/[pcre]/code/trunk/pcre_study.c
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revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC revision 729 by ph10, Mon Oct 10 16:02:20 2011 UTC
# Line 6  Line 6 
6  and semantics are as close as possible to those of the Perl 5 language.  and semantics are as close as possible to those of the Perl 5 language.
7    
8                         Written by Philip Hazel                         Written by Philip Hazel
9             Copyright (c) 1997-2006 University of Cambridge             Copyright (c) 1997-2010 University of Cambridge
10    
11  -----------------------------------------------------------------------------  -----------------------------------------------------------------------------
12  Redistribution and use in source and binary forms, with or without  Redistribution and use in source and binary forms, with or without
# Line 42  POSSIBILITY OF SUCH DAMAGE. Line 42  POSSIBILITY OF SUCH DAMAGE.
42  supporting functions. */  supporting functions. */
43    
44    
45    #ifdef HAVE_CONFIG_H
46    #include "config.h"
47    #endif
48    
49  #include "pcre_internal.h"  #include "pcre_internal.h"
50    
51    #define SET_BIT(c) start_bits[c/8] |= (1 << (c&7))
52    
53    /* Returns from set_start_bits() */
54    
55    enum { SSB_FAIL, SSB_DONE, SSB_CONTINUE, SSB_UNKNOWN };
56    
57    
58    
59    /*************************************************
60    *   Find the minimum subject length for a group  *
61    *************************************************/
62    
63    /* Scan a parenthesized group and compute the minimum length of subject that
64    is needed to match it. This is a lower bound; it does not mean there is a
65    string of that length that matches. In UTF8 mode, the result is in characters
66    rather than bytes.
67    
68    Arguments:
69      code            pointer to start of group (the bracket)
70      startcode       pointer to start of the whole pattern
71      options         the compiling options
72      int             RECURSE depth
73    
74    Returns:   the minimum length
75               -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
76               -2 internal error (missing capturing bracket)
77               -3 internal error (opcode not listed)
78    */
79    
80    static int
81    find_minlength(const uschar *code, const uschar *startcode, int options,
82      int recurse_depth)
83    {
84    int length = -1;
85    BOOL utf8 = (options & PCRE_UTF8) != 0;
86    BOOL had_recurse = FALSE;
87    register int branchlength = 0;
88    register uschar *cc = (uschar *)code + 1 + LINK_SIZE;
89    
90    if (*code == OP_CBRA || *code == OP_SCBRA ||
91        *code == OP_CBRAPOS || *code == OP_SCBRAPOS) cc += 2;
92    
93    /* Scan along the opcodes for this branch. If we get to the end of the
94    branch, check the length against that of the other branches. */
95    
96    for (;;)
97      {
98      int d, min;
99      uschar *cs, *ce;
100      register int op = *cc;
101    
102      switch (op)
103        {
104        case OP_COND:
105        case OP_SCOND:
106    
107        /* If there is only one branch in a condition, the implied branch has zero
108        length, so we don't add anything. This covers the DEFINE "condition"
109        automatically. */
110    
111        cs = cc + GET(cc, 1);
112        if (*cs != OP_ALT)
113          {
114          cc = cs + 1 + LINK_SIZE;
115          break;
116          }
117    
118        /* Otherwise we can fall through and treat it the same as any other
119        subpattern. */
120    
121        case OP_CBRA:
122        case OP_SCBRA:
123        case OP_BRA:
124        case OP_SBRA:
125        case OP_CBRAPOS:
126        case OP_SCBRAPOS:
127        case OP_BRAPOS:
128        case OP_SBRAPOS:
129        case OP_ONCE:
130        case OP_ONCE_NC:
131        d = find_minlength(cc, startcode, options, recurse_depth);
132        if (d < 0) return d;
133        branchlength += d;
134        do cc += GET(cc, 1); while (*cc == OP_ALT);
135        cc += 1 + LINK_SIZE;
136        break;
137    
138        /* ACCEPT makes things far too complicated; we have to give up. */
139    
140        case OP_ACCEPT:
141        case OP_ASSERT_ACCEPT:
142        return -1;
143    
144        /* Reached end of a branch; if it's a ket it is the end of a nested
145        call. If it's ALT it is an alternation in a nested call. If it is END it's
146        the end of the outer call. All can be handled by the same code. If an
147        ACCEPT was previously encountered, use the length that was in force at that
148        time, and pass back the shortest ACCEPT length. */
149    
150        case OP_ALT:
151        case OP_KET:
152        case OP_KETRMAX:
153        case OP_KETRMIN:
154        case OP_KETRPOS:
155        case OP_END:
156        if (length < 0 || (!had_recurse && branchlength < length))
157          length = branchlength;
158        if (op != OP_ALT) return length;
159        cc += 1 + LINK_SIZE;
160        branchlength = 0;
161        had_recurse = FALSE;
162        break;
163    
164        /* Skip over assertive subpatterns */
165    
166        case OP_ASSERT:
167        case OP_ASSERT_NOT:
168        case OP_ASSERTBACK:
169        case OP_ASSERTBACK_NOT:
170        do cc += GET(cc, 1); while (*cc == OP_ALT);
171        /* Fall through */
172    
173        /* Skip over things that don't match chars */
174    
175        case OP_REVERSE:
176        case OP_CREF:
177        case OP_NCREF:
178        case OP_RREF:
179        case OP_NRREF:
180        case OP_DEF:
181        case OP_CALLOUT:
182        case OP_SOD:
183        case OP_SOM:
184        case OP_EOD:
185        case OP_EODN:
186        case OP_CIRC:
187        case OP_CIRCM:
188        case OP_DOLL:
189        case OP_DOLLM:
190        case OP_NOT_WORD_BOUNDARY:
191        case OP_WORD_BOUNDARY:
192        cc += _pcre_OP_lengths[*cc];
193        break;
194    
195        /* Skip over a subpattern that has a {0} or {0,x} quantifier */
196    
197        case OP_BRAZERO:
198        case OP_BRAMINZERO:
199        case OP_BRAPOSZERO:
200        case OP_SKIPZERO:
201        cc += _pcre_OP_lengths[*cc];
202        do cc += GET(cc, 1); while (*cc == OP_ALT);
203        cc += 1 + LINK_SIZE;
204        break;
205    
206        /* Handle literal characters and + repetitions */
207    
208        case OP_CHAR:
209        case OP_CHARI:
210        case OP_NOT:
211        case OP_NOTI:
212        case OP_PLUS:
213        case OP_PLUSI:
214        case OP_MINPLUS:
215        case OP_MINPLUSI:
216        case OP_POSPLUS:
217        case OP_POSPLUSI:
218        case OP_NOTPLUS:
219        case OP_NOTPLUSI:
220        case OP_NOTMINPLUS:
221        case OP_NOTMINPLUSI:
222        case OP_NOTPOSPLUS:
223        case OP_NOTPOSPLUSI:
224        branchlength++;
225        cc += 2;
226    #ifdef SUPPORT_UTF8
227        if (utf8 && cc[-1] >= 0xc0) cc += _pcre_utf8_table4[cc[-1] & 0x3f];
228    #endif
229        break;
230    
231        case OP_TYPEPLUS:
232        case OP_TYPEMINPLUS:
233        case OP_TYPEPOSPLUS:
234        branchlength++;
235        cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2;
236        break;
237    
238        /* Handle exact repetitions. The count is already in characters, but we
239        need to skip over a multibyte character in UTF8 mode.  */
240    
241        case OP_EXACT:
242        case OP_EXACTI:
243        case OP_NOTEXACT:
244        case OP_NOTEXACTI:
245        branchlength += GET2(cc,1);
246        cc += 4;
247    #ifdef SUPPORT_UTF8
248        if (utf8 && cc[-1] >= 0xc0) cc += _pcre_utf8_table4[cc[-1] & 0x3f];
249    #endif
250        break;
251    
252        case OP_TYPEEXACT:
253        branchlength += GET2(cc,1);
254        cc += (cc[3] == OP_PROP || cc[3] == OP_NOTPROP)? 6 : 4;
255        break;
256    
257        /* Handle single-char non-literal matchers */
258    
259        case OP_PROP:
260        case OP_NOTPROP:
261        cc += 2;
262        /* Fall through */
263    
264        case OP_NOT_DIGIT:
265        case OP_DIGIT:
266        case OP_NOT_WHITESPACE:
267        case OP_WHITESPACE:
268        case OP_NOT_WORDCHAR:
269        case OP_WORDCHAR:
270        case OP_ANY:
271        case OP_ALLANY:
272        case OP_EXTUNI:
273        case OP_HSPACE:
274        case OP_NOT_HSPACE:
275        case OP_VSPACE:
276        case OP_NOT_VSPACE:
277        branchlength++;
278        cc++;
279        break;
280    
281        /* "Any newline" might match two characters, but it also might match just
282        one. */
283    
284        case OP_ANYNL:
285        branchlength += 1;
286        cc++;
287        break;
288    
289        /* The single-byte matcher means we can't proceed in UTF-8 mode */
290    
291        case OP_ANYBYTE:
292    #ifdef SUPPORT_UTF8
293        if (utf8) return -1;
294    #endif
295        branchlength++;
296        cc++;
297        break;
298    
299        /* For repeated character types, we have to test for \p and \P, which have
300        an extra two bytes of parameters. */
301    
302        case OP_TYPESTAR:
303        case OP_TYPEMINSTAR:
304        case OP_TYPEQUERY:
305        case OP_TYPEMINQUERY:
306        case OP_TYPEPOSSTAR:
307        case OP_TYPEPOSQUERY:
308        if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2;
309        cc += _pcre_OP_lengths[op];
310        break;
311    
312        case OP_TYPEUPTO:
313        case OP_TYPEMINUPTO:
314        case OP_TYPEPOSUPTO:
315        if (cc[3] == OP_PROP || cc[3] == OP_NOTPROP) cc += 2;
316        cc += _pcre_OP_lengths[op];
317        break;
318    
319        /* Check a class for variable quantification */
320    
321    #ifdef SUPPORT_UTF8
322        case OP_XCLASS:
323        cc += GET(cc, 1) - 33;
324        /* Fall through */
325    #endif
326    
327        case OP_CLASS:
328        case OP_NCLASS:
329        cc += 33;
330    
331        switch (*cc)
332          {
333          case OP_CRPLUS:
334          case OP_CRMINPLUS:
335          branchlength++;
336          /* Fall through */
337    
338          case OP_CRSTAR:
339          case OP_CRMINSTAR:
340          case OP_CRQUERY:
341          case OP_CRMINQUERY:
342          cc++;
343          break;
344    
345          case OP_CRRANGE:
346          case OP_CRMINRANGE:
347          branchlength += GET2(cc,1);
348          cc += 5;
349          break;
350    
351          default:
352          branchlength++;
353          break;
354          }
355        break;
356    
357        /* Backreferences and subroutine calls are treated in the same way: we find
358        the minimum length for the subpattern. A recursion, however, causes an
359        a flag to be set that causes the length of this branch to be ignored. The
360        logic is that a recursion can only make sense if there is another
361        alternation that stops the recursing. That will provide the minimum length
362        (when no recursion happens). A backreference within the group that it is
363        referencing behaves in the same way.
