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                         && PL_curcop != &PL_compiling)
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 (PL_curcop == &PL_compiling)
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_Offset(ret, oregcomp_parse);
2515             Set_Node_Length(ret,  RExC_parse - oregcomp_parse + 2);
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 = 0;
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             goto defchar;
3060         }
3061         break;
3062
3063     case '#':
3064         if (RExC_flags & PMf_EXTENDED) {
3065             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
3066             if (RExC_parse < RExC_end)
3067                 goto tryagain;
3068         }
3069         /* FALL THROUGH */
3070
3071     default: {
3072             register STRLEN len;
3073             register UV ender;
3074             register char *p;
3075             char *oldp, *s;
3076             STRLEN numlen;
3077             STRLEN foldlen;
3078             U8 tmpbuf[UTF8_MAXLEN_FOLD+1], *foldbuf;
3079
3080             parse_start = RExC_parse - 1;
3081
3082             RExC_parse++;
3083
3084         defchar:
3085             ender = 0;
3086             ret = reg_node(pRExC_state,
3087                            (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
3088             s = STRING(ret);
3089             for (len = 0, p = RExC_parse - 1;
3090               len < 127 && p < RExC_end;
3091               len++)
3092             {
3093                 oldp = p;
3094
3095                 if (RExC_flags & PMf_EXTENDED)
3096                     p = regwhite(p, RExC_end);
3097                 switch (*p) {
3098                 case '^':
3099                 case '$':
3100                 case '.':
3101                 case '[':
3102                 case '(':
3103                 case ')':
3104                 case '|':
3105                     goto loopdone;
3106                 case '\\':
3107                     switch (*++p) {
3108                     case 'A':
3109                     case 'C':
3110                     case 'X':
3111                     case 'G':
3112                     case 'Z':
3113                     case 'z':
3114                     case 'w':
3115                     case 'W':
3116                     case 'b':
3117                     case 'B':
3118                     case 's':
3119                     case 'S':
3120                     case 'd':
3121                     case 'D':
3122                     case 'p':
3123                     case 'P':
3124                         --p;
3125                         goto loopdone;
3126                     case 'n':
3127                         ender = '\n';
3128                         p++;
3129                         break;
3130                     case 'r':
3131                         ender = '\r';
3132                         p++;
3133                         break;
3134                     case 't':
3135                         ender = '\t';
3136                         p++;
3137                         break;
3138                     case 'f':
3139                         ender = '\f';
3140                         p++;
3141                         break;
3142                     case 'e':
3143                           ender = ASCII_TO_NATIVE('\033');
3144                         p++;
3145                         break;
3146                     case 'a':
3147                           ender = ASCII_TO_NATIVE('\007');
3148                         p++;
3149                         break;
3150                     case 'x':
3151                         if (*++p == '{') {
3152                             char* e = strchr(p, '}');
3153
3154                             if (!e) {
3155                                 RExC_parse = p + 1;
3156                                 vFAIL("Missing right brace on \\x{}");
3157                             }
3158                             else {
3159                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3160                                     | PERL_SCAN_DISALLOW_PREFIX;
3161                                 numlen = e - p - 1;
3162                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3163                                 if (ender > 0xff)
3164                                     RExC_utf8 = 1;
3165                                 p = e + 1;
3166                             }
3167                         }
3168                         else {
3169                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3170                             numlen = 2;
3171                             ender = grok_hex(p, &numlen, &flags, NULL);
3172                             p += numlen;
3173                         }
3174                         break;
3175                     case 'c':
3176                         p++;
3177                         ender = UCHARAT(p++);
3178                         ender = toCTRL(ender);
3179                         break;
3180                     case '0': case '1': case '2': case '3':case '4':
3181                     case '5': case '6': case '7': case '8':case '9':
3182                         if (*p == '0' ||
3183                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3184                             I32 flags = 0;
3185                             numlen = 3;
3186                             ender = grok_oct(p, &numlen, &flags, NULL);
3187                             p += numlen;
3188                         }
3189                         else {
3190                             --p;
3191                             goto loopdone;
3192                         }
3193                         break;
3194                     case '\0':
3195                         if (p >= RExC_end)
3196                             FAIL("Trailing \\");
3197                         /* FALL THROUGH */
3198                     default:
3199                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3200                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3201                         goto normal_default;
3202                     }
3203                     break;
3204                 default:
3205                   normal_default:
3206                     if (UTF8_IS_START(*p) && UTF) {
3207                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3208                                                &numlen, 0);
3209                         p += numlen;
3210                     }
3211                     else
3212                         ender = *p++;
3213                     break;
3214                 }
3215                 if (RExC_flags & PMf_EXTENDED)
3216                     p = regwhite(p, RExC_end);
3217                 if (UTF && FOLD) {
3218                     /* Prime the casefolded buffer. */
3219                     ender = toFOLD_uni(ender, tmpbuf, &foldlen);
3220                 }
3221                 if (ISMULT2(p)) { /* Back off on ?+*. */
3222                     if (len)
3223                         p = oldp;
3224                     else if (UTF) {
3225                          STRLEN unilen;
3226
3227                          if (FOLD) {
3228                               /* Emit all the Unicode characters. */
3229                               for (foldbuf = tmpbuf;
3230                                    foldlen;
3231                                    foldlen -= numlen) {
3232                                    ender = utf8_to_uvchr(foldbuf, &numlen);
3233                                    if (numlen > 0) {
3234                                         reguni(pRExC_state, ender, s, &unilen);
3235                                         s       += unilen;
3236                                         len     += unilen;
3237                                         /* In EBCDIC the numlen
3238                                          * and unilen can differ. */
3239                                         foldbuf += numlen;
3240                                         if (numlen >= foldlen)
3241                                              break;
3242                                    }
3243                                    else
3244                                         break; /* "Can't happen." */
3245                               }
3246                          }
3247                          else {
3248                               reguni(pRExC_state, ender, s, &unilen);
3249                               if (unilen > 0) {
3250                                    s   += unilen;
3251                                    len += unilen;
3252                               }
3253                          }
3254                     }
3255                     else {
3256                         len++;
3257                         REGC((char)ender, s++);
3258                     }
3259                     break;
3260                 }
3261                 if (UTF) {
3262                      STRLEN unilen;
3263
3264                      if (FOLD) {
3265                           /* Emit all the Unicode characters. */
3266                           for (foldbuf = tmpbuf;
3267                                foldlen;
3268                                foldlen -= numlen) {
3269                                ender = utf8_to_uvchr(foldbuf, &numlen);
3270                                if (numlen > 0) {
3271                                     reguni(pRExC_state, ender, s, &unilen);
3272                                     len     += unilen;
3273                                     s       += unilen;
3274                                     /* In EBCDIC the numlen
3275                                      * and unilen can differ. */
3276                                     foldbuf += numlen;
3277                                     if (numlen >= foldlen)
3278                                          break;
3279                                }
3280                                else
3281                                     break;
3282                           }
3283                      }
3284                      else {
3285                           reguni(pRExC_state, ender, s, &unilen);
3286                           if (unilen > 0) {
3287                                s   += unilen;
3288                                len += unilen;
3289                           }
3290                      }
3291                      len--;
3292                 }
3293                 else
3294                     REGC((char)ender, s++);
3295             }
3296         loopdone:
3297             RExC_parse = p - 1;
3298             Set_Node_Cur_Length(ret); /* MJD */
3299             nextchar(pRExC_state);
3300             {
3301                 /* len is STRLEN which is unsigned, need to copy to signed */
3302                 IV iv = len;
3303                 if (iv < 0)
3304                     vFAIL("Internal disaster");
3305             }
3306             if (len > 0)
3307                 *flagp |= HASWIDTH;
3308             if (len == 1 && UNI_IS_INVARIANT(ender))
3309                 *flagp |= SIMPLE;
3310             if (!SIZE_ONLY)
3311                 STR_LEN(ret) = len;
3312             if (SIZE_ONLY)
3313                 RExC_size += STR_SZ(len);
3314             else
3315                 RExC_emit += STR_SZ(len);
3316         }
3317         break;
3318     }
3319
3320     /* If the encoding pragma is in effect recode the text of
3321      * any EXACT-kind nodes. */
3322     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3323         STRLEN oldlen = STR_LEN(ret);
3324         SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3325
3326         if (RExC_utf8)
3327             SvUTF8_on(sv);
3328         if (sv_utf8_downgrade(sv, TRUE)) {
3329             char *s       = sv_recode_to_utf8(sv, PL_encoding);
3330             STRLEN newlen = SvCUR(sv);
3331
3332             if (SvUTF8(sv))
3333                 RExC_utf8 = 1;
3334             if (!SIZE_ONLY) {
3335                 DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3336                                       (int)oldlen, STRING(ret),
3337                                       (int)newlen, s));
3338                 Copy(s, STRING(ret), newlen, char);
3339                 STR_LEN(ret) += newlen - oldlen;
3340                 RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3341             } else
3342                 RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3343         }
3344     }
3345
3346     return(ret);
3347 }
3348
3349 STATIC char *
3350 S_regwhite(pTHX_ char *p, char *e)
3351 {
3352     while (p < e) {
3353         if (isSPACE(*p))
3354             ++p;
3355         else if (*p == '#') {
3356             do {
3357                 p++;
3358             } while (p < e && *p != '\n');
3359         }
3360         else
3361             break;
3362     }
3363     return p;
3364 }
3365
3366 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3367    Character classes ([:foo:]) can also be negated ([:^foo:]).
