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pcre

    1: /*************************************************
    2: *      Perl-Compatible Regular Expressions       *
    3: *************************************************/
    4: 
    5: /* PCRE is a library of functions to support regular expressions whose syntax
    6: and semantics are as close as possible to those of the Perl 5 language.
    7: 
    8:                        Written by Philip Hazel
    9:            Copyright (c) 1997-2012 University of Cambridge
   10: 
   11: -----------------------------------------------------------------------------
   12: Redistribution and use in source and binary forms, with or without
   13: modification, are permitted provided that the following conditions are met:
   14: 
   15:     * Redistributions of source code must retain the above copyright notice,
   16:       this list of conditions and the following disclaimer.
   17: 
   18:     * Redistributions in binary form must reproduce the above copyright
   19:       notice, this list of conditions and the following disclaimer in the
   20:       documentation and/or other materials provided with the distribution.
   21: 
   22:     * Neither the name of the University of Cambridge nor the names of its
   23:       contributors may be used to endorse or promote products derived from
   24:       this software without specific prior written permission.
   25: 
   26: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   27: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   28: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   29: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   30: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   31: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   32: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   33: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   34: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   35: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   36: POSSIBILITY OF SUCH DAMAGE.
   37: -----------------------------------------------------------------------------
   38: */
   39: 
   40: 
   41: /* This module contains the external function pcre_refcount(), which is an
   42: auxiliary function that can be used to maintain a reference count in a compiled
   43: pattern data block. This might be helpful in applications where the block is
   44: shared by different users. */
   45: 
   46: 
   47: #ifdef HAVE_CONFIG_H
   48: #include "config.h"
   49: #endif
   50: 
   51: #include "pcre_internal.h"
   52: 
   53: 
   54: /*************************************************
   55: *           Maintain reference count             *
   56: *************************************************/
   57: 
   58: /* The reference count is a 16-bit field, initialized to zero. It is not
   59: possible to transfer a non-zero count from one host to a different host that
   60: has a different byte order - though I can't see why anyone in their right mind
   61: would ever want to do that!
   62: 
   63: Arguments:
   64:   argument_re   points to compiled code
   65:   adjust        value to add to the count
   66: 
   67: Returns:        the (possibly updated) count value (a non-negative number), or
   68:                 a negative error number
   69: */
   70: 
   71: #ifdef COMPILE_PCRE8
   72: PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
   73: pcre_refcount(pcre *argument_re, int adjust)
   74: #else
   75: PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
   76: pcre16_refcount(pcre16 *argument_re, int adjust)
   77: #endif
   78: {
   79: REAL_PCRE *re = (REAL_PCRE *)argument_re;
   80: if (re == NULL) return PCRE_ERROR_NULL;
   81: if (re->magic_number != MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC;
   82: if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
   83: re->ref_count = (-adjust > re->ref_count)? 0 :
   84:                 (adjust + re->ref_count > 65535)? 65535 :
   85:                 re->ref_count + adjust;
   86: return re->ref_count;
   87: }
   88: 
   89: /* End of pcre_refcount.c */