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         sv_setsv(*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                 }
2263
2264                 nextchar(pRExC_state);
2265                 if (logical) {
2266                     ret = reg_node(pRExC_state, LOGICAL);
2267                     if (!SIZE_ONLY)
2268                         ret->flags = 2;
2269                     regtail(pRExC_state, ret, reganode(pRExC_state, EVAL, n));
2270                     /* deal with the length of this later - MJD */
2271                     return ret;
2272                 }
2273                 ret = reganode(pRExC_state, EVAL, n);
2274                 Set_Node_Length(ret, RExC_parse - parse_start + 1);
2275                 Set_Node_Offset(ret, parse_start);
2276                 return ret;
2277             }
2278             case '(':           /* (?(?{...})...) and (?(?=...)...) */
2279             {
2280                 if (RExC_parse[0] == '?') {        /* (?(?...)) */
2281                     if (RExC_parse[1] == '=' || RExC_parse[1] == '!'
2282                         || RExC_parse[1] == '<'
2283                         || RExC_parse[1] == '{') { /* Lookahead or eval. */
2284                         I32 flag;
2285
2286                         ret = reg_node(pRExC_state, LOGICAL);
2287                         if (!SIZE_ONLY)
2288                             ret->flags = 1;
2289                         regtail(pRExC_state, ret, reg(pRExC_state, 1, &flag));
2290                         goto insert_if;
2291                     }
2292                 }
2293                 else if (RExC_parse[0] >= '1' && RExC_parse[0] <= '9' ) {
2294                     /* (?(1)...) */
2295                     parno = atoi(RExC_parse++);
2296
2297                     while (isDIGIT(*RExC_parse))
2298                         RExC_parse++;
2299                     ret = reganode(pRExC_state, GROUPP, parno);
2300
2301                     if ((c = *nextchar(pRExC_state)) != ')')
2302                         vFAIL("Switch condition not recognized");
2303                   insert_if:
2304                     regtail(pRExC_state, ret, reganode(pRExC_state, IFTHEN, 0));
2305                     br = regbranch(pRExC_state, &flags, 1);
2306                     if (br == NULL)
2307                         br = reganode(pRExC_state, LONGJMP, 0);
2308                     else
2309                         regtail(pRExC_state, br, reganode(pRExC_state, LONGJMP, 0));
2310                     c = *nextchar(pRExC_state);
2311                     if (flags&HASWIDTH)
2312                         *flagp |= HASWIDTH;
2313                     if (c == '|') {
2314                         lastbr = reganode(pRExC_state, IFTHEN, 0); /* Fake one for optimizer. */
2315                         regbranch(pRExC_state, &flags, 1);
2316                         regtail(pRExC_state, ret, lastbr);
2317                         if (flags&HASWIDTH)
2318                             *flagp |= HASWIDTH;
2319                         c = *nextchar(pRExC_state);
2320                     }
2321                     else
2322                         lastbr = NULL;
2323                     if (c != ')')
2324                         vFAIL("Switch (?(condition)... contains too many branches");
2325                     ender = reg_node(pRExC_state, TAIL);
2326                     regtail(pRExC_state, br, ender);
2327                     if (lastbr) {
2328                         regtail(pRExC_state, lastbr, ender);
2329                         regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender);
2330                     }
2331                     else
2332                         regtail(pRExC_state, ret, ender);
2333                     return ret;
2334                 }
2335                 else {
2336                     vFAIL2("Unknown switch condition (?(%.2s", RExC_parse);
2337                 }
2338             }
2339             case 0:
2340                 RExC_parse--; /* for vFAIL to print correctly */
2341                 vFAIL("Sequence (? incomplete");
2342                 break;
2343             default:
2344                 --RExC_parse;
2345               parse_flags:      /* (?i) */
2346                 while (*RExC_parse && strchr("iogcmsx", *RExC_parse)) {
2347                     /* (?g), (?gc) and (?o) are useless here
2348                        and must be globally applied -- japhy */
2349
2350                     if (*RExC_parse == 'o' || *RExC_parse == 'g') {
2351                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2352                             I32 wflagbit = *RExC_parse == 'o' ? wasted_o : wasted_g;
2353                             if (! (wastedflags & wflagbit) ) {
2354                                 wastedflags |= wflagbit;
2355                                 vWARN5(
2356                                     RExC_parse + 1,
2357                                     "Useless (%s%c) - %suse /%c modifier",
2358                                     flagsp == &negflags ? "?-" : "?",
2359                                     *RExC_parse,
2360                                     flagsp == &negflags ? "don't " : "",
2361                                     *RExC_parse
2362                                 );
2363                             }
2364                         }
2365                     }
2366                     else if (*RExC_parse == 'c') {
2367                         if (SIZE_ONLY && ckWARN(WARN_REGEXP)) {
2368                             if (! (wastedflags & wasted_c) ) {
2369                                 wastedflags |= wasted_gc;
2370                                 vWARN3(
2371                                     RExC_parse + 1,
2372                                     "Useless (%sc) - %suse /gc modifier",
2373                                     flagsp == &negflags ? "?-" : "?",
2374                                     flagsp == &negflags ? "don't " : ""
2375                                 );
2376                             }
2377                         }
2378                     }
2379                     else { pmflag(flagsp, *RExC_parse); }
2380
2381                     ++RExC_parse;
2382                 }
2383                 if (*RExC_parse == '-') {
2384                     flagsp = &negflags;
2385                     wastedflags = 0;  /* reset so (?g-c) warns twice */
2386                     ++RExC_parse;
2387                     goto parse_flags;
2388                 }
2389                 RExC_flags |= posflags;
2390                 RExC_flags &= ~negflags;
2391                 if (*RExC_parse == ':') {
2392                     RExC_parse++;
2393                     paren = ':';
2394                     break;
2395                 }
2396               unknown:
2397                 if (*RExC_parse != ')') {
2398                     RExC_parse++;
2399                     vFAIL3("Sequence (%.*s...) not recognized", RExC_parse-seqstart, seqstart);
2400                 }
2401                 nextchar(pRExC_state);
2402                 *flagp = TRYAGAIN;
2403                 return NULL;
2404             }
2405         }
2406         else {                  /* (...) */
2407             parno = RExC_npar;
2408             RExC_npar++;
2409             ret = reganode(pRExC_state, OPEN, parno);
2410             Set_Node_Length(ret, 1); /* MJD */
2411             Set_Node_Offset(ret, RExC_parse); /* MJD */
2412             open = 1;
2413         }
2414     }
2415     else                        /* ! paren */
2416         ret = NULL;
2417
2418     /* Pick up the branches, linking them together. */
2419     parse_start = RExC_parse;   /* MJD */
2420     br = regbranch(pRExC_state, &flags, 1);
2421     /*     branch_len = (paren != 0); */
2422
2423     if (br == NULL)
2424         return(NULL);
2425     if (*RExC_parse == '|') {
2426         if (!SIZE_ONLY && RExC_extralen) {
2427             reginsert(pRExC_state, BRANCHJ, br);
2428         }
2429         else {                  /* MJD */
2430             reginsert(pRExC_state, BRANCH, br);
2431             Set_Node_Length(br, paren != 0);
2432             Set_Node_Offset_To_R(br-RExC_emit_start, parse_start-RExC_start);
2433         }
2434         have_branch = 1;
2435         if (SIZE_ONLY)
2436             RExC_extralen += 1;         /* For BRANCHJ-BRANCH. */
2437     }
2438     else if (paren == ':') {
2439         *flagp |= flags&SIMPLE;
2440     }
2441     if (open) {                         /* Starts with OPEN. */
2442         regtail(pRExC_state, ret, br);          /* OPEN -> first. */
2443     }
2444     else if (paren != '?')              /* Not Conditional */
2445         ret = br;
2446     *flagp |= flags & (SPSTART | HASWIDTH);
2447     lastbr = br;
2448     while (*RExC_parse == '|') {
2449         if (!SIZE_ONLY && RExC_extralen) {
2450             ender = reganode(pRExC_state, LONGJMP,0);
2451             regtail(pRExC_state, NEXTOPER(NEXTOPER(lastbr)), ender); /* Append to the previous. */
2452         }
2453         if (SIZE_ONLY)
2454             RExC_extralen += 2;         /* Account for LONGJMP. */
2455         nextchar(pRExC_state);
2456         br = regbranch(pRExC_state, &flags, 0);
2457
2458         if (br == NULL)
2459             return(NULL);
2460         regtail(pRExC_state, lastbr, br);               /* BRANCH -> BRANCH. */
2461         lastbr = br;
2462         if (flags&HASWIDTH)
2463             *flagp |= HASWIDTH;
2464         *flagp |= flags&SPSTART;
2465     }
2466
2467     if (have_branch || paren != ':') {
2468         /* Make a closing node, and hook it on the end. */
2469         switch (paren) {
2470         case ':':
2471             ender = reg_node(pRExC_state, TAIL);
2472             break;
2473         case 1:
2474             ender = reganode(pRExC_state, CLOSE, parno);
2475             Set_Node_Offset(ender,RExC_parse+1); /* MJD */
2476             Set_Node_Length(ender,1); /* MJD */
2477             break;
2478         case '<':
2479         case ',':
2480         case '=':
2481         case '!':
2482             *flagp &= ~HASWIDTH;
2483             /* FALL THROUGH */
2484         case '>':
2485             ender = reg_node(pRExC_state, SUCCEED);
2486             break;
2487         case 0:
2488             ender = reg_node(pRExC_state, END);
2489             break;
2490         }
2491         regtail(pRExC_state, lastbr, ender);
2492
2493         if (have_branch) {
2494             /* Hook the tails of the branches to the closing node. */
2495             for (br = ret; br != NULL; br = regnext(br)) {
2496                 regoptail(pRExC_state, br, ender);
2497             }
2498         }
2499     }
2500
2501     {
2502         char *p;
2503         static char parens[] = "=!<,>";
2504
2505         if (paren && (p = strchr(parens, paren))) {
2506             U8 node = ((p - parens) % 2) ? UNLESSM : IFMATCH;
2507             int flag = (p - parens) > 1;
2508
2509             if (paren == '>')
2510                 node = SUSPEND, flag = 0;
2511             reginsert(pRExC_state, node,ret);
2512             Set_Node_Offset(ret, oregcomp_parse);
2513             Set_Node_Length(ret,  RExC_parse - oregcomp_parse + 2);
2514             ret->flags = flag;
2515             regtail(pRExC_state, ret, reg_node(pRExC_state, TAIL));
2516         }
2517     }
2518
2519     /* Check for proper termination. */
2520     if (paren) {
2521         RExC_flags = oregflags;
2522         if (RExC_parse >= RExC_end || *nextchar(pRExC_state) != ')') {
2523             RExC_parse = oregcomp_parse;
2524             vFAIL("Unmatched (");
2525         }
2526     }
2527     else if (!paren && RExC_parse < RExC_end) {
2528         if (*RExC_parse == ')') {
2529             RExC_parse++;
2530             vFAIL("Unmatched )");
2531         }
2532         else
2533             FAIL("Junk on end of regexp");      /* "Can't happen". */
2534         /* NOTREACHED */
2535     }
2536
2537     return(ret);
2538 }
2539
2540 /*
2541  - regbranch - one alternative of an | operator
2542  *
2543  * Implements the concatenation operator.
2544  */
2545 STATIC regnode *
2546 S_regbranch(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, I32 first)
2547 {
2548     register regnode *ret;
2549     register regnode *chain = NULL;
2550     register regnode *latest;
2551     I32 flags = 0, c = 0;
2552
2553     if (first)
2554         ret = NULL;
2555     else {
2556         if (!SIZE_ONLY && RExC_extralen)
2557             ret = reganode(pRExC_state, BRANCHJ,0);
2558         else {
2559             ret = reg_node(pRExC_state, BRANCH);
2560             Set_Node_Length(ret, 1);
2561         }
2562     }
2563
2564     if (!first && SIZE_ONLY)
2565         RExC_extralen += 1;                     /* BRANCHJ */
2566
2567     *flagp = WORST;                     /* Tentatively. */
2568
2569     RExC_parse--;
2570     nextchar(pRExC_state);
2571     while (RExC_parse < RExC_end && *RExC_parse != '|' && *RExC_parse != ')') {
2572         flags &= ~TRYAGAIN;
2573         latest = regpiece(pRExC_state, &flags);
2574         if (latest == NULL) {
2575             if (flags & TRYAGAIN)
2576                 continue;
2577             return(NULL);
2578         }
2579         else if (ret == NULL)
2580             ret = latest;
2581         *flagp |= flags&HASWIDTH;
2582         if (chain == NULL)      /* First piece. */
2583             *flagp |= flags&SPSTART;
2584         else {
2585             RExC_naughty++;
2586             regtail(pRExC_state, chain, latest);
2587         }
2588         chain = latest;
2589         c++;
2590     }
2591     if (chain == NULL) {        /* Loop ran zero times. */
2592         chain = reg_node(pRExC_state, NOTHING);
2593         if (ret == NULL)
2594             ret = chain;
2595     }
2596     if (c == 1) {
2597         *flagp |= flags&SIMPLE;
2598     }
2599
2600     return(ret);
2601 }
2602
2603 /*
2604  - regpiece - something followed by possible [*+?]
2605  *
2606  * Note that the branching code sequences used for ? and the general cases
2607  * of * and + are somewhat optimized:  they use the same NOTHING node as
2608  * both the endmarker for their branch list and the body of the last branch.
2609  * It might seem that this node could be dispensed with entirely, but the
2610  * endmarker role is not redundant.
