/[pcre]/code/trunk/pcre_compile.c

Diff of /code/trunk/pcre_compile.c

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-revision 635 by ph10,
Sat Jul 23 16:19:50 2011 UTC
+revision 637 by ph10,
Sun Jul 24 17:44:12 2011 UTC
 Line 393 
 static const char error_texts[] =
    "internal error: previously-checked referenced subpattern not found\0"
    "DEFINE group contains more than one branch\0"
    /* 55 */
-   "repeating a DEFINE group is not allowed\0"
+   "repeating a DEFINE group is not allowed\0"  /** DEAD **/
    "inconsistent NEWLINE options\0"
    "\\g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number\0"
    "a numbered reference must not be zero\0"
 Line 4210 
 for (;; ptr++)
      op_type = 0;                    /* Default single-char op codes */
      possessive_quantifier = FALSE;  /* Default not possessive quantifier */
-     /* Save start of previous item, in case we have to move it up to make space
+     /* Save start of previous item, in case we have to move it up in order to
-     for an inserted OP_ONCE for the additional '+' extension. */
+     insert something before it. */
      tempcode = previous;
 Line 4554 
 for (;; ptr++)
        }
      /* If previous was a bracket group, we may have to replicate it in certain
-     cases. Note that at this point we can encounter only the "basic" BRA and
+     cases. Note that at this point we can encounter only the "basic" bracket
-     KET opcodes, as this is the place where they get converted into the more
+     opcodes such as BRA and CBRA, as this is the place where they get converted
-     special varieties. */
+     into the more special varieties such as BRAPOS and SBRA. A test for >=
+     OP_ASSERT and <= OP_COND includes ASSERT, ASSERT_NOT, ASSERTBACK,
+     ASSERTBACK_NOT, ONCE, BRA, CBRA, and COND. Originally, PCRE did not allow
+     repetition of assertions, but now it does, for Perl compatibility. */
-     else if (*previous == OP_BRA  || *previous == OP_CBRA ||
+     else if (*previous >= OP_ASSERT && *previous <= OP_COND)
-              *previous == OP_ONCE || *previous == OP_COND)
        {
        register int i;
        int len = (int)(code - previous);
        uschar *bralink = NULL;
        uschar *brazeroptr = NULL;
-       /* Repeating a DEFINE group is pointless */
+       /* Repeating a DEFINE group is pointless, but Perl allows the syntax, so
+       we just ignore the repeat. */
        if (*previous == OP_COND && previous[LINK_SIZE+1] == OP_DEF)
-         {
+         goto END_REPEAT;
-         *errorcodeptr = ERR55;
-         goto FAILED;
+       /* There is no sense in actually repeating assertions. The only potential
-         }
+       use of repetition is in cases when the assertion is optional. Therefore,
+       if the minimum is greater than zero, just ignore the repeat. If the
+       maximum is not not zero or one, set it to 1. */
+       if (*previous < OP_ONCE)    /* Assertion */
+         {
+         if (repeat_min > 0) goto END_REPEAT;
+         if (repeat_max < 0 || repeat_max > 1) repeat_max = 1;
+         }
        /* The case of a zero minimum is special because of the need to stick
        OP_BRAZERO in front of it, and because the group appears once in the
-Line 4592 
 for (;; ptr++)
+Line 4603 
 for (;; ptr++)
          **   goto END_REPEAT;
          **   }
-         However, that fails when a group is referenced as a subroutine from
+         However, that fails when a group or a subgroup within it is referenced
-         elsewhere in the pattern, so now we stick in OP_SKIPZERO in front of it
+         as a subroutine from elsewhere in the pattern, so now we stick in
-         so that it is skipped on execution. As we don't have a list of which
+         OP_SKIPZERO in front of it so that it is skipped on execution. As we
-         groups are referenced, we cannot do this selectively.
+         don't have a list of which groups are referenced, we cannot do this
+         selectively.
          If the maximum is 1 or unlimited, we just have to stick in the BRAZERO
          and do no more at this point. However, we do need to adjust any
-Line 5860 
 for (;; ptr++)
+Line 5872 
 for (;; ptr++)
        skipbytes = 2;
        }
-     /* Process nested bracketed regex. Assertions may not be repeated, but
+     /* Process nested bracketed regex. Assertions used not to be repeatable,
-     other kinds can be. All their opcodes are >= OP_ONCE. We copy code into a
+     but this was changed for Perl compatibility, so all kinds can now be
-     non-register variable (tempcode) in order to be able to pass its address
+     repeated. We copy code into a non-register variable (tempcode) in order to
-     because some compilers complain otherwise. */
+     be able to pass its address because some compilers complain otherwise. */
-     previous = (bravalue >= OP_ONCE)? code : NULL;
+     previous = code;                   /* For handling repetition */
      *code = bravalue;
      tempcode = code;
      tempreqvary = cd->req_varyopt;     /* Save value before bracket */

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