/[pcre]/code/trunk/pcre.c
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revision 27 by nigel, Sat Feb 24 21:38:49 2007 UTC revision 31 by nigel, Sat Feb 24 21:38:57 2007 UTC
# Line 25  restrictions: Line 25  restrictions:
25    
26  3. Altered versions must be plainly marked as such, and must not be  3. Altered versions must be plainly marked as such, and must not be
27     misrepresented as being the original software.     misrepresented as being the original software.
28    
29    4. If PCRE is embedded in any software that is released under the GNU
30       General Purpose Licence (GPL), then the terms of that licence shall
31       supersede any condition above with which it is incompatible.
32  -----------------------------------------------------------------------------  -----------------------------------------------------------------------------
33  */  */
34    
# Line 1087  for (;; ptr++) Line 1091  for (;; ptr++)
1091      else if ((int)*previous >= OP_BRA || (int)*previous == OP_ONCE ||      else if ((int)*previous >= OP_BRA || (int)*previous == OP_ONCE ||
1092               (int)*previous == OP_COND)               (int)*previous == OP_COND)
1093        {        {
1094        int i, ketoffset = 0;        register int i;
1095          int ketoffset = 0;
1096        int len = code - previous;        int len = code - previous;
1097          uschar *bralink = NULL;
1098    
1099        /* If the maximum repeat count is unlimited, find the end of the bracket        /* If the maximum repeat count is unlimited, find the end of the bracket
1100        by scanning through from the start, and compute the offset back to it        by scanning through from the start, and compute the offset back to it
# Line 1103  for (;; ptr++) Line 1109  for (;; ptr++)
1109          ketoffset = code - ket;          ketoffset = code - ket;
1110          }          }
1111    
1112          /* The case of a zero minimum is special because of the need to stick
1113          OP_BRAZERO in front of it, and because the group appears once in the
1114          data, whereas in other cases it appears the minimum number of times. For
1115          this reason, it is simplest to treat this case separately, as otherwise
1116          the code gets far too mess. There are several special subcases when the
1117          minimum is zero. */
1118    
1119          if (repeat_min == 0)
1120            {
1121            /* If the maximum is also zero, we just omit the group from the output
1122            altogether. */
1123    
1124            if (repeat_max == 0)
1125              {
1126              code = previous;
1127              previous = NULL;
1128              break;
1129              }
1130    
1131            /* If the maximum is 1 or unlimited, we just have to stick in the
1132            BRAZERO and do no more at this point. */
1133    
1134            if (repeat_max <= 1)
1135              {
1136              memmove(previous+1, previous, len);
1137              code++;
1138              *previous++ = OP_BRAZERO + repeat_type;
1139              }
1140    
1141            /* If the maximum is greater than 1 and limited, we have to replicate
1142            in a nested fashion, sticking OP_BRAZERO before each set of brackets.
1143            The first one has to be handled carefully because it's the original
1144            copy, which has to be moved up. The remainder can be handled by code
1145            that is common with the non-zero minimum case below. We just have to
1146            adjust the value or repeat_max, since one less copy is required. */
1147    
1148            else
1149              {
1150              int offset;
1151              memmove(previous+4, previous, len);
1152              code += 4;
1153              *previous++ = OP_BRAZERO + repeat_type;
1154              *previous++ = OP_BRA;
1155    
1156              /* We chain together the bracket offset fields that have to be
1157              filled in later when the ends of the brackets are reached. */
1158    
1159              offset = (bralink == NULL)? 0 : previous - bralink;
1160              bralink = previous;
1161              *previous++ = offset >> 8;
1162              *previous++ = offset & 255;
1163              }
1164    
1165            repeat_max--;
1166            }
1167    
1168          /* If the minimum is greater than zero, replicate the group as many
1169          times as necessary, and adjust the maximum to the number of subsequent
1170          copies that we need. */
1171    
1172          else
1173            {
1174            for (i = 1; i < repeat_min; i++)
1175              {
1176              memcpy(code, previous, len);
1177              code += len;
1178              }
1179            if (repeat_max > 0) repeat_max -= repeat_min;
1180            }
1181    
1182          /* This code is common to both the zero and non-zero minimum cases. If
1183          the maximum is limited, it replicates the group in a nested fashion,
1184          remembering the bracket starts on a stack. In the case of a zero minimum,
1185          the first one was set up above. In all cases the repeat_max now specifies
1186          the number of additional copies needed. */
1187    
1188          if (repeat_max >= 0)
1189            {