2611  */
2612 STATIC regnode *
2613 S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2614 {
2615     register regnode *ret;
2616     register char op;
2617     register char *next;
2618     I32 flags;
2619     char *origparse = RExC_parse;
2620     char *maxpos;
2621     I32 min;
2622     I32 max = REG_INFTY;
2623     char *parse_start;
2624
2625     ret = regatom(pRExC_state, &flags);
2626     if (ret == NULL) {
2627         if (flags & TRYAGAIN)
2628             *flagp |= TRYAGAIN;
2629         return(NULL);
2630     }
2631
2632     op = *RExC_parse;
2633
2634     if (op == '{' && regcurly(RExC_parse)) {
2635         parse_start = RExC_parse; /* MJD */
2636         next = RExC_parse + 1;
2637         maxpos = Nullch;
2638         while (isDIGIT(*next) || *next == ',') {
2639             if (*next == ',') {
2640                 if (maxpos)
2641                     break;
2642                 else
2643                     maxpos = next;
2644             }
2645             next++;
2646         }
2647         if (*next == '}') {             /* got one */
2648             if (!maxpos)
2649                 maxpos = next;
2650             RExC_parse++;
2651             min = atoi(RExC_parse);
2652             if (*maxpos == ',')
2653                 maxpos++;
2654             else
2655                 maxpos = RExC_parse;
2656             max = atoi(maxpos);
2657             if (!max && *maxpos != '0')
2658                 max = REG_INFTY;                /* meaning "infinity" */
2659             else if (max >= REG_INFTY)
2660                 vFAIL2("Quantifier in {,} bigger than %d", REG_INFTY - 1);
2661             RExC_parse = next;
2662             nextchar(pRExC_state);
2663
2664         do_curly:
2665             if ((flags&SIMPLE)) {
2666                 RExC_naughty += 2 + RExC_naughty / 2;
2667                 reginsert(pRExC_state, CURLY, ret);
2668                 Set_Node_Offset(ret, parse_start+1); /* MJD */
2669                 Set_Node_Cur_Length(ret);
2670             }
2671             else {
2672                 regnode *w = reg_node(pRExC_state, WHILEM);
2673
2674                 w->flags = 0;
2675                 regtail(pRExC_state, ret, w);
2676                 if (!SIZE_ONLY && RExC_extralen) {
2677                     reginsert(pRExC_state, LONGJMP,ret);
2678                     reginsert(pRExC_state, NOTHING,ret);
2679                     NEXT_OFF(ret) = 3;  /* Go over LONGJMP. */
2680                 }
2681                 reginsert(pRExC_state, CURLYX,ret);
2682                                 /* MJD hk */
2683                 Set_Node_Offset(ret, parse_start+1);
2684                 Set_Node_Length(ret,
2685                                 op == '{' ? (RExC_parse - parse_start) : 1);
2686
2687                 if (!SIZE_ONLY && RExC_extralen)
2688                     NEXT_OFF(ret) = 3;  /* Go over NOTHING to LONGJMP. */
2689                 regtail(pRExC_state, ret, reg_node(pRExC_state, NOTHING));
2690                 if (SIZE_ONLY)
2691                     RExC_whilem_seen++, RExC_extralen += 3;
2692                 RExC_naughty += 4 + RExC_naughty;       /* compound interest */
2693             }
2694             ret->flags = 0;
2695
2696             if (min > 0)
2697                 *flagp = WORST;
2698             if (max > 0)
2699                 *flagp |= HASWIDTH;
2700             if (max && max < min)
2701                 vFAIL("Can't do {n,m} with n > m");
2702             if (!SIZE_ONLY) {
2703                 ARG1_SET(ret, (U16)min);
2704                 ARG2_SET(ret, (U16)max);
2705             }
2706
2707             goto nest_check;
2708         }
2709     }
2710
2711     if (!ISMULT1(op)) {
2712         *flagp = flags;
2713         return(ret);
2714     }
2715
2716 #if 0                           /* Now runtime fix should be reliable. */
2717
2718     /* if this is reinstated, don't forget to put this back into perldiag:
2719
2720             =item Regexp *+ operand could be empty at {#} in regex m/%s/
2721
2722            (F) The part of the regexp subject to either the * or + quantifier
2723            could match an empty string. The {#} shows in the regular
2724            expression about where the problem was discovered.
2725
2726     */
2727
2728     if (!(flags&HASWIDTH) && op != '?')
2729       vFAIL("Regexp *+ operand could be empty");
2730 #endif
2731
2732     parse_start = RExC_parse;
2733     nextchar(pRExC_state);
2734
2735     *flagp = (op != '+') ? (WORST|SPSTART|HASWIDTH) : (WORST|HASWIDTH);
2736
2737     if (op == '*' && (flags&SIMPLE)) {
2738         reginsert(pRExC_state, STAR, ret);
2739         ret->flags = 0;
2740         RExC_naughty += 4;
2741     }
2742     else if (op == '*') {
2743         min = 0;
2744         goto do_curly;
2745     }
2746     else if (op == '+' && (flags&SIMPLE)) {
2747         reginsert(pRExC_state, PLUS, ret);
2748         ret->flags = 0;
2749         RExC_naughty += 3;
2750     }
2751     else if (op == '+') {
2752         min = 1;
2753         goto do_curly;
2754     }
2755     else if (op == '?') {
2756         min = 0; max = 1;
2757         goto do_curly;
2758     }
2759   nest_check:
2760     if (ckWARN(WARN_REGEXP) && !SIZE_ONLY && !(flags&HASWIDTH) && max > REG_INFTY/3) {
2761         vWARN3(RExC_parse,
2762                "%.*s matches null string many times",
2763                RExC_parse - origparse,
2764                origparse);
2765     }
2766
2767     if (*RExC_parse == '?') {
2768         nextchar(pRExC_state);
2769         reginsert(pRExC_state, MINMOD, ret);
2770         regtail(pRExC_state, ret, ret + NODE_STEP_REGNODE);
2771     }
2772     if (ISMULT2(RExC_parse)) {
2773         RExC_parse++;
2774         vFAIL("Nested quantifiers");
2775     }
2776
2777     return(ret);
2778 }
2779
2780 /*
2781  - regatom - the lowest level
2782  *
2783  * Optimization:  gobbles an entire sequence of ordinary characters so that
2784  * it can turn them into a single node, which is smaller to store and
2785  * faster to run.  Backslashed characters are exceptions, each becoming a
2786  * separate node; the code is simpler that way and it's not worth fixing.
2787  *
2788  * [Yes, it is worth fixing, some scripts can run twice the speed.] */
2789 STATIC regnode *
2790 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
2791 {
2792     register regnode *ret = 0;
2793     I32 flags;
2794     char *parse_start = 0;
2795
2796     *flagp = WORST;             /* Tentatively. */
2797
2798 tryagain:
2799     switch (*RExC_parse) {
2800     case '^':
2801         RExC_seen_zerolen++;
2802         nextchar(pRExC_state);
2803         if (RExC_flags & PMf_MULTILINE)
2804             ret = reg_node(pRExC_state, MBOL);
2805         else if (RExC_flags & PMf_SINGLELINE)
2806             ret = reg_node(pRExC_state, SBOL);
2807         else
2808             ret = reg_node(pRExC_state, BOL);
2809         Set_Node_Length(ret, 1); /* MJD */
2810         break;
2811     case '$':
2812         nextchar(pRExC_state);
2813         if (*RExC_parse)
2814             RExC_seen_zerolen++;
2815         if (RExC_flags & PMf_MULTILINE)
2816             ret = reg_node(pRExC_state, MEOL);
2817         else if (RExC_flags & PMf_SINGLELINE)
2818             ret = reg_node(pRExC_state, SEOL);
2819         else
2820             ret = reg_node(pRExC_state, EOL);
2821         Set_Node_Length(ret, 1); /* MJD */
2822         break;
2823     case '.':
2824         nextchar(pRExC_state);
2825         if (RExC_flags & PMf_SINGLELINE)
2826             ret = reg_node(pRExC_state, SANY);
2827         else
2828             ret = reg_node(pRExC_state, REG_ANY);
2829         *flagp |= HASWIDTH|SIMPLE;
2830         RExC_naughty++;
2831         Set_Node_Length(ret, 1); /* MJD */
2832         break;
2833     case '[':
2834     {
2835         char *oregcomp_parse = ++RExC_parse;
2836         ret = regclass(pRExC_state);
2837         if (*RExC_parse != ']') {
2838             RExC_parse = oregcomp_parse;
2839             vFAIL("Unmatched [");
2840         }
2841         nextchar(pRExC_state);
2842         *flagp |= HASWIDTH|SIMPLE;
2843         Set_Node_Length(ret, RExC_parse - oregcomp_parse + 1); /* MJD */
2844         break;
2845     }
2846     case '(':
2847         nextchar(pRExC_state);
2848         ret = reg(pRExC_state, 1, &flags);
2849         if (ret == NULL) {
2850                 if (flags & TRYAGAIN) {
2851                     if (RExC_parse == RExC_end) {
2852                          /* Make parent create an empty node if needed. */
2853                         *flagp |= TRYAGAIN;
2854                         return(NULL);
2855                     }
2856                     goto tryagain;
2857                 }
2858                 return(NULL);
2859         }
2860         *flagp |= flags&(HASWIDTH|SPSTART|SIMPLE);
2861         break;
2862     case '|':
2863     case ')':
2864         if (flags & TRYAGAIN) {
2865             *flagp |= TRYAGAIN;
2866             return NULL;
2867         }
2868         vFAIL("Internal urp");
2869                                 /* Supposed to be caught earlier. */
2870         break;
2871     case '{':
2872         if (!regcurly(RExC_parse)) {
2873             RExC_parse++;
2874             goto defchar;
2875         }
2876         /* FALL THROUGH */
2877     case '?':
2878     case '+':
2879     case '*':
2880         RExC_parse++;
2881         vFAIL("Quantifier follows nothing");
2882         break;
2883     case '\\':
2884         switch (*++RExC_parse) {
2885         case 'A':
2886             RExC_seen_zerolen++;
2887             ret = reg_node(pRExC_state, SBOL);
2888             *flagp |= SIMPLE;
2889             nextchar(pRExC_state);
2890             Set_Node_Length(ret, 2); /* MJD */
2891             break;
2892         case 'G':
2893             ret = reg_node(pRExC_state, GPOS);
2894             RExC_seen |= REG_SEEN_GPOS;
2895             *flagp |= SIMPLE;
2896             nextchar(pRExC_state);
2897             Set_Node_Length(ret, 2); /* MJD */
2898             break;
2899         case 'Z':
2900             ret = reg_node(pRExC_state, SEOL);
2901             *flagp |= SIMPLE;
2902             RExC_seen_zerolen++;                /* Do not optimize RE away */
2903             nextchar(pRExC_state);
2904             break;
2905         case 'z':
2906             ret = reg_node(pRExC_state, EOS);
2907             *flagp |= SIMPLE;
2908             RExC_seen_zerolen++;                /* Do not optimize RE away */
2909             nextchar(pRExC_state);
2910             Set_Node_Length(ret, 2); /* MJD */
2911             break;
2912         case 'C':
2913             ret = reg_node(pRExC_state, CANY);
2914             RExC_seen |= REG_SEEN_CANY;
2915             *flagp |= HASWIDTH|SIMPLE;
2916             nextchar(pRExC_state);
2917             Set_Node_Length(ret, 2); /* MJD */
2918             break;
2919         case 'X':
2920             ret = reg_node(pRExC_state, CLUMP);
2921             *flagp |= HASWIDTH;
2922             nextchar(pRExC_state);
2923             Set_Node_Length(ret, 2); /* MJD */
2924             break;
2925         case 'w':
2926             ret = reg_node(pRExC_state, (U8)(LOC ? ALNUML     : ALNUM));
2927             *flagp |= HASWIDTH|SIMPLE;
2928             nextchar(pRExC_state);
2929             Set_Node_Length(ret, 2); /* MJD */
2930             break;
2931         case 'W':
2932             ret = reg_node(pRExC_state, (U8)(LOC ? NALNUML    : NALNUM));
2933             *flagp |= HASWIDTH|SIMPLE;
2934             nextchar(pRExC_state);
2935             Set_Node_Length(ret, 2); /* MJD */
2936             break;
2937         case 'b':
2938             RExC_seen_zerolen++;
2939             RExC_seen |= REG_SEEN_LOOKBEHIND;
2940             ret = reg_node(pRExC_state, (U8)(LOC ? BOUNDL     : BOUND));
2941             *flagp |= SIMPLE;
2942             nextchar(pRExC_state);
2943             Set_Node_Length(ret, 2); /* MJD */
2944             break;
2945         case 'B':
2946             RExC_seen_zerolen++;
2947             RExC_seen |= REG_SEEN_LOOKBEHIND;
2948             ret = reg_node(pRExC_state, (U8)(LOC ? NBOUNDL    : NBOUND));
2949             *flagp |= SIMPLE;
2950             nextchar(pRExC_state);
2951             Set_Node_Length(ret, 2); /* MJD */
2952             break;
2953         case 's':
2954             ret = reg_node(pRExC_state, (U8)(LOC ? SPACEL     : SPACE));
2955             *flagp |= HASWIDTH|SIMPLE;
2956             nextchar(pRExC_state);
2957             Set_Node_Length(ret, 2); /* MJD */
2958             break;
2959         case 'S':
2960             ret = reg_node(pRExC_state, (U8)(LOC ? NSPACEL    : NSPACE));
2961             *flagp |= HASWIDTH|SIMPLE;
2962             nextchar(pRExC_state);
2963             Set_Node_Length(ret, 2); /* MJD */
2964             break;
2965         case 'd':
2966             ret = reg_node(pRExC_state, DIGIT);
2967             *flagp |= HASWIDTH|SIMPLE;
2968             nextchar(pRExC_state);
2969             Set_Node_Length(ret, 2); /* MJD */
2970             break;
2971         case 'D':
2972             ret = reg_node(pRExC_state, NDIGIT);
2973             *flagp |= HASWIDTH|SIMPLE;
2974             nextchar(pRExC_state);
2975             Set_Node_Length(ret, 2); /* MJD */
2976             break;
2977         case 'p':
2978         case 'P':
2979             {
2980                 char* oldregxend = RExC_end;
2981                 char* parse_start = RExC_parse - 2;
2982
2983                 if (RExC_parse[1] == '{') {
2984                   /* a lovely hack--pretend we saw [\pX] instead */
2985                     RExC_end = strchr(RExC_parse, '}');
2986                     if (!RExC_end) {
2987                         U8 c = (U8)*RExC_parse;
2988                         RExC_parse += 2;
2989                         RExC_end = oldregxend;
2990                         vFAIL2("Missing right brace on \\%c{}", c);
2991                     }
2992                     RExC_end++;
2993                 }
2994                 else {
2995                     RExC_end = RExC_parse + 2;
2996                     if (RExC_end > oldregxend)
2997                         RExC_end = oldregxend;
2998                 }
2999                 RExC_parse--;
3000
3001                 ret = regclass(pRExC_state);
3002
3003                 RExC_end = oldregxend;
3004                 RExC_parse--;
3005
3006                 Set_Node_Offset(ret, parse_start + 2);
3007                 Set_Node_Cur_Length(ret);
3008                 nextchar(pRExC_state);
3009                 *flagp |= HASWIDTH|SIMPLE;
3010             }
3011             break;
3012         case 'n':
3013         case 'r':
3014         case 't':
3015         case 'f':
3016         case 'e':
3017         case 'a':
3018         case 'x':
3019         case 'c':
3020         case '0':
3021             goto defchar;
