(*RExC_parse))
2262                         RExC_parse++;
2263                     ret = reganode(pRExC_state, GROUPP, parno);
2264
2265                     if ((c = *nextchar(pRExC_state)) != ')')
2266                         vFAIL("Switch condition not recognized");
2267                   insert_if:
2268                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2269                     br = regbranch(pRExC_state, &flags, 1);
2270                     if (br == NULL)
2271                         br = reganode(pRExC_state, LONGJMP, 0);
2272                     else
2273                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2274                     c = *nextchar(pRExC_state);
2275                     if (flags&HASWIDTH)
2276                         *flagp |= HASWIDTH;
2277                     if (c == '|') {
2278                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2279                         regbranch(pRExC_state, &flags, 1);
2280                         regtail(pRExC_state, ret, lastbr);
2281                         if (flags&HASWIDTH)
2282                             *flagp |= HASWIDTH;
2283                         c = *nextchar(pRExC_state);
2284                     }
2285                     else
2286                         lastbr = NULL;
2287                     if (c != ')')
2288                         vFAIL("Switch (?(condition)... contains too many branches");
2289                     ender = reg_node(pRExC_state, TAIL);
2290                     regtail(pRExC_state, br, ender);
2291                     if (lastbr) {
2292                         regtail(pRExC_state, lastbr, ender);
2293                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2294                     }
2295                     else
2296                         regtail(pRExC_state, ret, ender);
2297                     return ret;
2298                 }
2299                 else {
2300                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2301                 }
2302             }
2303             case 0:
2304                 RExC_parse--; /* for vFAIL to print correctly */
2305                 vFAIL("Sequence (? incomplete");
2306                 break;
2307             default:
2308                 --RExC_parse;
2309               parse_flags:      /* (?i) */
2310                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2311                     /* (?g), (?gc) and (?o) are useless here
2312                        and must be globally applied -- japhy */
2313
2314                     if (*RExC_parse == 'o' || *RExC_parse == 'g') {
2315                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2316                             I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
2317                             if (! (wastedflags & wflagbit) ) {
2318                                 wastedflags |= wflagbit;
2319                                 vWARN5(
2320                                     RExC_parse + 1,
2321                                     "Useless (%s%c) - %suse /%c modifier",
2322                                     flagsp == &negflags ? "?-" : "?",
2323                                     *RExC_parse,
2324                                     flagsp == &negflags ? "don't " : "",
2325                                     *RExC_parse
2326                                 );
2327                             }
2328                         }
2329                     }
2330                     else if (*RExC_parse == 'c') {
2331                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2332                             if (! (wastedflags & wasted_c) ) {
2333                                 wastedflags |= wasted_gc;
2334                                 vWARN3(
2335                                     RExC_parse + 1,
2336                                     "Useless (%sc) - %suse /gc modifier",
2337                                     flagsp == &negflags ? "?-" : "?",
2338                                     flagsp == &negflags ? "don't " : ""
2339                                 );
2340                             }
2341                         }
2342                     }
2343                     else { pmflag(flagsp, *RExC_parse); }
2344
2345                     ++RExC_parse;
2346                 }
2347                 if (*RExC_parse == '-') {
2348                     flagsp = &negflags;
2349                     wastedflags = 0;  /* reset so (?g-c) warns twice */
2350                     ++RExC_parse;
2351                     goto parse_flags;
2352                 }
2353                 RExC_flags16 |= posflags;
2354                 RExC_flags16 &= ~negflags;
2355                 if (*RExC_parse == ':') {
2356                     RExC_parse++;
2357                     paren = ':';
2358                     break;
2359                 }
2360               unknown:
2361                 if (*RExC_parse != ')') {
2362                     RExC_parse++;
2363                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2364                 }
2365                 nextchar(pRExC_state);
2366                 *flagp = TRYAGAIN;
2367                 return NULL;
2368             }
2369         }
2370         else {                  /* (...) */
2371             parno = RExC_npar;
2372             RExC_npar++;
2373             ret = reganode(pRExC_state, OPEN, parno);
2374             Set_Node_Length(ret, 1); /* MJD */
2375             Set_Node_Offset(ret, RExC_parse); /* MJD */
2376             open = 1;
2377         }
2378     }
2379     else                        /* ! paren */
2380         ret = NULL;
2381
2382     /* Pick up the branches, linking them together. */
2383     parse_start = RExC_parse;   /* MJD */
2384     br = regbranch(pRExC_state, &flags, 1);
2385     /*     branch_len = (paren != 0); */
2386
2387     if (br == NULL)
2388         return(NULL);
2389     if (*RExC_parse == '|') {
2390         if (!SIZE_ONLY && RExC_extralen) {
2391             reginsert(pRExC_state, BRANCHJ, br);
2392         }
2393         else {                  /* MJD */
2394             reginsert(pRExC_state, BRANCH, br);
2395             Set_Node_Length(br, paren != 0);
2396             Set_Node_Offset_To_R(br-RExC_emit_start, parse_start-RExC_start);
2397         }
2398         have_branch = 1;
2399         if (SIZE_ONLY)
2400             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2401     }
2402     else if (paren == ':') {
2403         *flagp |= flags&SIMPLE;
2404     }
2405     if (open) {                         /* Starts with OPEN. */
2406         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2407     }
2408     else if (paren != '?')              /* Not Conditional */
2409         ret = br;
2410     *flagp |= flags & (SPSTART | HASWIDTH);
2411     lastbr = br;
2412     while (*RExC_parse == '|') {
2413         if (!SIZE_ONLY && RExC_extralen) {
2414             ender = reganode(pRExC_state, LONGJMP,0);
2415             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2416         }
2417         if (SIZE_ONLY)
2418             RExC_extralen += 2;         /* Account for LONGJMP. */
2419         nextchar(pRExC_state);
2420         br = regbranch(pRExC_state, &flags, 0);
2421
2422         if (br == NULL)
2423             return(NULL);
2424         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2425         lastbr = br;
2426         if (flags&HASWIDTH)
2427             *flagp |= HASWIDTH;
2428         *flagp |= flags&SPSTART;
2429     }
2430
2431     if (have_branch || paren != ':') {
2432         /* Make a closing node, and hook it on the end. */
2433         switch (paren) {
2434         case ':':
2435             ender = reg_node(pRExC_state, TAIL);
2436             break;
2437         case 1:
2438             ender = reganode(pRExC_state, CLOSE, parno);
2439             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
2440             Set_Node_Length(ender,1); /* MJD */
2441             break;
2442         case '<':
2443         case ',':
2444         case '=':
2445         case '!':
2446             *flagp &= ~HASWIDTH;
2447             /* FALL THROUGH */
2448         case '>':
2449             ender = reg_node(pRExC_state, SUCCEED);
2450             break;
2451         case 0:
2452             ender = reg_node(pRExC_state, END);
2453             break;
2454         }
2455         regtail(pRExC_state, lastbr, ender);
2456
2457         if (have_branch) {
2458             /* Hook the tails of the branches to the closing node. */
2459             for (br = ret; br != NULL; br = regnext(br)) {
2460                 regoptail(pRExC_state, br, ender);
2461             }
2462         }
2463     }
2464
2465     {
2466         char *p;
2467         static char parens[] = "=!<,>";
2468
2469         if (paren && (p = strchr(parens, paren))) {
2470             int node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2471             int flag = (p - parens) > 1;
2472
2473             if (paren == '>')
2474                 node = SUSPEND, flag = 0;
2475             reginsert(pRExC_state, node,ret);
2476             ret->flags = flag;
2477             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2478         }
2479     }
2480
2481     /* Check for proper termination. */
2482     if (paren) {
2483         RExC_flags16 = oregflags;
2484         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2485             RExC_parse = oregcomp_parse;
2486             vFAIL("Unmatched (");
2487         }
2488     }
2489     else if (!paren && RExC_parse < RExC_end) {
2490         if (*RExC_parse == ')') {
2491             RExC_parse++;
2492             vFAIL("Unmatched )");
2493         }
2494         else
2495             FAIL("Junk on end of regexp");      /* "Can't happen". */
2496         /* NOTREACHED */
2497     }
2498
2499     return(ret);
2500 }
2501
2502 /*
2503  - regbranch - one alternative of an | operator
2504  *
2505  * Implements the concatenation operator.
2506  */
2507 STATIC regnode *
2508 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2509 {
2510     register regnode *ret;
2511     register regnode *chain = NULL;
2512     register regnode *latest;
2513     I32 flags = 0, c = 0;
2514
2515     if (first)
2516         ret = NULL;
2517     else {
2518         if (!SIZE_ONLY && RExC_extralen)
2519             ret = reganode(pRExC_state, BRANCHJ,0);
2520         else {
2521             ret = reg_node(pRExC_state, BRANCH);
2522             Set_Node_Length(ret, 1);
2523         }
2524     }
2525
2526     if (!first && SIZE_ONLY)
2527         RExC_extralen += 1;                     /* BRANCHJ */
2528
2529     *flagp = WORST;                     /* Tentatively. */
2530
2531     RExC_parse--;
2532     nextchar(pRExC_state);
2533     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2534         flags &= ~TRYAGAIN;
2535         latest = regpiece(pRExC_state, &flags);
2536         if (latest == NULL) {
2537             if (flags & TRYAGAIN)
2538                 continue;
2539             return(NULL);
2540         }
2541         else if (ret == NULL)
2542             ret = latest;
2543         *flagp |= flags&HASWIDTH;
2544         if (chain == NULL)      /* First piece. */
2545             *flagp |= flags&SPSTART;
2546         else {
2547             RExC_naughty++;
2548             regtail(pRExC_state, chain, latest);
2549         }
2550         chain = latest;
2551         c++;
2552     }
2553     if (chain == NULL) {        /* Loop ran zero times. */
2554         chain = reg_node(pRExC_state, NOTHING);
2555         if (ret == NULL)
2556             ret = chain;
2557     }
2558     if (c == 1) {
2559         *flagp |= flags&SIMPLE;
2560     }
2561
2562     return(ret);
2563 }
2564
2565 /*
2566  - regpiece - something followed by possible [*+?]
2567  *
2568  * Note that the branching code sequences used for ? and the general cases
2569  * of * and + are somewhat optimized:  they use the same NOTHING node as
2570  * both the endmarker for their branch list and the body of the last branch.
2571  * It might seem that this node could be dispensed with entirely, but the
2572  * endmarker role is not redundant.
