/[pcre]/code/trunk/pcre_study.c
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revision 688 by ph10, Fri Sep 9 09:35:48 2011 UTC revision 787 by ph10, Tue Dec 6 15:37:24 2011 UTC
# Line 66  string of that length that matches. In U Line 66  string of that length that matches. In U
66  rather than bytes.  rather than bytes.
67    
68  Arguments:  Arguments:
69    code        pointer to start of group (the bracket)    code            pointer to start of group (the bracket)
70    startcode   pointer to start of the whole pattern    startcode       pointer to start of the whole pattern
71    options     the compiling options    options         the compiling options
72    had_accept  pointer to flag for (*ACCEPT) encountered    int             RECURSE depth
   int         RECURSE depth  
73    
74  Returns:   the minimum length  Returns:   the minimum length
75             -1 if \C was encountered             -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
76             -2 internal error (missing capturing bracket)             -2 internal error (missing capturing bracket)
77             -3 internal error (opcode not listed)             -3 internal error (opcode not listed)
78  */  */
79    
80  static int  static int
81  find_minlength(const uschar *code, const uschar *startcode, int options,  find_minlength(const uschar *code, const uschar *startcode, int options,
82    BOOL *had_accept_ptr, int recurse_depth)    int recurse_depth)
83  {  {
84  int length = -1;  int length = -1;
85  BOOL utf8 = (options & PCRE_UTF8) != 0;  BOOL utf8 = (options & PCRE_UTF8) != 0;
# Line 128  for (;;) Line 127  for (;;)
127      case OP_BRAPOS:      case OP_BRAPOS:
128      case OP_SBRAPOS:      case OP_SBRAPOS:
129      case OP_ONCE:      case OP_ONCE:
130      d = find_minlength(cc, startcode, options, had_accept_ptr, recurse_depth);      case OP_ONCE_NC:
131        d = find_minlength(cc, startcode, options, recurse_depth);
132      if (d < 0) return d;      if (d < 0) return d;
133      branchlength += d;      branchlength += d;
     if (*had_accept_ptr) return branchlength;  
134      do cc += GET(cc, 1); while (*cc == OP_ALT);      do cc += GET(cc, 1); while (*cc == OP_ALT);
135      cc += 1 + LINK_SIZE;      cc += 1 + LINK_SIZE;
136      break;      break;
137    
138      /* Reached end of a branch; if it's a ket it is the end of a nested      /* ACCEPT makes things far too complicated; we have to give up. */
     call. If it's ALT it is an alternation in a nested call. If it is END it's  
     the end of the outer call. All can be handled by the same code. If it is  
     ACCEPT, it is essentially the same as END, but we set a flag so that  
     counting stops. */  
139    
140      case OP_ACCEPT:      case OP_ACCEPT:
141      case OP_ASSERT_ACCEPT:      case OP_ASSERT_ACCEPT:
142      *had_accept_ptr = TRUE;      return -1;
143      /* Fall through */  
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:      case OP_ALT:
151      case OP_KET:      case OP_KET:
152      case OP_KETRMAX:      case OP_KETRMAX:
# Line 285  for (;;) Line 286  for (;;)
286      cc++;      cc++;
287      break;      break;
288    
289      /* The single-byte matcher means we can't proceed in UTF-8 mode */      /* The single-byte matcher means we can't proceed in UTF-8 mode. (In
290        non-UTF-8 mode \C will actually be turned into OP_ALLANY, so won't ever
291        appear, but leave the code, just in case.) */
292    
293      case OP_ANYBYTE:      case OP_ANYBYTE:
294  #ifdef SUPPORT_UTF8  #ifdef SUPPORT_UTF8
# Line 379  for (;;) Line 382  for (;;)
382          }          }
383        else        else
384          {          {
385          d = find_minlength(cs, startcode, options, had_accept_ptr,          d = find_minlength(cs, startcode, options, recurse_depth);