3368    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3369    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3370    but trigger failures because they are currently unimplemented. */
3371
3372 #define POSIXCC_DONE(c)   ((c) == ':')
3373 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3374 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3375
3376 STATIC I32
3377 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3378 {
3379     char *posixcc = 0;
3380     I32 namedclass = OOB_NAMEDCLASS;
3381
3382     if (value == '[' && RExC_parse + 1 < RExC_end &&
3383         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3384         POSIXCC(UCHARAT(RExC_parse))) {
3385         char  c = UCHARAT(RExC_parse);
3386         char* s = RExC_parse++;
3387
3388         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3389             RExC_parse++;
3390         if (RExC_parse == RExC_end)
3391             /* Grandfather lone [:, [=, [. */
3392             RExC_parse = s;
3393         else {
3394             char* t = RExC_parse++; /* skip over the c */
3395
3396             if (UCHARAT(RExC_parse) == ']') {
3397                 RExC_parse++; /* skip over the ending ] */
3398                 posixcc = s + 1;
3399                 if (*s == ':') {
3400                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3401                     I32 skip = 5; /* the most common skip */
3402
3403                     switch (*posixcc) {
3404                     case 'a':
3405                         if (strnEQ(posixcc, "alnum", 5))
3406                             namedclass =
3407                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3408                         else if (strnEQ(posixcc, "alpha", 5))
3409                             namedclass =
3410                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3411                         else if (strnEQ(posixcc, "ascii", 5))
3412                             namedclass =
3413                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3414                         break;
3415                     case 'b':
3416                         if (strnEQ(posixcc, "blank", 5))
3417                             namedclass =
3418                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3419                         break;
3420                     case 'c':
3421                         if (strnEQ(posixcc, "cntrl", 5))
3422                             namedclass =
3423                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3424                         break;
3425                     case 'd':
3426                         if (strnEQ(posixcc, "digit", 5))
3427                             namedclass =
3428                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3429                         break;
3430                     case 'g':
3431                         if (strnEQ(posixcc, "graph", 5))
3432                             namedclass =
3433                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3434                         break;
3435                     case 'l':
3436                         if (strnEQ(posixcc, "lower", 5))
3437                             namedclass =
3438                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3439                         break;
3440                     case 'p':
3441                         if (strnEQ(posixcc, "print", 5))
3442                             namedclass =
3443                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3444                         else if (strnEQ(posixcc, "punct", 5))
3445                             namedclass =
3446                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3447                         break;
3448                     case 's':
3449                         if (strnEQ(posixcc, "space", 5))
3450                             namedclass =
3451                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3452                         break;
3453                     case 'u':
3454                         if (strnEQ(posixcc, "upper", 5))
3455                             namedclass =
3456                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3457                         break;
3458                     case 'w': /* this is not POSIX, this is the Perl \w */
3459                         if (strnEQ(posixcc, "word", 4)) {
3460                             namedclass =
3461                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3462                             skip = 4;
3463                         }
3464                         break;
3465                     case 'x':
3466                         if (strnEQ(posixcc, "xdigit", 6)) {
3467                             namedclass =
3468                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3469                             skip = 6;
3470                         }
3471                         break;
3472                     }
3473                     if (namedclass == OOB_NAMEDCLASS ||
3474                         posixcc[skip] != ':' ||
3475                         posixcc[skip+1] != ']')
3476                     {
3477                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3478                                       t - s - 1, s + 1);
3479                     }
3480                 } else if (!SIZE_ONLY) {
3481                     /* [[=foo=]] and [[.foo.]] are still future. */
3482
3483                     /* adjust RExC_parse so the warning shows after
3484                        the class closes */
3485                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3486                         RExC_parse++;
3487                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3488                 }
3489             } else {
3490                 /* Maternal grandfather:
3491                  * "[:" ending in ":" but not in ":]" */
3492                 RExC_parse = s;
3493             }
3494         }
3495     }
3496
3497     return namedclass;
3498 }
3499
3500 STATIC void
3501 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3502 {
3503     if (!SIZE_ONLY && POSIXCC(UCHARAT(RExC_parse))) {
3504         char *s = RExC_parse;
3505         char  c = *s++;
3506
3507         while(*s && isALNUM(*s))
3508             s++;
3509         if (*s && c == *s && s[1] == ']') {
3510             if (ckWARN(WARN_REGEXP))
3511                 vWARN3(s+2,
3512                         "POSIX syntax [%c %c] belongs inside character classes",
3513                         c, c);
3514
3515             /* [[=foo=]] and [[.foo.]] are still future. */
3516             if (POSIXCC_NOTYET(c)) {
3517                 /* adjust RExC_parse so the error shows after
3518                    the class closes */
3519                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3520                     ;
3521                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3522             }
3523         }
3524     }
3525 }
3526
3527 STATIC regnode *
3528 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3529 {
3530     register UV value;
3531     register UV nextvalue;
3532     register IV prevvalue = OOB_UNICODE;
3533     register IV range = 0;
3534     register regnode *ret;
3535     STRLEN numlen;
3536     IV namedclass;
3537     char *rangebegin = 0;
3538     bool need_class = 0;
3539     SV *listsv = Nullsv;
3540     register char *e;
3541     UV n;
3542     bool optimize_invert   = TRUE;
3543     AV* unicode_alternate  = 0;
3544 #ifdef EBCDIC
3545     UV literal_endpoint = 0;
3546 #endif
3547
3548     ret = reganode(pRExC_state, ANYOF, 0);
3549
3550     if (!SIZE_ONLY)
3551         ANYOF_FLAGS(ret) = 0;
3552
3553     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3554         RExC_naughty++;
3555         RExC_parse++;
3556         if (!SIZE_ONLY)
3557             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3558     }
3559
3560     if (SIZE_ONLY)
3561         RExC_size += ANYOF_SKIP;
3562     else {
3563         RExC_emit += ANYOF_SKIP;
3564         if (FOLD)
3565             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3566         if (LOC)
3567             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3568         ANYOF_BITMAP_ZERO(ret);
3569         listsv = newSVpvn("# comment\n", 10);
3570     }
3571
3572     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3573
3574     if (!SIZE_ONLY && POSIXCC(nextvalue))
3575         checkposixcc(pRExC_state);
3576
3577     /* allow 1st char to be ] (allowing it to be - is dealt with later) */
3578     if (UCHARAT(RExC_parse) == ']')
3579         goto charclassloop;
3580
3581     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3582
3583     charclassloop:
3584
3585         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3586
3587         if (!range)
3588             rangebegin = RExC_parse;
3589         if (UTF) {
3590             value = utf8n_to_uvchr((U8*)RExC_parse,
3591                                    RExC_end - RExC_parse,
3592                                    &numlen, 0);
3593             RExC_parse += numlen;
3594         }
3595         else
3596             value = UCHARAT(RExC_parse++);
3597         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3598         if (value == '[' && POSIXCC(nextvalue))
3599             namedclass = regpposixcc(pRExC_state, value);
3600         else if (value == '\\') {
3601             if (UTF) {
3602                 value = utf8n_to_uvchr((U8*)RExC_parse,
3603                                    RExC_end - RExC_parse,
3604                                    &numlen, 0);
3605                 RExC_parse += numlen;
3606             }
3607             else
3608                 value = UCHARAT(RExC_parse++);
3609             /* Some compilers cannot handle switching on 64-bit integer
3610              * values, therefore value cannot be an UV.  Yes, this will
3611              * be a problem later if we want switch on Unicode.