2573  */
2574 STATIC regnode *
2575 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2576 {
2577     register regnode *ret;
2578     register char op;
2579     register char *next;
2580     I32 flags;
2581     char *origparse = RExC_parse;
2582     char *maxpos;
2583     I32 min;
2584     I32 max = REG_INFTY;
2585     char *parse_start;
2586
2587     ret = regatom(pRExC_state, &flags);
2588     if (ret == NULL) {
2589         if (flags & TRYAGAIN)
2590             *flagp |= TRYAGAIN;
2591         return(NULL);
2592     }
2593
2594     op = *RExC_parse;
2595
2596     if (op == '{' && regcurly(RExC_parse)) {
2597         parse_start = RExC_parse; /* MJD */
2598         next = RExC_parse + 1;
2599         maxpos = Nullch;
2600         while (isDIGIT(*next) || *next == ',') {
2601             if (*next == ',') {
2602                 if (maxpos)
2603                     break;
2604                 else
2605                     maxpos = next;
2606             }
2607             next++;
2608         }
2609         if (*next == '}') {             /* got one */
2610             if (!maxpos)
2611                 maxpos = next;
2612             RExC_parse++;
2613             min = atoi(RExC_parse);
2614             if (*maxpos == ',')
2615                 maxpos++;
2616             else
2617                 maxpos = RExC_parse;
2618             max = atoi(maxpos);
2619             if (!max && *maxpos != '0')
2620                 max = REG_INFTY;                /* meaning "infinity" */
2621             else if (max >= REG_INFTY)
2622                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2623             RExC_parse = next;
2624             nextchar(pRExC_state);
2625
2626         do_curly:
2627             if ((flags&SIMPLE)) {
2628                 RExC_naughty += 2 + RExC_naughty / 2;
2629                 reginsert(pRExC_state, CURLY, ret);
2630                 Set_Node_Offset(ret, parse_start+1); /* MJD */
2631                 Set_Node_Cur_Length(ret);
2632             }
2633             else {
2634                 regnode *w = reg_node(pRExC_state, WHILEM);
2635
2636                 w->flags = 0;
2637                 regtail(pRExC_state, ret, w);
2638                 if (!SIZE_ONLY && RExC_extralen) {
2639                     reginsert(pRExC_state, LONGJMP,ret);
2640                     reginsert(pRExC_state, NOTHING,ret);
2641                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2642                 }
2643                 reginsert(pRExC_state, CURLYX,ret);
2644                                 /* MJD hk */
2645                 Set_Node_Offset(ret, parse_start+1);
2646                 Set_Node_Length(ret,
2647                                 op == '{' ? (RExC_parse - parse_start) : 1);
2648
2649                 if (!SIZE_ONLY && RExC_extralen)
2650                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2651                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2652                 if (SIZE_ONLY)
2653                     RExC_whilem_seen++, RExC_extralen += 3;
2654                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2655             }
2656             ret->flags = 0;
2657
2658             if (min > 0)
2659                 *flagp = WORST;
2660             if (max > 0)
2661                 *flagp |= HASWIDTH;
2662             if (max && max < min)
2663                 vFAIL("Can't do {n,m} with n > m");
2664             if (!SIZE_ONLY) {
2665                 ARG1_SET(ret, min);
2666                 ARG2_SET(ret, max);
2667             }
2668
2669             goto nest_check;
2670         }
2671     }
2672
2673     if (!ISMULT1(op)) {
2674         *flagp = flags;
2675         return(ret);
2676     }
2677
2678 #if 0                           /* Now runtime fix should be reliable. */
2679
2680     /* if this is reinstated, don't forget to put this back into perldiag:
2681
2682             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2683
2684            (F) The part of the regexp subject to either the * or + quantifier
2685            could match an empty string. The {#} shows in the regular
2686            expression about where the problem was discovered.
2687
2688     */
2689
2690     if (!(flags&HASWIDTH) && op != '?')
2691       vFAIL("Regexp *+ operand could be empty");
2692 #endif
2693
2694     parse_start = RExC_parse;
2695     nextchar(pRExC_state);
2696
2697     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2698
2699     if (op == '*' && (flags&SIMPLE)) {
2700         reginsert(pRExC_state, STAR, ret);
2701         ret->flags = 0;
2702         RExC_naughty += 4;
2703     }
2704     else if (op == '*') {
2705         min = 0;
2706         goto do_curly;
2707     }
2708     else if (op == '+' && (flags&SIMPLE)) {
2709         reginsert(pRExC_state, PLUS, ret);
2710         ret->flags = 0;
2711         RExC_naughty += 3;
2712     }
2713     else if (op == '+') {
2714         min = 1;
2715         goto do_curly;
2716     }
2717     else if (op == '?') {
2718         min = 0; max = 1;
2719         goto do_curly;
2720     }
2721   nest_check:
2722     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2723         vWARN3(RExC_parse,
2724                "%.*s matches null string many times",
2725                RExC_parse - origparse,
2726                origparse);
2727     }
2728
2729     if (*RExC_parse == '?') {
2730         nextchar(pRExC_state);
2731         reginsert(pRExC_state, MINMOD, ret);
2732         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2733     }
2734     if (ISMULT2(RExC_parse)) {
2735         RExC_parse++;
2736         vFAIL("Nested quantifiers");
2737     }
2738
2739     return(ret);
2740 }
2741
2742 /*
2743  - regatom - the lowest level
2744  *
2745  * Optimization:  gobbles an entire sequence of ordinary characters so that
2746  * it can turn them into a single node, which is smaller to store and
2747  * faster to run.  Backslashed characters are exceptions, each becoming a
2748  * separate node; the code is simpler that way and it's not worth fixing.
2749  *
2750  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2751 STATIC regnode *
2752 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2753 {
2754     register regnode *ret = 0;
2755     I32 flags;
2756     char *parse_start = 0;
2757
2758     *flagp = WORST;             /* Tentatively. */
2759
2760 tryagain:
2761     switch (*RExC_parse) {
2762     case '^':
2763         RExC_seen_zerolen++;
2764         nextchar(pRExC_state);
2765         if (RExC_flags16 & PMf_MULTILINE)
2766             ret = reg_node(pRExC_state, MBOL);
2767         else if (RExC_flags16 & PMf_SINGLELINE)
2768             ret = reg_node(pRExC_state, SBOL);
2769         else
2770             ret = reg_node(pRExC_state, BOL);
2771         Set_Node_Length(ret, 1); /* MJD */
2772         break;
2773     case '$':
2774         nextchar(pRExC_state);
2775         if (*RExC_parse)
2776             RExC_seen_zerolen++;
2777         if (RExC_flags16 & PMf_MULTILINE)
2778             ret = reg_node(pRExC_state, MEOL);
2779         else if (RExC_flags16 & PMf_SINGLELINE)
2780             ret = reg_node(pRExC_state, SEOL);
2781         else
2782             ret = reg_node(pRExC_state, EOL);
2783         Set_Node_Length(ret, 1); /* MJD */
2784         break;
2785     case '.':
2786         nextchar(pRExC_state);
2787         if (RExC_flags16 & PMf_SINGLELINE)
2788             ret = reg_node(pRExC_state, SANY);
2789         else
2790             ret = reg_node(pRExC_state, REG_ANY);
2791         *flagp |= HASWIDTH|SIMPLE;
2792         RExC_naughty++;
2793         Set_Node_Length(ret, 1); /* MJD */
2794         break;
2795     case '[':
2796     {
2797         char *oregcomp_parse = ++RExC_parse;
2798         ret = regclass(pRExC_state);
2799         if (*RExC_parse != ']') {
2800             RExC_parse = oregcomp_parse;
2801             vFAIL("Unmatched [");
2802         }
2803         nextchar(pRExC_state);
2804         *flagp |= HASWIDTH|SIMPLE;
2805         Set_Node_Length(ret, RExC_parse - oregcomp_parse + 1); /* MJD */
2806         break;
2807     }
2808     case '(':
2809         nextchar(pRExC_state);
2810         ret = reg(pRExC_state, 1, &flags);
2811         if (ret == NULL) {
2812                 if (flags & TRYAGAIN) {
2813                     if (RExC_parse == RExC_end) {
2814                          /* Make parent create an empty node if needed. */
2815                         *flagp |= TRYAGAIN;
2816                         return(NULL);
2817                     }
2818                     goto tryagain;
2819                 }
2820                 return(NULL);
2821         }
2822         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2823         break;
2824     case '|':
2825     case ')':
2826         if (flags & TRYAGAIN) {
2827             *flagp |= TRYAGAIN;
2828             return NULL;
2829         }
2830         vFAIL("Internal urp");
2831                                 /* Supposed to be caught earlier. */
2832         break;
2833     case '{':
2834         if (!regcurly(RExC_parse)) {
2835             RExC_parse++;
2836             goto defchar;
2837         }
2838         /* FALL THROUGH */
2839     case '?':
2840     case '+':
2841     case '*':
2842         RExC_parse++;
2843         vFAIL("Quantifier follows nothing");
2844         break;
2845     case '\\':
2846         switch (*++RExC_parse) {
2847         case 'A':
2848             RExC_seen_zerolen++;
2849             ret = reg_node(pRExC_state, SBOL);
2850             *flagp |= SIMPLE;
2851             nextchar(pRExC_state);
2852             Set_Node_Length(ret, 2); /* MJD */
2853             break;
2854         case 'G':
2855             ret = reg_node(pRExC_state, GPOS);
2856             RExC_seen |= REG_SEEN_GPOS;
2857             *flagp |= SIMPLE;
2858             nextchar(pRExC_state);
2859             Set_Node_Length(ret, 2); /* MJD */
2860             break;
2861         case 'Z':
2862             ret = reg_node(pRExC_state, SEOL);
2863             *flagp |= SIMPLE;
2864             RExC_seen_zerolen++;                /* Do not optimize RE away */
2865             nextchar(pRExC_state);
2866             break;
2867         case 'z':
2868             ret = reg_node(pRExC_state, EOS);
2869             *flagp |= SIMPLE;
2870             RExC_seen_zerolen++;                /* Do not optimize RE away */
2871             nextchar(pRExC_state);
2872             Set_Node_Length(ret, 2); /* MJD */
2873             break;
2874         case 'C':
2875             ret = reg_node(pRExC_state, CANY);
2876             RExC_seen |= REG_SEEN_CANY;
2877             *flagp |= HASWIDTH|SIMPLE;
2878             nextchar(pRExC_state);
2879             Set_Node_Length(ret, 2); /* MJD */
2880             break;
2881         case 'X':
2882             ret = reg_node(pRExC_state, CLUMP);
2883             *flagp |= HASWIDTH;
2884             nextchar(pRExC_state);
2885             Set_Node_Length(ret, 2); /* MJD */
2886             break;
2887         case 'w':
2888             ret = reg_node(pRExC_state, LOC ? ALNUML     : ALNUM);
2889             *flagp |= HASWIDTH|SIMPLE;
2890             nextchar(pRExC_state);
2891             Set_Node_Length(ret, 2); /* MJD */
2892             break;
2893         case 'W':
2894             ret = reg_node(pRExC_state, LOC ? NALNUML     : NALNUM);
2895             *flagp |= HASWIDTH|SIMPLE;
2896             nextchar(pRExC_state);
2897             Set_Node_Length(ret, 2); /* MJD */
2898             break;
2899         case 'b':
2900             RExC_seen_zerolen++;
2901             RExC_seen |= REG_SEEN_LOOKBEHIND;
2902             ret = reg_node(pRExC_state, LOC ? BOUNDL     : BOUND);
2903             *flagp |= SIMPLE;
2904             nextchar(pRExC_state);
2905             Set_Node_Length(ret, 2); /* MJD */
2906             break;
2907         case 'B':
2908             RExC_seen_zerolen++;
2909             RExC_seen |= REG_SEEN_LOOKBEHIND;
2910             ret = reg_node(pRExC_state, LOC ? NBOUNDL     : NBOUND);
2911             *flagp |= SIMPLE;
2912             nextchar(pRExC_state);
2913             Set_Node_Length(ret, 2); /* MJD */
2914             break;
2915         case 's':
2916             ret = reg_node(pRExC_state, LOC ? SPACEL     : SPACE);
2917             *flagp |= HASWIDTH|SIMPLE;
2918             nextchar(pRExC_state);
2919             Set_Node_Length(ret, 2); /* MJD */
2920             break;
2921         case 'S':
2922             ret = reg_node(pRExC_state, LOC ? NSPACEL     : NSPACE);
2923             *flagp |= HASWIDTH|SIMPLE;
2924             nextchar(pRExC_state);
2925             Set_Node_Length(ret, 2); /* MJD */
2926             break;
2927         case 'd':
2928             ret = reg_node(pRExC_state, DIGIT);
2929             *flagp |= HASWIDTH|SIMPLE;
2930             nextchar(pRExC_state);
2931             Set_Node_Length(ret, 2); /* MJD */
2932             break;
2933         case 'D':
2934             ret = reg_node(pRExC_state, NDIGIT);
2935             *flagp |= HASWIDTH|SIMPLE;
2936             nextchar(pRExC_state);
2937             Set_Node_Length(ret, 2); /* MJD */
2938             break;
2939         case 'p':
2940         case 'P':
2941             {
2942                 char* oldregxend = RExC_end;
2943                 char* parse_start = RExC_parse;
2944
2945                 if (RExC_parse[1] == '{') {
2946                   /* a lovely hack--pretend we saw [\pX] instead */
2947                     RExC_end = strchr(RExC_parse, '}');
2948                     if (!RExC_end) {
2949                         U8 c = (U8)*RExC_parse;
2950                         RExC_parse += 2;
2951                         RExC_end = oldregxend;
2952                         vFAIL2("Missing right brace on \\%c{}", c);
2953                     }
2954                     RExC_end++;
2955                 }
2956                 else
2957                     RExC_end = RExC_parse + 2;
2958                 RExC_parse--;
2959
2960                 ret = regclass(pRExC_state);
2961
2962                 RExC_end = oldregxend;
2963                 RExC_parse--;
2964                 Set_Node_Cur_Length(ret); /* MJD */
2965                 nextchar(pRExC_state);
2966                 *flagp |= HASWIDTH|SIMPLE;