364    
365        If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket
366        matches an empty string (by default it causes a matching failure), so in
367        that case we must set the minimum length to zero. */
368    
369        case OP_REF:
370        case OP_REFI:
371        if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
372          {
373          ce = cs = (uschar *)_pcre_find_bracket(startcode, utf8, GET2(cc, 1));
374          if (cs == NULL) return -2;
375          do ce += GET(ce, 1); while (*ce == OP_ALT);
376          if (cc > cs && cc < ce)
377            {
378            d = 0;
379            had_recurse = TRUE;
380            }
381          else
382            {
383            d = find_minlength(cs, startcode, options, recurse_depth);
384            }
385          }
386        else d = 0;
387        cc += 3;
388    
389        /* Handle repeated back references */
390    
391        switch (*cc)
392          {
393          case OP_CRSTAR:
394          case OP_CRMINSTAR:
395          case OP_CRQUERY:
396          case OP_CRMINQUERY:
397          min = 0;
398          cc++;
399          break;
400    
401          case OP_CRPLUS:
402          case OP_CRMINPLUS:
403          min = 1;
404          cc++;
405          break;
406    
407          case OP_CRRANGE:
408          case OP_CRMINRANGE:
409          min = GET2(cc, 1);
410          cc += 5;
411          break;
412    
413          default:
414          min = 1;
415          break;
416          }
417    
418        branchlength += min * d;
419        break;
420    
421        /* We can easily detect direct recursion, but not mutual recursion. This is
422        caught by a recursion depth count. */
423    
424        case OP_RECURSE:
425        cs = ce = (uschar *)startcode + GET(cc, 1);
426        if (cs == NULL) return -2;
427        do ce += GET(ce, 1); while (*ce == OP_ALT);
428        if ((cc > cs && cc < ce) || recurse_depth > 10)
429          had_recurse = TRUE;
430        else
431          {
432          branchlength += find_minlength(cs, startcode, options, recurse_depth + 1);
433          }
434        cc += 1 + LINK_SIZE;
435        break;
436    
437        /* Anything else does not or need not match a character. We can get the
438        item's length from the table, but for those that can match zero occurrences
439        of a character, we must take special action for UTF-8 characters. As it
440        happens, the "NOT" versions of these opcodes are used at present only for
441        ASCII characters, so they could be omitted from this list. However, in
442        future that may change, so we include them here so as not to leave a
443        gotcha for a future maintainer. */
444    
445        case OP_UPTO:
446        case OP_UPTOI:
447        case OP_NOTUPTO:
448        case OP_NOTUPTOI:
449        case OP_MINUPTO:
450        case OP_MINUPTOI:
451        case OP_NOTMINUPTO:
452        case OP_NOTMINUPTOI:
453        case OP_POSUPTO:
454        case OP_POSUPTOI:
455        case OP_NOTPOSUPTO:
456        case OP_NOTPOSUPTOI:
457    
458        case OP_STAR:
459        case OP_STARI:
460        case OP_NOTSTAR:
461        case OP_NOTSTARI:
462        case OP_MINSTAR:
463        case OP_MINSTARI:
464        case OP_NOTMINSTAR:
465        case OP_NOTMINSTARI:
466        case OP_POSSTAR:
467        case OP_POSSTARI:
468        case OP_NOTPOSSTAR:
469        case OP_NOTPOSSTARI:
470    
471        case OP_QUERY:
472        case OP_QUERYI:
473        case OP_NOTQUERY:
474        case OP_NOTQUERYI:
475        case OP_MINQUERY:
476        case OP_MINQUERYI:
477        case OP_NOTMINQUERY:
478        case OP_NOTMINQUERYI:
479        case OP_POSQUERY:
480        case OP_POSQUERYI:
481        case OP_NOTPOSQUERY:
482        case OP_NOTPOSQUERYI:
483    
484        cc += _pcre_OP_lengths[op];
485    #ifdef SUPPORT_UTF8
486        if (utf8 && cc[-1] >= 0xc0) cc += _pcre_utf8_table4[cc[-1] & 0x3f];
487    #endif
488        break;
489    
490        /* Skip these, but we need to add in the name length. */
491    
492        case OP_MARK:
493        case OP_PRUNE_ARG:
494        case OP_SKIP_ARG:
495        case OP_THEN_ARG:
496        cc += _pcre_OP_lengths[op] + cc[1];
497        break;
498    
499        /* The remaining opcodes are just skipped over. */
500    
501        case OP_CLOSE:
502        case OP_COMMIT:
503        case OP_FAIL:
504        case OP_PRUNE:
505        case OP_SET_SOM:
506        case OP_SKIP:
507        case OP_THEN:
508        cc += _pcre_OP_lengths[op];
509        break;
510    
511        /* This should not occur: we list all opcodes explicitly so that when
512        new ones get added they are properly considered. */
513    
514        default:
515        return -3;
516        }
517      }
518    /* Control never gets here */
519    }
520    
521    
522    
523  /*************************************************  /*************************************************
524  *      Set a bit and maybe its alternate case    *  *      Set a bit and maybe its alternate case    *
525  *************************************************/  *************************************************/
526    
527  /* Given a character, set its bit in the table, and also the bit for the other  /* Given a character, set its first byte's bit in the table, and also the
528  version of a letter if we are caseless.  corresponding bit for the other version of a letter if we are caseless. In
529    UTF-8 mode, for characters greater than 127, we can only do the caseless thing
530    when Unicode property support is available.
531    
532  Arguments:  Arguments:
533    start_bits    points to the bit map    start_bits    points to the bit map
534    c             is the character    p             points to the character
535    caseless      the caseless flag    caseless      the caseless flag
536    cd            the block with char table pointers    cd            the block with char table pointers
537      utf8          TRUE for UTF-8 mode
538    
539    Returns:        pointer after the character
540    */
541    
542    static const uschar *
543    set_table_bit(uschar *start_bits, const uschar *p, BOOL caseless,
544      compile_data *cd, BOOL utf8)
545    {
546    unsigned int c = *p;
547    
548    SET_BIT(c);
549    
550    #ifdef SUPPORT_UTF8
551    if (utf8 && c > 127)
552      {
553      GETCHARINC(c, p);
554    #ifdef SUPPORT_UCP
555      if (caseless)
556        {
557        uschar buff[8];
558        c = UCD_OTHERCASE(c);
559        (void)_pcre_ord2utf8(c, buff);
560        SET_BIT(buff[0]);
561        }
562    #endif
563      return p;
564      }
565    #endif
566    
567    /* Not UTF-8 mode, or character is less than 127. */
568    
569    if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
570    return p + 1;
571    }
572    
573    
574    
575    /*************************************************
576    *     Set bits for a positive character type     *
577    *************************************************/
578    
579    /* This function sets starting bits for a character type. In UTF-8 mode, we can
580    only do a direct setting for bytes less than 128, as otherwise there can be
581    confusion with bytes in the middle of UTF-8 characters. In a "traditional"
582    environment, the tables will only recognize ASCII characters anyway, but in at
583    least one Windows environment, some higher bytes bits were set in the tables.
584    So we deal with that case by considering the UTF-8 encoding.
585    
586    Arguments:
587      start_bits     the starting bitmap
588      cbit type      the type of character wanted
589      table_limit    32 for non-UTF-8; 16 for UTF-8
590      cd             the block with char table pointers
591    
592    Returns:         nothing
593    */
594    
595    static void
596    set_type_bits(uschar *start_bits, int cbit_type, int table_limit,
597      compile_data *cd)
598    {
599    register int c;
600    for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type];
601    if (table_limit == 32) return;
602    for (c = 128; c < 256; c++)
603      {
604      if ((cd->cbits[c/8] & (1 << (c&7))) != 0)
605        {
606        uschar buff[8];
607        (void)_pcre_ord2utf8(c, buff);
608        SET_BIT(buff[0]);
609        }
610      }
611    }
612    
613  Returns:        nothing  
614    /*************************************************
615    *     Set bits for a negative character type     *
616    *************************************************/
617    
618    /* This function sets starting bits for a negative character type such as \D.
619    In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
620    otherwise there can be confusion with bytes in the middle of UTF-8 characters.