3612              * A similar issue a little bit later when switching on
3613              * namedclass. --jhi */
3614             switch ((I32)value) {
3615             case 'w':   namedclass = ANYOF_ALNUM;       break;
3616             case 'W':   namedclass = ANYOF_NALNUM;      break;
3617             case 's':   namedclass = ANYOF_SPACE;       break;
3618             case 'S':   namedclass = ANYOF_NSPACE;      break;
3619             case 'd':   namedclass = ANYOF_DIGIT;       break;
3620             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3621             case 'p':
3622             case 'P':
3623                 if (RExC_parse >= RExC_end)
3624                     vFAIL2("Empty \\%c{}", (U8)value);
3625                 if (*RExC_parse == '{') {
3626                     U8 c = (U8)value;
3627                     e = strchr(RExC_parse++, '}');
3628                     if (!e)
3629                         vFAIL2("Missing right brace on \\%c{}", c);
3630                     while (isSPACE(UCHARAT(RExC_parse)))
3631                         RExC_parse++;
3632                     if (e == RExC_parse)
3633                         vFAIL2("Empty \\%c{}", c);
3634                     n = e - RExC_parse;
3635                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3636                         n--;
3637                 }
3638                 else {
3639                     e = RExC_parse;
3640                     n = 1;
3641                 }
3642                 if (!SIZE_ONLY) {
3643                     if (UCHARAT(RExC_parse) == '^') {
3644                          RExC_parse++;
3645                          n--;
3646                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3647                          while (isSPACE(UCHARAT(RExC_parse))) {
3648                               RExC_parse++;
3649                               n--;
3650                          }
3651                     }
3652                     if (value == 'p')
3653                          Perl_sv_catpvf(aTHX_ listsv,
3654                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3655                     else
3656                          Perl_sv_catpvf(aTHX_ listsv,
3657                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3658                 }
3659                 RExC_parse = e + 1;
3660                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3661                 continue;
3662             case 'n':   value = '\n';                   break;
3663             case 'r':   value = '\r';                   break;
3664             case 't':   value = '\t';                   break;
3665             case 'f':   value = '\f';                   break;
3666             case 'b':   value = '\b';                   break;
3667             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3668             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3669             case 'x':
3670                 if (*RExC_parse == '{') {
3671                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3672                         | PERL_SCAN_DISALLOW_PREFIX;
3673                     e = strchr(RExC_parse++, '}');
3674                     if (!e)
3675                         vFAIL("Missing right brace on \\x{}");
3676
3677                     numlen = e - RExC_parse;
3678                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3679                     RExC_parse = e + 1;
3680                 }
3681                 else {
3682                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3683                     numlen = 2;
3684                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3685                     RExC_parse += numlen;
3686                 }
3687                 break;
3688             case 'c':
3689                 value = UCHARAT(RExC_parse++);
3690                 value = toCTRL(value);
3691                 break;
3692             case '0': case '1': case '2': case '3': case '4':
3693             case '5': case '6': case '7': case '8': case '9':
3694             {
3695                 I32 flags = 0;
3696                 numlen = 3;
3697                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3698                 RExC_parse += numlen;
3699                 break;
3700             }
3701             default:
3702                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3703                     vWARN2(RExC_parse,
3704                            "Unrecognized escape \\%c in character class passed through",
3705                            (int)value);
3706                 break;
3707             }
3708         } /* end of \blah */
3709 #ifdef EBCDIC
3710         else
3711             literal_endpoint++;
3712 #endif
3713
3714         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3715
3716             if (!SIZE_ONLY && !need_class)
3717                 ANYOF_CLASS_ZERO(ret);
3718
3719             need_class = 1;
3720
3721             /* a bad range like a-\d, a-[:digit:] ? */
3722             if (range) {
3723                 if (!SIZE_ONLY) {
3724                     if (ckWARN(WARN_REGEXP))
3725                         vWARN4(RExC_parse,
3726                                "False [] range \"%*.*s\"",
3727                                RExC_parse - rangebegin,
3728                                RExC_parse - rangebegin,
3729                                rangebegin);
3730                     if (prevvalue < 256) {
3731                         ANYOF_BITMAP_SET(ret, prevvalue);
3732                         ANYOF_BITMAP_SET(ret, '-');
3733                     }
3734                     else {
3735                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3736                         Perl_sv_catpvf(aTHX_ listsv,
3737                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3738                     }
3739                 }
3740
3741                 range = 0; /* this was not a true range */
3742             }
3743
3744             if (!SIZE_ONLY) {
3745                 if (namedclass > OOB_NAMEDCLASS)
3746                     optimize_invert = FALSE;
3747                 /* Possible truncation here but in some 64-bit environments
3748                  * the compiler gets heartburn about switch on 64-bit values.
3749                  * A similar issue a little earlier when switching on value.
3750                  * --jhi */
3751                 switch ((I32)namedclass) {
3752                 case ANYOF_ALNUM:
3753                     if (LOC)
3754                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3755                     else {
3756                         for (value = 0; value < 256; value++)
3757                             if (isALNUM(value))
3758                                 ANYOF_BITMAP_SET(ret, value);
3759                     }
3760                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");
3761                     break;
3762                 case ANYOF_NALNUM:
3763                     if (LOC)
3764                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3765                     else {
3766                         for (value = 0; value < 256; value++)
3767                             if (!isALNUM(value))
3768                                 ANYOF_BITMAP_SET(ret, value);
3769                     }
3770                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3771                     break;
3772                 case ANYOF_ALNUMC:
3773                     if (LOC)
3774                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3775                     else {
3776                         for (value = 0; value < 256; value++)
3777                             if (isALNUMC(value))
3778                                 ANYOF_BITMAP_SET(ret, value);
3779                     }
3780                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3781                     break;
3782                 case ANYOF_NALNUMC:
3783                     if (LOC)
3784                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3785                     else {
3786                         for (value = 0; value < 256; value++)
3787                             if (!isALNUMC(value))
3788                                 ANYOF_BITMAP_SET(ret, value);
3789                     }
3790                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3791                     break;
3792                 case ANYOF_ALPHA:
3793                     if (LOC)
3794                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3795                     else {
3796                         for (value = 0; value < 256; value++)
3797                             if (isALPHA(value))
3798                                 ANYOF_BITMAP_SET(ret, value);
3799                     }
3800                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3801                     break;
3802                 case ANYOF_NALPHA:
3803                     if (LOC)
3804                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3805                     else {
3806                         for (value = 0; value < 256; value++)
3807                             if (!isALPHA(value))
3808                                 ANYOF_BITMAP_SET(ret, value);
3809                     }
3810                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3811                     break;
3812                 case ANYOF_ASCII:
3813                     if (LOC)
3814                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3815                     else {
3816 #ifndef EBCDIC
3817                         for (value = 0; value < 128; value++)
3818                             ANYOF_BITMAP_SET(ret, value);
3819 #else  /* EBCDIC */
3820                         for (value = 0; value < 256; value++) {
3821                             if (isASCII(value))
3822                                 ANYOF_BITMAP_SET(ret, value);
3823                         }
3824 #endif /* EBCDIC */
3825                     }
3826                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3827                     break;
3828                 case ANYOF_NASCII:
3829                     if (LOC)
3830                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3831                     else {
3832 #ifndef EBCDIC
3833                         for (value = 128; value < 256; value++)
3834                             ANYOF_BITMAP_SET(ret, value);
3835 #else  /* EBCDIC */
3836                         for (value = 0; value < 256; value++) {
3837                             if (!isASCII(value))
3838                                 ANYOF_BITMAP_SET(ret, value);
3839                         }
3840 #endif /* EBCDIC */
3841                     }
3842                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3843                     break;
3844                 case ANYOF_BLANK:
3845                     if (LOC)
3846                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3847                     else {
3848                         for (value = 0; value < 256; value++)
3849                             if (isBLANK(value))
3850                                 ANYOF_BITMAP_SET(ret, value);
3851                     }
3852                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3853                     break;
3854                 case ANYOF_NBLANK:
3855                     if (LOC)
3856                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3857                     else {
3858                         for (value = 0; value < 256; value++)
3859                             if (!isBLANK(value))
3860                                 ANYOF_BITMAP_SET(ret, value);
3861                     }
3862                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3863                     break;
3864                 case ANYOF_CNTRL:
3865                     if (LOC)
3866                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3867                     else {
3868                         for (value = 0; value < 256; value++)
3869                             if (isCNTRL(value))
3870                                 ANYOF_BITMAP_SET(ret, value);
3871                     }
3872                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3873                     break;
3874                 case ANYOF_NCNTRL:
3875                     if (LOC)
3876                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3877                     else {
3878                         for (value = 0; value < 256; value++)
3879                             if (!isCNTRL(value))
3880                                 ANYOF_BITMAP_SET(ret, value);
3881                     }
3882                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3883                     break;
3884                 case ANYOF_DIGIT:
3885                     if (LOC)
3886                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3887                     else {
3888                         /* consecutive digits assumed */
3889                         for (value = '0'; value <= '9'; value++)
3890                             ANYOF_BITMAP_SET(ret, value);
3891                     }
3892                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3893                     break;
3894                 case ANYOF_NDIGIT:
3895                     if (LOC)
3896                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3897                     else {
3898                         /* consecutive digits assumed */
3899                         for (value = 0; value < '0'; value++)
3900                             ANYOF_BITMAP_SET(ret, value);
3901                         for (value = '9' + 1; value < 256; value++)