2967             }
2968             break;
2969         case 'n':
2970         case 'r':
2971         case 't':
2972         case 'f':
2973         case 'e':
2974         case 'a':
2975         case 'x':
2976         case 'c':
2977         case '0':
2978             goto defchar;
2979         case '1': case '2': case '3': case '4':
2980         case '5': case '6': case '7': case '8': case '9':
2981             {
2982                 I32 num = atoi(RExC_parse);
2983
2984                 if (num > 9 && num >= RExC_npar)
2985                     goto defchar;
2986                 else {
2987                     char * parse_start = RExC_parse - 1; /* MJD */
2988                     while (isDIGIT(*RExC_parse))
2989                         RExC_parse++;
2990
2991                     if (!SIZE_ONLY && num > RExC_rx->nparens)
2992                         vFAIL("Reference to nonexistent group");
2993                     RExC_sawback = 1;
2994                     ret = reganode(pRExC_state, FOLD
2995                                    ? (LOC ? REFFL : REFF)
2996                                    : REF, num);
2997                     *flagp |= HASWIDTH;
2998
2999                     /* override incorrect value set in reganode MJD */
3000                     Set_Node_Offset(ret, parse_start+1);
3001                     Set_Node_Cur_Length(ret); /* MJD */
3002                     RExC_parse--;
3003                     nextchar(pRExC_state);
3004                 }
3005             }
3006             break;
3007         case '\0':
3008             if (RExC_parse >= RExC_end)
3009                 FAIL("Trailing \\");
3010             /* FALL THROUGH */
3011         default:
3012             /* Do not generate `unrecognized' warnings here, we fall
3013                back into the quick-grab loop below */
3014             goto defchar;
3015         }
3016         break;
3017
3018     case '#':
3019         if (RExC_flags16 & PMf_EXTENDED) {
3020             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
3021             if (RExC_parse < RExC_end)
3022                 goto tryagain;
3023         }
3024         /* FALL THROUGH */
3025
3026     default: {
3027             register STRLEN len;
3028             register UV ender;
3029             register char *p;
3030             char *oldp, *s;
3031             STRLEN numlen;
3032             STRLEN foldlen;
3033             U8 tmpbuf[UTF8_MAXLEN_FOLD+1], *foldbuf;
3034
3035             parse_start = RExC_parse - 1;
3036
3037             RExC_parse++;
3038
3039         defchar:
3040             ret = reg_node(pRExC_state, FOLD
3041                           ? (LOC ? EXACTFL : EXACTF)
3042                           : EXACT);
3043             s = STRING(ret);
3044             for (len = 0, p = RExC_parse - 1;
3045               len < 127 && p < RExC_end;
3046               len++)
3047             {
3048                 oldp = p;
3049
3050                 if (RExC_flags16 & PMf_EXTENDED)
3051                     p = regwhite(p, RExC_end);
3052                 switch (*p) {
3053                 case '^':
3054                 case '$':
3055                 case '.':
3056                 case '[':
3057                 case '(':
3058                 case ')':
3059                 case '|':
3060                     goto loopdone;
3061                 case '\\':
3062                     switch (*++p) {
3063                     case 'A':
3064                     case 'C':
3065                     case 'X':
3066                     case 'G':
3067                     case 'Z':
3068                     case 'z':
3069                     case 'w':
3070                     case 'W':
3071                     case 'b':
3072                     case 'B':
3073                     case 's':
3074                     case 'S':
3075                     case 'd':
3076                     case 'D':
3077                     case 'p':
3078                     case 'P':
3079                         --p;
3080                         goto loopdone;
3081                     case 'n':
3082                         ender = '\n';
3083                         p++;
3084                         break;
3085                     case 'r':
3086                         ender = '\r';
3087                         p++;
3088                         break;
3089                     case 't':
3090                         ender = '\t';
3091                         p++;
3092                         break;
3093                     case 'f':
3094                         ender = '\f';
3095                         p++;
3096                         break;
3097                     case 'e':
3098                           ender = ASCII_TO_NATIVE('\033');
3099                         p++;
3100                         break;
3101                     case 'a':
3102                           ender = ASCII_TO_NATIVE('\007');
3103                         p++;
3104                         break;
3105                     case 'x':
3106                         if (*++p == '{') {
3107                             char* e = strchr(p, '}');
3108
3109                             if (!e) {
3110                                 RExC_parse = p + 1;
3111                                 vFAIL("Missing right brace on \\x{}");
3112                             }
3113                             else {
3114                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3115                                     | PERL_SCAN_DISALLOW_PREFIX;
3116                                 numlen = e - p - 1;
3117                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3118                                 if (ender > 0xff)
3119                                     RExC_utf8 = 1;
3120                                 /* numlen is generous */
3121                                 if (numlen + len >= 127) {
3122                                     p--;
3123                                     goto loopdone;
3124                                 }
3125                                 p = e + 1;
3126                             }
3127                         }
3128                         else {
3129                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3130                             numlen = 2;
3131                             ender = grok_hex(p, &numlen, &flags, NULL);
3132                             p += numlen;
3133                         }
3134                         break;
3135                     case 'c':
3136                         p++;
3137                         ender = UCHARAT(p++);
3138                         ender = toCTRL(ender);
3139                         break;
3140                     case '0': case '1': case '2': case '3':case '4':
3141                     case '5': case '6': case '7': case '8':case '9':
3142                         if (*p == '0' ||
3143                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3144                             I32 flags = 0;
3145                             numlen = 3;
3146                             ender = grok_oct(p, &numlen, &flags, NULL);
3147                             p += numlen;
3148                         }
3149                         else {
3150                             --p;
3151                             goto loopdone;
3152                         }
3153                         break;
3154                     case '\0':
3155                         if (p >= RExC_end)
3156                             FAIL("Trailing \\");
3157                         /* FALL THROUGH */
3158                     default:
3159                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3160                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3161                         goto normal_default;
3162                     }
3163                     break;
3164                 default:
3165                   normal_default:
3166                     if (UTF8_IS_START(*p) && UTF) {
3167                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3168                                                &numlen, 0);
3169                         p += numlen;
3170                     }
3171                     else
3172                         ender = *p++;
3173                     break;
3174                 }
3175                 if (RExC_flags16 & PMf_EXTENDED)
3176                     p = regwhite(p, RExC_end);
3177                 if (UTF && FOLD) {
3178                     /* Prime the casefolded buffer. */
3179                     ender = toFOLD_uni(ender, tmpbuf, &foldlen);
3180                 }
3181                 if (ISMULT2(p)) { /* Back off on ?+*. */
3182                     if (len)
3183                         p = oldp;
3184                     else if (UTF) {
3185                          if (FOLD) {
3186                               /* Emit all the Unicode characters. */
3187                               for (foldbuf = tmpbuf;
3188                                    foldlen;
3189                                    foldlen -= numlen) {
3190                                    ender = utf8_to_uvchr(foldbuf, &numlen);
3191                                    if (numlen > 0) {
3192                                         reguni(pRExC_state, ender, s, &numlen);
3193                                         s       += numlen;
3194                                         len     += numlen;
3195                                         foldbuf += numlen;
3196                                         if (numlen >= foldlen)
3197                                              break;
3198                                    }
3199                                    else
3200                                         break; /* "Can't happen." */
3201                               }
3202                          }
3203                          else {
3204                               reguni(pRExC_state, ender, s, &numlen);
3205                               if (numlen > 0) {
3206                                    s   += numlen;
3207                                    len += numlen;
3208                               }
3209                          }
3210                     }
3211                     else {
3212                         len++;
3213                         REGC(ender, s++);
3214                     }
3215                     break;
3216                 }
3217                 if (UTF) {
3218                      if (FOLD) {
3219                           /* Emit all the Unicode characters. */
3220                           for (foldbuf = tmpbuf;
3221                                foldlen;
3222                                foldlen -= numlen) {
3223                                ender = utf8_to_uvchr(foldbuf, &numlen);
3224                                if (numlen > 0) {
3225                                     reguni(pRExC_state, ender, s, &numlen);
3226                                     len     += numlen;
3227                                     s       += numlen;
3228                                     foldbuf += numlen;
3229                                     if (numlen >= foldlen)
3230                                          break;
3231                                }
3232                                else
3233                                     break;
3234                           }
3235                      }
3236                      else {
3237                           reguni(pRExC_state, ender, s, &numlen);
3238                           if (numlen > 0) {
3239                                s   += numlen;
3240                                len += numlen;
3241                           }
3242                      }
3243                      len--;
3244                 }
3245                 else
3246                     REGC(ender, s++);
3247             }
3248         loopdone:
3249             RExC_parse = p - 1;
3250             Set_Node_Cur_Length(ret); /* MJD */
3251             nextchar(pRExC_state);
3252             {
3253                 /* len is STRLEN which is unsigned, need to copy to signed */
3254                 IV iv = len;
3255                 if (iv < 0)
3256                     vFAIL("Internal disaster");
3257             }
3258             if (len > 0)
3259                 *flagp |= HASWIDTH;
3260             if (len == 1)
3261                 *flagp |= SIMPLE;
3262             if (!SIZE_ONLY)
3263                 STR_LEN(ret) = len;
3264             if (SIZE_ONLY)
3265                 RExC_size += STR_SZ(len);
3266             else
3267                 RExC_emit += STR_SZ(len);
3268         }
3269         break;
3270     }
3271
3272     /* If the encoding pragma is in effect recode the text of
3273      * any EXACT-kind nodes. */
3274     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3275          STRLEN oldlen = STR_LEN(ret);
3276          SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3277
3278          if (RExC_utf8)
3279               SvUTF8_on(sv);
3280          if (sv_utf8_downgrade(sv, TRUE)) {
3281               char *s       = Perl_sv_recode_to_utf8(aTHX_ sv, PL_encoding);
3282               STRLEN newlen = SvCUR(sv);
3283
3284               if (!SIZE_ONLY) {
3285                    DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3286                                          (int)oldlen, STRING(ret),
3287                                          (int)newlen, s));
3288                    Copy(s, STRING(ret), newlen, char);
3289                    STR_LEN(ret) += newlen - oldlen;
3290                    RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3291               } else
3292                    RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3293          }
3294     }
3295
3296     return(ret);
3297 }
3298
3299 STATIC char *
3300 S_regwhite(pTHX_ char *p, char *e)
3301 {
3302     while (p < e) {
3303         if (isSPACE(*p))
3304             ++p;
3305         else if (*p == '#') {
3306             do {
3307                 p++;
3308             } while (p < e && *p != '\n');
3309         }
3310         else
3311             break;
3312     }
3313     return p;
3314 }
3315
3316 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3317    Character classes ([:foo:]) can also be negated ([:^foo:]).