621    Unlike in the positive case, where we can set appropriate starting bits for
622    specific high-valued UTF-8 characters, in this case we have to set the bits for
623    all high-valued characters. The lowest is 0xc2, but we overkill by starting at
624    0xc0 (192) for simplicity.
625    
626    Arguments:
627      start_bits     the starting bitmap
628      cbit type      the type of character wanted
629      table_limit    32 for non-UTF-8; 16 for UTF-8
630      cd             the block with char table pointers
631    
632    Returns:         nothing
633  */  */
634    
635  static void  static void
636  set_bit(uschar *start_bits, unsigned int c, BOOL caseless, compile_data *cd)  set_nottype_bits(uschar *start_bits, int cbit_type, int table_limit,
637      compile_data *cd)
638  {  {
639  start_bits[c/8] |= (1 << (c&7));  register int c;
640  if (caseless && (cd->ctypes[c] & ctype_letter) != 0)  for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type];
641    start_bits[cd->fcc[c]/8] |= (1 << (cd->fcc[c]&7));  if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff;
642  }  }
643    
644    
645    
646  /*************************************************  /*************************************************
647  *          Create bitmap of starting chars       *  *          Create bitmap of starting bytes       *
648  *************************************************/  *************************************************/
649    
650  /* This function scans a compiled unanchored expression and attempts to build a  /* This function scans a compiled unanchored expression recursively and
651  bitmap of the set of initial characters. If it can't, it returns FALSE. As time  attempts to build a bitmap of the set of possible starting bytes. As time goes
652  goes by, we may be able to get more clever at doing this.  by, we may be able to get more clever at doing this. The SSB_CONTINUE return is
653    useful for parenthesized groups in patterns such as (a*)b where the group
654    provides some optional starting bytes but scanning must continue at the outer
655    level to find at least one mandatory byte. At the outermost level, this
656    function fails unless the result is SSB_DONE.
657    
658  Arguments:  Arguments:
659    code         points to an expression    code         points to an expression
660    start_bits   points to a 32-byte table, initialized to 0    start_bits   points to a 32-byte table, initialized to 0
   caseless     the current state of the caseless flag  
661    utf8         TRUE if in UTF-8 mode    utf8         TRUE if in UTF-8 mode
662    cd           the block with char table pointers    cd           the block with char table pointers
663    
664  Returns:       TRUE if table built, FALSE otherwise  Returns:       SSB_FAIL     => Failed to find any starting bytes
665                   SSB_DONE     => Found mandatory starting bytes
666                   SSB_CONTINUE => Found optional starting bytes
667                   SSB_UNKNOWN  => Hit an unrecognized opcode
668  */  */
669    
670  static BOOL  static int
671  set_start_bits(const uschar *code, uschar *start_bits, BOOL caseless,  set_start_bits(const uschar *code, uschar *start_bits, BOOL utf8,
672    BOOL utf8, compile_data *cd)    compile_data *cd)
673  {  {
674  register int c;  register int c;
675    int yield = SSB_DONE;
676    int table_limit = utf8? 16:32;
677    
678  #if 0  #if 0
679  /* ========================================================================= */  /* ========================================================================= */
# Line 114  volatile int dummy; Line 694  volatile int dummy;
694    
695  do  do
696    {    {
   const uschar *tcode = code + 1 + LINK_SIZE;  
697    BOOL try_next = TRUE;    BOOL try_next = TRUE;
698      const uschar *tcode = code + 1 + LINK_SIZE;
699    
700    while (try_next)    if (*code == OP_CBRA || *code == OP_SCBRA ||
701          *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += 2;
702    
703      while (try_next)    /* Loop for items in this branch */
704      {      {
705      /* If a branch starts with a bracket or a positive lookahead assertion,      int rc;
     recurse to set bits from within them. That's all for this branch. */  
706    
707      if ((int)*tcode >= OP_BRA || *tcode == OP_ASSERT)      switch(*tcode)
708        {        {
709        if (!set_start_bits(tcode, start_bits, caseless, utf8, cd))        /* If we reach something we don't understand, it means a new opcode has
710          return FALSE;        been created that hasn't been added to this code. Hopefully this problem
711        try_next = FALSE;        will be discovered during testing. */
       }  
712    
     else switch(*tcode)  
       {  
713        default:        default:
714        return FALSE;        return SSB_UNKNOWN;
715    
716        /* Skip over callout */        /* Fail for a valid opcode that implies no starting bits. */
717    
718        case OP_CALLOUT:        case OP_ACCEPT:
719        tcode += 2 + 2*LINK_SIZE;        case OP_ASSERT_ACCEPT:
720          case OP_ALLANY:
721          case OP_ANY:
722          case OP_ANYBYTE:
723          case OP_CIRC:
724          case OP_CIRCM:
725          case OP_CLOSE:
726          case OP_COMMIT:
727          case OP_COND:
728          case OP_CREF:
729          case OP_DEF:
730          case OP_DOLL:
731          case OP_DOLLM:
732          case OP_END:
733          case OP_EOD:
734          case OP_EODN:
735          case OP_EXTUNI:
736          case OP_FAIL:
737          case OP_MARK:
738          case OP_NCREF:
739          case OP_NOT:
740          case OP_NOTEXACT:
741          case OP_NOTEXACTI:
742          case OP_NOTI:
743          case OP_NOTMINPLUS:
744          case OP_NOTMINPLUSI:
745          case OP_NOTMINQUERY:
746          case OP_NOTMINQUERYI:
747          case OP_NOTMINSTAR:
748          case OP_NOTMINSTARI:
749          case OP_NOTMINUPTO:
750          case OP_NOTMINUPTOI:
751          case OP_NOTPLUS:
752          case OP_NOTPLUSI:
753          case OP_NOTPOSPLUS:
754          case OP_NOTPOSPLUSI:
755          case OP_NOTPOSQUERY:
756          case OP_NOTPOSQUERYI:
757          case OP_NOTPOSSTAR:
758          case OP_NOTPOSSTARI:
759          case OP_NOTPOSUPTO:
760          case OP_NOTPOSUPTOI:
761          case OP_NOTPROP:
762          case OP_NOTQUERY:
763          case OP_NOTQUERYI:
764          case OP_NOTSTAR:
765          case OP_NOTSTARI:
766          case OP_NOTUPTO:
767          case OP_NOTUPTOI:
768          case OP_NOT_HSPACE:
769          case OP_NOT_VSPACE:
770          case OP_NRREF:
771          case OP_PROP:
772          case OP_PRUNE:
773          case OP_PRUNE_ARG:
774          case OP_RECURSE:
775          case OP_REF:
776          case OP_REFI:
777          case OP_REVERSE:
778          case OP_RREF:
779          case OP_SCOND:
780          case OP_SET_SOM:
781          case OP_SKIP:
782          case OP_SKIP_ARG:
783          case OP_SOD:
784          case OP_SOM:
785          case OP_THEN:
786          case OP_THEN_ARG:
787          case OP_XCLASS:
788          return SSB_FAIL;
789    
790          /* We can ignore word boundary tests. */
791    
792          case OP_WORD_BOUNDARY:
793          case OP_NOT_WORD_BOUNDARY:
794          tcode++;
795        break;        break;
796    
797        /* Skip over extended extraction bracket number */        /* If we hit a bracket or a positive lookahead assertion, recurse to set
798          bits from within the subpattern. If it can't find anything, we have to
799          give up. If it finds some mandatory character(s), we are done for this
800          branch. Otherwise, carry on scanning after the subpattern. */
801    
802          case OP_BRA:
803          case OP_SBRA:
804          case OP_CBRA:
805          case OP_SCBRA:
806          case OP_BRAPOS:
807          case OP_SBRAPOS:
808          case OP_CBRAPOS:
809          case OP_SCBRAPOS:
810          case OP_ONCE:
811          case OP_ONCE_NC:
812          case OP_ASSERT:
813          rc = set_start_bits(tcode, start_bits, utf8, cd);
814          if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
815          if (rc == SSB_DONE) try_next = FALSE; else
816            {
817            do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
818            tcode += 1 + LINK_SIZE;
819            }
820          break;
821    
822        case OP_BRANUMBER:        /* If we hit ALT or KET, it means we haven't found anything mandatory in
823        tcode += 3;        this branch, though we might have found something optional. For ALT, we
824          continue with the next alternative, but we have to arrange that the final
825          result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
826          return SSB_CONTINUE: if this is the top level, that indicates failure,
827          but after a nested subpattern, it causes scanning to continue. */
828    
829          case OP_ALT:
830          yield = SSB_CONTINUE;
831          try_next = FALSE;
832          break;
833    
834          case OP_KET:
835          case OP_KETRMAX:
836          case OP_KETRMIN:
837          case OP_KETRPOS:
838          return SSB_CONTINUE;
839    
840          /* Skip over callout */
841    
842          case OP_CALLOUT:
843          tcode += 2 + 2*LINK_SIZE;
844        break;        break;
845    
846        /* Skip over lookbehind and negative lookahead assertions */        /* Skip over lookbehind and negative lookahead assertions */
# Line 152  do Line 849  do
849        case OP_ASSERTBACK:        case OP_ASSERTBACK:
850        case OP_ASSERTBACK_NOT:        case OP_ASSERTBACK_NOT:
851        do tcode += GET(tcode, 1); while (*tcode == OP_ALT);        do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
852        tcode += 1+LINK_SIZE;        tcode += 1 + LINK_SIZE;
       break;  
   
       /* Skip over an option setting, changing the caseless flag */  
   
       case OP_OPT:  
       caseless = (tcode[1] & PCRE_CASELESS) != 0;  
       tcode += 2;  
853        break;        break;
854    
855        /* BRAZERO does the bracket, but carries on. */        /* BRAZERO does the bracket, but carries on. */
856    
857        case OP_BRAZERO:        case OP_BRAZERO:
858        case OP_BRAMINZERO:        case OP_BRAMINZERO:
859        if (!set_start_bits(++tcode, start_bits, caseless, utf8, cd))        case OP_BRAPOSZERO:
860          return FALSE;        rc = set_start_bits(++tcode, start_bits, utf8, cd);
861          if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
862  /* =========================================================================  /* =========================================================================
863        See the comment at the head of this function concerning the next line,        See the comment at the head of this function concerning the next line,
864        which was an old fudge for the benefit of OS/2.        which was an old fudge for the benefit of OS/2.
865        dummy = 1;        dummy = 1;
866    ========================================================================= */    ========================================================================= */
867        do tcode += GET(tcode,1); while (*tcode == OP_ALT);        do tcode += GET(tcode,1); while (*tcode == OP_ALT);
868        tcode += 1+LINK_SIZE;        tcode += 1 + LINK_SIZE;
869          break;
870    
871          /* SKIPZERO skips the bracket. */
872    
873          case OP_SKIPZERO:
874          tcode++;
875          do tcode += GET(tcode,1); while (*tcode == OP_ALT);
876          tcode += 1 + LINK_SIZE;
877        break;        break;
878    
879        /* Single-char * or ? sets the bit and tries the next item */        /* Single-char * or ? sets the bit and tries the next item */
880    
881        case OP_STAR:        case OP_STAR:
882        case OP_MINSTAR:        case OP_MINSTAR:
883          case OP_POSSTAR:
884        case OP_QUERY:        case OP_QUERY:
885        case OP_MINQUERY:        case OP_MINQUERY:
886        set_bit(start_bits, tcode[1], caseless, cd);        case OP_POSQUERY:
887        tcode += 2;        tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf8);
888  #ifdef SUPPORT_UTF8        break;
889        if (utf8) while ((*tcode & 0xc0) == 0x80) tcode++;  
890  #endif        case OP_STARI:
891          case OP_MINSTARI:
892          case OP_POSSTARI:
893          case OP_QUERYI:
894          case OP_MINQUERYI:
895          case OP_POSQUERYI:
896          tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf8);
897        break;        break;
898    
899        /* Single-char upto sets the bit and tries the next */        /* Single-char upto sets the bit and tries the next */
900    
901        case OP_UPTO:        case OP_UPTO:
902        case OP_MINUPTO:        case OP_MINUPTO:
903        set_bit(start_bits, tcode[3], caseless, cd);        case OP_POSUPTO:
904        tcode += 4;        tcode = set_table_bit(start_bits, tcode + 3, FALSE, cd, utf8);
905  #ifdef SUPPORT_UTF8        break;
906        if (utf8) while ((*tcode & 0xc0) == 0x80) tcode++;  
907  #endif        case OP_UPTOI:
908          case OP_MINUPTOI:
909          case OP_POSUPTOI:
910          tcode = set_table_bit(start_bits, tcode + 3, TRUE, cd, utf8);
911        break;        break;
912    
913        /* At least one single char sets the bit and stops */        /* At least one single char sets the bit and stops */
914    
