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 #include "config.h"
48
49 #include "pcre_internal.h"
50
51
52 /*************************************************
53 * Maintain reference count *
54 *************************************************/
55
56 /* The reference count is a 16-bit field, initialized to zero. It is not
57 possible to transfer a non-zero count from one host to a different host that
58 has a different byte order - though I can't see why anyone in their right mind
59 would ever want to do that!
60
61 Arguments:
62 argument_re points to compiled code
63 adjust value to add to the count
64
65 Returns: the (possibly updated) count value (a non-negative number), or
66 a negative error number
67 */
68
69 #if defined COMPILE_PCRE8
70 PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
71 pcre_refcount(pcre *argument_re, int adjust)
72 #elif defined COMPILE_PCRE16
73 PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
74 pcre16_refcount(pcre16 *argument_re, int adjust)
75 #elif defined COMPILE_PCRE32
76 PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
77 pcre32_refcount(pcre32 *argument_re, int adjust)
78 #endif
79 {
80 REAL_PCRE *re = (REAL_PCRE *)argument_re;
81 if (re == NULL) return PCRE_ERROR_NULL;
82 if (re->magic_number != MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC;
83 if ((re->flags & PCRE_MODE) == 0) return PCRE_ERROR_BADMODE;
84 re->ref_count = (-adjust > re->ref_count)? 0 :
85 (adjust + re->ref_count > 65535)? 65535 :
86 re->ref_count + adjust;
87 return re->ref_count;
88 }
89
90 /* End of pcre_refcount.c */