3318    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3319    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3320    but trigger failures because they are currently unimplemented. */
3321
3322 #define POSIXCC_DONE(c)   ((c) == ':')
3323 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3324 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3325
3326 STATIC I32
3327 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3328 {
3329     char *posixcc = 0;
3330     I32 namedclass = OOB_NAMEDCLASS;
3331
3332     if (value == '[' && RExC_parse + 1 < RExC_end &&
3333         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3334         POSIXCC(UCHARAT(RExC_parse))) {
3335         char  c = UCHARAT(RExC_parse);
3336         char* s = RExC_parse++;
3337
3338         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3339             RExC_parse++;
3340         if (RExC_parse == RExC_end)
3341             /* Grandfather lone [:, [=, [. */
3342             RExC_parse = s;
3343         else {
3344             char* t = RExC_parse++; /* skip over the c */
3345
3346             if (UCHARAT(RExC_parse) == ']') {
3347                 RExC_parse++; /* skip over the ending ] */
3348                 posixcc = s + 1;
3349                 if (*s == ':') {
3350                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3351                     I32 skip = 5; /* the most common skip */
3352
3353                     switch (*posixcc) {
3354                     case 'a':
3355                         if (strnEQ(posixcc, "alnum", 5))
3356                             namedclass =
3357                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3358                         else if (strnEQ(posixcc, "alpha", 5))
3359                             namedclass =
3360                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3361                         else if (strnEQ(posixcc, "ascii", 5))
3362                             namedclass =
3363                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3364                         break;
3365                     case 'b':
3366                         if (strnEQ(posixcc, "blank", 5))
3367                             namedclass =
3368                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3369                         break;
3370                     case 'c':
3371                         if (strnEQ(posixcc, "cntrl", 5))
3372                             namedclass =
3373                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3374                         break;
3375                     case 'd':
3376                         if (strnEQ(posixcc, "digit", 5))
3377                             namedclass =
3378                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3379                         break;
3380                     case 'g':
3381                         if (strnEQ(posixcc, "graph", 5))
3382                             namedclass =
3383                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3384                         break;
3385                     case 'l':
3386                         if (strnEQ(posixcc, "lower", 5))
3387                             namedclass =
3388                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3389                         break;
3390                     case 'p':
3391                         if (strnEQ(posixcc, "print", 5))
3392                             namedclass =
3393                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3394                         else if (strnEQ(posixcc, "punct", 5))
3395                             namedclass =
3396                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3397                         break;
3398                     case 's':
3399                         if (strnEQ(posixcc, "space", 5))
3400                             namedclass =
3401                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3402                         break;
3403                     case 'u':
3404                         if (strnEQ(posixcc, "upper", 5))
3405                             namedclass =
3406                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3407                         break;
3408                     case 'w': /* this is not POSIX, this is the Perl \w */
3409                         if (strnEQ(posixcc, "word", 4)) {
3410                             namedclass =
3411                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3412                             skip = 4;
3413                         }
3414                         break;
3415                     case 'x':
3416                         if (strnEQ(posixcc, "xdigit", 6)) {
3417                             namedclass =
3418                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3419                             skip = 6;
3420                         }
3421                         break;
3422                     }
3423                     if (namedclass == OOB_NAMEDCLASS ||
3424                         posixcc[skip] != ':' ||
3425                         posixcc[skip+1] != ']')
3426                     {
3427                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3428                                       t - s - 1, s + 1);
3429                     }
3430                 } else if (!SIZE_ONLY) {
3431                     /* [[=foo=]] and [[.foo.]] are still future. */
3432
3433                     /* adjust RExC_parse so the warning shows after
3434                        the class closes */
3435                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3436                         RExC_parse++;
3437                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3438                 }
3439             } else {
3440                 /* Maternal grandfather:
3441                  * "[:" ending in ":" but not in ":]" */
3442                 RExC_parse = s;
3443             }
3444         }
3445     }
3446
3447     return namedclass;
3448 }
3449
3450 STATIC void
3451 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3452 {
3453     if (!SIZE_ONLY && POSIXCC(UCHARAT(RExC_parse))) {
3454         char *s = RExC_parse;
3455         char  c = *s++;
3456
3457         while(*s && isALNUM(*s))
3458             s++;
3459         if (*s && c == *s && s[1] == ']') {
3460             vWARN3(s+2, "POSIX syntax [%c %c] belongs inside character classes", c, c);
3461
3462             /* [[=foo=]] and [[.foo.]] are still future. */
3463             if (POSIXCC_NOTYET(c)) {
3464                 /* adjust RExC_parse so the error shows after
3465                    the class closes */
3466                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3467                     ;
3468                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3469             }
3470         }
3471     }
3472 }
3473
3474 STATIC regnode *
3475 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3476 {
3477     register UV value;
3478     register UV nextvalue;
3479     register IV prevvalue = OOB_UNICODE;
3480     register IV range = 0;
3481     register regnode *ret;
3482     STRLEN numlen;
3483     IV namedclass;
3484     char *rangebegin = 0;
3485     bool need_class = 0;
3486     SV *listsv = Nullsv;
3487     register char *e;
3488     UV n;
3489     bool optimize_invert   = TRUE;
3490     AV* unicode_alternate  = 0;
3491
3492     ret = reganode(pRExC_state, ANYOF, 0);
3493
3494     if (!SIZE_ONLY)
3495         ANYOF_FLAGS(ret) = 0;
3496
3497     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3498         RExC_naughty++;
3499         RExC_parse++;
3500         if (!SIZE_ONLY)
3501             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3502     }
3503
3504     if (SIZE_ONLY)
3505         RExC_size += ANYOF_SKIP;
3506     else {
3507         RExC_emit += ANYOF_SKIP;
3508         if (FOLD)
3509             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3510         if (LOC)
3511             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3512         ANYOF_BITMAP_ZERO(ret);
3513         listsv = newSVpvn("# comment\n", 10);
3514     }
3515
3516     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3517
3518     if (!SIZE_ONLY && POSIXCC(nextvalue))
3519         checkposixcc(pRExC_state);
3520
3521     /* allow 1st char to be ] (allowing it to be - is dealt with later) */
3522     if (UCHARAT(RExC_parse) == ']')
3523         goto charclassloop;
3524
3525     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3526
3527     charclassloop:
3528
3529         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3530
3531         if (!range)
3532             rangebegin = RExC_parse;
3533         if (UTF) {
3534             value = utf8n_to_uvchr((U8*)RExC_parse,
3535                                    RExC_end - RExC_parse,
3536                                    &numlen, 0);
3537             RExC_parse += numlen;
3538         }
3539         else
3540             value = UCHARAT(RExC_parse++);
3541         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3542         if (value == '[' && POSIXCC(nextvalue))
3543             namedclass = regpposixcc(pRExC_state, value);
3544         else if (value == '\\') {
3545             if (UTF) {
3546                 value = utf8n_to_uvchr((U8*)RExC_parse,
3547                                    RExC_end - RExC_parse,
3548                                    &numlen, 0);
3549                 RExC_parse += numlen;
3550             }
3551             else
3552                 value = UCHARAT(RExC_parse++);
3553             /* Some compilers cannot handle switching on 64-bit integer
3554              * values, therefore value cannot be an UV.  Yes, this will
3555              * be a problem later if we want switch on Unicode.
3556              * A similar issue a little bit later when switching on
3557              * namedclass. --jhi */
3558             switch ((I32)value) {
3559             case 'w':   namedclass = ANYOF_ALNUM;       break;
3560             case 'W':   namedclass = ANYOF_NALNUM;      break;
3561             case 's':   namedclass = ANYOF_SPACE;       break;
3562             case 'S':   namedclass = ANYOF_NSPACE;      break;
3563             case 'd':   namedclass = ANYOF_DIGIT;       break;
3564             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3565             case 'p':
3566             case 'P':
3567                 if (*RExC_parse == '{') {
3568                     U8 c = (U8)value;
3569                     e = strchr(RExC_parse++, '}');
3570                     if (!e)
3571                         vFAIL2("Missing right brace on \\%c{}", c);
3572                     while (isSPACE(UCHARAT(RExC_parse)))
3573                         RExC_parse++;
3574                     if (e == RExC_parse)
3575                         vFAIL2("Empty \\%c{}", c);
3576                     n = e - RExC_parse;
3577                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3578                         n--;
3579                 }
3580                 else {
3581                     e = RExC_parse;
3582                     n = 1;
3583                 }
3584                 if (!SIZE_ONLY) {
3585                     if (UCHARAT(RExC_parse) == '^') {
3586                          RExC_parse++;
3587                          n--;
3588                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3589                          while (isSPACE(UCHARAT(RExC_parse))) {
3590                               RExC_parse++;
3591                               n--;
3592                          }
3593                     }
3594                     if (value == 'p')
3595                          Perl_sv_catpvf(aTHX_ listsv,
3596                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3597                     else
3598                          Perl_sv_catpvf(aTHX_ listsv,
3599                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3600                 }
3601                 RExC_parse = e + 1;
3602                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3603                 continue;
3604             case 'n':   value = '\n';                   break;
3605             case 'r':   value = '\r';                   break;
3606             case 't':   value = '\t';                   break;
3607             case 'f':   value = '\f';                   break;
3608             case 'b':   value = '\b';                   break;
3609             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3610             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3611             case 'x':
3612                 if (*RExC_parse == '{') {
3613                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3614                         | PERL_SCAN_DISALLOW_PREFIX;
3615                     e = strchr(RExC_parse++, '}');
3616                     if (!e)
3617                         vFAIL("Missing right brace on \\x{}");
3618
3619                     numlen = e - RExC_parse;
3620                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3621                     RExC_parse = e + 1;
3622                 }
3623                 else {
3624                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3625                     numlen = 2;
3626                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3627                     RExC_parse += numlen;
3628                 }
3629                 break;
3630             case 'c':
3631                 value = UCHARAT(RExC_parse++);
3632                 value = toCTRL(value);
3633                 break;
3634             case '0': case '1': case '2': case '3': case '4':
3635             case '5': case '6': case '7': case '8': case '9':
3636             {
3637                 I32 flags = 0;
3638                 numlen = 3;
3639                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3640                 RExC_parse += numlen;
3641                 break;
3642             }
3643             default:
3644                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3645                     vWARN2(RExC_parse,
3646                            "Unrecognized escape \\%c in character class passed through",
3647                            (int)value);
3648                 break;
3649             }
3650         } /* end of \blah */
3651
3652         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3653
3654             if (!SIZE_ONLY && !need_class)
3655                 ANYOF_CLASS_ZERO(ret);
3656
3657             need_class = 1;
3658
3659             /* a bad range like a-\d, a-[:digit:] ? */
3660             if (range) {
3661                 if (!SIZE_ONLY) {
3662                     if (ckWARN(WARN_REGEXP))
3663                         vWARN4(RExC_parse,
3664                                "False [] range \"%*.*s\"",
3665                                RExC_parse - rangebegin,
3666                                RExC_parse - rangebegin,
3667                                rangebegin);
3668                     if (prevvalue < 256) {
3669                         ANYOF_BITMAP_SET(ret, prevvalue);
3670                         ANYOF_BITMAP_SET(ret, '-');
3671                     }
3672                     else {
3673                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3674                         Perl_sv_catpvf(aTHX_ listsv,
3675                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3676                     }
3677                 }
3678
3679                 range = 0; /* this was not a true range */
3680             }
3681
3682             if (!SIZE_ONLY) {
3683                 if (namedclass > OOB_NAMEDCLASS)
3684                     optimize_invert = FALSE;
3685                 /* Possible truncation here but in some 64-bit environments
3686                  * the compiler gets heartburn about switch on 64-bit values.