3902                             ANYOF_BITMAP_SET(ret, value);
3903                     }
3904                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3905                     break;
3906                 case ANYOF_GRAPH:
3907                     if (LOC)
3908                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3909                     else {
3910                         for (value = 0; value < 256; value++)
3911                             if (isGRAPH(value))
3912                                 ANYOF_BITMAP_SET(ret, value);
3913                     }
3914                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3915                     break;
3916                 case ANYOF_NGRAPH:
3917                     if (LOC)
3918                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3919                     else {
3920                         for (value = 0; value < 256; value++)
3921                             if (!isGRAPH(value))
3922                                 ANYOF_BITMAP_SET(ret, value);
3923                     }
3924                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3925                     break;
3926                 case ANYOF_LOWER:
3927                     if (LOC)
3928                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3929                     else {
3930                         for (value = 0; value < 256; value++)
3931                             if (isLOWER(value))
3932                                 ANYOF_BITMAP_SET(ret, value);
3933                     }
3934                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3935                     break;
3936                 case ANYOF_NLOWER:
3937                     if (LOC)
3938                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3939                     else {
3940                         for (value = 0; value < 256; value++)
3941                             if (!isLOWER(value))
3942                                 ANYOF_BITMAP_SET(ret, value);
3943                     }
3944                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3945                     break;
3946                 case ANYOF_PRINT:
3947                     if (LOC)
3948                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3949                     else {
3950                         for (value = 0; value < 256; value++)
3951                             if (isPRINT(value))
3952                                 ANYOF_BITMAP_SET(ret, value);
3953                     }
3954                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3955                     break;
3956                 case ANYOF_NPRINT:
3957                     if (LOC)
3958                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3959                     else {
3960                         for (value = 0; value < 256; value++)
3961                             if (!isPRINT(value))
3962                                 ANYOF_BITMAP_SET(ret, value);
3963                     }
3964                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3965                     break;
3966                 case ANYOF_PSXSPC:
3967                     if (LOC)
3968                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3969                     else {
3970                         for (value = 0; value < 256; value++)
3971                             if (isPSXSPC(value))
3972                                 ANYOF_BITMAP_SET(ret, value);
3973                     }
3974                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3975                     break;
3976                 case ANYOF_NPSXSPC:
3977                     if (LOC)
3978                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3979                     else {
3980                         for (value = 0; value < 256; value++)
3981                             if (!isPSXSPC(value))
3982                                 ANYOF_BITMAP_SET(ret, value);
3983                     }
3984                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3985                     break;
3986                 case ANYOF_PUNCT:
3987                     if (LOC)
3988                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3989                     else {
3990                         for (value = 0; value < 256; value++)
3991                             if (isPUNCT(value))
3992                                 ANYOF_BITMAP_SET(ret, value);
3993                     }
3994                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3995                     break;
3996                 case ANYOF_NPUNCT:
3997                     if (LOC)
3998                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
3999                     else {
4000                         for (value = 0; value < 256; value++)
4001                             if (!isPUNCT(value))
4002                                 ANYOF_BITMAP_SET(ret, value);
4003                     }
4004                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
4005                     break;
4006                 case ANYOF_SPACE:
4007                     if (LOC)
4008                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
4009                     else {
4010                         for (value = 0; value < 256; value++)
4011                             if (isSPACE(value))
4012                                 ANYOF_BITMAP_SET(ret, value);
4013                     }
4014                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
4015                     break;
4016                 case ANYOF_NSPACE:
4017                     if (LOC)
4018                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
4019                     else {
4020                         for (value = 0; value < 256; value++)
4021                             if (!isSPACE(value))
4022                                 ANYOF_BITMAP_SET(ret, value);
4023                     }
4024                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
4025                     break;
4026                 case ANYOF_UPPER:
4027                     if (LOC)
4028                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
4029                     else {
4030                         for (value = 0; value < 256; value++)
4031                             if (isUPPER(value))
4032                                 ANYOF_BITMAP_SET(ret, value);
4033                     }
4034                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
4035                     break;
4036                 case ANYOF_NUPPER:
4037                     if (LOC)
4038                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
4039                     else {
4040                         for (value = 0; value < 256; value++)
4041                             if (!isUPPER(value))
4042                                 ANYOF_BITMAP_SET(ret, value);
4043                     }
4044                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
4045                     break;
4046                 case ANYOF_XDIGIT:
4047                     if (LOC)
4048                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
4049                     else {
4050                         for (value = 0; value < 256; value++)
4051                             if (isXDIGIT(value))
4052                                 ANYOF_BITMAP_SET(ret, value);
4053                     }
4054                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
4055                     break;
4056                 case ANYOF_NXDIGIT:
4057                     if (LOC)
4058                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
4059                     else {
4060                         for (value = 0; value < 256; value++)
4061                             if (!isXDIGIT(value))
4062                                 ANYOF_BITMAP_SET(ret, value);
4063                     }
4064                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
4065                     break;
4066                 default:
4067                     vFAIL("Invalid [::] class");
4068                     break;
4069                 }
4070                 if (LOC)
4071                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
4072                 continue;
4073             }
4074         } /* end of namedclass \blah */
4075
4076         if (range) {
4077             if (prevvalue > (IV)value) /* b-a */ {
4078                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
4079                               RExC_parse - rangebegin,
4080                               RExC_parse - rangebegin,
4081                               rangebegin);
4082                 range = 0; /* not a valid range */
4083             }
4084         }
4085         else {
4086             prevvalue = value; /* save the beginning of the range */
4087             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
4088                 RExC_parse[1] != ']') {
4089                 RExC_parse++;
4090
4091                 /* a bad range like \w-, [:word:]- ? */
4092                 if (namedclass > OOB_NAMEDCLASS) {
4093                     if (ckWARN(WARN_REGEXP))
4094                         vWARN4(RExC_parse,
4095                                "False [] range \"%*.*s\"",
4096                                RExC_parse - rangebegin,
4097                                RExC_parse - rangebegin,
4098                                rangebegin);
4099                     if (!SIZE_ONLY)
4100                         ANYOF_BITMAP_SET(ret, '-');
4101                 } else
4102                     range = 1;  /* yeah, it's a range! */
4103                 continue;       /* but do it the next time */
4104             }
4105         }
4106
4107         /* now is the next time */
4108         if (!SIZE_ONLY) {
4109             IV i;
4110
4111             if (prevvalue < 256) {
4112                 IV ceilvalue = value < 256 ? value : 255;
4113
4114 #ifdef EBCDIC
4115                 /* In EBCDIC [\x89-\x91] should include
4116                  * the \x8e but [i-j] should not. */
4117                 if (literal_endpoint == 2 &&
4118                     ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
4119                      (isUPPER(prevvalue) && isUPPER(ceilvalue))))
4120                 {
4121                     if (isLOWER(prevvalue)) {
4122                         for (i = prevvalue; i <= ceilvalue; i++)
4123                             if (isLOWER(i))
4124                                 ANYOF_BITMAP_SET(ret, i);
4125                     } else {
4126                         for (i = prevvalue; i <= ceilvalue; i++)
4127                             if (isUPPER(i))
4128                                 ANYOF_BITMAP_SET(ret, i);
4129                     }
4130                 }
4131                 else
4132 #endif
4133                       for (i = prevvalue; i <= ceilvalue; i++)
4134                           ANYOF_BITMAP_SET(ret, i);
4135           }
4136           if (value > 255 || UTF) {
4137                 UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
4138                 UV natvalue      = NATIVE_TO_UNI(value);
4139
4140                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
4141                 if (prevnatvalue < natvalue) { /* what about > ? */
4142                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
4143                                    prevnatvalue, natvalue);
4144                 }
4145                 else if (prevnatvalue == natvalue) {
4146                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", natvalue);
4147                     if (FOLD) {
4148                          U8 foldbuf[UTF8_MAXLEN_FOLD+1];
4149                          STRLEN foldlen;
4150                          UV f = to_uni_fold(natvalue, foldbuf, &foldlen);
4151
4152                          /* If folding and foldable and a single
4153                           * character, insert also the folded version
4154                           * to the charclass. */
4155                          if (f != value) {
4156                               if (foldlen == (STRLEN)UNISKIP(f))
4157                                   Perl_sv_catpvf(aTHX_ listsv,
4158                                                  "%04"UVxf"\n", f);
4159                               else {
4160                                   /* Any multicharacter foldings
4161                                    * require the following transform:
4162                                    * [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst)
4163                                    * where E folds into "pq" and F folds
4164                                    * into "rst", all other characters
4165                                    * fold to single characters.  We save
4166                                    * away these multicharacter foldings,
4167                                    * to be later saved as part of the
4168                                    * additional "s" data. */
4169                                   SV *sv;
4170
4171                                   if (!unicode_alternate)
4172                                       unicode_alternate = newAV();
4173                                   sv = newSVpvn((char*)foldbuf, foldlen);
4174                                   SvUTF8_on(sv);
4175                                   av_push(unicode_alternate, sv);
4176                               }
4177                          }
4178
4179                          /* If folding and the value is one of the Greek
4180                           * sigmas insert a few more sigmas to make the
4181                           * folding rules of the sigmas to work right.