3022         case '1': case '2': case '3': case '4':
3023         case '5': case '6': case '7': case '8': case '9':
3024             {
3025                 I32 num = atoi(RExC_parse);
3026
3027                 if (num > 9 && num >= RExC_npar)
3028                     goto defchar;
3029                 else {
3030                     char * parse_start = RExC_parse - 1; /* MJD */
3031                     while (isDIGIT(*RExC_parse))
3032                         RExC_parse++;
3033
3034                     if (!SIZE_ONLY && num > (I32)RExC_rx->nparens)
3035                         vFAIL("Reference to nonexistent group");
3036                     RExC_sawback = 1;
3037                     ret = reganode(pRExC_state,
3038                                    (U8)(FOLD ? (LOC ? REFFL : REFF) : REF),
3039                                    num);
3040                     *flagp |= HASWIDTH;
3041
3042                     /* override incorrect value set in reganode MJD */
3043                     Set_Node_Offset(ret, parse_start+1);
3044                     Set_Node_Cur_Length(ret); /* MJD */
3045                     RExC_parse--;
3046                     nextchar(pRExC_state);
3047                 }
3048             }
3049             break;
3050         case '\0':
3051             if (RExC_parse >= RExC_end)
3052                 FAIL("Trailing \\");
3053             /* FALL THROUGH */
3054         default:
3055             /* Do not generate `unrecognized' warnings here, we fall
3056                back into the quick-grab loop below */
3057             goto defchar;
3058         }
3059         break;
3060
3061     case '#':
3062         if (RExC_flags & PMf_EXTENDED) {
3063             while (RExC_parse < RExC_end && *RExC_parse != '\n') RExC_parse++;
3064             if (RExC_parse < RExC_end)
3065                 goto tryagain;
3066         }
3067         /* FALL THROUGH */
3068
3069     default: {
3070             register STRLEN len;
3071             register UV ender;
3072             register char *p;
3073             char *oldp, *s;
3074             STRLEN numlen;
3075             STRLEN foldlen;
3076             U8 tmpbuf[UTF8_MAXLEN_FOLD+1], *foldbuf;
3077
3078             parse_start = RExC_parse - 1;
3079
3080             RExC_parse++;
3081
3082         defchar:
3083             ender = 0;
3084             ret = reg_node(pRExC_state,
3085                            (U8)(FOLD ? (LOC ? EXACTFL : EXACTF) : EXACT));
3086             s = STRING(ret);
3087             for (len = 0, p = RExC_parse - 1;
3088               len < 127 && p < RExC_end;
3089               len++)
3090             {
3091                 oldp = p;
3092
3093                 if (RExC_flags & PMf_EXTENDED)
3094                     p = regwhite(p, RExC_end);
3095                 switch (*p) {
3096                 case '^':
3097                 case '$':
3098                 case '.':
3099                 case '[':
3100                 case '(':
3101                 case ')':
3102                 case '|':
3103                     goto loopdone;
3104                 case '\\':
3105                     switch (*++p) {
3106                     case 'A':
3107                     case 'C':
3108                     case 'X':
3109                     case 'G':
3110                     case 'Z':
3111                     case 'z':
3112                     case 'w':
3113                     case 'W':
3114                     case 'b':
3115                     case 'B':
3116                     case 's':
3117                     case 'S':
3118                     case 'd':
3119                     case 'D':
3120                     case 'p':
3121                     case 'P':
3122                         --p;
3123                         goto loopdone;
3124                     case 'n':
3125                         ender = '\n';
3126                         p++;
3127                         break;
3128                     case 'r':
3129                         ender = '\r';
3130                         p++;
3131                         break;
3132                     case 't':
3133                         ender = '\t';
3134                         p++;
3135                         break;
3136                     case 'f':
3137                         ender = '\f';
3138                         p++;
3139                         break;
3140                     case 'e':
3141                           ender = ASCII_TO_NATIVE('\033');
3142                         p++;
3143                         break;
3144                     case 'a':
3145                           ender = ASCII_TO_NATIVE('\007');
3146                         p++;
3147                         break;
3148                     case 'x':
3149                         if (*++p == '{') {
3150                             char* e = strchr(p, '}');
3151
3152                             if (!e) {
3153                                 RExC_parse = p + 1;
3154                                 vFAIL("Missing right brace on \\x{}");
3155                             }
3156                             else {
3157                                 I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3158                                     | PERL_SCAN_DISALLOW_PREFIX;
3159                                 numlen = e - p - 1;
3160                                 ender = grok_hex(p + 1, &numlen, &flags, NULL);
3161                                 if (ender > 0xff)
3162                                     RExC_utf8 = 1;
3163                                 /* numlen is generous */
3164                                 if (numlen + len >= 127) {
3165                                     p--;
3166                                     goto loopdone;
3167                                 }
3168                                 p = e + 1;
3169                             }
3170                         }
3171                         else {
3172                             I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3173                             numlen = 2;
3174                             ender = grok_hex(p, &numlen, &flags, NULL);
3175                             p += numlen;
3176                         }
3177                         break;
3178                     case 'c':
3179                         p++;
3180                         ender = UCHARAT(p++);
3181                         ender = toCTRL(ender);
3182                         break;
3183                     case '0': case '1': case '2': case '3':case '4':
3184                     case '5': case '6': case '7': case '8':case '9':
3185                         if (*p == '0' ||
3186                           (isDIGIT(p[1]) && atoi(p) >= RExC_npar) ) {
3187                             I32 flags = 0;
3188                             numlen = 3;
3189                             ender = grok_oct(p, &numlen, &flags, NULL);
3190                             p += numlen;
3191                         }
3192                         else {
3193                             --p;
3194                             goto loopdone;
3195                         }
3196                         break;
3197                     case '\0':
3198                         if (p >= RExC_end)
3199                             FAIL("Trailing \\");
3200                         /* FALL THROUGH */
3201                     default:
3202                         if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(*p))
3203                             vWARN2(p + 1, "Unrecognized escape \\%c passed through", UCHARAT(p));
3204                         goto normal_default;
3205                     }
3206                     break;
3207                 default:
3208                   normal_default:
3209                     if (UTF8_IS_START(*p) && UTF) {
3210                         ender = utf8n_to_uvchr((U8*)p, RExC_end - p,
3211                                                &numlen, 0);
3212                         p += numlen;
3213                     }
3214                     else
3215                         ender = *p++;
3216                     break;
3217                 }
3218                 if (RExC_flags & PMf_EXTENDED)
3219                     p = regwhite(p, RExC_end);
3220                 if (UTF && FOLD) {
3221                     /* Prime the casefolded buffer. */
3222                     ender = toFOLD_uni(ender, tmpbuf, &foldlen);
3223                 }
3224                 if (ISMULT2(p)) { /* Back off on ?+*. */
3225                     if (len)
3226                         p = oldp;
3227                     else if (UTF) {
3228                          STRLEN unilen;
3229
3230                          if (FOLD) {
3231                               /* Emit all the Unicode characters. */
3232                               for (foldbuf = tmpbuf;
3233                                    foldlen;
3234                                    foldlen -= numlen) {
3235                                    ender = utf8_to_uvchr(foldbuf, &numlen);
3236                                    if (numlen > 0) {
3237                                         reguni(pRExC_state, ender, s, &unilen);
3238                                         s       += unilen;
3239                                         len     += unilen;
3240                                         /* In EBCDIC the numlen
3241                                          * and unilen can differ. */
3242                                         foldbuf += numlen;
3243                                         if (numlen >= foldlen)
3244                                              break;
3245                                    }
3246                                    else
3247                                         break; /* "Can't happen." */
3248                               }
3249                          }
3250                          else {
3251                               reguni(pRExC_state, ender, s, &unilen);
3252                               if (unilen > 0) {
3253                                    s   += unilen;
3254                                    len += unilen;
3255                               }
3256                          }
3257                     }
3258                     else {
3259                         len++;
3260                         REGC((char)ender, s++);
3261                     }
3262                     break;
3263                 }
3264                 if (UTF) {
3265                      STRLEN unilen;
3266
3267                      if (FOLD) {
3268                           /* Emit all the Unicode characters. */
3269                           for (foldbuf = tmpbuf;
3270                                foldlen;
3271                                foldlen -= numlen) {
3272                                ender = utf8_to_uvchr(foldbuf, &numlen);
3273                                if (numlen > 0) {
3274                                     reguni(pRExC_state, ender, s, &unilen);
3275                                     len     += unilen;
3276                                     s       += unilen;
3277                                     /* In EBCDIC the numlen
3278                                      * and unilen can differ. */
3279                                     foldbuf += numlen;
3280                                     if (numlen >= foldlen)
3281                                          break;
3282                                }
3283                                else
3284                                     break;
3285                           }
3286                      }
3287                      else {
3288                           reguni(pRExC_state, ender, s, &unilen);
3289                           if (unilen > 0) {
3290                                s   += unilen;
3291                                len += unilen;
3292                           }
3293                      }
3294                      len--;
3295                 }
3296                 else
3297                     REGC((char)ender, s++);
3298             }
3299         loopdone:
3300             RExC_parse = p - 1;
3301             Set_Node_Cur_Length(ret); /* MJD */
3302             nextchar(pRExC_state);
3303             {
3304                 /* len is STRLEN which is unsigned, need to copy to signed */
3305                 IV iv = len;
3306                 if (iv < 0)
3307                     vFAIL("Internal disaster");
3308             }
3309             if (len > 0)
3310                 *flagp |= HASWIDTH;
3311             if (len == 1)
3312                 *flagp |= SIMPLE;
3313             if (!SIZE_ONLY)
3314                 STR_LEN(ret) = len;
3315             if (SIZE_ONLY)
3316                 RExC_size += STR_SZ(len);
3317             else
3318                 RExC_emit += STR_SZ(len);
3319         }
3320         break;
3321     }
3322
3323     /* If the encoding pragma is in effect recode the text of
3324      * any EXACT-kind nodes. */
3325     if (PL_encoding && PL_regkind[(U8)OP(ret)] == EXACT) {
3326         STRLEN oldlen = STR_LEN(ret);
3327         SV *sv        = sv_2mortal(newSVpvn(STRING(ret), oldlen));
3328
3329         if (RExC_utf8)
3330             SvUTF8_on(sv);
3331         if (sv_utf8_downgrade(sv, TRUE)) {
3332             char *s       = sv_recode_to_utf8(sv, PL_encoding);
3333             STRLEN newlen = SvCUR(sv);
3334
3335             if (SvUTF8(sv))
3336                 RExC_utf8 = 1;
3337             if (!SIZE_ONLY) {
3338                 DEBUG_r(PerlIO_printf(Perl_debug_log, "recode %*s to %*s\n",
3339                                       (int)oldlen, STRING(ret),
3340                                       (int)newlen, s));
3341                 Copy(s, STRING(ret), newlen, char);
3342                 STR_LEN(ret) += newlen - oldlen;
3343                 RExC_emit += STR_SZ(newlen) - STR_SZ(oldlen);
3344             } else
3345                 RExC_size += STR_SZ(newlen) - STR_SZ(oldlen);
3346         }
3347     }
3348
3349     return(ret);
3350 }
3351
3352 STATIC char *
3353 S_regwhite(pTHX_ char *p, char *e)
3354 {
3355     while (p < e) {
3356         if (isSPACE(*p))
3357             ++p;
3358         else if (*p == '#') {
3359             do {
3360                 p++;
3361             } while (p < e && *p != '\n');
3362         }
3363         else
3364             break;
3365     }
3366     return p;
3367 }
3368
3369 /* Parse POSIX character classes: [[:foo:]], [[=foo=]], [[.foo.]].
3370    Character classes ([:foo:]) can also be negated ([:^foo:]).
3371    Returns a named class id (ANYOF_XXX) if successful, -1 otherwise.
3372    Equivalence classes ([=foo=]) and composites ([.foo.]) are parsed,
3373    but trigger failures because they are currently unimplemented. */
3374
3375 #define POSIXCC_DONE(c)   ((c) == ':')
3376 #define POSIXCC_NOTYET(c) ((c) == '=' || (c) == '.')