3687                  * A similar issue a little earlier when switching on value.
3688                  * --jhi */
3689                 switch ((I32)namedclass) {
3690                 case ANYOF_ALNUM:
3691                     if (LOC)
3692                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3693                     else {
3694                         for (value = 0; value < 256; value++)
3695                             if (isALNUM(value))
3696                                 ANYOF_BITMAP_SET(ret, value);
3697                     }
3698                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");
3699                     break;
3700                 case ANYOF_NALNUM:
3701                     if (LOC)
3702                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3703                     else {
3704                         for (value = 0; value < 256; value++)
3705                             if (!isALNUM(value))
3706                                 ANYOF_BITMAP_SET(ret, value);
3707                     }
3708                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3709                     break;
3710                 case ANYOF_ALNUMC:
3711                     if (LOC)
3712                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3713                     else {
3714                         for (value = 0; value < 256; value++)
3715                             if (isALNUMC(value))
3716                                 ANYOF_BITMAP_SET(ret, value);
3717                     }
3718                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3719                     break;
3720                 case ANYOF_NALNUMC:
3721                     if (LOC)
3722                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3723                     else {
3724                         for (value = 0; value < 256; value++)
3725                             if (!isALNUMC(value))
3726                                 ANYOF_BITMAP_SET(ret, value);
3727                     }
3728                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3729                     break;
3730                 case ANYOF_ALPHA:
3731                     if (LOC)
3732                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3733                     else {
3734                         for (value = 0; value < 256; value++)
3735                             if (isALPHA(value))
3736                                 ANYOF_BITMAP_SET(ret, value);
3737                     }
3738                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3739                     break;
3740                 case ANYOF_NALPHA:
3741                     if (LOC)
3742                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3743                     else {
3744                         for (value = 0; value < 256; value++)
3745                             if (!isALPHA(value))
3746                                 ANYOF_BITMAP_SET(ret, value);
3747                     }
3748                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3749                     break;
3750                 case ANYOF_ASCII:
3751                     if (LOC)
3752                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3753                     else {
3754 #ifndef EBCDIC
3755                         for (value = 0; value < 128; value++)
3756                             ANYOF_BITMAP_SET(ret, value);
3757 #else  /* EBCDIC */
3758                         for (value = 0; value < 256; value++) {
3759                             if (isASCII(value))
3760                                 ANYOF_BITMAP_SET(ret, value);
3761                         }
3762 #endif /* EBCDIC */
3763                     }
3764                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3765                     break;
3766                 case ANYOF_NASCII:
3767                     if (LOC)
3768                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3769                     else {
3770 #ifndef EBCDIC
3771                         for (value = 128; value < 256; value++)
3772                             ANYOF_BITMAP_SET(ret, value);
3773 #else  /* EBCDIC */
3774                         for (value = 0; value < 256; value++) {
3775                             if (!isASCII(value))
3776                                 ANYOF_BITMAP_SET(ret, value);
3777                         }
3778 #endif /* EBCDIC */
3779                     }
3780                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3781                     break;
3782                 case ANYOF_BLANK:
3783                     if (LOC)
3784                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3785                     else {
3786                         for (value = 0; value < 256; value++)
3787                             if (isBLANK(value))
3788                                 ANYOF_BITMAP_SET(ret, value);
3789                     }
3790                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3791                     break;
3792                 case ANYOF_NBLANK:
3793                     if (LOC)
3794                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3795                     else {
3796                         for (value = 0; value < 256; value++)
3797                             if (!isBLANK(value))
3798                                 ANYOF_BITMAP_SET(ret, value);
3799                     }
3800                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3801                     break;
3802                 case ANYOF_CNTRL:
3803                     if (LOC)
3804                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3805                     else {
3806                         for (value = 0; value < 256; value++)
3807                             if (isCNTRL(value))
3808                                 ANYOF_BITMAP_SET(ret, value);
3809                     }
3810                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3811                     break;
3812                 case ANYOF_NCNTRL:
3813                     if (LOC)
3814                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3815                     else {
3816                         for (value = 0; value < 256; value++)
3817                             if (!isCNTRL(value))
3818                                 ANYOF_BITMAP_SET(ret, value);
3819                     }
3820                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3821                     break;
3822                 case ANYOF_DIGIT:
3823                     if (LOC)
3824                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3825                     else {
3826                         /* consecutive digits assumed */
3827                         for (value = '0'; value <= '9'; value++)
3828                             ANYOF_BITMAP_SET(ret, value);
3829                     }
3830                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3831                     break;
3832                 case ANYOF_NDIGIT:
3833                     if (LOC)
3834                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3835                     else {
3836                         /* consecutive digits assumed */
3837                         for (value = 0; value < '0'; value++)
3838                             ANYOF_BITMAP_SET(ret, value);
3839                         for (value = '9' + 1; value < 256; value++)
3840                             ANYOF_BITMAP_SET(ret, value);
3841                     }
3842                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3843                     break;
3844                 case ANYOF_GRAPH:
3845                     if (LOC)
3846                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3847                     else {
3848                         for (value = 0; value < 256; value++)
3849                             if (isGRAPH(value))
3850                                 ANYOF_BITMAP_SET(ret, value);
3851                     }
3852                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3853                     break;
3854                 case ANYOF_NGRAPH:
3855                     if (LOC)
3856                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3857                     else {
3858                         for (value = 0; value < 256; value++)
3859                             if (!isGRAPH(value))
3860                                 ANYOF_BITMAP_SET(ret, value);
3861                     }
3862                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3863                     break;
3864                 case ANYOF_LOWER:
3865                     if (LOC)
3866                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3867                     else {
3868                         for (value = 0; value < 256; value++)
3869                             if (isLOWER(value))
3870                                 ANYOF_BITMAP_SET(ret, value);
3871                     }
3872                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3873                     break;
3874                 case ANYOF_NLOWER:
3875                     if (LOC)
3876                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3877                     else {
3878                         for (value = 0; value < 256; value++)
3879                             if (!isLOWER(value))
3880                                 ANYOF_BITMAP_SET(ret, value);
3881                     }
3882                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3883                     break;
3884                 case ANYOF_PRINT:
3885                     if (LOC)
3886                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3887                     else {
3888                         for (value = 0; value < 256; value++)
3889                             if (isPRINT(value))
3890                                 ANYOF_BITMAP_SET(ret, value);
3891                     }
3892                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3893                     break;
3894                 case ANYOF_NPRINT:
3895                     if (LOC)
3896                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3897                     else {
3898                         for (value = 0; value < 256; value++)
3899                             if (!isPRINT(value))
3900                                 ANYOF_BITMAP_SET(ret, value);
3901                     }
3902                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3903                     break;
3904                 case ANYOF_PSXSPC:
3905                     if (LOC)
3906                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3907                     else {
3908                         for (value = 0; value < 256; value++)
3909                             if (isPSXSPC(value))
3910                                 ANYOF_BITMAP_SET(ret, value);
3911                     }
3912                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3913                     break;
3914                 case ANYOF_NPSXSPC:
3915                     if (LOC)
3916                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3917                     else {
3918                         for (value = 0; value < 256; value++)
3919                             if (!isPSXSPC(value))
3920                                 ANYOF_BITMAP_SET(ret, value);
3921                     }
3922                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3923                     break;
3924                 case ANYOF_PUNCT:
3925                     if (LOC)
3926                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3927                     else {
3928                         for (value = 0; value < 256; value++)
3929                             if (isPUNCT(value))
3930                                 ANYOF_BITMAP_SET(ret, value);
3931                     }
3932                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3933                     break;
3934                 case ANYOF_NPUNCT:
3935                     if (LOC)
3936                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3937                     else {
3938                         for (value = 0; value < 256; value++)
3939                             if (!isPUNCT(value))
3940                                 ANYOF_BITMAP_SET(ret, value);
3941                     }
3942                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
3943                     break;
3944                 case ANYOF_SPACE:
3945                     if (LOC)
3946                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
3947                     else {
3948                         for (value = 0; value < 256; value++)
3949                             if (isSPACE(value))
3950                                 ANYOF_BITMAP_SET(ret, value);
3951                     }
3952                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
3953                     break;
3954                 case ANYOF_NSPACE:
3955                     if (LOC)
3956                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
3957                     else {
3958                         for (value = 0; value < 256; value++)
3959                             if (!isSPACE(value))
3960                                 ANYOF_BITMAP_SET(ret, value);
3961                     }
3962                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
3963                     break;
3964                 case ANYOF_UPPER:
3965                     if (LOC)
3966                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
3967                     else {
3968                         for (value = 0; value < 256; value++)
3969                             if (isUPPER(value))
3970                                 ANYOF_BITMAP_SET(ret, value);
3971                     }
3972                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