915        case OP_EXACT:       /* Fall through */        case OP_EXACT:
916        tcode += 2;        tcode += 2;
917          /* Fall through */
918        case OP_CHAR:        case OP_CHAR:
       case OP_CHARNC:  
919        case OP_PLUS:        case OP_PLUS:
920        case OP_MINPLUS:        case OP_MINPLUS:
921        set_bit(start_bits, tcode[1], caseless, cd);        case OP_POSPLUS:
922          (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf8);
923        try_next = FALSE;        try_next = FALSE;
924        break;        break;
925    
926        /* Single character type sets the bits and stops */        case OP_EXACTI:
927          tcode += 2;
928          /* Fall through */
929          case OP_CHARI:
930          case OP_PLUSI:
931          case OP_MINPLUSI:
932          case OP_POSPLUSI:
933          (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf8);
934          try_next = FALSE;
935          break;
936    
937          /* Special spacing and line-terminating items. These recognize specific
938          lists of characters. The difference between VSPACE and ANYNL is that the
939          latter can match the two-character CRLF sequence, but that is not
940          relevant for finding the first character, so their code here is
941          identical. */
942    
943          case OP_HSPACE:
944          SET_BIT(0x09);
945          SET_BIT(0x20);
946          if (utf8)
947            {
948            SET_BIT(0xC2);  /* For U+00A0 */
949            SET_BIT(0xE1);  /* For U+1680, U+180E */
950            SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
951            SET_BIT(0xE3);  /* For U+3000 */
952            }
953          else SET_BIT(0xA0);
954          try_next = FALSE;
955          break;
956    
957          case OP_ANYNL:
958          case OP_VSPACE:
959          SET_BIT(0x0A);
960          SET_BIT(0x0B);
961          SET_BIT(0x0C);
962          SET_BIT(0x0D);
963          if (utf8)
964            {
965            SET_BIT(0xC2);  /* For U+0085 */
966            SET_BIT(0xE2);  /* For U+2028, U+2029 */
967            }
968          else SET_BIT(0x85);
969          try_next = FALSE;
970          break;
971    
972          /* Single character types set the bits and stop. Note that if PCRE_UCP
973          is set, we do not see these op codes because \d etc are converted to
974          properties. Therefore, these apply in the case when only characters less
975          than 256 are recognized to match the types. */
976    
977        case OP_NOT_DIGIT:        case OP_NOT_DIGIT:
978        for (c = 0; c < 32; c++)        set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
         start_bits[c] |= ~cd->cbits[c+cbit_digit];  
979        try_next = FALSE;        try_next = FALSE;
980        break;        break;
981    
982        case OP_DIGIT:        case OP_DIGIT:
983        for (c = 0; c < 32; c++)        set_type_bits(start_bits, cbit_digit, table_limit, cd);
         start_bits[c] |= cd->cbits[c+cbit_digit];  
984        try_next = FALSE;        try_next = FALSE;
985        break;        break;
986    
987        /* The cbit_space table has vertical tab as whitespace; we have to        /* The cbit_space table has vertical tab as whitespace; we have to
988        discard it. */        ensure it is set as not whitespace. */
989    
990        case OP_NOT_WHITESPACE:        case OP_NOT_WHITESPACE:
991        for (c = 0; c < 32; c++)        set_nottype_bits(start_bits, cbit_space, table_limit, cd);
992          {        start_bits[1] |= 0x08;
         int d = cd->cbits[c+cbit_space];  
         if (c == 1) d &= ~0x08;  
         start_bits[c] |= ~d;  
         }  
993        try_next = FALSE;        try_next = FALSE;
994        break;        break;
995    
996        /* The cbit_space table has vertical tab as whitespace; we have to        /* The cbit_space table has vertical tab as whitespace; we have to
997        discard it. */        not set it from the table. */
998    
999        case OP_WHITESPACE:        case OP_WHITESPACE:
1000        for (c = 0; c < 32; c++)        c = start_bits[1];    /* Save in case it was already set */
1001          {        set_type_bits(start_bits, cbit_space, table_limit, cd);
1002          int d = cd->cbits[c+cbit_space];        start_bits[1] = (start_bits[1] & ~0x08) | c;
         if (c == 1) d &= ~0x08;  
         start_bits[c] |= d;  
         }  
1003        try_next = FALSE;        try_next = FALSE;
1004        break;        break;
1005    
1006        case OP_NOT_WORDCHAR:        case OP_NOT_WORDCHAR:
1007        for (c = 0; c < 32; c++)        set_nottype_bits(start_bits, cbit_word, table_limit, cd);
         start_bits[c] |= ~cd->cbits[c+cbit_word];  
1008        try_next = FALSE;        try_next = FALSE;
1009        break;        break;
1010    
1011        case OP_WORDCHAR:        case OP_WORDCHAR:
1012        for (c = 0; c < 32; c++)        set_type_bits(start_bits, cbit_word, table_limit, cd);
         start_bits[c] |= cd->cbits[c+cbit_word];  
1013        try_next = FALSE;        try_next = FALSE;
1014        break;        break;
1015    
# Line 271  do Line 1018  do
1018    
1019        case OP_TYPEPLUS:        case OP_TYPEPLUS:
1020        case OP_TYPEMINPLUS:        case OP_TYPEMINPLUS:
1021          case OP_TYPEPOSPLUS:
1022        tcode++;        tcode++;
1023        break;        break;
1024    
# Line 283  do Line 1031  do
1031    
1032        case OP_TYPEUPTO:        case OP_TYPEUPTO:
1033        case OP_TYPEMINUPTO:        case OP_TYPEMINUPTO:
1034          case OP_TYPEPOSUPTO:
1035        tcode += 2;               /* Fall through */        tcode += 2;               /* Fall through */
1036    
1037        case OP_TYPESTAR:        case OP_TYPESTAR:
1038        case OP_TYPEMINSTAR:        case OP_TYPEMINSTAR:
1039          case OP_TYPEPOSSTAR:
1040        case OP_TYPEQUERY:        case OP_TYPEQUERY:
1041        case OP_TYPEMINQUERY:        case OP_TYPEMINQUERY:
1042          case OP_TYPEPOSQUERY:
1043        switch(tcode[1])        switch(tcode[1])
1044          {          {
1045            default:
1046          case OP_ANY:          case OP_ANY:
1047          return FALSE;          case OP_ALLANY:
1048            return SSB_FAIL;
1049    
1050            case OP_HSPACE:
1051            SET_BIT(0x09);
1052            SET_BIT(0x20);
1053            if (utf8)
1054              {
1055              SET_BIT(0xC2);  /* For U+00A0 */
1056              SET_BIT(0xE1);  /* For U+1680, U+180E */
1057              SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
1058              SET_BIT(0xE3);  /* For U+3000 */
1059              }
1060            else SET_BIT(0xA0);
1061            break;
1062    
1063            case OP_ANYNL:
1064            case OP_VSPACE:
1065            SET_BIT(0x0A);
1066            SET_BIT(0x0B);
1067            SET_BIT(0x0C);
1068            SET_BIT(0x0D);
1069            if (utf8)
1070              {
1071              SET_BIT(0xC2);  /* For U+0085 */
1072              SET_BIT(0xE2);  /* For U+2028, U+2029 */
1073              }
1074            else SET_BIT(0x85);
1075            break;
1076    
1077          case OP_NOT_DIGIT:          case OP_NOT_DIGIT:
1078          for (c = 0; c < 32; c++)          set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
           start_bits[c] |= ~cd->cbits[c+cbit_digit];  
1079          break;          break;
1080    
1081          case OP_DIGIT:          case OP_DIGIT:
1082          for (c = 0; c < 32; c++)          set_type_bits(start_bits, cbit_digit, table_limit, cd);
           start_bits[c] |= cd->cbits[c+cbit_digit];  
1083          break;          break;
1084    
1085          /* The cbit_space table has vertical tab as whitespace; we have to          /* The cbit_space table has vertical tab as whitespace; we have to
1086          discard it. */          ensure it gets set as not whitespace. */
1087    
1088          case OP_NOT_WHITESPACE:          case OP_NOT_WHITESPACE:
1089          for (c = 0; c < 32; c++)          set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1090            {          start_bits[1] |= 0x08;
           int d = cd->cbits[c+cbit_space];  
           if (c == 1) d &= ~0x08;  
           start_bits[c] |= ~d;  
           }  
1091          break;          break;
1092    
1093          /* The cbit_space table has vertical tab as whitespace; we have to          /* The cbit_space table has vertical tab as whitespace; we have to
1094          discard it. */          avoid setting it. */
1095    
1096          case OP_WHITESPACE:          case OP_WHITESPACE:
1097          for (c = 0; c < 32; c++)          c = start_bits[1];    /* Save in case it was already set */
1098            {          set_type_bits(start_bits, cbit_space, table_limit, cd);
1099            int d = cd->cbits[c+cbit_space];          start_bits[1] = (start_bits[1] & ~0x08) | c;
           if (c == 1) d &= ~0x08;  
           start_bits[c] |= d;  
           }  
1100          break;          break;
1101    
1102          case OP_NOT_WORDCHAR:          case OP_NOT_WORDCHAR:
1103          for (c = 0; c < 32; c++)          set_nottype_bits(start_bits, cbit_word, table_limit, cd);
           start_bits[c] |= ~cd->cbits[c+cbit_word];  
1104          break;          break;
1105    
1106          case OP_WORDCHAR:          case OP_WORDCHAR:
1107          for (c = 0; c < 32; c++)          set_type_bits(start_bits, cbit_word, table_limit, cd);
           start_bits[c] |= cd->cbits[c+cbit_word];  
1108          break;          break;
1109          }          }
1110    
# Line 349  do Line 1118  do
1118        character with a value > 255. */        character with a value > 255. */
1119    
1120        case OP_NCLASS:        case OP_NCLASS:
1121    #ifdef SUPPORT_UTF8
1122        if (utf8)        if (utf8)
1123          {          {
1124          start_bits[24] |= 0xf0;              /* Bits for 0xc4 - 0xc8 */          start_bits[24] |= 0xf0;              /* Bits for 0xc4 - 0xc8 */
1125          memset(start_bits+25, 0xff, 7);      /* Bits for 0xc9 - 0xff */          memset(start_bits+25, 0xff, 7);      /* Bits for 0xc9 - 0xff */
1126          }          }
1127    #endif
1128        /* Fall through */        /* Fall through */
1129    
1130        case OP_CLASS:        case OP_CLASS:
# Line 366  do Line 1137  do
1137          value is > 127. In fact, there are only two possible starting bytes for          value is > 127. In fact, there are only two possible starting bytes for
1138          characters in the range 128 - 255. */          characters in the range 128 - 255. */
1139    
1140    #ifdef SUPPORT_UTF8
1141          if (utf8)          if (utf8)
1142            {            {
1143            for (c = 0; c < 16; c++) start_bits[c] |= tcode[c];            for (c = 0; c < 16; c++) start_bits[c] |= tcode[c];
# Line 383  do Line 1155  do
1155          /* In non-UTF-8 mode, the two bit maps are completely compatible. */          /* In non-UTF-8 mode, the two bit maps are completely compatible. */
1156    
1157          else          else
1158    #endif
1159            {            {
1160            for (c = 0; c < 32; c++) start_bits[c] |= tcode[c];            for (c = 0; c < 32; c++) start_bits[c] |= tcode[c];
1161            }            }
1162    
1163          /* Advance past the bit map, and act on what follows */          /* Advance past the bit map, and act on what follows. For a zero
1164            minimum repeat, continue; otherwise stop processing. */
1165    
1166          tcode += 32;          tcode += 32;
1167          switch (*tcode)          switch (*tcode)
# Line 418  do Line 1192  do
1192    code += GET(code, 1);   /* Advance to next branch */    code += GET(code, 1);   /* Advance to next branch */
1193    }    }
1194  while (*code == OP_ALT);  while (*code == OP_ALT);
1195  return TRUE;  return yield;
1196  }  }
1197    
1198    
1199    
1200    
1201    
1202  /*************************************************  /*************************************************
1203  *          Study a compiled expression           *  *          Study a compiled expression           *
1204  *************************************************/  *************************************************/
# Line 438  Arguments: Line 1214  Arguments:
1214              set NULL unless error              set NULL unless error
1215    
1216  Returns:    pointer to a pcre_extra block, with study_data filled in and the  Returns:    pointer to a pcre_extra block, with study_data filled in and the
1217                appropriate flag set;                appropriate flags set;
1218              NULL on error or if no optimization possible              NULL on error or if no optimization possible
1219  */  */
1220    
1221  PCRE_DATA_SCOPE pcre_extra *  PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION
1222  pcre_study(const pcre *external_re, int options, const char **errorptr)  pcre_study(const pcre *external_re, int options, const char **errorptr)
1223  {  {
1224    int min;
1225    BOOL bits_set = FALSE;
1226  uschar start_bits[32];  uschar start_bits[32];
1227  pcre_extra *extra;  pcre_extra *extra = NULL;
1228  pcre_study_data *study;  pcre_study_data *study;
1229  const uschar *tables;  const uschar *tables;
1230  uschar *code;  uschar *code;
# Line 471  code = (uschar *)re + re->name_table_off Line 1249  code = (uschar *)re + re->name_table_off
1249    (re->name_count * re->name_entry_size);    (re->name_count * re->name_entry_size);