3377 #define POSIXCC(c) (POSIXCC_DONE(c) || POSIXCC_NOTYET(c))
3378
3379 STATIC I32
3380 S_regpposixcc(pTHX_ RExC_state_t *pRExC_state, I32 value)
3381 {
3382     char *posixcc = 0;
3383     I32 namedclass = OOB_NAMEDCLASS;
3384
3385     if (value == '[' && RExC_parse + 1 < RExC_end &&
3386         /* I smell either [: or [= or [. -- POSIX has been here, right? */
3387         POSIXCC(UCHARAT(RExC_parse))) {
3388         char  c = UCHARAT(RExC_parse);
3389         char* s = RExC_parse++;
3390
3391         while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != c)
3392             RExC_parse++;
3393         if (RExC_parse == RExC_end)
3394             /* Grandfather lone [:, [=, [. */
3395             RExC_parse = s;
3396         else {
3397             char* t = RExC_parse++; /* skip over the c */
3398
3399             if (UCHARAT(RExC_parse) == ']') {
3400                 RExC_parse++; /* skip over the ending ] */
3401                 posixcc = s + 1;
3402                 if (*s == ':') {
3403                     I32 complement = *posixcc == '^' ? *posixcc++ : 0;
3404                     I32 skip = 5; /* the most common skip */
3405
3406                     switch (*posixcc) {
3407                     case 'a':
3408                         if (strnEQ(posixcc, "alnum", 5))
3409                             namedclass =
3410                                 complement ? ANYOF_NALNUMC : ANYOF_ALNUMC;
3411                         else if (strnEQ(posixcc, "alpha", 5))
3412                             namedclass =
3413                                 complement ? ANYOF_NALPHA : ANYOF_ALPHA;
3414                         else if (strnEQ(posixcc, "ascii", 5))
3415                             namedclass =
3416                                 complement ? ANYOF_NASCII : ANYOF_ASCII;
3417                         break;
3418                     case 'b':
3419                         if (strnEQ(posixcc, "blank", 5))
3420                             namedclass =
3421                                 complement ? ANYOF_NBLANK : ANYOF_BLANK;
3422                         break;
3423                     case 'c':
3424                         if (strnEQ(posixcc, "cntrl", 5))
3425                             namedclass =
3426                                 complement ? ANYOF_NCNTRL : ANYOF_CNTRL;
3427                         break;
3428                     case 'd':
3429                         if (strnEQ(posixcc, "digit", 5))
3430                             namedclass =
3431                                 complement ? ANYOF_NDIGIT : ANYOF_DIGIT;
3432                         break;
3433                     case 'g':
3434                         if (strnEQ(posixcc, "graph", 5))
3435                             namedclass =
3436                                 complement ? ANYOF_NGRAPH : ANYOF_GRAPH;
3437                         break;
3438                     case 'l':
3439                         if (strnEQ(posixcc, "lower", 5))
3440                             namedclass =
3441                                 complement ? ANYOF_NLOWER : ANYOF_LOWER;
3442                         break;
3443                     case 'p':
3444                         if (strnEQ(posixcc, "print", 5))
3445                             namedclass =
3446                                 complement ? ANYOF_NPRINT : ANYOF_PRINT;
3447                         else if (strnEQ(posixcc, "punct", 5))
3448                             namedclass =
3449                                 complement ? ANYOF_NPUNCT : ANYOF_PUNCT;
3450                         break;
3451                     case 's':
3452                         if (strnEQ(posixcc, "space", 5))
3453                             namedclass =
3454                                 complement ? ANYOF_NPSXSPC : ANYOF_PSXSPC;
3455                         break;
3456                     case 'u':
3457                         if (strnEQ(posixcc, "upper", 5))
3458                             namedclass =
3459                                 complement ? ANYOF_NUPPER : ANYOF_UPPER;
3460                         break;
3461                     case 'w': /* this is not POSIX, this is the Perl \w */
3462                         if (strnEQ(posixcc, "word", 4)) {
3463                             namedclass =
3464                                 complement ? ANYOF_NALNUM : ANYOF_ALNUM;
3465                             skip = 4;
3466                         }
3467                         break;
3468                     case 'x':
3469                         if (strnEQ(posixcc, "xdigit", 6)) {
3470                             namedclass =
3471                                 complement ? ANYOF_NXDIGIT : ANYOF_XDIGIT;
3472                             skip = 6;
3473                         }
3474                         break;
3475                     }
3476                     if (namedclass == OOB_NAMEDCLASS ||
3477                         posixcc[skip] != ':' ||
3478                         posixcc[skip+1] != ']')
3479                     {
3480                         Simple_vFAIL3("POSIX class [:%.*s:] unknown",
3481                                       t - s - 1, s + 1);
3482                     }
3483                 } else if (!SIZE_ONLY) {
3484                     /* [[=foo=]] and [[.foo.]] are still future. */
3485
3486                     /* adjust RExC_parse so the warning shows after
3487                        the class closes */
3488                     while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse) != ']')
3489                         RExC_parse++;
3490                     Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3491                 }
3492             } else {
3493                 /* Maternal grandfather:
3494                  * "[:" ending in ":" but not in ":]" */
3495                 RExC_parse = s;
3496             }
3497         }
3498     }
3499
3500     return namedclass;
3501 }
3502
3503 STATIC void
3504 S_checkposixcc(pTHX_ RExC_state_t *pRExC_state)
3505 {
3506     if (!SIZE_ONLY && POSIXCC(UCHARAT(RExC_parse))) {
3507         char *s = RExC_parse;
3508         char  c = *s++;
3509
3510         while(*s && isALNUM(*s))
3511             s++;
3512         if (*s && c == *s && s[1] == ']') {
3513             if (ckWARN(WARN_REGEXP))
3514                 vWARN3(s+2,
3515                         "POSIX syntax [%c %c] belongs inside character classes",
3516                         c, c);
3517
3518             /* [[=foo=]] and [[.foo.]] are still future. */
3519             if (POSIXCC_NOTYET(c)) {
3520                 /* adjust RExC_parse so the error shows after
3521                    the class closes */
3522                 while (UCHARAT(RExC_parse) && UCHARAT(RExC_parse++) != ']')
3523                     ;
3524                 Simple_vFAIL3("POSIX syntax [%c %c] is reserved for future extensions", c, c);
3525             }
3526         }
3527     }
3528 }
3529
3530 STATIC regnode *
3531 S_regclass(pTHX_ RExC_state_t *pRExC_state)
3532 {
3533     register UV value;
3534     register UV nextvalue;
3535     register IV prevvalue = OOB_UNICODE;
3536     register IV range = 0;
3537     register regnode *ret;
3538     STRLEN numlen;
3539     IV namedclass;
3540     char *rangebegin = 0;
3541     bool need_class = 0;
3542     SV *listsv = Nullsv;
3543     register char *e;
3544     UV n;
3545     bool optimize_invert   = TRUE;
3546     AV* unicode_alternate  = 0;
3547 #ifdef EBCDIC
3548     UV literal_endpoint = 0;
3549 #endif
3550
3551     ret = reganode(pRExC_state, ANYOF, 0);
3552
3553     if (!SIZE_ONLY)
3554         ANYOF_FLAGS(ret) = 0;
3555
3556     if (UCHARAT(RExC_parse) == '^') {   /* Complement of range. */
3557         RExC_naughty++;
3558         RExC_parse++;
3559         if (!SIZE_ONLY)
3560             ANYOF_FLAGS(ret) |= ANYOF_INVERT;
3561     }
3562
3563     if (SIZE_ONLY)
3564         RExC_size += ANYOF_SKIP;
3565     else {
3566         RExC_emit += ANYOF_SKIP;
3567         if (FOLD)
3568             ANYOF_FLAGS(ret) |= ANYOF_FOLD;
3569         if (LOC)
3570             ANYOF_FLAGS(ret) |= ANYOF_LOCALE;
3571         ANYOF_BITMAP_ZERO(ret);
3572         listsv = newSVpvn("# comment\n", 10);
3573     }
3574
3575     nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3576
3577     if (!SIZE_ONLY && POSIXCC(nextvalue))
3578         checkposixcc(pRExC_state);
3579
3580     /* allow 1st char to be ] (allowing it to be - is dealt with later) */
3581     if (UCHARAT(RExC_parse) == ']')
3582         goto charclassloop;
3583
3584     while (RExC_parse < RExC_end && UCHARAT(RExC_parse) != ']') {
3585
3586     charclassloop:
3587
3588         namedclass = OOB_NAMEDCLASS; /* initialize as illegal */
3589
3590         if (!range)
3591             rangebegin = RExC_parse;
3592         if (UTF) {
3593             value = utf8n_to_uvchr((U8*)RExC_parse,
3594                                    RExC_end - RExC_parse,
3595                                    &numlen, 0);
3596             RExC_parse += numlen;
3597         }
3598         else
3599             value = UCHARAT(RExC_parse++);
3600         nextvalue = RExC_parse < RExC_end ? UCHARAT(RExC_parse) : 0;
3601         if (value == '[' && POSIXCC(nextvalue))
3602             namedclass = regpposixcc(pRExC_state, value);
3603         else if (value == '\\') {
3604             if (UTF) {
3605                 value = utf8n_to_uvchr((U8*)RExC_parse,
3606                                    RExC_end - RExC_parse,
3607                                    &numlen, 0);
3608                 RExC_parse += numlen;
3609             }
3610             else
3611                 value = UCHARAT(RExC_parse++);
3612             /* Some compilers cannot handle switching on 64-bit integer
3613              * values, therefore value cannot be an UV.  Yes, this will
3614              * be a problem later if we want switch on Unicode.
3615              * A similar issue a little bit later when switching on
3616              * namedclass. --jhi */
3617             switch ((I32)value) {
3618             case 'w':   namedclass = ANYOF_ALNUM;       break;
3619             case 'W':   namedclass = ANYOF_NALNUM;      break;
3620             case 's':   namedclass = ANYOF_SPACE;       break;
3621             case 'S':   namedclass = ANYOF_NSPACE;      break;
3622             case 'd':   namedclass = ANYOF_DIGIT;       break;
3623             case 'D':   namedclass = ANYOF_NDIGIT;      break;
3624             case 'p':
3625             case 'P':
3626                 if (RExC_parse >= RExC_end)
3627                     vFAIL2("Empty \\%c{}", (U8)value);
3628                 if (*RExC_parse == '{') {
3629                     U8 c = (U8)value;
3630                     e = strchr(RExC_parse++, '}');
3631                     if (!e)
3632                         vFAIL2("Missing right brace on \\%c{}", c);
3633                     while (isSPACE(UCHARAT(RExC_parse)))
3634                         RExC_parse++;
3635                     if (e == RExC_parse)
3636                         vFAIL2("Empty \\%c{}", c);
3637                     n = e - RExC_parse;
3638                     while (isSPACE(UCHARAT(RExC_parse + n - 1)))
3639                         n--;
3640                 }
3641                 else {
3642                     e = RExC_parse;
3643                     n = 1;
3644                 }
3645                 if (!SIZE_ONLY) {
3646                     if (UCHARAT(RExC_parse) == '^') {
3647                          RExC_parse++;
3648                          n--;
3649                          value = value == 'p' ? 'P' : 'p'; /* toggle */
3650                          while (isSPACE(UCHARAT(RExC_parse))) {
3651                               RExC_parse++;
3652                               n--;
3653                          }
3654                     }
3655                     if (value == 'p')
3656                          Perl_sv_catpvf(aTHX_ listsv,
3657                                         "+utf8::%.*s\n", (int)n, RExC_parse);
3658                     else
3659                          Perl_sv_catpvf(aTHX_ listsv,
3660                                         "!utf8::%.*s\n", (int)n, RExC_parse);
3661                 }
3662                 RExC_parse = e + 1;
3663                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3664                 continue;
3665             case 'n':   value = '\n';                   break;
3666             case 'r':   value = '\r';                   break;
3667             case 't':   value = '\t';                   break;
3668             case 'f':   value = '\f';                   break;
3669             case 'b':   value = '\b';                   break;
3670             case 'e':   value = ASCII_TO_NATIVE('\033');break;
3671             case 'a':   value = ASCII_TO_NATIVE('\007');break;
3672             case 'x':
3673                 if (*RExC_parse == '{') {
3674                     I32 flags = PERL_SCAN_ALLOW_UNDERSCORES
3675                         | PERL_SCAN_DISALLOW_PREFIX;
3676                     e = strchr(RExC_parse++, '}');
3677                     if (!e)
3678                         vFAIL("Missing right brace on \\x{}");
3679
3680                     numlen = e - RExC_parse;
3681                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3682                     RExC_parse = e + 1;
3683                 }
3684                 else {
3685                     I32 flags = PERL_SCAN_DISALLOW_PREFIX;
3686                     numlen = 2;
3687                     value = grok_hex(RExC_parse, &numlen, &flags, NULL);
3688                     RExC_parse += numlen;
3689                 }
3690                 break;
3691             case 'c':
3692                 value = UCHARAT(RExC_parse++);
3693                 value = toCTRL(value);
3694                 break;
3695             case '0': case '1': case '2': case '3': case '4':
3696             case '5': case '6': case '7': case '8': case '9':
3697             {
3698                 I32 flags = 0;
3699                 numlen = 3;
3700                 value = grok_oct(--RExC_parse, &numlen, &flags, NULL);
3701                 RExC_parse += numlen;
3702                 break;
3703             }
3704             default:
3705                 if (!SIZE_ONLY && ckWARN(WARN_REGEXP) && isALPHA(value))
3706                     vWARN2(RExC_parse,
3707                            "Unrecognized escape \\%c in character class passed through",
3708                            (int)value);
3709                 break;
3710             }
3711         } /* end of \blah */
3712 #ifdef EBCDIC
3713         else
3714             literal_endpoint++;
3715 #endif
3716
3717         if (namedclass > OOB_NAMEDCLASS) { /* this is a named class \blah */
3718
3719             if (!SIZE_ONLY && !need_class)
3720                 ANYOF_CLASS_ZERO(ret);
3721
3722             need_class = 1;
3723
3724             /* a bad range like a-\d, a-[:digit:] ? */
3725             if (range) {
3726                 if (!SIZE_ONLY) {
3727                     if (ckWARN(WARN_REGEXP))
3728                         vWARN4(RExC_parse,
3729                                "False [] range \"%*.*s\"",
3730                                RExC_parse - rangebegin,
3731                                RExC_parse - rangebegin,
3732                                rangebegin);
3733                     if (prevvalue < 256) {
3734                         ANYOF_BITMAP_SET(ret, prevvalue);
3735                         ANYOF_BITMAP_SET(ret, '-');
3736                     }
3737                     else {
3738                         ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
3739                         Perl_sv_catpvf(aTHX_ listsv,
3740                                        "%04"UVxf"\n%04"UVxf"\n", (UV)prevvalue, (UV) '-');
3741                     }
3742                 }
3743
3744                 range = 0; /* this was not a true range */
3745             }
3746
3747             if (!SIZE_ONLY) {
3748                 if (namedclass > OOB_NAMEDCLASS)
3749                     optimize_invert = FALSE;
3750                 /* Possible truncation here but in some 64-bit environments
3751                  * the compiler gets heartburn about switch on 64-bit values.