           recurse_depth);  
         *had_accept_ptr = FALSE;  
386          }          }
387        }        }
388      else d = 0;      else d = 0;
# Line 424  for (;;) Line 425  for (;;)
425    
426      case OP_RECURSE:      case OP_RECURSE:
427      cs = ce = (uschar *)startcode + GET(cc, 1);      cs = ce = (uschar *)startcode + GET(cc, 1);
     if (cs == NULL) return -2;  
428      do ce += GET(ce, 1); while (*ce == OP_ALT);      do ce += GET(ce, 1); while (*ce == OP_ALT);
429      if ((cc > cs && cc < ce) || recurse_depth > 10)      if ((cc > cs && cc < ce) || recurse_depth > 10)
430        had_recurse = TRUE;        had_recurse = TRUE;
431      else      else
432        {        {
433        branchlength += find_minlength(cs, startcode, options, had_accept_ptr,        branchlength += find_minlength(cs, startcode, options, recurse_depth + 1);
         recurse_depth + 1);  
       *had_accept_ptr = FALSE;  
434        }        }
435      cc += 1 + LINK_SIZE;      cc += 1 + LINK_SIZE;
436      break;      break;
# Line 495  for (;;) Line 493  for (;;)
493      case OP_MARK:      case OP_MARK:
494      case OP_PRUNE_ARG:      case OP_PRUNE_ARG:
495      case OP_SKIP_ARG:      case OP_SKIP_ARG:
     cc += _pcre_OP_lengths[op] + cc[1];  
     break;  
   
496      case OP_THEN_ARG:      case OP_THEN_ARG:
497      cc += _pcre_OP_lengths[op] + cc[1+LINK_SIZE];      cc += _pcre_OP_lengths[op] + cc[1];
498      break;      break;
499    
500      /* The remaining opcodes are just skipped over. */      /* The remaining opcodes are just skipped over. */
# Line 814  do Line 809  do
809        case OP_CBRAPOS:        case OP_CBRAPOS:
810        case OP_SCBRAPOS:        case OP_SCBRAPOS:
811        case OP_ONCE:        case OP_ONCE:
812          case OP_ONCE_NC:
813        case OP_ASSERT:        case OP_ASSERT:
814        rc = set_start_bits(tcode, start_bits, utf8, cd);        rc = set_start_bits(tcode, start_bits, utf8, cd);
815        if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;        if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
# Line 1228  pcre_study(const pcre *external_re, int Line 1224  pcre_study(const pcre *external_re, int
1224  {  {
1225  int min;  int min;
1226  BOOL bits_set = FALSE;  BOOL bits_set = FALSE;
 BOOL had_accept = FALSE;  
1227  uschar start_bits[32];  uschar start_bits[32];
1228  pcre_extra *extra = NULL;  pcre_extra *extra = NULL;
1229  pcre_study_data *study;  pcre_study_data *study;
# Line 1281  if ((re->options & PCRE_ANCHORED) == 0 & Line 1276  if ((re->options & PCRE_ANCHORED) == 0 &
1276    rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,    rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
1277      &compile_block);      &compile_block);
1278    bits_set = rc == SSB_DONE;    bits_set = rc == SSB_DONE;
1279    if (rc == SSB_UNKNOWN)    if (rc == SSB_UNKNOWN)
1280      {      {
1281      *errorptr = "internal error: opcode not recognized";      *errorptr = "internal error: opcode not recognized";
1282      return NULL;      return NULL;
1283      }      }
1284    }    }
1285    
1286  /* Find the minimum length of subject string. */  /* Find the minimum length of subject string. */
1287    
1288  switch(min = find_minlength(code, code, re->options, &had_accept, 0))  switch(min = find_minlength(code, code, re->options, 0))
1289    {    {
1290    case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;    case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
1291    case -3: *errorptr = "internal error: opcode not recognized"; return NULL;    case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
# Line 1306  nevertheless save it in a field for retu Line 1301  nevertheless save it in a field for retu
1301  so that if it becomes variable in the future, we don't have to change that  so that if it becomes variable in the future, we don't have to change that
