regcomp.c

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