3752                  * A similar issue a little earlier when switching on value.
3753                  * --jhi */
3754                 switch ((I32)namedclass) {
3755                 case ANYOF_ALNUM:
3756                     if (LOC)
3757                         ANYOF_CLASS_SET(ret, ANYOF_ALNUM);
3758                     else {
3759                         for (value = 0; value < 256; value++)
3760                             if (isALNUM(value))
3761                                 ANYOF_BITMAP_SET(ret, value);
3762                     }
3763                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsWord\n");
3764                     break;
3765                 case ANYOF_NALNUM:
3766                     if (LOC)
3767                         ANYOF_CLASS_SET(ret, ANYOF_NALNUM);
3768                     else {
3769                         for (value = 0; value < 256; value++)
3770                             if (!isALNUM(value))
3771                                 ANYOF_BITMAP_SET(ret, value);
3772                     }
3773                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsWord\n");
3774                     break;
3775                 case ANYOF_ALNUMC:
3776                     if (LOC)
3777                         ANYOF_CLASS_SET(ret, ANYOF_ALNUMC);
3778                     else {
3779                         for (value = 0; value < 256; value++)
3780                             if (isALNUMC(value))
3781                                 ANYOF_BITMAP_SET(ret, value);
3782                     }
3783                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlnum\n");
3784                     break;
3785                 case ANYOF_NALNUMC:
3786                     if (LOC)
3787                         ANYOF_CLASS_SET(ret, ANYOF_NALNUMC);
3788                     else {
3789                         for (value = 0; value < 256; value++)
3790                             if (!isALNUMC(value))
3791                                 ANYOF_BITMAP_SET(ret, value);
3792                     }
3793                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlnum\n");
3794                     break;
3795                 case ANYOF_ALPHA:
3796                     if (LOC)
3797                         ANYOF_CLASS_SET(ret, ANYOF_ALPHA);
3798                     else {
3799                         for (value = 0; value < 256; value++)
3800                             if (isALPHA(value))
3801                                 ANYOF_BITMAP_SET(ret, value);
3802                     }
3803                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsAlpha\n");
3804                     break;
3805                 case ANYOF_NALPHA:
3806                     if (LOC)
3807                         ANYOF_CLASS_SET(ret, ANYOF_NALPHA);
3808                     else {
3809                         for (value = 0; value < 256; value++)
3810                             if (!isALPHA(value))
3811                                 ANYOF_BITMAP_SET(ret, value);
3812                     }
3813                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsAlpha\n");
3814                     break;
3815                 case ANYOF_ASCII:
3816                     if (LOC)
3817                         ANYOF_CLASS_SET(ret, ANYOF_ASCII);
3818                     else {
3819 #ifndef EBCDIC
3820                         for (value = 0; value < 128; value++)
3821                             ANYOF_BITMAP_SET(ret, value);
3822 #else  /* EBCDIC */
3823                         for (value = 0; value < 256; value++) {
3824                             if (isASCII(value))
3825                                 ANYOF_BITMAP_SET(ret, value);
3826                         }
3827 #endif /* EBCDIC */
3828                     }
3829                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsASCII\n");
3830                     break;
3831                 case ANYOF_NASCII:
3832                     if (LOC)
3833                         ANYOF_CLASS_SET(ret, ANYOF_NASCII);
3834                     else {
3835 #ifndef EBCDIC
3836                         for (value = 128; value < 256; value++)
3837                             ANYOF_BITMAP_SET(ret, value);
3838 #else  /* EBCDIC */
3839                         for (value = 0; value < 256; value++) {
3840                             if (!isASCII(value))
3841                                 ANYOF_BITMAP_SET(ret, value);
3842                         }
3843 #endif /* EBCDIC */
3844                     }
3845                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsASCII\n");
3846                     break;
3847                 case ANYOF_BLANK:
3848                     if (LOC)
3849                         ANYOF_CLASS_SET(ret, ANYOF_BLANK);
3850                     else {
3851                         for (value = 0; value < 256; value++)
3852                             if (isBLANK(value))
3853                                 ANYOF_BITMAP_SET(ret, value);
3854                     }
3855                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsBlank\n");
3856                     break;
3857                 case ANYOF_NBLANK:
3858                     if (LOC)
3859                         ANYOF_CLASS_SET(ret, ANYOF_NBLANK);
3860                     else {
3861                         for (value = 0; value < 256; value++)
3862                             if (!isBLANK(value))
3863                                 ANYOF_BITMAP_SET(ret, value);
3864                     }
3865                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsBlank\n");
3866                     break;
3867                 case ANYOF_CNTRL:
3868                     if (LOC)
3869                         ANYOF_CLASS_SET(ret, ANYOF_CNTRL);
3870                     else {
3871                         for (value = 0; value < 256; value++)
3872                             if (isCNTRL(value))
3873                                 ANYOF_BITMAP_SET(ret, value);
3874                     }
3875                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsCntrl\n");
3876                     break;
3877                 case ANYOF_NCNTRL:
3878                     if (LOC)
3879                         ANYOF_CLASS_SET(ret, ANYOF_NCNTRL);
3880                     else {
3881                         for (value = 0; value < 256; value++)
3882                             if (!isCNTRL(value))
3883                                 ANYOF_BITMAP_SET(ret, value);
3884                     }
3885                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsCntrl\n");
3886                     break;
3887                 case ANYOF_DIGIT:
3888                     if (LOC)
3889                         ANYOF_CLASS_SET(ret, ANYOF_DIGIT);
3890                     else {
3891                         /* consecutive digits assumed */
3892                         for (value = '0'; value <= '9'; value++)
3893                             ANYOF_BITMAP_SET(ret, value);
3894                     }
3895                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsDigit\n");
3896                     break;
3897                 case ANYOF_NDIGIT:
3898                     if (LOC)
3899                         ANYOF_CLASS_SET(ret, ANYOF_NDIGIT);
3900                     else {
3901                         /* consecutive digits assumed */
3902                         for (value = 0; value < '0'; value++)
3903                             ANYOF_BITMAP_SET(ret, value);
3904                         for (value = '9' + 1; value < 256; value++)
3905                             ANYOF_BITMAP_SET(ret, value);
3906                     }
3907                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsDigit\n");
3908                     break;
3909                 case ANYOF_GRAPH:
3910                     if (LOC)
3911                         ANYOF_CLASS_SET(ret, ANYOF_GRAPH);
3912                     else {
3913                         for (value = 0; value < 256; value++)
3914                             if (isGRAPH(value))
3915                                 ANYOF_BITMAP_SET(ret, value);
3916                     }
3917                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsGraph\n");
3918                     break;
3919                 case ANYOF_NGRAPH:
3920                     if (LOC)
3921                         ANYOF_CLASS_SET(ret, ANYOF_NGRAPH);
3922                     else {
3923                         for (value = 0; value < 256; value++)
3924                             if (!isGRAPH(value))
3925                                 ANYOF_BITMAP_SET(ret, value);
3926                     }
3927                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsGraph\n");
3928                     break;
3929                 case ANYOF_LOWER:
3930                     if (LOC)
3931                         ANYOF_CLASS_SET(ret, ANYOF_LOWER);
3932                     else {
3933                         for (value = 0; value < 256; value++)
3934                             if (isLOWER(value))
3935                                 ANYOF_BITMAP_SET(ret, value);
3936                     }
3937                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsLower\n");
3938                     break;
3939                 case ANYOF_NLOWER:
3940                     if (LOC)
3941                         ANYOF_CLASS_SET(ret, ANYOF_NLOWER);
3942                     else {
3943                         for (value = 0; value < 256; value++)
3944                             if (!isLOWER(value))
3945                                 ANYOF_BITMAP_SET(ret, value);
3946                     }
3947                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsLower\n");
3948                     break;
3949                 case ANYOF_PRINT:
3950                     if (LOC)
3951                         ANYOF_CLASS_SET(ret, ANYOF_PRINT);
3952                     else {
3953                         for (value = 0; value < 256; value++)
3954                             if (isPRINT(value))
3955                                 ANYOF_BITMAP_SET(ret, value);
3956                     }
3957                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPrint\n");
3958                     break;
3959                 case ANYOF_NPRINT:
3960                     if (LOC)
3961                         ANYOF_CLASS_SET(ret, ANYOF_NPRINT);
3962                     else {
3963                         for (value = 0; value < 256; value++)
3964                             if (!isPRINT(value))
3965                                 ANYOF_BITMAP_SET(ret, value);
3966                     }
3967                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPrint\n");
3968                     break;
3969                 case ANYOF_PSXSPC:
3970                     if (LOC)
3971                         ANYOF_CLASS_SET(ret, ANYOF_PSXSPC);
3972                     else {
3973                         for (value = 0; value < 256; value++)
3974                             if (isPSXSPC(value))
3975                                 ANYOF_BITMAP_SET(ret, value);
3976                     }
3977                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpace\n");
3978                     break;
3979                 case ANYOF_NPSXSPC:
3980                     if (LOC)
3981                         ANYOF_CLASS_SET(ret, ANYOF_NPSXSPC);
3982                     else {
3983                         for (value = 0; value < 256; value++)
3984                             if (!isPSXSPC(value))
3985                                 ANYOF_BITMAP_SET(ret, value);
3986                     }
3987                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpace\n");
3988                     break;
3989                 case ANYOF_PUNCT:
3990                     if (LOC)
3991                         ANYOF_CLASS_SET(ret, ANYOF_PUNCT);
3992                     else {
3993                         for (value = 0; value < 256; value++)
3994                             if (isPUNCT(value))
3995                                 ANYOF_BITMAP_SET(ret, value);
3996                     }
3997                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsPunct\n");
3998                     break;
3999                 case ANYOF_NPUNCT:
4000                     if (LOC)
4001                         ANYOF_CLASS_SET(ret, ANYOF_NPUNCT);
4002                     else {
4003                         for (value = 0; value < 256; value++)
4004                             if (!isPUNCT(value))
4005                                 ANYOF_BITMAP_SET(ret, value);
4006                     }
4007                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsPunct\n");
4008                     break;
4009                 case ANYOF_SPACE:
4010                     if (LOC)
4011                         ANYOF_CLASS_SET(ret, ANYOF_SPACE);
4012                     else {
4013                         for (value = 0; value < 256; value++)
4014                             if (isSPACE(value))
4015                                 ANYOF_BITMAP_SET(ret, value);
4016                     }
4017                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsSpacePerl\n");
4018                     break;
4019                 case ANYOF_NSPACE:
4020                     if (LOC)
4021                         ANYOF_CLASS_SET(ret, ANYOF_NSPACE);
4022                     else {
4023                         for (value = 0; value < 256; value++)
4024                             if (!isSPACE(value))
4025                                 ANYOF_BITMAP_SET(ret, value);
4026                     }
4027                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsSpacePerl\n");
4028                     break;
4029                 case ANYOF_UPPER:
4030                     if (LOC)
4031                         ANYOF_CLASS_SET(ret, ANYOF_UPPER);
4032                     else {
4033                         for (value = 0; value < 256; value++)
4034                             if (isUPPER(value))
4035                                 ANYOF_BITMAP_SET(ret, value);
4036                     }
4037                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsUpper\n");
4038                     break;
4039                 case ANYOF_NUPPER:
4040                     if (LOC)
4041                         ANYOF_CLASS_SET(ret, ANYOF_NUPPER);
4042                     else {
4043                         for (value = 0; value < 256; value++)
4044                             if (!isUPPER(value))
4045                                 ANYOF_BITMAP_SET(ret, value);
4046                     }
4047                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsUpper\n");
4048                     break;
4049                 case ANYOF_XDIGIT:
4050                     if (LOC)
4051                         ANYOF_CLASS_SET(ret, ANYOF_XDIGIT);
4052                     else {
4053                         for (value = 0; value < 256; value++)
4054                             if (isXDIGIT(value))
4055                                 ANYOF_BITMAP_SET(ret, value);
4056                     }
4057                     Perl_sv_catpvf(aTHX_ listsv, "+utf8::IsXDigit\n");
4058                     break;
4059                 case ANYOF_NXDIGIT:
4060                     if (LOC)
4061                         ANYOF_CLASS_SET(ret, ANYOF_NXDIGIT);
4062                     else {
4063                         for (value = 0; value < 256; value++)
4064                             if (!isXDIGIT(value))
4065                                 ANYOF_BITMAP_SET(ret, value);
4066                     }
4067                     Perl_sv_catpvf(aTHX_ listsv, "!utf8::IsXDigit\n");
4068                     break;
4069                 default:
4070                     vFAIL("Invalid [::] class");
4071                     break;
4072                 }
4073                 if (LOC)
4074                     ANYOF_FLAGS(ret) |= ANYOF_CLASS;
4075                 continue;
4076             }
4077         } /* end of namedclass \blah */
4078
4079         if (range) {
4080             if (prevvalue > (IV)value) /* b-a */ {
4081                 Simple_vFAIL4("Invalid [] range \"%*.*s\"",
4082                               RExC_parse - rangebegin,
4083                               RExC_parse - rangebegin,
4084                               rangebegin);
4085                 range = 0; /* not a valid range */
4086             }
4087         }
4088         else {
4089             prevvalue = value; /* save the beginning of the range */
4090             if (*RExC_parse == '-' && RExC_parse+1 < RExC_end &&
4091                 RExC_parse[1] != ']') {
4092                 RExC_parse++;
4093
4094                 /* a bad range like \w-, [:word:]- ? */
4095                 if (namedclass > OOB_NAMEDCLASS) {
4096                     if (ckWARN(WARN_REGEXP))
4097                         vWARN4(RExC_parse,
4098                                "False [] range \"%*.*s\"",
4099                                RExC_parse - rangebegin,
4100                                RExC_parse - rangebegin,
4101                                rangebegin);
4102                     if (!SIZE_ONLY)
4103                         ANYOF_BITMAP_SET(ret, '-');
4104                 } else
4105                     range = 1;  /* yeah, it's a range! */
4106                 continue;       /* but do it the next time */
4107             }
4108         }
4109
4110         /* now is the next time */
4111         if (!SIZE_ONLY) {
4112             IV i;
4113
4114             if (prevvalue < 256) {
4115                 IV ceilvalue = value < 256 ? value : 255;
4116
4117 #ifdef EBCDIC
4118                 /* In EBCDIC [\x89-\x91] should include
4119                  * the \x8e but [i-j] should not. */
4120                 if (literal_endpoint == 2 &&
4121                     ((isLOWER(prevvalue) && isLOWER(ceilvalue)) ||
4122                      (isUPPER(prevvalue) && isUPPER(ceilvalue))))
4123                 {
4124                     if (isLOWER(prevvalue)) {
4125                         for (i = prevvalue; i <= ceilvalue; i++)
4126                             if (isLOWER(i))
4127                                 ANYOF_BITMAP_SET(ret, i);
4128                     } else {
4129                         for (i = prevvalue; i <= ceilvalue; i++)
4130                             if (isUPPER(i))
4131                                 ANYOF_BITMAP_SET(ret, i);
4132                     }
4133                 }
4134                 else
4135 #endif
4136                       for (i = prevvalue; i <= ceilvalue; i++)
4137                           ANYOF_BITMAP_SET(ret, i);
4138           }
4139           if (value > 255 || UTF) {
4140                 UV prevnatvalue  = NATIVE_TO_UNI(prevvalue);
4141                 UV natvalue      = NATIVE_TO_UNI(value);
4142
4143                 ANYOF_FLAGS(ret) |= ANYOF_UNICODE;
4144                 if (prevnatvalue < natvalue) { /* what about > ? */
4145                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\t%04"UVxf"\n",
4146                                    prevnatvalue, natvalue);
4147                 }
4148                 else if (prevnatvalue == natvalue) {
4149                     Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n", natvalue);
4150                     if (FOLD) {
4151                          U8 foldbuf[UTF8_MAXLEN_FOLD+1];
4152                          STRLEN foldlen;
4153                          UV f = to_uni_fold(natvalue, foldbuf, &foldlen);
4154
4155                          /* If folding and foldable and a single
4156                           * character, insert also the folded version
4157                           * to the charclass. */
4158                          if (f != value) {
4159                               if (foldlen == (STRLEN)UNISKIP(f))
4160                                   Perl_sv_catpvf(aTHX_ listsv,
4161                                                  "%04"UVxf"\n", f);
4162                               else {
4163                                   /* Any multicharacter foldings
4164                                    * require the following transform:
4165                                    * [ABCDEF] -> (?:[ABCabcDEFd]|pq|rst)
4166                                    * where E folds into "pq" and F folds
4167                                    * into "rst", all other characters
4168                                    * fold to single characters.  We save
4169                                    * away these multicharacter foldings,
4170                                    * to be later saved as part of the
4171                                    * additional "s" data. */
4172                                   SV *sv;
4173
4174                                   if (!unicode_alternate)
4175                                       unicode_alternate = newAV();
4176                                   sv = newSVpvn((char*)foldbuf, foldlen);
4177                                   SvUTF8_on(sv);
4178                                   av_push(unicode_alternate, sv);
4179                               }
4180                          }
4181
4182                          /* If folding and the value is one of the Greek
4183                           * sigmas insert a few more sigmas to make the
4184                           * folding rules of the sigmas to work right.