4182                           * Note that not all the possible combinations
4183                           * are handled here: some of them are handled
4184                           * by the standard folding rules, and some of
4185                           * them (literal or EXACTF cases) are handled
4186                           * during runtime in regexec.c:S_find_byclass(). */
4187                          if (value == UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA) {
4188                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4189                                              (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA);
4190                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4191                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4192                          }
4193                          else if (value == UNICODE_GREEK_CAPITAL_LETTER_SIGMA)
4194                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4195                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4196                     }
4197                 }
4198             }
4199 #ifdef EBCDIC
4200             literal_endpoint = 0;
4201 #endif
4202         }
4203
4204         range = 0; /* this range (if it was one) is done now */
4205     }
4206
4207     if (need_class) {
4208         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
4209         if (SIZE_ONLY)
4210             RExC_size += ANYOF_CLASS_ADD_SKIP;
4211         else
4212             RExC_emit += ANYOF_CLASS_ADD_SKIP;
4213     }
4214
4215     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4216     if (!SIZE_ONLY &&
4217          /* If the only flag is folding (plus possibly inversion). */
4218         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4219        ) {
4220         for (value = 0; value < 256; ++value) {
4221             if (ANYOF_BITMAP_TEST(ret, value)) {
4222                 UV fold = PL_fold[value];
4223
4224                 if (fold != value)
4225                     ANYOF_BITMAP_SET(ret, fold);
4226             }
4227         }
4228         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4229     }
4230
4231     /* optimize inverted simple patterns (e.g. [^a-z]) */
4232     if (!SIZE_ONLY && optimize_invert &&
4233         /* If the only flag is inversion. */
4234         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4235         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4236             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4237         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4238     }
4239
4240     if (!SIZE_ONLY) {
4241         AV *av = newAV();
4242         SV *rv;
4243
4244         /* The 0th element stores the character class description
4245          * in its textual form: used later (regexec.c:Perl_regclass_swash())
4246          * to initialize the appropriate swash (which gets stored in
4247          * the 1st element), and also useful for dumping the regnode.
4248          * The 2nd element stores the multicharacter foldings,
4249          * used later (regexec.c:S_reginclass()). */
4250         av_store(av, 0, listsv);
4251         av_store(av, 1, NULL);
4252         av_store(av, 2, (SV*)unicode_alternate);
4253         rv = newRV_noinc((SV*)av);
4254         n = add_data(pRExC_state, 1, "s");
4255         RExC_rx->data->data[n] = (void*)rv;
4256         ARG_SET(ret, n);
4257     }
4258
4259     return ret;
4260 }
4261
4262 STATIC char*
4263 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4264 {
4265     char* retval = RExC_parse++;
4266
4267     for (;;) {
4268         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4269                 RExC_parse[2] == '#') {
4270             while (*RExC_parse != ')') {
4271                 if (RExC_parse == RExC_end)
4272                     FAIL("Sequence (?#... not terminated");
4273                 RExC_parse++;
4274             }
4275             RExC_parse++;
4276             continue;
4277         }
4278         if (RExC_flags & PMf_EXTENDED) {
4279             if (isSPACE(*RExC_parse)) {
4280                 RExC_parse++;
4281                 continue;
4282             }
4283             else if (*RExC_parse == '#') {
4284                 while (RExC_parse < RExC_end)
4285                     if (*RExC_parse++ == '\n') break;
4286                 continue;
4287             }
4288         }
4289         return retval;
4290     }
4291 }
4292
4293 /*
4294 - reg_node - emit a node
4295 */
4296 STATIC regnode *                        /* Location. */
4297 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4298 {
4299     register regnode *ret;
4300     register regnode *ptr;
4301
4302     ret = RExC_emit;
4303     if (SIZE_ONLY) {
4304         SIZE_ALIGN(RExC_size);
4305         RExC_size += 1;
4306         return(ret);
4307     }
4308
4309     NODE_ALIGN_FILL(ret);
4310     ptr = ret;
4311     FILL_ADVANCE_NODE(ptr, op);
4312     if (RExC_offsets) {         /* MJD */
4313         MJD_OFFSET_DEBUG(("%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n",
4314               "reg_node", __LINE__,
4315               reg_name[op],
4316               RExC_emit - RExC_emit_start > RExC_offsets[0]
4317               ? "Overwriting end of array!\n" : "OK",
4318               RExC_emit - RExC_emit_start,
4319               RExC_parse - RExC_start,
4320               RExC_offsets[0]));
4321         Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4322     }
4323
4324     RExC_emit = ptr;
4325
4326     return(ret);
4327 }
4328
4329 /*
4330 - reganode - emit a node with an argument
4331 */
4332 STATIC regnode *                        /* Location. */
4333 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4334 {
4335     register regnode *ret;
4336     register regnode *ptr;
4337
4338     ret = RExC_emit;
4339     if (SIZE_ONLY) {
4340         SIZE_ALIGN(RExC_size);
4341         RExC_size += 2;
4342         return(ret);
4343     }
4344
4345     NODE_ALIGN_FILL(ret);
4346     ptr = ret;
4347     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4348     if (RExC_offsets) {         /* MJD */
4349         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4350               "reganode",
4351               __LINE__,
4352               reg_name[op],
4353               RExC_emit - RExC_emit_start > RExC_offsets[0] ?
4354               "Overwriting end of array!\n" : "OK",
4355               RExC_emit - RExC_emit_start,
4356               RExC_parse - RExC_start,
4357               RExC_offsets[0]));
4358         Set_Cur_Node_Offset;
4359     }
4360
4361     RExC_emit = ptr;
4362
4363     return(ret);
4364 }
4365
4366 /*
4367 - reguni - emit (if appropriate) a Unicode character
4368 */
4369 STATIC void
4370 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4371 {
4372     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4373 }
4374
4375 /*
4376 - reginsert - insert an operator in front of already-emitted operand
4377 *
4378 * Means relocating the operand.