3973                     break;
3974                 case ANYOF_NUPPER:
3975                     if (LOC)
3976                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
3977                     else {
3978                         for (value = 0; value < 256; value++)
3979                             if (!isUPPER(value))
3980                                 ANYOF_BITMAP_SET(ret, value);
3981                     }
3982                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
3983                     break;
3984                 case ANYOF_XDIGIT:
3985                     if (LOC)
3986                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
3987                     else {
3988                         for (value = 0; value < 256; value++)
3989                             if (isXDIGIT(value))
3990                                 ANYOF_BITMAP_SET(ret, value);
3991                     }
3992                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
3993                     break;
3994                 case ANYOF_NXDIGIT:
3995                     if (LOC)
3996                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
3997                     else {
3998                         for (value = 0; value < 256; value++)
3999                             if (!isXDIGIT(value))
4000                                 ANYOF_BITMAP_SET(ret, value);
4001                     }
4002                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
4003                     break;
4004                 default:
4005                     vFAIL("Invalid [::] class");
4006                     break;
4007                 }
4008                 if (LOC)
4009                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
4010                 continue;
4011             }
4012         } /* end of namedclass \blah */
4013
4014         if (range) {
4015             if (prevvalue > value) /* b-a */ {
4016                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
4017                               RExC_parse - rangebegin,
4018                               RExC_parse - rangebegin,
4019                               rangebegin);
4020                 range = 0; /* not a valid range */
4021             }
4022         }
4023         else {
4024             prevvalue = value; /* save the beginning of the range */
4025             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
4026                 RExC_parse[1] != ']') {
4027                 RExC_parse++;
4028
4029                 /* a bad range like \w-, [:word:]- ? */
4030                 if (namedclass > OOB_NAMEDCLASS) {
4031                     if (ckWARN(WARN_REGEXP))
4032                         vWARN4(RExC_parse,
4033                                "False [] range \"%*.*s\"",
4034                                RExC_parse - rangebegin,
4035                                RExC_parse - rangebegin,
4036                                rangebegin);
4037                     if (!SIZE_ONLY)
4038                         ANYOF_BITMAP_SET(ret, '-');
4039                 } else
4040                     range = 1;  /* yeah, it's a range! */
4041                 continue;       /* but do it the next time */
4042             }
4043         }
4044
4045         /* now is the next time */
4046         if (!SIZE_ONLY) {
4047             IV i;
4048
4049             if (prevvalue < 256) {
4050                 IV ceilvalue = value < 256 ? value : 255;
4051
4052 #ifdef EBCDIC
4053                 if ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
4054                     (isUPPER(prevvalue) && isUPPER(ceilvalue)))
4055                 {
4056                     if (isLOWER(prevvalue)) {
4057                         for (i = prevvalue; i <= ceilvalue; i++)
4058                             if (isLOWER(i))
4059                                 ANYOF_BITMAP_SET(ret, i);
4060                     } else {
4061                         for (i = prevvalue; i <= ceilvalue; i++)
4062                             if (isUPPER(i))
4063                                 ANYOF_BITMAP_SET(ret, i);
4064                     }
4065                 }
4066                 else
4067 #endif
4068                       for (i = prevvalue; i <= ceilvalue; i++)
4069                           ANYOF_BITMAP_SET(ret, i);
4070           }
4071           if (value > 255 || UTF) {
4072                 UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
4073                 UV natvalue      = NATIVE_TO_UNI(value);
4074
4075                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
4076                 if (prevnatvalue < natvalue) { /* what about > ? */
4077                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
4078                                    prevnatvalue, natvalue);
4079                 }
4080                 else if (prevnatvalue == natvalue) {
4081                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", natvalue);
4082                     if (FOLD) {
4083                          U8 tmpbuf [UTF8_MAXLEN+1];
4084                          U8 foldbuf[UTF8_MAXLEN_FOLD+1];
4085                          STRLEN foldlen;
4086                          UV f;
4087
4088                          uvchr_to_utf8(tmpbuf, natvalue);
4089                          to_utf8_fold(tmpbuf, foldbuf, &foldlen);
4090                          f = UNI_TO_NATIVE(utf8_to_uvchr(foldbuf, 0));
4091
4092                          /* If folding and foldable and a single
4093                           * character, insert also the folded version
4094                           * to the charclass. */
4095                          if (f != value) {
4096                               if (foldlen == UNISKIP(f))
4097                                   Perl_sv_catpvf(aTHX_ listsv,
4098                                                  "%04"UVxf"\n", f);
4099                               else {
4100                                   /* Any multicharacter foldings
4101                                    * require the following transform:
4102                                    * [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst)
4103                                    * where E folds into "pq" and F folds
4104                                    * into "rst", all other characters
4105                                    * fold to single characters.  We save
4106                                    * away these multicharacter foldings,
4107                                    * to be later saved as part of the
4108                                    * additional "s" data. */
4109                                   SV *sv;
4110
4111                                   if (!unicode_alternate)
4112                                       unicode_alternate = newAV();
4113                                   sv = newSVpvn((char*)foldbuf, foldlen);
4114                                   SvUTF8_on(sv);
4115                                   av_push(unicode_alternate, sv);
4116                               }
4117                          }
4118
4119                          /* If folding and the value is one of the Greek
4120                           * sigmas insert a few more sigmas to make the
4121                           * folding rules of the sigmas to work right.
4122                           * Note that not all the possible combinations
4123                           * are handled here: some of them are handled
4124                           * by the standard folding rules, and some of
4125                           * them (literal or EXACTF cases) are handled
4126                           * during runtime in regexec.c:S_find_byclass(). */
4127                          if (value == UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA) {
4128                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4129                                              (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA);
4130                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4131                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4132                          }
4133                          else if (value == UNICODE_GREEK_CAPITAL_LETTER_SIGMA)
4134                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4135                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4136                     }
4137                 }
4138             }
4139         }
4140
4141         range = 0; /* this range (if it was one) is done now */
4142     }
4143
4144     if (need_class) {
4145         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
4146         if (SIZE_ONLY)
4147             RExC_size += ANYOF_CLASS_ADD_SKIP;
4148         else
4149             RExC_emit += ANYOF_CLASS_ADD_SKIP;
4150     }
4151
4152     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4153     if (!SIZE_ONLY &&
4154          /* If the only flag is folding (plus possibly inversion). */
4155         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4156        ) {
4157         for (value = 0; value < 256; ++value) {
4158             if (ANYOF_BITMAP_TEST(ret, value)) {
4159                 IV fold = PL_fold[value];
4160
4161                 if (fold != value)
4162                     ANYOF_BITMAP_SET(ret, fold);
4163             }
4164         }
4165         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4166     }
4167
4168     /* optimize inverted simple patterns (e.g. [^a-z]) */
4169     if (!SIZE_ONLY && optimize_invert &&
4170         /* If the only flag is inversion. */
4171         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4172         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4173             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4174         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4175     }
4176
4177     if (!SIZE_ONLY) {
4178         AV *av = newAV();
4179         SV *rv;
4180
4181         /* The 0th element stores the character class description
4182          * in its textual form: used later (regexec.c:Perl_regclass_swatch())
4183          * to initialize the appropriate swash (which gets stored in
4184          * the 1st element), and also useful for dumping the regnode.
4185          * The 2nd element stores the multicharacter foldings,
4186          * used later (regexec.c:s_reginclasslen()). */
4187         av_store(av, 0, listsv);
4188         av_store(av, 1, NULL);
4189         av_store(av, 2, (SV*)unicode_alternate);
4190         rv = newRV_noinc((SV*)av);
4191         n = add_data(pRExC_state, 1, "s");
4192         RExC_rx->data->data[n] = (void*)rv;
4193         ARG_SET(ret, n);
4194     }
4195
4196     return ret;
4197 }
4198
4199 STATIC char*
4200 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4201 {
4202     char* retval = RExC_parse++;
4203
4204     for (;;) {
4205         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4206                 RExC_parse[2] == '#') {
4207             while (*RExC_parse && *RExC_parse != ')')
4208                 RExC_parse++;
4209             RExC_parse++;
4210             continue;
4211         }
4212         if (RExC_flags16 & PMf_EXTENDED) {
4213             if (isSPACE(*RExC_parse)) {
4214                 RExC_parse++;
4215                 continue;
4216             }
4217             else if (*RExC_parse == '#') {
4218                 while (*RExC_parse && *RExC_parse != '\n')
4219                     RExC_parse++;
4220                 RExC_parse++;
4221                 continue;
4222             }
4223         }
4224         return retval;
4225     }
4226 }
4227
4228 /*
4229 - reg_node - emit a node
4230 */
4231 STATIC regnode *                        /* Location. */
4232 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4233 {
4234     register regnode *ret;
4235     register regnode *ptr;
4236
4237     ret = RExC_emit;
4238     if (SIZE_ONLY) {
4239         SIZE_ALIGN(RExC_size);
4240         RExC_size += 1;
4241         return(ret);
4242     }
4243
4244     NODE_ALIGN_FILL(ret);
4245     ptr = ret;
4246     FILL_ADVANCE_NODE(ptr, op);
4247     if (RExC_offsets) {         /* MJD */
4248       MJD_OFFSET_DEBUG((stderr, "%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n",
4249               "reg_node", __LINE__,
4250               reg_name[op],
4251               RExC_emit - RExC_emit_start > RExC_offsets[0]
4252               ? "Overwriting end of array!\n" : "OK",
4253               RExC_emit - RExC_emit_start,
4254               RExC_parse - RExC_start,
4255               RExC_offsets[0]));
4256       Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4257     }
4258
4259     RExC_emit = ptr;
4260
4261     return(ret);
4262 }
4263
4264 /*
4265 - reganode - emit a node with an argument
4266 */
4267 STATIC regnode *                        /* Location. */
4268 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4269 {
4270     register regnode *ret;
4271     register regnode *ptr;
4272
4273     ret = RExC_emit;
4274     if (SIZE_ONLY) {
4275         SIZE_ALIGN(RExC_size);
4276         RExC_size += 2;
4277         return(ret);
4278     }
4279
4280     NODE_ALIGN_FILL(ret);
4281     ptr = ret;
4282     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4283     if (RExC_offsets) {         /* MJD */
4284       MJD_OFFSET_DEBUG((stderr, "%s: %s %u <- %u (max %u).\n",
4285               "reganode",
4286               RExC_emit - RExC_emit_start > RExC_offsets[0] ?
4287               "Overwriting end of array!\n" : "OK",
4288               RExC_emit - RExC_emit_start,
4289               RExC_parse - RExC_start,
4290               RExC_offsets[0]));
4291       Set_Cur_Node_Offset;
4292     }
4293
4294     RExC_emit = ptr;
4295
4296     return(ret);
4297 }
4298
4299 /*
4300 - reguni - emit (if appropriate) a Unicode character
4301 */
4302 STATIC void
4303 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4304 {
4305     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4306 }
4307
4308 /*
4309 - reginsert - insert an operator in front of already-emitted operand
4310 *
4311 * Means relocating the operand.