4185                           * Note that not all the possible combinations
4186                           * are handled here: some of them are handled
4187                           * by the standard folding rules, and some of
4188                           * them (literal or EXACTF cases) are handled
4189                           * during runtime in regexec.c:S_find_byclass(). */
4190                          if (value == UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA) {
4191                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4192                                              (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA);
4193                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4194                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4195                          }
4196                          else if (value == UNICODE_GREEK_CAPITAL_LETTER_SIGMA)
4197                               Perl_sv_catpvf(aTHX_ listsv, "%04"UVxf"\n",
4198                                              (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA);
4199                     }
4200                 }
4201             }
4202 #ifdef EBCDIC
4203             literal_endpoint = 0;
4204 #endif
4205         }
4206
4207         range = 0; /* this range (if it was one) is done now */
4208     }
4209
4210     if (need_class) {
4211         ANYOF_FLAGS(ret) |= ANYOF_LARGE;
4212         if (SIZE_ONLY)
4213             RExC_size += ANYOF_CLASS_ADD_SKIP;
4214         else
4215             RExC_emit += ANYOF_CLASS_ADD_SKIP;
4216     }
4217
4218     /* optimize case-insensitive simple patterns (e.g. /[a-z]/i) */
4219     if (!SIZE_ONLY &&
4220          /* If the only flag is folding (plus possibly inversion). */
4221         ((ANYOF_FLAGS(ret) & (ANYOF_FLAGS_ALL ^ ANYOF_INVERT)) == ANYOF_FOLD)
4222        ) {
4223         for (value = 0; value < 256; ++value) {
4224             if (ANYOF_BITMAP_TEST(ret, value)) {
4225                 UV fold = PL_fold[value];
4226
4227                 if (fold != value)
4228                     ANYOF_BITMAP_SET(ret, fold);
4229             }
4230         }
4231         ANYOF_FLAGS(ret) &= ~ANYOF_FOLD;
4232     }
4233
4234     /* optimize inverted simple patterns (e.g. [^a-z]) */
4235     if (!SIZE_ONLY && optimize_invert &&
4236         /* If the only flag is inversion. */
4237         (ANYOF_FLAGS(ret) & ANYOF_FLAGS_ALL) == ANYOF_INVERT) {
4238         for (value = 0; value < ANYOF_BITMAP_SIZE; ++value)
4239             ANYOF_BITMAP(ret)[value] ^= ANYOF_FLAGS_ALL;
4240         ANYOF_FLAGS(ret) = ANYOF_UNICODE_ALL;
4241     }
4242
4243     if (!SIZE_ONLY) {
4244         AV *av = newAV();
4245         SV *rv;
4246
4247         /* The 0th element stores the character class description
4248          * in its textual form: used later (regexec.c:Perl_regclass_swash())
4249          * to initialize the appropriate swash (which gets stored in
4250          * the 1st element), and also useful for dumping the regnode.
4251          * The 2nd element stores the multicharacter foldings,
4252          * used later (regexec.c:S_reginclass()). */
4253         av_store(av, 0, listsv);
4254         av_store(av, 1, NULL);
4255         av_store(av, 2, (SV*)unicode_alternate);
4256         rv = newRV_noinc((SV*)av);
4257         n = add_data(pRExC_state, 1, "s");
4258         RExC_rx->data->data[n] = (void*)rv;
4259         ARG_SET(ret, n);
4260     }
4261
4262     return ret;
4263 }
4264
4265 STATIC char*
4266 S_nextchar(pTHX_ RExC_state_t *pRExC_state)
4267 {
4268     char* retval = RExC_parse++;
4269
4270     for (;;) {
4271         if (*RExC_parse == '(' && RExC_parse[1] == '?' &&
4272                 RExC_parse[2] == '#') {
4273             while (*RExC_parse && *RExC_parse != ')')
4274                 RExC_parse++;
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_parse != '\n')
4285                     RExC_parse++;
4286                 RExC_parse++;
4287                 continue;
4288             }
4289         }
4290         return retval;
4291     }
4292 }
4293
4294 /*
4295 - reg_node - emit a node
4296 */
4297 STATIC regnode *                        /* Location. */
4298 S_reg_node(pTHX_ RExC_state_t *pRExC_state, U8 op)
4299 {
4300     register regnode *ret;
4301     register regnode *ptr;
4302
4303     ret = RExC_emit;
4304     if (SIZE_ONLY) {
4305         SIZE_ALIGN(RExC_size);
4306         RExC_size += 1;
4307         return(ret);
4308     }
4309
4310     NODE_ALIGN_FILL(ret);
4311     ptr = ret;
4312     FILL_ADVANCE_NODE(ptr, op);
4313     if (RExC_offsets) {         /* MJD */
4314         MJD_OFFSET_DEBUG(("%s:%u: (op %s) %s %u <- %u (len %u) (max %u).\n",
4315               "reg_node", __LINE__,
4316               reg_name[op],
4317               RExC_emit - RExC_emit_start > RExC_offsets[0]
4318               ? "Overwriting end of array!\n" : "OK",
4319               RExC_emit - RExC_emit_start,
4320               RExC_parse - RExC_start,
4321               RExC_offsets[0]));
4322         Set_Node_Offset(RExC_emit, RExC_parse + (op == END));
4323     }
4324
4325     RExC_emit = ptr;
4326
4327     return(ret);
4328 }
4329
4330 /*
4331 - reganode - emit a node with an argument
4332 */
4333 STATIC regnode *                        /* Location. */
4334 S_reganode(pTHX_ RExC_state_t *pRExC_state, U8 op, U32 arg)
4335 {
4336     register regnode *ret;
4337     register regnode *ptr;
4338
4339     ret = RExC_emit;
4340     if (SIZE_ONLY) {
4341         SIZE_ALIGN(RExC_size);
4342         RExC_size += 2;
4343         return(ret);
4344     }
4345
4346     NODE_ALIGN_FILL(ret);
4347     ptr = ret;
4348     FILL_ADVANCE_NODE_ARG(ptr, op, arg);
4349     if (RExC_offsets) {         /* MJD */
4350         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4351               "reganode",
4352               __LINE__,
4353               reg_name[op],
4354               RExC_emit - RExC_emit_start > RExC_offsets[0] ?
4355               "Overwriting end of array!\n" : "OK",
4356               RExC_emit - RExC_emit_start,
4357               RExC_parse - RExC_start,
4358               RExC_offsets[0]));
4359         Set_Cur_Node_Offset;
4360     }
4361
4362     RExC_emit = ptr;
4363
4364     return(ret);
4365 }
4366
4367 /*
4368 - reguni - emit (if appropriate) a Unicode character
4369 */
4370 STATIC void
4371 S_reguni(pTHX_ RExC_state_t *pRExC_state, UV uv, char* s, STRLEN* lenp)
4372 {
4373     *lenp = SIZE_ONLY ? UNISKIP(uv) : (uvchr_to_utf8((U8*)s, uv) - (U8*)s);
4374 }
4375
4376 /*
4377 - reginsert - insert an operator in front of already-emitted operand
4378 *
4379 * Means relocating the operand.
4380 */
4381 STATIC void
4382 S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd)
4383 {
4384     register regnode *src;
4385     register regnode *dst;
4386     register regnode *place;
4387     register int offset = regarglen[(U8)op];
4388
4389 /* (PL_regkind[(U8)op] == CURLY ? EXTRA_STEP_2ARGS : 0); */
4390
4391     if (SIZE_ONLY) {
4392         RExC_size += NODE_STEP_REGNODE + offset;
4393         return;
4394     }
4395
4396     src = RExC_emit;
4397     RExC_emit += NODE_STEP_REGNODE + offset;
4398     dst = RExC_emit;
4399     while (src > opnd) {
4400         StructCopy(--src, --dst, regnode);
4401         if (RExC_offsets) {     /* MJD 20010112 */
4402             MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s copy %u -> %u (max %u).\n",
4403                   "reg_insert",
4404                   __LINE__,
4405                   reg_name[op],
4406                   dst - RExC_emit_start > RExC_offsets[0]
4407                   ? "Overwriting end of array!\n" : "OK",
4408                   src - RExC_emit_start,
4409                   dst - RExC_emit_start,
4410                   RExC_offsets[0]));
4411             Set_Node_Offset_To_R(dst-RExC_emit_start, Node_Offset(src));
4412             Set_Node_Length_To_R(dst-RExC_emit_start, Node_Length(src));
4413         }
4414     }
4415
4416
4417     place = opnd;               /* Op node, where operand used to be. */
4418     if (RExC_offsets) {         /* MJD */
4419         MJD_OFFSET_DEBUG(("%s(%d): (op %s) %s %u <- %u (max %u).\n",
4420               "reginsert",
4421               __LINE__,
4422               reg_name[op],
4423               place - RExC_emit_start > RExC_offsets[0]
4424               ? "Overwriting end of array!\n" : "OK",
4425               place - RExC_emit_start,
4426               RExC_parse - RExC_start,
4427               RExC_offsets[0]));
4428         Set_Node_Offset(place, RExC_parse);
4429     }
4430     src = NEXTOPER(place);
4431     FILL_ADVANCE_NODE(place, op);
4432     Zero(src, offset, regnode);
4433 }
4434
4435 /*
4436 - regtail - set the next-pointer at the end of a node chain of p to val.