4379 */
4380 STATIC void
4381 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4382 {
4383     register regnode *src;
4384     register regnode *dst;
4385     register regnode *place;
4386     register int offset = regarglen[(U8)op];
4387
4388 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4389
4390     if (SIZE_ONLY) {
4391         RExC_size += NODE_STEP_REGNODE + offset;
4392         return;
4393     }
4394
4395     src = RExC_emit;
4396     RExC_emit += NODE_STEP_REGNODE + offset;
4397     dst = RExC_emit;
4398     while (src > opnd) {
4399         StructCopy(--src, --dst, regnode);
4400         if (RExC_offsets) {     /* MJD 20010112 */
4401             MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s copy %u -> %u (max %u).\n",
4402                   "reg_insert",
4403                   __LINE__,
4404                   reg_name[op],
4405                   dst - RExC_emit_start > RExC_offsets[0]
4406                   ? "Overwriting end of array!\n" : "OK",
4407                   src - RExC_emit_start,
4408                   dst - RExC_emit_start,
4409                   RExC_offsets[0]));
4410             Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4411             Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4412         }
4413     }
4414
4415
4416     place = opnd;               /* Op node, where operand used to be. */
4417     if (RExC_offsets) {         /* MJD */
4418         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4419               "reginsert",
4420               __LINE__,
4421               reg_name[op],
4422               place - RExC_emit_start > RExC_offsets[0]
4423               ? "Overwriting end of array!\n" : "OK",
4424               place - RExC_emit_start,
4425               RExC_parse - RExC_start,
4426               RExC_offsets[0]));
4427         Set_Node_Offset(place, RExC_parse);
4428     }
4429     src = NEXTOPER(place);
4430     FILL_ADVANCE_NODE(place, op);
4431     Zero(src, offset, regnode);
4432 }
4433
4434 /*
4435 - regtail - set the next-pointer at the end of a node chain of p to val.
4436 */
4437 STATIC void
4438 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4439 {
4440     register regnode *scan;
4441     register regnode *temp;
4442
4443     if (SIZE_ONLY)
4444         return;
4445
4446     /* Find last node. */
4447     scan = p;
4448     for (;;) {
4449         temp = regnext(scan);
4450         if (temp == NULL)
4451             break;
4452         scan = temp;
4453     }
4454
4455     if (reg_off_by_arg[OP(scan)]) {
4456         ARG_SET(scan, val - scan);
4457     }
4458     else {
4459         NEXT_OFF(scan) = val - scan;
4460     }
4461 }
4462
4463 /*
4464 - regoptail - regtail on operand of first argument; nop if operandless
4465 */
4466 STATIC void
4467 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4468 {
4469     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4470     if (p == NULL || SIZE_ONLY)
4471         return;
4472     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4473         regtail(pRExC_state, NEXTOPER(p), val);
4474     }
4475     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4476         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4477     }
4478     else
4479         return;
4480 }
4481
4482 /*
4483  - regcurly - a little FSA that accepts {\d+,?\d*}
4484  */
4485 STATIC I32
4486 S_regcurly(pTHX_ register char *s)
4487 {
4488     if (*s++ != '{')
4489         return FALSE;
4490     if (!isDIGIT(*s))
4491         return FALSE;
4492     while (isDIGIT(*s))
4493         s++;
4494     if (*s == ',')
4495         s++;
4496     while (isDIGIT(*s))
4497         s++;
4498     if (*s != '}')
4499         return FALSE;
4500     return TRUE;
4501 }
4502
4503
4504 #ifdef DEBUGGING
4505
4506 STATIC regnode *
4507 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4508 {
4509     register U8 op = EXACT;     /* Arbitrary non-END op. */
4510     register regnode *next;
4511
4512     while (op != END && (!last || node < last)) {
4513         /* While that wasn't END last time... */
4514
4515         NODE_ALIGN(node);
4516         op = OP(node);
4517         if (op == CLOSE)
4518             l--;
4519         next = regnext(node);
4520         /* Where, what. */
4521         if (OP(node) == OPTIMIZED)
4522             goto after_print;
4523         regprop(sv, node);
4524         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4525                       (int)(2*l + 1), "", SvPVX(sv));
4526         if (next == NULL)               /* Next ptr. */
4527             PerlIO_printf(Perl_debug_log, "(0)");
4528         else
4529             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4530         (void)PerlIO_putc(Perl_debug_log, '\n');
4531       after_print:
4532         if (PL_regkind[(U8)op] == BRANCHJ) {
4533             register regnode *nnode = (OP(next) == LONGJMP
4534                                        ? regnext(next)
4535                                        : next);
4536             if (last && nnode > last)
4537                 nnode = last;
4538             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4539         }
4540         else if (PL_regkind[(U8)op] == BRANCH) {
4541             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4542         }
4543         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4544             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4545                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4546         }
4547         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4548             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4549                              next, sv, l + 1);
4550         }
4551         else if ( op == PLUS || op == STAR) {
4552             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4553         }
4554         else if (op == ANYOF) {
4555             /* arglen 1 + class block */
4556             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4557                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4558             node = NEXTOPER(node);
4559         }
4560         else if (PL_regkind[(U8)op] == EXACT) {
4561             /* Literal string, where present. */
4562             node += NODE_SZ_STR(node) - 1;
4563             node = NEXTOPER(node);
4564         }
4565         else {
4566             node = NEXTOPER(node);
4567             node += regarglen[(U8)op];
4568         }
4569         if (op == CURLYX || op == OPEN)
4570             l++;
4571         else if (op == WHILEM)
4572             l--;
4573     }
4574     return node;
4575 }
4576
4577 #endif  /* DEBUGGING */
4578
4579 /*
4580  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4581  */
4582 void
4583 Perl_regdump(pTHX_ regexp *r)
4584 {
4585 #ifdef DEBUGGING
4586     SV *sv = sv_newmortal();
4587
4588     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4589
4590     /* Header fields of interest. */
4591     if (r->anchored_substr)
4592         PerlIO_printf(Perl_debug_log,
4593                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4594                       PL_colors[0],
4595                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4596                       SvPVX(r->anchored_substr),
4597                       PL_colors[1],
4598                       SvTAIL(r->anchored_substr) ? "$" : "",
4599                       (IV)r->anchored_offset);
4600     else if (r->anchored_utf8)
4601         PerlIO_printf(Perl_debug_log,
4602                       "anchored utf8 `%s%.*s%s'%s at %"IVdf" ",
4603                       PL_colors[0],
4604                       (int)(SvCUR(r->anchored_utf8) - (SvTAIL(r->anchored_utf8)!=0)),
4605                       SvPVX(r->anchored_utf8),
4606                       PL_colors[1],
4607                       SvTAIL(r->anchored_utf8) ? "$" : "",
4608                       (IV)r->anchored_offset);
4609     if (r->float_substr)
4610         PerlIO_printf(Perl_debug_log,
4611                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4612                       PL_colors[0],
4613                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4614                       SvPVX(r->float_substr),
4615                       PL_colors[1],
4616                       SvTAIL(r->float_substr) ? "$" : "",
4617                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4618     else if (r->float_utf8)
4619         PerlIO_printf(Perl_debug_log,
4620                       "floating utf8 `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4621                       PL_colors[0],
4622                       (int)(SvCUR(r->float_utf8) - (SvTAIL(r->float_utf8)!=0)),
4623                       SvPVX(r->float_utf8),
4624                       PL_colors[1],
4625                       SvTAIL(r->float_utf8) ? "$" : "",
4626                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4627     if (r->check_substr || r->check_utf8)
4628         PerlIO_printf(Perl_debug_log,
4629                       r->check_substr == r->float_substr
4630                       && r->check_utf8 == r->float_utf8
4631                       ? "(checking floating" : "(checking anchored");
4632     if (r->reganch & ROPT_NOSCAN)
4633         PerlIO_printf(Perl_debug_log, " noscan");