1190            for (i = repeat_max - 1; i >= 0; i--)
1191              {
1192              *code++ = OP_BRAZERO + repeat_type;
1193    
1194              /* All but the final copy start a new nesting, maintaining the
1195              chain of brackets outstanding. */
1196    
1197              if (i != 0)
1198                {
1199                int offset;
1200                *code++ = OP_BRA;
1201                offset = (bralink == NULL)? 0 : code - bralink;
1202                bralink = code;
1203                *code++ = offset >> 8;
1204                *code++ = offset & 255;
1205                }
1206    
1207              memcpy(code, previous, len);
1208              code += len;
1209              }
1210    
1211            /* Now chain through the pending brackets, and fill in their length
1212            fields (which are holding the chain links pro tem). */
1213    
1214            while (bralink != NULL)
1215              {
1216              int oldlinkoffset;
1217              int offset = code - bralink + 1;
1218              uschar *bra = code - offset;
1219              oldlinkoffset = (bra[1] << 8) + bra[2];
1220              bralink = (oldlinkoffset == 0)? NULL : bralink - oldlinkoffset;
1221              *code++ = OP_KET;
1222              *code++ = bra[1] = offset >> 8;
1223              *code++ = bra[2] = (offset & 255);
1224              }
1225            }
1226    
1227          /* If the maximum is unlimited, set a repeater in the final copy. We
1228          can't just offset backwards from the current code point, because we
1229          don't know if there's been an options resetting after the ket. The
1230          correct offset was computed above. */
1231    
1232          else code[-ketoffset] = OP_KETRMAX + repeat_type;
1233    
1234    
1235    #ifdef NEVER
1236        /* If the minimum is greater than zero, and the maximum is unlimited or        /* If the minimum is greater than zero, and the maximum is unlimited or
1237        equal to the minimum, the first copy remains where it is, and is        equal to the minimum, the first copy remains where it is, and is
1238        replicated up to the minimum number of times. This case includes the +        replicated up to the minimum number of times. This case includes the +
# Line 1150  for (;; ptr++) Line 1280  for (;; ptr++)
1280        correct offset was computed above. */        correct offset was computed above. */
1281    
1282        if (repeat_max == -1) code[-ketoffset] = OP_KETRMAX + repeat_type;        if (repeat_max == -1) code[-ketoffset] = OP_KETRMAX + repeat_type;
1283    #endif
1284    
1285    
1286        }        }
1287    
1288      /* Else there's some kind of shambles */      /* Else there's some kind of shambles */
# Line 2268  while ((c = *(++ptr)) != 0) Line 2401  while ((c = *(++ptr)) != 0)
2401        else if (c == '+') { maxval = -1; ptr++; }        else if (c == '+') { maxval = -1; ptr++; }
2402        else if (c == '?') { minval = 0; ptr++; }        else if (c == '?') { minval = 0; ptr++; }
2403    
2404        /* If there is a minimum > 1 we have to replicate up to minval-1 times;        /* If the minimum is zero, we have to allow for an OP_BRAZERO before the
2405        if there is a limited maximum we have to replicate up to maxval-1 times        group, and if the maximum is greater than zero, we have to replicate
2406        and allow for a BRAZERO item before each optional copy, as we also have        maxval-1 times; each replication acquires an OP_BRAZERO plus a nesting
2407        to do before the first copy if the minimum is zero. */        bracket set - hence the 7. */
2408    
2409        if (minval == 0) length++;        if (minval == 0)
2410          else if (minval > 1) length += (minval - 1) * duplength;          {
2411        if (maxval > minval) length += (maxval - minval) * (duplength + 1);          length++;
2412            if (maxval > 0) length += (maxval - 1) * (duplength + 7);
2413            }
2414    
2415          /* When the minimum is greater than zero, 1 we have to replicate up to
2416          minval-1 times, with no additions required in the copies. Then, if
2417          there is a limited maximum we have to replicate up to maxval-1 times
2418          allowing for a BRAZERO item before each optional copy and nesting
2419          brackets for all but one of the optional copies. */
2420    
2421          else
2422            {
2423            length += (minval - 1) * duplength;
2424            if (maxval > minval)   /* Need this test as maxval=-1 means no limit */
2425              length += (maxval - minval) * (duplength + 7) - 6;
2426            }
2427        }        }
2428      continue;      continue;
2429    
# Line 2771  for (;;) Line 2919  for (;;)
2919      int number = op - OP_BRA;      int number = op - OP_BRA;
2920      int offset = number << 1;      int offset = number << 1;
2921    
2922      DPRINTF(("start bracket %d\n", number));  #ifdef DEBUG
2923        printf("start bracket %d subject=", number);
2924        pchars(eptr, 16, TRUE, md);
2925        printf("\n");
2926    #endif
2927    
2928      if (offset < md->offset_max)      if (offset < md->offset_max)
2929        {        {
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