4312 */
4313 STATIC void
4314 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4315 {
4316     register regnode *src;
4317     register regnode *dst;
4318     register regnode *place;
4319     register int offset = regarglen[(U8)op];
4320
4321 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4322
4323     if (SIZE_ONLY) {
4324         RExC_size += NODE_STEP_REGNODE + offset;
4325         return;
4326     }
4327
4328     src = RExC_emit;
4329     RExC_emit += NODE_STEP_REGNODE + offset;
4330     dst = RExC_emit;
4331     while (src > opnd) {
4332         StructCopy(--src, --dst, regnode);
4333         if (RExC_offsets) {     /* MJD 20010112 */
4334           MJD_OFFSET_DEBUG((stderr, "%s: %s copy %u -> %u (max %u).\n",
4335                   "reg_insert",
4336                   dst - RExC_emit_start > RExC_offsets[0]
4337                   ? "Overwriting end of array!\n" : "OK",
4338                   src - RExC_emit_start,
4339                   dst - RExC_emit_start,
4340                   RExC_offsets[0]));
4341           Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4342           Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4343         }
4344     }
4345
4346
4347     place = opnd;               /* Op node, where operand used to be. */
4348     if (RExC_offsets) {         /* MJD */
4349       MJD_OFFSET_DEBUG((stderr, "%s: %s %u <- %u (max %u).\n",
4350               "reginsert",
4351               place - RExC_emit_start > RExC_offsets[0]
4352               ? "Overwriting end of array!\n" : "OK",
4353               place - RExC_emit_start,
4354               RExC_parse - RExC_start,
4355               RExC_offsets[0]));
4356       Set_Node_Offset(place, RExC_parse);
4357     }
4358     src = NEXTOPER(place);
4359     FILL_ADVANCE_NODE(place, op);
4360     Zero(src, offset, regnode);
4361 }
4362
4363 /*
4364 - regtail - set the next-pointer at the end of a node chain of p to val.
4365 */
4366 STATIC void
4367 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4368 {
4369     register regnode *scan;
4370     register regnode *temp;
4371
4372     if (SIZE_ONLY)
4373         return;
4374
4375     /* Find last node. */
4376     scan = p;
4377     for (;;) {
4378         temp = regnext(scan);
4379         if (temp == NULL)
4380             break;
4381         scan = temp;
4382     }
4383
4384     if (reg_off_by_arg[OP(scan)]) {
4385         ARG_SET(scan, val - scan);
4386     }
4387     else {
4388         NEXT_OFF(scan) = val - scan;
4389     }
4390 }
4391
4392 /*
4393 - regoptail - regtail on operand of first argument; nop if operandless
4394 */
4395 STATIC void
4396 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4397 {
4398     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4399     if (p == NULL || SIZE_ONLY)
4400         return;
4401     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4402         regtail(pRExC_state, NEXTOPER(p), val);
4403     }
4404     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4405         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4406     }
4407     else
4408         return;
4409 }
4410
4411 /*
4412  - regcurly - a little FSA that accepts {\d+,?\d*}
4413  */
4414 STATIC I32
4415 S_regcurly(pTHX_ register char *s)
4416 {
4417     if (*s++ != '{')
4418         return FALSE;
4419     if (!isDIGIT(*s))
4420         return FALSE;
4421     while (isDIGIT(*s))
4422         s++;
4423     if (*s == ',')
4424         s++;
4425     while (isDIGIT(*s))
4426         s++;
4427     if (*s != '}')
4428         return FALSE;
4429     return TRUE;
4430 }
4431
4432
4433 #ifdef DEBUGGING
4434
4435 STATIC regnode *
4436 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4437 {
4438     register U8 op = EXACT;     /* Arbitrary non-END op. */
4439     register regnode *next;
4440
4441     while (op != END && (!last || node < last)) {
4442         /* While that wasn't END last time... */
4443
4444         NODE_ALIGN(node);
4445         op = OP(node);
4446         if (op == CLOSE)
4447             l--;
4448         next = regnext(node);
4449         /* Where, what. */
4450         if (OP(node) == OPTIMIZED)
4451             goto after_print;
4452         regprop(sv, node);
4453         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4454                       (int)(2*l + 1), "", SvPVX(sv));
4455         if (next == NULL)               /* Next ptr. */
4456             PerlIO_printf(Perl_debug_log, "(0)");
4457         else
4458             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4459         (void)PerlIO_putc(Perl_debug_log, '\n');
4460       after_print:
4461         if (PL_regkind[(U8)op] == BRANCHJ) {
4462             register regnode *nnode = (OP(next) == LONGJMP
4463                                        ? regnext(next)
4464                                        : next);
4465             if (last && nnode > last)
4466                 nnode = last;
4467             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4468         }
4469         else if (PL_regkind[(U8)op] == BRANCH) {
4470             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4471         }
4472         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4473             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4474                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4475         }
4476         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4477             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4478                              next, sv, l + 1);
4479         }
4480         else if ( op == PLUS || op == STAR) {
4481             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4482         }
4483         else if (op == ANYOF) {
4484             /* arglen 1 + class block */
4485             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4486                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4487             node = NEXTOPER(node);
4488         }
4489         else if (PL_regkind[(U8)op] == EXACT) {
4490             /* Literal string, where present. */
4491             node += NODE_SZ_STR(node) - 1;
4492             node = NEXTOPER(node);
4493         }
4494         else {
4495             node = NEXTOPER(node);
4496             node += regarglen[(U8)op];
4497         }
4498         if (op == CURLYX || op == OPEN)
4499             l++;
4500         else if (op == WHILEM)
4501             l--;
4502     }
4503     return node;
4504 }
4505
4506 #endif  /* DEBUGGING */
4507
4508 /*
4509  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4510  */
4511 void
4512 Perl_regdump(pTHX_ regexp *r)
4513 {
4514 #ifdef DEBUGGING
4515     SV *sv = sv_newmortal();
4516
4517     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4518
4519     /* Header fields of interest. */
4520     if (r->anchored_substr)
4521         PerlIO_printf(Perl_debug_log,
4522                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4523                       PL_colors[0],
4524                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4525                       SvPVX(r->anchored_substr),
4526                       PL_colors[1],
4527                       SvTAIL(r->anchored_substr) ? "$" : "",
4528                       (IV)r->anchored_offset);
4529     if (r->float_substr)
4530         PerlIO_printf(Perl_debug_log,
4531                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4532                       PL_colors[0],
4533                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4534                       SvPVX(r->float_substr),
4535                       PL_colors[1],
4536                       SvTAIL(r->float_substr) ? "$" : "",
4537                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4538     if (r->check_substr)
4539         PerlIO_printf(Perl_debug_log,
4540                       r->check_substr == r->float_substr
4541                       ? "(checking floating" : "(checking anchored");
4542     if (r->reganch & ROPT_NOSCAN)
4543         PerlIO_printf(Perl_debug_log, " noscan");
4544     if (r->reganch & ROPT_CHECK_ALL)
4545         PerlIO_printf(Perl_debug_log, " isall");
4546     if (r->check_substr)
4547         PerlIO_printf(Perl_debug_log, ") ");
4548
4549     if (r->regstclass) {
4550         regprop(sv, r->regstclass);
4551         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4552     }
4553     if (r->reganch & ROPT_ANCH) {
4554         PerlIO_printf(Perl_debug_log, "anchored");
4555         if (r->reganch & ROPT_ANCH_BOL)
4556             PerlIO_printf(Perl_debug_log, "(BOL)");
4557         if (r->reganch & ROPT_ANCH_MBOL)
4558             PerlIO_printf(Perl_debug_log, "(MBOL)");
4559         if (r->reganch & ROPT_ANCH_SBOL)
4560             PerlIO_printf(Perl_debug_log, "(SBOL)");
4561         if (r->reganch & ROPT_ANCH_GPOS)
4562             PerlIO_printf(Perl_debug_log, "(GPOS)");
4563         PerlIO_putc(Perl_debug_log, ' ');
4564     }
4565     if (r->reganch & ROPT_GPOS_SEEN)
4566         PerlIO_printf(Perl_debug_log, "GPOS ");
4567     if (r->reganch & ROPT_SKIP)
4568         PerlIO_printf(Perl_debug_log, "plus ");
4569     if (r->reganch & ROPT_IMPLICIT)
4570         PerlIO_printf(Perl_debug_log, "implicit ");
4571     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4572     if (r->reganch & ROPT_EVAL_SEEN)
4573         PerlIO_printf(Perl_debug_log, "with eval ");
4574     PerlIO_printf(Perl_debug_log, "\n");
4575     if (r->offsets) {
4576       U32 i;
4577       U32 len = r->offsets[0];
4578       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4579       for (i = 1; i <= len; i++)
4580         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ",
4581                       (UV)r->offsets[i*2-1],
4582                       (UV)r->offsets[i*2]);
4583       PerlIO_printf(Perl_debug_log, "\n");
4584     }
4585 #endif  /* DEBUGGING */
4586 }
4587
4588 #ifdef DEBUGGING
4589
4590 STATIC void
4591 S_put_byte(pTHX_ SV *sv, int c)
4592 {
4593     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4594         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4595     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4596         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4597     else
4598         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4599 }
4600
4601 #endif  /* DEBUGGING */
4602
4603 /*
4604 - regprop - printable representation of opcode
4605 */
4606 void
4607 Perl_regprop(pTHX_ SV *sv, regnode *o)
4608 {
4609 #ifdef DEBUGGING
4610     register int k;
4611
4612     sv_setpvn(sv, "", 0);
4613     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4614         /* It would be nice to FAIL() here, but this may be called from
4615            regexec.c, and it would be hard to supply pRExC_state. */
4616         Perl_croak(aTHX_ "Corrupted regexp opcode");
4617     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4618
4619     k = PL_regkind[(U8)OP(o)];
4620
4621     if (k == EXACT) {
4622         SV *dsv = sv_2mortal(newSVpvn("", 0));
4623         /* Using is_utf8_string() is a crude hack but it may
4624          * be the best for now since we have no flag "this EXACTish
4625          * node was UTF-8" --jhi */
4626         bool do_utf8 = is_utf8_string((U8*)STRING(o), STR_LEN(o));
4627         char *s    = do_utf8 ?
4628           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60,
4629                          UNI_DISPLAY_REGEX) :
4630           STRING(o);
4631         int len = do_utf8 ?