4634     if (r->reganch & ROPT_CHECK_ALL)
4635         PerlIO_printf(Perl_debug_log, " isall");
4636     if (r->check_substr || r->check_utf8)
4637         PerlIO_printf(Perl_debug_log, ") ");
4638
4639     if (r->regstclass) {
4640         regprop(sv, r->regstclass);
4641         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4642     }
4643     if (r->reganch & ROPT_ANCH) {
4644         PerlIO_printf(Perl_debug_log, "anchored");
4645         if (r->reganch & ROPT_ANCH_BOL)
4646             PerlIO_printf(Perl_debug_log, "(BOL)");
4647         if (r->reganch & ROPT_ANCH_MBOL)
4648             PerlIO_printf(Perl_debug_log, "(MBOL)");
4649         if (r->reganch & ROPT_ANCH_SBOL)
4650             PerlIO_printf(Perl_debug_log, "(SBOL)");
4651         if (r->reganch & ROPT_ANCH_GPOS)
4652             PerlIO_printf(Perl_debug_log, "(GPOS)");
4653         PerlIO_putc(Perl_debug_log, ' ');
4654     }
4655     if (r->reganch & ROPT_GPOS_SEEN)
4656         PerlIO_printf(Perl_debug_log, "GPOS ");
4657     if (r->reganch & ROPT_SKIP)
4658         PerlIO_printf(Perl_debug_log, "plus ");
4659     if (r->reganch & ROPT_IMPLICIT)
4660         PerlIO_printf(Perl_debug_log, "implicit ");
4661     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4662     if (r->reganch & ROPT_EVAL_SEEN)
4663         PerlIO_printf(Perl_debug_log, "with eval ");
4664     PerlIO_printf(Perl_debug_log, "\n");
4665     if (r->offsets) {
4666       U32 i;
4667       U32 len = r->offsets[0];
4668       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4669       for (i = 1; i <= len; i++)
4670         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ",
4671                       (UV)r->offsets[i*2-1],
4672                       (UV)r->offsets[i*2]);
4673       PerlIO_printf(Perl_debug_log, "\n");
4674     }
4675 #endif  /* DEBUGGING */
4676 }
4677
4678 #ifdef DEBUGGING
4679
4680 STATIC void
4681 S_put_byte(pTHX_ SV *sv, int c)
4682 {
4683     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4684         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4685     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4686         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4687     else
4688         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4689 }
4690
4691 #endif  /* DEBUGGING */
4692
4693 /*
4694 - regprop - printable representation of opcode
4695 */
4696 void
4697 Perl_regprop(pTHX_ SV *sv, regnode *o)
4698 {
4699 #ifdef DEBUGGING
4700     register int k;
4701
4702     sv_setpvn(sv, "", 0);
4703     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4704         /* It would be nice to FAIL() here, but this may be called from
4705            regexec.c, and it would be hard to supply pRExC_state. */
4706         Perl_croak(aTHX_ "Corrupted regexp opcode");
4707     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4708
4709     k = PL_regkind[(U8)OP(o)];
4710
4711     if (k == EXACT) {
4712         SV *dsv = sv_2mortal(newSVpvn("", 0));
4713         /* Using is_utf8_string() is a crude hack but it may
4714          * be the best for now since we have no flag "this EXACTish
4715          * node was UTF-8" --jhi */
4716         bool do_utf8 = is_utf8_string((U8*)STRING(o), STR_LEN(o));
4717         char *s    = do_utf8 ?
4718           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60,
4719                          UNI_DISPLAY_REGEX) :
4720           STRING(o);
4721         int len = do_utf8 ?
4722           strlen(s) :
4723           STR_LEN(o);
4724         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4725                        PL_colors[0],
4726                        len, s,
4727                        PL_colors[1]);
4728     }
4729     else if (k == CURLY) {
4730         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4731             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4732         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4733     }
4734     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4735         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4736     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4737         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4738     else if (k == LOGICAL)
4739         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4740     else if (k == ANYOF) {
4741         int i, rangestart = -1;
4742         U8 flags = ANYOF_FLAGS(o);
4743         const char * const anyofs[] = { /* Should be synchronized with
4744                                          * ANYOF_ #xdefines in regcomp.h */
4745             "\\w",
4746             "\\W",
4747             "\\s",
4748             "\\S",
4749             "\\d",
4750             "\\D",
4751             "[:alnum:]",
4752             "[:^alnum:]",
4753             "[:alpha:]",
4754             "[:^alpha:]",
4755             "[:ascii:]",
4756             "[:^ascii:]",
4757             "[:ctrl:]",
4758             "[:^ctrl:]",
4759             "[:graph:]",
4760             "[:^graph:]",
4761             "[:lower:]",
4762             "[:^lower:]",
4763             "[:print:]",
4764             "[:^print:]",
4765             "[:punct:]",
4766             "[:^punct:]",
4767             "[:upper:]",
4768             "[:^upper:]",
4769             "[:xdigit:]",
4770             "[:^xdigit:]",
4771             "[:space:]",
4772             "[:^space:]",
4773             "[:blank:]",
4774             "[:^blank:]"
4775         };
4776
4777         if (flags & ANYOF_LOCALE)
4778             sv_catpv(sv, "{loc}");
4779         if (flags & ANYOF_FOLD)
4780             sv_catpv(sv, "{i}");
4781         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4782         if (flags & ANYOF_INVERT)
4783             sv_catpv(sv, "^");
4784         for (i = 0; i <= 256; i++) {
4785             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4786                 if (rangestart == -1)
4787                     rangestart = i;
4788             } else if (rangestart != -1) {
4789                 if (i <= rangestart + 3)
4790                     for (; rangestart < i; rangestart++)
4791                         put_byte(sv, rangestart);
4792                 else {
4793                     put_byte(sv, rangestart);
4794                     sv_catpv(sv, "-");
4795                     put_byte(sv, i - 1);
4796                 }
4797                 rangestart = -1;
4798             }
4799         }
4800
4801         if (o->flags & ANYOF_CLASS)
4802             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4803                 if (ANYOF_CLASS_TEST(o,i))
4804                     sv_catpv(sv, anyofs[i]);
4805
4806         if (flags & ANYOF_UNICODE)
4807             sv_catpv(sv, "{unicode}");
4808         else if (flags & ANYOF_UNICODE_ALL)
4809             sv_catpv(sv, "{unicode_all}");
4810
4811         {
4812             SV *lv;
4813             SV *sw = regclass_swash(o, FALSE, &lv, 0);
4814
4815             if (lv) {
4816                 if (sw) {
4817                     U8 s[UTF8_MAXLEN+1];
4818
4819                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4820                         U8 *e = uvchr_to_utf8(s, i);
4821
4822                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4823                             if (rangestart == -1)
4824                                 rangestart = i;
4825                         } else if (rangestart != -1) {
4826                             U8 *p;
4827
4828                             if (i <= rangestart + 3)
4829                                 for (; rangestart < i; rangestart++) {
4830                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4831                                         put_byte(sv, *p);
4832                                 }
4833                             else {
4834                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4835                                     put_byte(sv, *p);
4836                                 sv_catpv(sv, "-");
4837                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4838                                         put_byte(sv, *p);
4839                                 }
4840                                 rangestart = -1;
4841                             }
4842                         }
4843
4844                     sv_catpv(sv, "..."); /* et cetera */
4845                 }
4846
4847                 {
4848                     char *s = savepv(SvPVX(lv));
4849                     char *origs = s;
4850
4851                     while(*s && *s != '\n') s++;
4852
4853                     if (*s == '\n') {
4854                         char *t = ++s;
4855
4856                         while (*s) {
4857                             if (*s == '\n')
4858                                 *s = ' ';
4859                             s++;
4860                         }
4861                         if (s[-1] == ' ')
4862                             s[-1] = 0;
4863
4864                         sv_catpv(sv, t);
4865                     }
4866
4867                     Safefree(origs);
4868                 }
4869             }
4870         }
4871
4872         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4873     }
4874     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4875         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4876 #endif  /* DEBUGGING */