4437 */
4438 STATIC void
4439 S_regtail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4440 {
4441     register regnode *scan;
4442     register regnode *temp;
4443
4444     if (SIZE_ONLY)
4445         return;
4446
4447     /* Find last node. */
4448     scan = p;
4449     for (;;) {
4450         temp = regnext(scan);
4451         if (temp == NULL)
4452             break;
4453         scan = temp;
4454     }
4455
4456     if (reg_off_by_arg[OP(scan)]) {
4457         ARG_SET(scan, val - scan);
4458     }
4459     else {
4460         NEXT_OFF(scan) = val - scan;
4461     }
4462 }
4463
4464 /*
4465 - regoptail - regtail on operand of first argument; nop if operandless
4466 */
4467 STATIC void
4468 S_regoptail(pTHX_ RExC_state_t *pRExC_state, regnode *p, regnode *val)
4469 {
4470     /* "Operandless" and "op != BRANCH" are synonymous in practice. */
4471     if (p == NULL || SIZE_ONLY)
4472         return;
4473     if (PL_regkind[(U8)OP(p)] == BRANCH) {
4474         regtail(pRExC_state, NEXTOPER(p), val);
4475     }
4476     else if ( PL_regkind[(U8)OP(p)] == BRANCHJ) {
4477         regtail(pRExC_state, NEXTOPER(NEXTOPER(p)), val);
4478     }
4479     else
4480         return;
4481 }
4482
4483 /*
4484  - regcurly - a little FSA that accepts {\d+,?\d*}
4485  */
4486 STATIC I32
4487 S_regcurly(pTHX_ register char *s)
4488 {
4489     if (*s++ != '{')
4490         return FALSE;
4491     if (!isDIGIT(*s))
4492         return FALSE;
4493     while (isDIGIT(*s))
4494         s++;
4495     if (*s == ',')
4496         s++;
4497     while (isDIGIT(*s))
4498         s++;
4499     if (*s != '}')
4500         return FALSE;
4501     return TRUE;
4502 }
4503
4504
4505 #ifdef DEBUGGING
4506
4507 STATIC regnode *
4508 S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
4509 {
4510     register U8 op = EXACT;     /* Arbitrary non-END op. */
4511     register regnode *next;
4512
4513     while (op != END && (!last || node < last)) {
4514         /* While that wasn't END last time... */
4515
4516         NODE_ALIGN(node);
4517         op = OP(node);
4518         if (op == CLOSE)
4519             l--;
4520         next = regnext(node);
4521         /* Where, what. */
4522         if (OP(node) == OPTIMIZED)
4523             goto after_print;
4524         regprop(sv, node);
4525         PerlIO_printf(Perl_debug_log, "%4"IVdf":%*s%s", (IV)(node - start),
4526                       (int)(2*l + 1), "", SvPVX(sv));
4527         if (next == NULL)               /* Next ptr. */
4528             PerlIO_printf(Perl_debug_log, "(0)");
4529         else
4530             PerlIO_printf(Perl_debug_log, "(%"IVdf")", (IV)(next - start));
4531         (void)PerlIO_putc(Perl_debug_log, '\n');
4532       after_print:
4533         if (PL_regkind[(U8)op] == BRANCHJ) {
4534             register regnode *nnode = (OP(next) == LONGJMP
4535                                        ? regnext(next)
4536                                        : next);
4537             if (last && nnode > last)
4538                 nnode = last;
4539             node = dumpuntil(start, NEXTOPER(NEXTOPER(node)), nnode, sv, l + 1);
4540         }
4541         else if (PL_regkind[(U8)op] == BRANCH) {
4542             node = dumpuntil(start, NEXTOPER(node), next, sv, l + 1);
4543         }
4544         else if ( op == CURLY) {   /* `next' might be very big: optimizer */
4545             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4546                              NEXTOPER(node) + EXTRA_STEP_2ARGS + 1, sv, l + 1);
4547         }
4548         else if (PL_regkind[(U8)op] == CURLY && op != CURLYX) {
4549             node = dumpuntil(start, NEXTOPER(node) + EXTRA_STEP_2ARGS,
4550                              next, sv, l + 1);
4551         }
4552         else if ( op == PLUS || op == STAR) {
4553             node = dumpuntil(start, NEXTOPER(node), NEXTOPER(node) + 1, sv, l + 1);
4554         }
4555         else if (op == ANYOF) {
4556             /* arglen 1 + class block */
4557             node += 1 + ((ANYOF_FLAGS(node) & ANYOF_LARGE)
4558                     ? ANYOF_CLASS_SKIP : ANYOF_SKIP);
4559             node = NEXTOPER(node);
4560         }
4561         else if (PL_regkind[(U8)op] == EXACT) {
4562             /* Literal string, where present. */
4563             node += NODE_SZ_STR(node) - 1;
4564             node = NEXTOPER(node);
4565         }
4566         else {
4567             node = NEXTOPER(node);
4568             node += regarglen[(U8)op];
4569         }
4570         if (op == CURLYX || op == OPEN)
4571             l++;
4572         else if (op == WHILEM)
4573             l--;
4574     }
4575     return node;
4576 }
4577
4578 #endif  /* DEBUGGING */
4579
4580 /*
4581  - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
4582  */
4583 void
4584 Perl_regdump(pTHX_ regexp *r)
4585 {
4586 #ifdef DEBUGGING
4587     SV *sv = sv_newmortal();
4588
4589     (void)dumpuntil(r->program, r->program + 1, NULL, sv, 0);
4590
4591     /* Header fields of interest. */
4592     if (r->anchored_substr)
4593         PerlIO_printf(Perl_debug_log,
4594                       "anchored `%s%.*s%s'%s at %"IVdf" ",
4595                       PL_colors[0],
4596                       (int)(SvCUR(r->anchored_substr) - (SvTAIL(r->anchored_substr)!=0)),
4597                       SvPVX(r->anchored_substr),
4598                       PL_colors[1],
4599                       SvTAIL(r->anchored_substr) ? "$" : "",
4600                       (IV)r->anchored_offset);
4601     else if (r->anchored_utf8)
4602         PerlIO_printf(Perl_debug_log,
4603                       "anchored utf8 `%s%.*s%s'%s at %"IVdf" ",
4604                       PL_colors[0],
4605                       (int)(SvCUR(r->anchored_utf8) - (SvTAIL(r->anchored_utf8)!=0)),
4606                       SvPVX(r->anchored_utf8),
4607                       PL_colors[1],
4608                       SvTAIL(r->anchored_utf8) ? "$" : "",
4609                       (IV)r->anchored_offset);
4610     if (r->float_substr)
4611         PerlIO_printf(Perl_debug_log,
4612                       "floating `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4613                       PL_colors[0],
4614                       (int)(SvCUR(r->float_substr) - (SvTAIL(r->float_substr)!=0)),
4615                       SvPVX(r->float_substr),
4616                       PL_colors[1],
4617                       SvTAIL(r->float_substr) ? "$" : "",
4618                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4619     else if (r->float_utf8)
4620         PerlIO_printf(Perl_debug_log,
4621                       "floating utf8 `%s%.*s%s'%s at %"IVdf"..%"UVuf" ",
4622                       PL_colors[0],
4623                       (int)(SvCUR(r->float_utf8) - (SvTAIL(r->float_utf8)!=0)),
4624                       SvPVX(r->float_utf8),
4625                       PL_colors[1],
4626                       SvTAIL(r->float_utf8) ? "$" : "",
4627                       (IV)r->float_min_offset, (UV)r->float_max_offset);
4628     if (r->check_substr || r->check_utf8)
4629         PerlIO_printf(Perl_debug_log,
4630                       r->check_substr == r->float_substr
4631                       && r->check_utf8 == r->float_utf8
4632                       ? "(checking floating" : "(checking anchored");
4633     if (r->reganch & ROPT_NOSCAN)
4634         PerlIO_printf(Perl_debug_log, " noscan");
4635     if (r->reganch & ROPT_CHECK_ALL)
4636         PerlIO_printf(Perl_debug_log, " isall");
4637     if (r->check_substr || r->check_utf8)
4638         PerlIO_printf(Perl_debug_log, ") ");
4639
4640     if (r->regstclass) {
4641         regprop(sv, r->regstclass);
4642         PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
4643     }
4644     if (r->reganch & ROPT_ANCH) {
4645         PerlIO_printf(Perl_debug_log, "anchored");
4646         if (r->reganch & ROPT_ANCH_BOL)
4647             PerlIO_printf(Perl_debug_log, "(BOL)");
4648         if (r->reganch & ROPT_ANCH_MBOL)
4649             PerlIO_printf(Perl_debug_log, "(MBOL)");
4650         if (r->reganch & ROPT_ANCH_SBOL)
4651             PerlIO_printf(Perl_debug_log, "(SBOL)");
4652         if (r->reganch & ROPT_ANCH_GPOS)
4653             PerlIO_printf(Perl_debug_log, "(GPOS)");
4654         PerlIO_putc(Perl_debug_log, ' ');
4655     }
4656     if (r->reganch & ROPT_GPOS_SEEN)
4657         PerlIO_printf(Perl_debug_log, "GPOS ");
4658     if (r->reganch & ROPT_SKIP)
4659         PerlIO_printf(Perl_debug_log, "plus ");
4660     if (r->reganch & ROPT_IMPLICIT)
4661         PerlIO_printf(Perl_debug_log, "implicit ");
4662     PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
4663     if (r->reganch & ROPT_EVAL_SEEN)
4664         PerlIO_printf(Perl_debug_log, "with eval ");
4665     PerlIO_printf(Perl_debug_log, "\n");
4666     if (r->offsets) {
4667       U32 i;
4668       U32 len = r->offsets[0];
4669       PerlIO_printf(Perl_debug_log, "Offsets: [%"UVuf"]\n\t", (UV)r->offsets[0]);
4670       for (i = 1; i <= len; i++)
4671         PerlIO_printf(Perl_debug_log, "%"UVuf"[%"UVuf"] ",
4672                       (UV)r->offsets[i*2-1],
4673                       (UV)r->offsets[i*2]);
4674       PerlIO_printf(Perl_debug_log, "\n");
4675     }
4676 #endif  /* DEBUGGING */
4677 }
4678
4679 #ifdef DEBUGGING
4680
4681 STATIC void
4682 S_put_byte(pTHX_ SV *sv, int c)
4683 {
4684     if (isCNTRL(c) || c == 255 || !isPRINT(c))
4685         Perl_sv_catpvf(aTHX_ sv, "\\%o", c);
4686     else if (c == '-' || c == ']' || c == '\\' || c == '^')
4687         Perl_sv_catpvf(aTHX_ sv, "\\%c", c);
4688     else
4689         Perl_sv_catpvf(aTHX_ sv, "%c", c);
4690 }
4691
4692 #endif  /* DEBUGGING */
4693
4694 /*
4695 - regprop - printable representation of opcode
4696 */
4697 void
4698 Perl_regprop(pTHX_ SV *sv, regnode *o)
4699 {
4700 #ifdef DEBUGGING
4701     register int k;
4702
4703     sv_setpvn(sv, "", 0);
4704     if (OP(o) >= reg_num)               /* regnode.type is unsigned */
4705         /* It would be nice to FAIL() here, but this may be called from
4706            regexec.c, and it would be hard to supply pRExC_state. */
4707         Perl_croak(aTHX_ "Corrupted regexp opcode");
4708     sv_catpv(sv, (char*)reg_name[OP(o)]); /* Take off const! */
4709
4710     k = PL_regkind[(U8)OP(o)];
4711
4712     if (k == EXACT) {
4713         SV *dsv = sv_2mortal(newSVpvn("", 0));
4714         /* Using is_utf8_string() is a crude hack but it may
4715          * be the best for now since we have no flag "this EXACTish
4716          * node was UTF-8" --jhi */
4717         bool do_utf8 = is_utf8_string((U8*)STRING(o), STR_LEN(o));
4718         char *s    = do_utf8 ?
4719           pv_uni_display(dsv, (U8*)STRING(o), STR_LEN(o), 60,
4720                          UNI_DISPLAY_REGEX) :
4721           STRING(o);
4722         int len = do_utf8 ?