4632           strlen(s) :
4633           STR_LEN(o);
4634         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4635                        PL_colors[0],
4636                        len, s,
4637                        PL_colors[1]);
4638     }
4639     else if (k == CURLY) {
4640         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4641             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4642         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4643     }
4644     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4645         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4646     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4647         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4648     else if (k == LOGICAL)
4649         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4650     else if (k == ANYOF) {
4651         int i, rangestart = -1;
4652         U8 flags = ANYOF_FLAGS(o);
4653         const char * const anyofs[] = { /* Should be syncronized with
4654                                          * ANYOF_ #xdefines in regcomp.h */
4655             "\\w",
4656             "\\W",
4657             "\\s",
4658             "\\S",
4659             "\\d",
4660             "\\D",
4661             "[:alnum:]",
4662             "[:^alnum:]",
4663             "[:alpha:]",
4664             "[:^alpha:]",
4665             "[:ascii:]",
4666             "[:^ascii:]",
4667             "[:ctrl:]",
4668             "[:^ctrl:]",
4669             "[:graph:]",
4670             "[:^graph:]",
4671             "[:lower:]",
4672             "[:^lower:]",
4673             "[:print:]",
4674             "[:^print:]",
4675             "[:punct:]",
4676             "[:^punct:]",
4677             "[:upper:]",
4678             "[:^upper:]",
4679             "[:xdigit:]",
4680             "[:^xdigit:]",
4681             "[:space:]",
4682             "[:^space:]",
4683             "[:blank:]",
4684             "[:^blank:]"
4685         };
4686
4687         if (flags & ANYOF_LOCALE)
4688             sv_catpv(sv, "{loc}");
4689         if (flags & ANYOF_FOLD)
4690             sv_catpv(sv, "{i}");
4691         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4692         if (flags & ANYOF_INVERT)
4693             sv_catpv(sv, "^");
4694         for (i = 0; i <= 256; i++) {
4695             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4696                 if (rangestart == -1)
4697                     rangestart = i;
4698             } else if (rangestart != -1) {
4699                 if (i <= rangestart + 3)
4700                     for (; rangestart < i; rangestart++)
4701                         put_byte(sv, rangestart);
4702                 else {
4703                     put_byte(sv, rangestart);
4704                     sv_catpv(sv, "-");
4705                     put_byte(sv, i - 1);
4706                 }
4707                 rangestart = -1;
4708             }
4709         }
4710
4711         if (o->flags & ANYOF_CLASS)
4712             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4713                 if (ANYOF_CLASS_TEST(o,i))
4714                     sv_catpv(sv, anyofs[i]);
4715
4716         if (flags & ANYOF_UNICODE)
4717             sv_catpv(sv, "{unicode}");
4718         else if (flags & ANYOF_UNICODE_ALL)
4719             sv_catpv(sv, "{unicode_all}");
4720
4721         {
4722             SV *lv;
4723             SV *sw = regclass_swash(o, FALSE, &lv, 0);
4724
4725             if (lv) {
4726                 if (sw) {
4727                     UV i;
4728                     U8 s[UTF8_MAXLEN+1];
4729
4730                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4731                         U8 *e = uvchr_to_utf8(s, i);
4732
4733                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4734                             if (rangestart == -1)
4735                                 rangestart = i;
4736                         } else if (rangestart != -1) {
4737                             U8 *p;
4738
4739                             if (i <= rangestart + 3)
4740                                 for (; rangestart < i; rangestart++) {
4741                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4742                                         put_byte(sv, *p);
4743                                 }
4744                             else {
4745                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4746                                     put_byte(sv, *p);
4747                                 sv_catpv(sv, "-");
4748                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4749                                         put_byte(sv, *p);
4750                                 }
4751                                 rangestart = -1;
4752                             }
4753                         }
4754
4755                     sv_catpv(sv, "..."); /* et cetera */
4756                 }
4757
4758                 {
4759                     char *s = savepv(SvPVX(lv));
4760                     char *origs = s;
4761
4762                     while(*s && *s != '\n') s++;
4763
4764                     if (*s == '\n') {
4765                         char *t = ++s;
4766
4767                         while (*s) {
4768                             if (*s == '\n')
4769                                 *s = ' ';
4770                             s++;
4771                         }
4772                         if (s[-1] == ' ')
4773                             s[-1] = 0;
4774
4775                         sv_catpv(sv, t);
4776                     }
4777
4778                     Safefree(origs);
4779                 }
4780             }
4781         }
4782
4783         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4784     }
4785     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4786         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4787 #endif  /* DEBUGGING */
4788 }
4789
4790 SV *
4791 Perl_re_intuit_string(pTHX_ regexp *prog)
4792 {                               /* Assume that RE_INTUIT is set */
4793     DEBUG_r(
4794         {   STRLEN n_a;
4795             char *s = SvPV(prog->check_substr,n_a);
4796
4797             if (!PL_colorset) reginitcolors();
4798             PerlIO_printf(Perl_debug_log,
4799                       "%sUsing REx substr:%s `%s%.60s%s%s'\n",
4800                       PL_colors[4],PL_colors[5],PL_colors[0],
4801                       s,
4802                       PL_colors[1],
4803                       (strlen(s) > 60 ? "..." : ""));
4804         } );
4805
4806     return prog->check_substr;
4807 }
4808
4809 void
4810 Perl_pregfree(pTHX_ struct regexp *r)
4811 {
4812 #ifdef DEBUGGING
4813     SV *dsv = PERL_DEBUG_PAD_ZERO(0);
4814 #endif
4815
4816     if (!r || (--r->refcnt > 0))
4817         return;
4818     DEBUG_r({
4819          char *s = pv_uni_display(dsv, (U8*)r->precomp, r->prelen, 60,
4820                                   UNI_DISPLAY_REGEX);
4821          int len = SvCUR(dsv);
4822          if (!PL_colorset)
4823               reginitcolors();
4824          PerlIO_printf(Perl_debug_log,
4825                        "%sFreeing REx:%s `%s%*.*s%s%s'\n",
4826                        PL_colors[4],PL_colors[5],PL_colors[0],
4827                        len, len, s,
4828                        PL_colors[1],
4829                        len > 60 ? "..." : "");
4830     });
4831
4832     if (r->precomp)
4833         Safefree(r->precomp);
4834     if (r->offsets)             /* 20010421 MJD */
4835         Safefree(r->offsets);
4836     if (RX_MATCH_COPIED(r))
4837         Safefree(r->subbeg);
4838     if (r->substrs) {
4839         if (r->anchored_substr)
4840             SvREFCNT_dec(r->anchored_substr);
4841         if (r->float_substr)
4842             SvREFCNT_dec(r->float_substr);
4843         Safefree(r->substrs);
4844     }
4845     if (r->data) {
4846         int n = r->data->count;
4847         AV* new_comppad = NULL;
4848         AV* old_comppad;
4849         SV** old_curpad;
4850
4851         while (--n >= 0) {
4852           /* If you add a ->what type here, update the comment in regcomp.h */
4853             switch (r->data->what[n]) {
4854             case 's':
4855                 SvREFCNT_dec((SV*)r->data->data[n]);
4856                 break;
4857             case 'f':
4858                 Safefree(r->data->data[n]);
4859                 break;
4860             case 'p':
4861                 new_comppad = (AV*)r->data->data[n];
4862                 break;
4863             case 'o':
4864                 if (new_comppad == NULL)
4865                     Perl_croak(aTHX_ "panic: pregfree comppad");
4866                 old_comppad = PL_comppad;
4867                 old_curpad = PL_curpad;
4868                 /* Watch out for global destruction's random ordering. */
4869                 if (SvTYPE(new_comppad) == SVt_PVAV) {
4870                     PL_comppad = new_comppad;
4871                     PL_curpad = AvARRAY(new_comppad);
4872                 }
4873                 else
4874                     PL_curpad = NULL;
4875
4876                 if (!OpREFCNT_dec((OP_4tree*)r->data->data[n])) {
4877                     op_free((OP_4tree*)r->data->data[n]);
4878                 }
4879
4880                 PL_comppad = old_comppad;
4881                 PL_curpad = old_curpad;
4882                 SvREFCNT_dec((SV*)new_comppad);
4883                 new_comppad = NULL;
4884                 break;
4885             case 'n':
4886                 break;
4887             default:
4888                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4889             }
4890         }
4891         Safefree(r->data->what);
4892         Safefree(r->data);
4893     }
4894     Safefree(r->startp);
4895     Safefree(r->endp);
4896     Safefree(r);
4897 }
4898
4899 /*
4900  - regnext - dig the "next" pointer out of a node
4901  *
4902  * [Note, when REGALIGN is defined there are two places in regmatch()
4903  * that bypass this code for speed.]
4904  */
4905 regnode *
4906 Perl_regnext(pTHX_ register regnode *p)
4907 {
4908     register I32 offset;
4909
4910     if (p == &PL_regdummy)
4911         return(NULL);
4912
4913     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
4914     if (offset == 0)
4915         return(NULL);
4916
4917     return(p+offset);
4918 }
4919
4920 STATIC void
4921 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
4922 {
4923     va_list args;
4924     STRLEN l1 = strlen(pat1);
4925     STRLEN l2 = strlen(pat2);
4926     char buf[512];
4927     SV *msv;
4928     char *message;
4929
4930     if (l1 > 510)
4931         l1 = 510;
4932     if (l1 + l2 > 510)
4933         l2 = 510 - l1;
4934     Copy(pat1, buf, l1 , char);
4935     Copy(pat2, buf + l1, l2 , char);
4936     buf[l1 + l2] = '\n';
4937     buf[l1 + l2 + 1] = '\0';
4938 #ifdef I_STDARG
4939     /* ANSI variant takes additional second argument */
4940     va_start(args, pat2);
4941 #else
4942     va_start(args);
4943 #endif
4944     msv = vmess(buf, &args);
4945     va_end(args);
4946     message = SvPV(msv,l1);
4947     if (l1 > 512)
4948         l1 = 512;
4949     Copy(message, buf, l1 , char);
4950     buf[l1] = '\0';                     /* Overwrite \n */
4951     Perl_croak(aTHX_ "%s", buf);
4952 }
4953
4954 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
4955
4956 void
4957 Perl_save_re_context(pTHX)
4958 {
4959 #if 0
4960     SAVEPPTR(RExC_precomp);             /* uncompiled string. */
4961     SAVEI32(RExC_npar);         /* () count. */
4962     SAVEI32(RExC_size);         /* Code size. */
4963     SAVEI16(RExC_flags16);              /* are we folding, multilining? */
4964     SAVEVPTR(RExC_rx);          /* from regcomp.c */
4965     SAVEI32(RExC_seen);         /* from regcomp.c */
4966     SAVEI32(RExC_sawback);              /* Did we see \1, ...? */
4967     SAVEI32(RExC_naughty);              /* How bad is this pattern? */
4968     SAVEVPTR(RExC_emit);                /* Code-emit pointer; &regdummy = don't */
4969     SAVEPPTR(RExC_end);         /* End of input for compile */
4970     SAVEPPTR(RExC_parse);               /* Input-scan pointer. */
4971 #endif
4972
4973     SAVEI32(PL_reg_flags);              /* from regexec.c */
4974     SAVEPPTR(PL_bostr);
4975     SAVEPPTR(PL_reginput);              /* String-input pointer. */
4976     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
4977     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
4978     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
4979     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
4980     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
4981     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
4982     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
4983     PL_reg_start_tmp = 0;
4984     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
4985     PL_reg_start_tmpl = 0;
4986     SAVEVPTR(PL_regdata);
4987     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
4988     SAVEI32(PL_regnarrate);             /* from regexec.c */
4989     SAVEVPTR(PL_regprogram);            /* from regexec.c */
4990     SAVEINT(PL_regindent);              /* from regexec.c */
4991     SAVEVPTR(PL_regcc);                 /* from regexec.c */
4992     SAVEVPTR(PL_curcop);
4993     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
4994     SAVEVPTR(PL_reg_re);                /* from regexec.c */
4995     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
4996     SAVESPTR(PL_reg_sv);                /* from regexec.c */
4997     SAVEI8(PL_reg_match_utf8);          /* from regexec.c */
4998     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
4999     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
5000     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
5001     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
5002     SAVEI32(PL_regnpar);                /* () count. */
5003     SAVEI32(PL_regsize);                /* from regexec.c */
5004 #ifdef DEBUGGING
5005     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
5006 #endif
5007 }
5008
5009 static void
5010 clear_re(pTHX_ void *r)
5011 {
5012     ReREFCNT_dec((regexp *)r);
5013 }
5014