4877 }
4878
4879 SV *
4880 Perl_re_intuit_string(pTHX_ regexp *prog)
4881 {                               /* Assume that RE_INTUIT is set */
4882     DEBUG_r(
4883         {   STRLEN n_a;
4884             char *s = SvPV(prog->check_substr
4885                       ? prog->check_substr : prog->check_utf8, n_a);
4886
4887             if (!PL_colorset) reginitcolors();
4888             PerlIO_printf(Perl_debug_log,
4889                       "%sUsing REx %ssubstr:%s `%s%.60s%s%s'\n",
4890                       PL_colors[4],
4891                       prog->check_substr ? "" : "utf8 ",
4892                       PL_colors[5],PL_colors[0],
4893                       s,
4894                       PL_colors[1],
4895                       (strlen(s) > 60 ? "..." : ""));
4896         } );
4897
4898     return prog->check_substr ? prog->check_substr : prog->check_utf8;
4899 }
4900
4901 void
4902 Perl_pregfree(pTHX_ struct regexp *r)
4903 {
4904 #ifdef DEBUGGING
4905     SV *dsv = PERL_DEBUG_PAD_ZERO(0);
4906 #endif
4907
4908     if (!r || (--r->refcnt > 0))
4909         return;
4910     DEBUG_r({
4911          int len;
4912          char *s;
4913
4914          s = (r->reganch & ROPT_UTF8) ? pv_uni_display(dsv, (U8*)r->precomp,
4915                 r->prelen, 60, UNI_DISPLAY_REGEX)
4916             : pv_display(dsv, r->precomp, r->prelen, 0, 60);
4917          len = SvCUR(dsv);
4918          if (!PL_colorset)
4919               reginitcolors();
4920          PerlIO_printf(Perl_debug_log,
4921                        "%sFreeing REx:%s `%s%*.*s%s%s'\n",
4922                        PL_colors[4],PL_colors[5],PL_colors[0],
4923                        len, len, s,
4924                        PL_colors[1],
4925                        len > 60 ? "..." : "");
4926     });
4927
4928     if (r->precomp)
4929         Safefree(r->precomp);
4930     if (r->offsets)             /* 20010421 MJD */
4931         Safefree(r->offsets);
4932     RX_MATCH_COPY_FREE(r);
4933 #ifdef PERL_COPY_ON_WRITE
4934     if (r->saved_copy)
4935         SvREFCNT_dec(r->saved_copy);
4936 #endif
4937     if (r->substrs) {
4938         if (r->anchored_substr)
4939             SvREFCNT_dec(r->anchored_substr);
4940         if (r->anchored_utf8)
4941             SvREFCNT_dec(r->anchored_utf8);
4942         if (r->float_substr)
4943             SvREFCNT_dec(r->float_substr);
4944         if (r->float_utf8)
4945             SvREFCNT_dec(r->float_utf8);
4946         Safefree(r->substrs);
4947     }
4948     if (r->data) {
4949         int n = r->data->count;
4950         PAD* new_comppad = NULL;
4951         PAD* old_comppad;
4952
4953         while (--n >= 0) {
4954           /* If you add a ->what type here, update the comment in regcomp.h */
4955             switch (r->data->what[n]) {
4956             case 's':
4957                 SvREFCNT_dec((SV*)r->data->data[n]);
4958                 break;
4959             case 'f':
4960                 Safefree(r->data->data[n]);
4961                 break;
4962             case 'p':
4963                 new_comppad = (AV*)r->data->data[n];
4964                 break;
4965             case 'o':
4966                 if (new_comppad == NULL)
4967                     Perl_croak(aTHX_ "panic: pregfree comppad");
4968                 PAD_SAVE_LOCAL(old_comppad,
4969                     /* Watch out for global destruction's random ordering. */
4970                     (SvTYPE(new_comppad) == SVt_PVAV) ?
4971                                 new_comppad : Null(PAD *)
4972                 );
4973                 if (!OpREFCNT_dec((OP_4tree*)r->data->data[n])) {
4974                     op_free((OP_4tree*)r->data->data[n]);
4975                 }
4976
4977                 PAD_RESTORE_LOCAL(old_comppad);
4978                 SvREFCNT_dec((SV*)new_comppad);
4979                 new_comppad = NULL;
4980                 break;
4981             case 'n':
4982                 break;
4983             default:
4984                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4985             }
4986         }
4987         Safefree(r->data->what);
4988         Safefree(r->data);
4989     }
4990     Safefree(r->startp);
4991     Safefree(r->endp);
4992     Safefree(r);
4993 }
4994
4995 /*
4996  - regnext - dig the "next" pointer out of a node
4997  *
4998  * [Note, when REGALIGN is defined there are two places in regmatch()
4999  * that bypass this code for speed.]
5000  */
5001 regnode *
5002 Perl_regnext(pTHX_ register regnode *p)
5003 {
5004     register I32 offset;
5005
5006     if (p == &PL_regdummy)
5007         return(NULL);
5008
5009     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
5010     if (offset == 0)
5011         return(NULL);
5012
5013     return(p+offset);
5014 }
5015
5016 STATIC void
5017 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
5018 {
5019     va_list args;
5020     STRLEN l1 = strlen(pat1);
5021     STRLEN l2 = strlen(pat2);
5022     char buf[512];
5023     SV *msv;
5024     char *message;
5025
5026     if (l1 > 510)
5027         l1 = 510;
5028     if (l1 + l2 > 510)
5029         l2 = 510 - l1;
5030     Copy(pat1, buf, l1 , char);
5031     Copy(pat2, buf + l1, l2 , char);
5032     buf[l1 + l2] = '\n';
5033     buf[l1 + l2 + 1] = '\0';
5034 #ifdef I_STDARG
5035     /* ANSI variant takes additional second argument */
5036     va_start(args, pat2);
5037 #else
5038     va_start(args);
5039 #endif
5040     msv = vmess(buf, &args);
5041     va_end(args);
5042     message = SvPV(msv,l1);
5043     if (l1 > 512)
5044         l1 = 512;
5045     Copy(message, buf, l1 , char);
5046     buf[l1] = '\0';                     /* Overwrite \n */
5047     Perl_croak(aTHX_ "%s", buf);
5048 }
5049
5050 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
5051
5052 void
5053 Perl_save_re_context(pTHX)
5054 {
5055     SAVEI32(PL_reg_flags);              /* from regexec.c */
5056     SAVEPPTR(PL_bostr);
5057     SAVEPPTR(PL_reginput);              /* String-input pointer. */
5058     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
5059     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
5060     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
5061     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
5062     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
5063     SAVEVPTR(PL_reglastcloseparen);     /* Similarly for lastcloseparen. */
5064     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
5065     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
5066     PL_reg_start_tmp = 0;
5067     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
5068     PL_reg_start_tmpl = 0;
5069     SAVEVPTR(PL_regdata);
5070     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
5071     SAVEI32(PL_regnarrate);             /* from regexec.c */
5072     SAVEVPTR(PL_regprogram);            /* from regexec.c */
5073     SAVEINT(PL_regindent);              /* from regexec.c */
5074     SAVEVPTR(PL_regcc);                 /* from regexec.c */
5075     SAVEVPTR(PL_curcop);
5076     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
5077     SAVEVPTR(PL_reg_re);                /* from regexec.c */
5078     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
5079     SAVESPTR(PL_reg_sv);                /* from regexec.c */
5080     SAVEBOOL(PL_reg_match_utf8);        /* from regexec.c */
5081     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
5082     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
5083     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
5084     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
5085     SAVEPPTR(PL_reg_oldsaved);          /* old saved substr during match */
5086     PL_reg_oldsaved = Nullch;
5087     SAVEI32(PL_reg_oldsavedlen);        /* old length of saved substr during match */
5088     PL_reg_oldsavedlen = 0;
5089 #ifdef PERL_COPY_ON_WRITE
5090     SAVESPTR(PL_nrs);
5091     PL_nrs = Nullsv;
5092 #endif
5093     SAVEI32(PL_reg_maxiter);            /* max wait until caching pos */
5094     PL_reg_maxiter = 0;
5095     SAVEI32(PL_reg_leftiter);           /* wait until caching pos */
5096     PL_reg_leftiter = 0;
5097     SAVEGENERICPV(PL_reg_poscache);     /* cache of pos of WHILEM */
5098     PL_reg_poscache = Nullch;
5099     SAVEI32(PL_reg_poscache_size);      /* size of pos cache of WHILEM */
5100     PL_reg_poscache_size = 0;
5101     SAVEPPTR(PL_regprecomp);            /* uncompiled string. */
5102     SAVEI32(PL_regnpar);                /* () count. */
5103     SAVEI32(PL_regsize);                /* from regexec.c */
5104
5105     {
5106         /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
5107         U32 i;
5108         GV *mgv;
5109         REGEXP *rx;
5110         char digits[16];
5111
5112         if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
5113             for (i = 1; i <= rx->nparens; i++) {
5114                 sprintf(digits, "%lu", (long)i);
5115                 if ((mgv = gv_fetchpv(digits, FALSE, SVt_PV)))
5116                     save_scalar(mgv);
5117             }
5118         }
5119     }
5120
5121 #ifdef DEBUGGING
5122     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
5123 #endif
5124 }
5125
5126 static void
5127 clear_re(pTHX_ void *r)
5128 {
5129     ReREFCNT_dec((regexp *)r);
5130 }
5131