1250    
1251  /* For an anchored pattern, or an unanchored pattern that has a first char, or  /* For an anchored pattern, or an unanchored pattern that has a first char, or
1252  a multiline pattern that matches only at "line starts", no further processing  a multiline pattern that matches only at "line starts", there is no point in
1253  at present. */  seeking a list of starting bytes. */
1254    
1255  if ((re->options & (PCRE_ANCHORED|PCRE_FIRSTSET|PCRE_STARTLINE)) != 0)  if ((re->options & PCRE_ANCHORED) == 0 &&
1256    return NULL;      (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0)
1257      {
1258      int rc;
1259    
1260  /* Set the character tables in the block that is passed around */    /* Set the character tables in the block that is passed around */
1261    
1262  tables = re->tables;    tables = re->tables;
1263  if (tables == NULL)    if (tables == NULL)
1264    (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,      (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1265    (void *)(&tables));      (void *)(&tables));
1266    
1267  compile_block.lcc = tables + lcc_offset;    compile_block.lcc = tables + lcc_offset;
1268  compile_block.fcc = tables + fcc_offset;    compile_block.fcc = tables + fcc_offset;
1269  compile_block.cbits = tables + cbits_offset;    compile_block.cbits = tables + cbits_offset;
1270  compile_block.ctypes = tables + ctypes_offset;    compile_block.ctypes = tables + ctypes_offset;
1271    
1272  /* See if we can find a fixed set of initial characters for the pattern. */    /* See if we can find a fixed set of initial characters for the pattern. */
1273    
1274  memset(start_bits, 0, 32 * sizeof(uschar));    memset(start_bits, 0, 32 * sizeof(uschar));
1275  if (!set_start_bits(code, start_bits, (re->options & PCRE_CASELESS) != 0,    rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
1276    (re->options & PCRE_UTF8) != 0, &compile_block)) return NULL;      &compile_block);
1277      bits_set = rc == SSB_DONE;
1278  /* Get a pcre_extra block and a pcre_study_data block. The study data is put in    if (rc == SSB_UNKNOWN)
1279  the latter, which is pointed to by the former, which may also get additional      {
1280  data set later by the calling program. At the moment, the size of      *errorptr = "internal error: opcode not recognized";
1281  pcre_study_data is fixed. We nevertheless save it in a field for returning via      return NULL;
1282  the pcre_fullinfo() function so that if it becomes variable in the future, we      }
1283  don't have to change that code. */    }
1284    
1285  extra = (pcre_extra *)(pcre_malloc)  /* Find the minimum length of subject string. */
   (sizeof(pcre_extra) + sizeof(pcre_study_data));  
1286    
1287  if (extra == NULL)  switch(min = find_minlength(code, code, re->options, 0))
1288    {    {
1289    *errorptr = "failed to get memory";    case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
1290    return NULL;    case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
1291      default: break;
1292    }    }
1293    
1294  study = (pcre_study_data *)((char *)extra + sizeof(pcre_extra));  /* If a set of starting bytes has been identified, or if the minimum length is
1295  extra->flags = PCRE_EXTRA_STUDY_DATA;  greater than zero, or if JIT optimization has been requested, get a pcre_extra
1296  extra->study_data = study;  block and a pcre_study_data block. The study data is put in the latter, which
1297    is pointed to by the former, which may also get additional data set later by
1298  study->size = sizeof(pcre_study_data);  the calling program. At the moment, the size of pcre_study_data is fixed. We
1299  study->options = PCRE_STUDY_MAPPED;  nevertheless save it in a field for returning via the pcre_fullinfo() function
1300  memcpy(study->start_bits, start_bits, sizeof(start_bits));  so that if it becomes variable in the future, we don't have to change that
1301    code. */
1302    
1303    if (bits_set || min > 0
1304    #ifdef SUPPORT_JIT
1305        || (options & PCRE_STUDY_JIT_COMPILE) != 0
1306    #endif
1307      )
1308      {
1309      extra = (pcre_extra *)(pcre_malloc)
1310        (sizeof(pcre_extra) + sizeof(pcre_study_data));
1311      if (extra == NULL)
1312        {
1313        *errorptr = "failed to get memory";
1314        return NULL;
1315        }
1316    
1317      study = (pcre_study_data *)((char *)extra + sizeof(pcre_extra));
1318      extra->flags = PCRE_EXTRA_STUDY_DATA;
1319      extra->study_data = study;
1320    
1321      study->size = sizeof(pcre_study_data);
1322      study->flags = 0;
1323    
1324      if (bits_set)
1325        {
1326        study->flags |= PCRE_STUDY_MAPPED;
1327        memcpy(study->start_bits, start_bits, sizeof(start_bits));
1328        }
1329    
1330      /* Always set the minlength value in the block, because the JIT compiler
1331      makes use of it. However, don't set the bit unless the length is greater than
1332      zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
1333      checking the zero case. */
1334    
1335      if (min > 0)
1336        {
1337        study->flags |= PCRE_STUDY_MINLEN;
1338        study->minlength = min;
1339        }
1340      else study->minlength = 0;
1341    
1342      /* If JIT support was compiled and requested, attempt the JIT compilation.
1343      If no starting bytes were found, and the minimum length is zero, and JIT
1344      compilation fails, abandon the extra block and return NULL. */
1345    
1346    #ifdef SUPPORT_JIT
1347      extra->executable_jit = NULL;
1348      if ((options & PCRE_STUDY_JIT_COMPILE) != 0) _pcre_jit_compile(re, extra);
1349      if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0)
1350        {
1351        pcre_free_study(extra);
1352        extra = NULL;
1353        }
1354    #endif
1355      }
1356    
1357  return extra;  return extra;
1358  }  }
1359    
1360    
1361    /*************************************************
1362    *          Free the study data                   *
1363    *************************************************/
1364    
1365    /* This function frees the memory that was obtained by pcre_study().
1366    
1367    Argument:   a pointer to the pcre_extra block
1368    Returns:    nothing
1369    */
1370    
1371    PCRE_EXP_DEFN void
1372    pcre_free_study(pcre_extra *extra)
1373    {
1374    #ifdef SUPPORT_JIT
1375    if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
1376         extra->executable_jit != NULL)
1377      _pcre_jit_free(extra->executable_jit);
1378    #endif
1379    pcre_free(extra);
1380    }
1381    
1382  /* End of pcre_study.c */  /* End of pcre_study.c */

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