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6bf342e1 | 1 | /* $Cambridge: exim/src/src/pcre/pcre_version.c,v 1.4 2007/01/23 15:08:45 ph10 Exp $ */ |
8ac170f3 PH |
2 | |
3 | /************************************************* | |
4 | * Perl-Compatible Regular Expressions * | |
5 | *************************************************/ | |
6 | ||
7 | /* PCRE is a library of functions to support regular expressions whose syntax | |
8 | and semantics are as close as possible to those of the Perl 5 language. | |
9 | ||
10 | Written by Philip Hazel | |
aa41d2de | 11 | Copyright (c) 1997-2006 University of Cambridge |
8ac170f3 PH |
12 | |
13 | ----------------------------------------------------------------------------- | |
14 | Redistribution and use in source and binary forms, with or without | |
15 | modification, are permitted provided that the following conditions are met: | |
16 | ||
17 | * Redistributions of source code must retain the above copyright notice, | |
18 | this list of conditions and the following disclaimer. | |
19 | ||
20 | * Redistributions in binary form must reproduce the above copyright | |
21 | notice, this list of conditions and the following disclaimer in the | |
22 | documentation and/or other materials provided with the distribution. | |
23 | ||
24 | * Neither the name of the University of Cambridge nor the names of its | |
25 | contributors may be used to endorse or promote products derived from | |
26 | this software without specific prior written permission. | |
27 | ||
28 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
29 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
30 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
31 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
32 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
33 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
34 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
35 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
36 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
37 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
38 | POSSIBILITY OF SUCH DAMAGE. | |
39 | ----------------------------------------------------------------------------- | |
40 | */ | |
41 | ||
42 | ||
43 | /* This module contains the external function pcre_version(), which returns a | |
44 | string that identifies the PCRE version that is in use. */ | |
45 | ||
46 | ||
47 | #include "pcre_internal.h" | |
48 | ||
49 | ||
50 | /************************************************* | |
51 | * Return version string * | |
52 | *************************************************/ | |
53 | ||
6bf342e1 PH |
54 | /* These macros are the standard way of turning unquoted text into C strings. |
55 | They allow macros like PCRE_MAJOR to be defined without quotes, which is | |
56 | convenient for user programs that want to test its value. */ | |
57 | ||
8ac170f3 PH |
58 | #define STRING(a) # a |
59 | #define XSTRING(s) STRING(s) | |
60 | ||
6bf342e1 PH |
61 | /* A problem turned up with PCRE_PRERELEASE, which is defined empty for |
62 | production releases. Originally, it was used naively in this code: | |
63 | ||
64 | return XSTRING(PCRE_MAJOR) | |
65 | "." XSTRING(PCRE_MINOR) | |
66 | XSTRING(PCRE_PRERELEASE) | |
67 | " " XSTRING(PCRE_DATE); | |
68 | ||
69 | However, when PCRE_PRERELEASE is empty, this leads to an attempted expansion of | |
70 | STRING(). The C standard states: "If (before argument substitution) any | |
71 | argument consists of no preprocessing tokens, the behavior is undefined." It | |
72 | turns out the gcc treats this case as a single empty string - which is what we | |
73 | really want - but Visual C grumbles about the lack of an argument for the | |
74 | macro. Unfortunately, both are within their rights. To cope with both ways of | |
75 | handling this, I had resort to some messy hackery that does a test at run time. | |
76 | I could find no way of detecting that a macro is defined as an empty string at | |
77 | pre-processor time. This hack uses a standard trick for avoiding calling | |
78 | the STRING macro with an empty argument when doing the test. */ | |
79 | ||
aa41d2de | 80 | PCRE_DATA_SCOPE const char * |
8ac170f3 PH |
81 | pcre_version(void) |
82 | { | |
6bf342e1 PH |
83 | return (XSTRING(Z PCRE_PRERELEASE)[1] == 0)? |
84 | XSTRING(PCRE_MAJOR.PCRE_MINOR PCRE_DATE) : | |
85 | XSTRING(PCRE_MAJOR.PCRE_MINOR) XSTRING(PCRE_PRERELEASE PCRE_DATE); | |
8ac170f3 PH |
86 | } |
87 | ||
88 | /* End of pcre_version.c */ |