4723           strlen(s) :
4724           STR_LEN(o);
4725         Perl_sv_catpvf(aTHX_ sv, " <%s%.*s%s>",
4726                        PL_colors[0],
4727                        len, s,
4728                        PL_colors[1]);
4729     }
4730     else if (k == CURLY) {
4731         if (OP(o) == CURLYM || OP(o) == CURLYN || OP(o) == CURLYX)
4732             Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags); /* Parenth number */
4733         Perl_sv_catpvf(aTHX_ sv, " {%d,%d}", ARG1(o), ARG2(o));
4734     }
4735     else if (k == WHILEM && o->flags)                   /* Ordinal/of */
4736         Perl_sv_catpvf(aTHX_ sv, "[%d/%d]", o->flags & 0xf, o->flags>>4);
4737     else if (k == REF || k == OPEN || k == CLOSE || k == GROUPP )
4738         Perl_sv_catpvf(aTHX_ sv, "%d", (int)ARG(o));    /* Parenth number */
4739     else if (k == LOGICAL)
4740         Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);     /* 2: embedded, otherwise 1 */
4741     else if (k == ANYOF) {
4742         int i, rangestart = -1;
4743         U8 flags = ANYOF_FLAGS(o);
4744         const char * const anyofs[] = { /* Should be synchronized with
4745                                          * ANYOF_ #xdefines in regcomp.h */
4746             "\\w",
4747             "\\W",
4748             "\\s",
4749             "\\S",
4750             "\\d",
4751             "\\D",
4752             "[:alnum:]",
4753             "[:^alnum:]",
4754             "[:alpha:]",
4755             "[:^alpha:]",
4756             "[:ascii:]",
4757             "[:^ascii:]",
4758             "[:ctrl:]",
4759             "[:^ctrl:]",
4760             "[:graph:]",
4761             "[:^graph:]",
4762             "[:lower:]",
4763             "[:^lower:]",
4764             "[:print:]",
4765             "[:^print:]",
4766             "[:punct:]",
4767             "[:^punct:]",
4768             "[:upper:]",
4769             "[:^upper:]",
4770             "[:xdigit:]",
4771             "[:^xdigit:]",
4772             "[:space:]",
4773             "[:^space:]",
4774             "[:blank:]",
4775             "[:^blank:]"
4776         };
4777
4778         if (flags & ANYOF_LOCALE)
4779             sv_catpv(sv, "{loc}");
4780         if (flags & ANYOF_FOLD)
4781             sv_catpv(sv, "{i}");
4782         Perl_sv_catpvf(aTHX_ sv, "[%s", PL_colors[0]);
4783         if (flags & ANYOF_INVERT)
4784             sv_catpv(sv, "^");
4785         for (i = 0; i <= 256; i++) {
4786             if (i < 256 && ANYOF_BITMAP_TEST(o,i)) {
4787                 if (rangestart == -1)
4788                     rangestart = i;
4789             } else if (rangestart != -1) {
4790                 if (i <= rangestart + 3)
4791                     for (; rangestart < i; rangestart++)
4792                         put_byte(sv, rangestart);
4793                 else {
4794                     put_byte(sv, rangestart);
4795                     sv_catpv(sv, "-");
4796                     put_byte(sv, i - 1);
4797                 }
4798                 rangestart = -1;
4799             }
4800         }
4801
4802         if (o->flags & ANYOF_CLASS)
4803             for (i = 0; i < sizeof(anyofs)/sizeof(char*); i++)
4804                 if (ANYOF_CLASS_TEST(o,i))
4805                     sv_catpv(sv, anyofs[i]);
4806
4807         if (flags & ANYOF_UNICODE)
4808             sv_catpv(sv, "{unicode}");
4809         else if (flags & ANYOF_UNICODE_ALL)
4810             sv_catpv(sv, "{unicode_all}");
4811
4812         {
4813             SV *lv;
4814             SV *sw = regclass_swash(o, FALSE, &lv, 0);
4815
4816             if (lv) {
4817                 if (sw) {
4818                     U8 s[UTF8_MAXLEN+1];
4819
4820                     for (i = 0; i <= 256; i++) { /* just the first 256 */
4821                         U8 *e = uvchr_to_utf8(s, i);
4822
4823                         if (i < 256 && swash_fetch(sw, s, TRUE)) {
4824                             if (rangestart == -1)
4825                                 rangestart = i;
4826                         } else if (rangestart != -1) {
4827                             U8 *p;
4828
4829                             if (i <= rangestart + 3)
4830                                 for (; rangestart < i; rangestart++) {
4831                                     for(e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4832                                         put_byte(sv, *p);
4833                                 }
4834                             else {
4835                                 for (e = uvchr_to_utf8(s, rangestart), p = s; p < e; p++)
4836                                     put_byte(sv, *p);
4837                                 sv_catpv(sv, "-");
4838                                     for (e = uvchr_to_utf8(s, i - 1), p = s; p < e; p++)
4839                                         put_byte(sv, *p);
4840                                 }
4841                                 rangestart = -1;
4842                             }
4843                         }
4844
4845                     sv_catpv(sv, "..."); /* et cetera */
4846                 }
4847
4848                 {
4849                     char *s = savepv(SvPVX(lv));
4850                     char *origs = s;
4851
4852                     while(*s && *s != '\n') s++;
4853
4854                     if (*s == '\n') {
4855                         char *t = ++s;
4856
4857                         while (*s) {
4858                             if (*s == '\n')
4859                                 *s = ' ';
4860                             s++;
4861                         }
4862                         if (s[-1] == ' ')
4863                             s[-1] = 0;
4864
4865                         sv_catpv(sv, t);
4866                     }
4867
4868                     Safefree(origs);
4869                 }
4870             }
4871         }
4872
4873         Perl_sv_catpvf(aTHX_ sv, "%s]", PL_colors[1]);
4874     }
4875     else if (k == BRANCHJ && (OP(o) == UNLESSM || OP(o) == IFMATCH))
4876         Perl_sv_catpvf(aTHX_ sv, "[-%d]", o->flags);
4877 #endif  /* DEBUGGING */
4878 }
4879
4880 SV *
4881 Perl_re_intuit_string(pTHX_ regexp *prog)
4882 {                               /* Assume that RE_INTUIT is set */
4883     DEBUG_r(
4884         {   STRLEN n_a;
4885             char *s = SvPV(prog->check_substr
4886                       ? prog->check_substr : prog->check_utf8, n_a);
4887
4888             if (!PL_colorset) reginitcolors();
4889             PerlIO_printf(Perl_debug_log,
4890                       "%sUsing REx %ssubstr:%s `%s%.60s%s%s'\n",
4891                       PL_colors[4],
4892                       prog->check_substr ? "" : "utf8 ",
4893                       PL_colors[5],PL_colors[0],
4894                       s,
4895                       PL_colors[1],
4896                       (strlen(s) > 60 ? "..." : ""));
4897         } );
4898
4899     return prog->check_substr ? prog->check_substr : prog->check_utf8;
4900 }
4901
4902 void
4903 Perl_pregfree(pTHX_ struct regexp *r)
4904 {
4905 #ifdef DEBUGGING
4906     SV *dsv = PERL_DEBUG_PAD_ZERO(0);
4907 #endif
4908
4909     if (!r || (--r->refcnt > 0))
4910         return;
4911     DEBUG_r({
4912          int len;
4913          char *s;
4914
4915          s = (r->reganch & ROPT_UTF8) ? pv_uni_display(dsv, (U8*)r->precomp,
4916                 r->prelen, 60, UNI_DISPLAY_REGEX)
4917             : pv_display(dsv, r->precomp, r->prelen, 0, 60);
4918          len = SvCUR(dsv);
4919          if (!PL_colorset)
4920               reginitcolors();
4921          PerlIO_printf(Perl_debug_log,
4922                        "%sFreeing REx:%s `%s%*.*s%s%s'\n",
4923                        PL_colors[4],PL_colors[5],PL_colors[0],
4924                        len, len, s,
4925                        PL_colors[1],
4926                        len > 60 ? "..." : "");
4927     });
4928
4929     if (r->precomp)
4930         Safefree(r->precomp);
4931     if (r->offsets)             /* 20010421 MJD */
4932         Safefree(r->offsets);
4933     RX_MATCH_COPY_FREE(r);
4934 #ifdef PERL_COPY_ON_WRITE
4935     if (r->saved_copy)
4936         SvREFCNT_dec(r->saved_copy);
4937 #endif
4938     if (r->substrs) {
4939         if (r->anchored_substr)
4940             SvREFCNT_dec(r->anchored_substr);
4941         if (r->anchored_utf8)
4942             SvREFCNT_dec(r->anchored_utf8);
4943         if (r->float_substr)
4944             SvREFCNT_dec(r->float_substr);
4945         if (r->float_utf8)
4946             SvREFCNT_dec(r->float_utf8);
4947         Safefree(r->substrs);
4948     }
4949     if (r->data) {
4950         int n = r->data->count;
4951         PAD* new_comppad = NULL;
4952         PAD* old_comppad;
4953
4954         while (--n >= 0) {
4955           /* If you add a ->what type here, update the comment in regcomp.h */
4956             switch (r->data->what[n]) {
4957             case 's':
4958                 SvREFCNT_dec((SV*)r->data->data[n]);
4959                 break;
4960             case 'f':
4961                 Safefree(r->data->data[n]);
4962                 break;
4963             case 'p':
4964                 new_comppad = (AV*)r->data->data[n];
4965                 break;
4966             case 'o':
4967                 if (new_comppad == NULL)
4968                     Perl_croak(aTHX_ "panic: pregfree comppad");
4969                 PAD_SAVE_LOCAL(old_comppad,
4970                     /* Watch out for global destruction's random ordering. */
4971                     (SvTYPE(new_comppad) == SVt_PVAV) ?
4972                                 new_comppad : Null(PAD *)
4973                 );
4974                 if (!OpREFCNT_dec((OP_4tree*)r->data->data[n])) {
4975                     op_free((OP_4tree*)r->data->data[n]);
4976                 }
4977
4978                 PAD_RESTORE_LOCAL(old_comppad);
4979                 SvREFCNT_dec((SV*)new_comppad);
4980                 new_comppad = NULL;
4981                 break;
4982             case 'n':
4983                 break;
4984             default:
4985                 Perl_croak(aTHX_ "panic: regfree data code '%c'", r->data->what[n]);
4986             }
4987         }
4988         Safefree(r->data->what);
4989         Safefree(r->data);
4990     }
4991     Safefree(r->startp);
4992     Safefree(r->endp);
4993     Safefree(r);
4994 }
4995
4996 /*
4997  - regnext - dig the "next" pointer out of a node
4998  *
4999  * [Note, when REGALIGN is defined there are two places in regmatch()
5000  * that bypass this code for speed.]
5001  */
5002 regnode *
5003 Perl_regnext(pTHX_ register regnode *p)
5004 {
5005     register I32 offset;
5006
5007     if (p == &PL_regdummy)
5008         return(NULL);
5009
5010     offset = (reg_off_by_arg[OP(p)] ? ARG(p) : NEXT_OFF(p));
5011     if (offset == 0)
5012         return(NULL);
5013
5014     return(p+offset);
5015 }
5016
5017 STATIC void
5018 S_re_croak2(pTHX_ const char* pat1,const char* pat2,...)
5019 {
5020     va_list args;
5021     STRLEN l1 = strlen(pat1);
5022     STRLEN l2 = strlen(pat2);
5023     char buf[512];
5024     SV *msv;
5025     char *message;
5026
5027     if (l1 > 510)
5028         l1 = 510;
5029     if (l1 + l2 > 510)
5030         l2 = 510 - l1;
5031     Copy(pat1, buf, l1 , char);
5032     Copy(pat2, buf + l1, l2 , char);
5033     buf[l1 + l2] = '\n';
5034     buf[l1 + l2 + 1] = '\0';
5035 #ifdef I_STDARG
5036     /* ANSI variant takes additional second argument */
5037     va_start(args, pat2);
5038 #else
5039     va_start(args);
5040 #endif
5041     msv = vmess(buf, &args);
5042     va_end(args);
5043     message = SvPV(msv,l1);
5044     if (l1 > 512)
5045         l1 = 512;
5046     Copy(message, buf, l1 , char);
5047     buf[l1] = '\0';                     /* Overwrite \n */
5048     Perl_croak(aTHX_ "%s", buf);
5049 }
5050
5051 /* XXX Here's a total kludge.  But we need to re-enter for swash routines. */
5052
5053 void
5054 Perl_save_re_context(pTHX)
5055 {
5056     SAVEI32(PL_reg_flags);              /* from regexec.c */
5057     SAVEPPTR(PL_bostr);
5058     SAVEPPTR(PL_reginput);              /* String-input pointer. */
5059     SAVEPPTR(PL_regbol);                /* Beginning of input, for ^ check. */
5060     SAVEPPTR(PL_regeol);                /* End of input, for $ check. */
5061     SAVEVPTR(PL_regstartp);             /* Pointer to startp array. */
5062     SAVEVPTR(PL_regendp);               /* Ditto for endp. */
5063     SAVEVPTR(PL_reglastparen);          /* Similarly for lastparen. */
5064     SAVEVPTR(PL_reglastcloseparen);     /* Similarly for lastcloseparen. */
5065     SAVEPPTR(PL_regtill);               /* How far we are required to go. */
5066     SAVEGENERICPV(PL_reg_start_tmp);            /* from regexec.c */
5067     PL_reg_start_tmp = 0;
5068     SAVEI32(PL_reg_start_tmpl);         /* from regexec.c */
5069     PL_reg_start_tmpl = 0;
5070     SAVEVPTR(PL_regdata);
5071     SAVEI32(PL_reg_eval_set);           /* from regexec.c */
5072     SAVEI32(PL_regnarrate);             /* from regexec.c */
5073     SAVEVPTR(PL_regprogram);            /* from regexec.c */
5074     SAVEINT(PL_regindent);              /* from regexec.c */
5075     SAVEVPTR(PL_regcc);                 /* from regexec.c */
5076     SAVEVPTR(PL_curcop);
5077     SAVEVPTR(PL_reg_call_cc);           /* from regexec.c */
5078     SAVEVPTR(PL_reg_re);                /* from regexec.c */
5079     SAVEPPTR(PL_reg_ganch);             /* from regexec.c */
5080     SAVESPTR(PL_reg_sv);                /* from regexec.c */
5081     SAVEBOOL(PL_reg_match_utf8);        /* from regexec.c */
5082     SAVEVPTR(PL_reg_magic);             /* from regexec.c */
5083     SAVEI32(PL_reg_oldpos);                     /* from regexec.c */
5084     SAVEVPTR(PL_reg_oldcurpm);          /* from regexec.c */
5085     SAVEVPTR(PL_reg_curpm);             /* from regexec.c */
5086     SAVEPPTR(PL_reg_oldsaved);          /* old saved substr during match */
5087     PL_reg_oldsaved = Nullch;
5088     SAVEI32(PL_reg_oldsavedlen);        /* old length of saved substr during match */
5089     PL_reg_oldsavedlen = 0;
5090 #ifdef PERL_COPY_ON_WRITE
5091     SAVESPTR(PL_nrs);
5092     PL_nrs = Nullsv;
5093 #endif
5094     SAVEI32(PL_reg_maxiter);            /* max wait until caching pos */
5095     PL_reg_maxiter = 0;
5096     SAVEI32(PL_reg_leftiter);           /* wait until caching pos */
5097     PL_reg_leftiter = 0;
5098     SAVEGENERICPV(PL_reg_poscache);     /* cache of pos of WHILEM */
5099     PL_reg_poscache = Nullch;
5100     SAVEI32(PL_reg_poscache_size);      /* size of pos cache of WHILEM */
5101     PL_reg_poscache_size = 0;
5102     SAVEPPTR(PL_regprecomp);            /* uncompiled string. */
5103     SAVEI32(PL_regnpar);                /* () count. */
5104     SAVEI32(PL_regsize);                /* from regexec.c */
5105
5106     {
5107         /* Save $1..$n (#18107: UTF-8 s/(\w+)/uc($1)/e); AMS 20021106. */
5108         U32 i;
5109         GV *mgv;
5110         REGEXP *rx;
5111         char digits[16];
5112
5113         if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
5114             for (i = 1; i <= rx->nparens; i++) {
5115                 sprintf(digits, "%lu", (long)i);
5116                 if ((mgv = gv_fetchpv(digits, FALSE, SVt_PV)))
5117                     save_scalar(mgv);
5118             }
5119         }
5120     }
5121
5122 #ifdef DEBUGGING
5123     SAVEPPTR(PL_reg_starttry);          /* from regexec.c */
5124 #endif
5125 }
5126
5127 static void
5128 clear_re(pTHX_ void *r)
5129 {
5130     ReREFCNT_dec((regexp *)r);
5131 }
5132