1302  code. */  code. */
1303    
1304  if (bits_set || min > 0  if (bits_set || min > 0
1305  #ifdef SUPPORT_JIT  #ifdef SUPPORT_JIT
1306      || (options & PCRE_STUDY_JIT_COMPILE) != 0      || (options & PCRE_STUDY_JIT_COMPILE) != 0
1307  #endif  #endif
# Line 1319  if (bits_set || min > 0 Line 1314  if (bits_set || min > 0
1314      *errorptr = "failed to get memory";      *errorptr = "failed to get memory";
1315      return NULL;      return NULL;
1316      }      }
1317    
1318    study = (pcre_study_data *)((char *)extra + sizeof(pcre_extra));    study = (pcre_study_data *)((char *)extra + sizeof(pcre_extra));
1319    extra->flags = PCRE_EXTRA_STUDY_DATA;    extra->flags = PCRE_EXTRA_STUDY_DATA;
1320    extra->study_data = study;    extra->study_data = study;
1321    
1322    study->size = sizeof(pcre_study_data);    study->size = sizeof(pcre_study_data);
1323    study->flags = 0;    study->flags = 0;
1324    
1325    if (bits_set)    /* Set the start bits always, to avoid unset memory errors if the
1326      study data is written to a file, but set the flag only if any of the bits
1327      are set, to save time looking when none are. */
1328    
1329      if (bits_set)
1330      {      {
1331      study->flags |= PCRE_STUDY_MAPPED;      study->flags |= PCRE_STUDY_MAPPED;
1332      memcpy(study->start_bits, start_bits, sizeof(start_bits));      memcpy(study->start_bits, start_bits, sizeof(start_bits));
1333      }      }
1334      else memset(study->start_bits, 0, 32 * sizeof(uschar));
1335    
1336      /* Always set the minlength value in the block, because the JIT compiler
1337      makes use of it. However, don't set the bit unless the length is greater than
1338      zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
1339      checking the zero case. */
1340    
1341    if (min > 0)    if (min > 0)
1342      {      {
1343      study->flags |= PCRE_STUDY_MINLEN;      study->flags |= PCRE_STUDY_MINLEN;
1344      study->minlength = min;      study->minlength = min;
1345      }      }
1346      else study->minlength = 0;
1347    
1348    /* If JIT support was compiled and requested, attempt the JIT compilation.    /* If JIT support was compiled and requested, attempt the JIT compilation.
1349    If no starting bytes were found, and the minimum length is zero, and JIT    If no starting bytes were found, and the minimum length is zero, and JIT
1350    compilation fails, no flags will be set, so abandon the extra block and    compilation fails, abandon the extra block and return NULL. */
1351    return NULL. */  
   
1352  #ifdef SUPPORT_JIT  #ifdef SUPPORT_JIT
1353    extra->executable_jit = NULL;    extra->executable_jit = NULL;
1354    if ((options & PCRE_STUDY_JIT_COMPILE) != 0) _pcre_jit_compile(re, extra);    if ((options & PCRE_STUDY_JIT_COMPILE) != 0) _pcre_jit_compile(re, extra);
1355    if (study->flags == 0)    if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0)
1356      {      {
1357      pcre_free_study(extra);      pcre_free_study(extra);
1358      extra = NULL;      extra = NULL;
1359      }      }
1360  #endif  #endif
1361    }    }
1362    
# Line 1373  PCRE_EXP_DEFN void Line 1378  PCRE_EXP_DEFN void
1378  pcre_free_study(pcre_extra *extra)  pcre_free_study(pcre_extra *extra)
1379  {  {
1380  #ifdef SUPPORT_JIT  #ifdef SUPPORT_JIT
1381  if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&  if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
1382       extra->executable_jit != NULL)       extra->executable_jit != NULL)
1383    _pcre_jit_free(extra->executable_jit);    _pcre_jit_free(extra->executable_jit);
1384  #endif  #endif
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