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pcre_maketables.c
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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) 1997-2008 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_maketables(), which builds
42 character tables for PCRE in the current locale. The file is compiled on its
43 own as part of the PCRE library. However, it is also included in the
44 compilation of dftables.c, in which case the macro DFTABLES is defined. */
45 
46 
47 #ifndef DFTABLES
48 #define HAVE_CONFIG_H
49 # ifdef HAVE_CONFIG_H
50 # include "config.h"
51 # endif
52 # include "pcre_internal.h"
53 #endif
54 
55 
56 /*************************************************
57 * Create PCRE character tables *
58 *************************************************/
59 
60 /* This function builds a set of character tables for use by PCRE and returns
61 a pointer to them. They are build using the ctype functions, and consequently
62 their contents will depend upon the current locale setting. When compiled as
63 part of the library, the store is obtained via pcre_malloc(), but when compiled
64 inside dftables, use malloc().
65 
66 Arguments: none
67 Returns: pointer to the contiguous block of data
68 */
69 
70 const unsigned char *
71 pcre_maketables(void)
72 {
73 unsigned char *yield, *p;
74 int i;
75 
76 #ifndef DFTABLES
77 yield = (unsigned char*)(pcre_malloc)(tables_length);
78 #else
79 yield = (unsigned char*)malloc(tables_length);
80 #endif
81 
82 if (yield == NULL) return NULL;
83 p = yield;
84 
85 /* First comes the lower casing table */
86 
87 for (i = 0; i < 256; i++) *p++ = tolower(i);
88 
89 /* Next the case-flipping table */
90 
91 for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
92 
93 /* Then the character class tables. Don't try to be clever and save effort on
94 exclusive ones - in some locales things may be different. Note that the table
95 for "space" includes everything "isspace" gives, including VT in the default
96 locale. This makes it work for the POSIX class [:space:]. Note also that it is
97 possible for a character to be alnum or alpha without being lower or upper,
98 such as "male and female ordinals" (\xAA and \xBA) in the fr_FR locale (at
99 least under Debian Linux's locales as of 12/2005). So we must test for alnum
100 specially. */
101 
102 memset(p, 0, cbit_length);
103 for (i = 0; i < 256; i++)
104  {
105  if (isdigit(i)) p[cbit_digit + i/8] |= 1 << (i&7);
106  if (isupper(i)) p[cbit_upper + i/8] |= 1 << (i&7);
107  if (islower(i)) p[cbit_lower + i/8] |= 1 << (i&7);
108  if (isalnum(i)) p[cbit_word + i/8] |= 1 << (i&7);
109  if (i == '_') p[cbit_word + i/8] |= 1 << (i&7);
110  if (isspace(i)) p[cbit_space + i/8] |= 1 << (i&7);
111  if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
112  if (isgraph(i)) p[cbit_graph + i/8] |= 1 << (i&7);
113  if (isprint(i)) p[cbit_print + i/8] |= 1 << (i&7);
114  if (ispunct(i)) p[cbit_punct + i/8] |= 1 << (i&7);
115  if (iscntrl(i)) p[cbit_cntrl + i/8] |= 1 << (i&7);
116  }
117 p += cbit_length;
118 
119 /* Finally, the character type table. In this, we exclude VT from the white
120 space chars, because Perl doesn't recognize it as such for \s and for comments
121 within regexes. */
122 
123 for (i = 0; i < 256; i++)
124  {
125  int x = 0;
126  if (i != 0x0b && isspace(i)) x += ctype_space;
127  if (isalpha(i)) x += ctype_letter;
128  if (isdigit(i)) x += ctype_digit;
129  if (isxdigit(i)) x += ctype_xdigit;
130  if (isalnum(i) || i == '_') x += ctype_word;
131 
132  /* Note: strchr includes the terminating zero in the characters it considers.
133  In this instance, that is ok because we want binary zero to be flagged as a
134  meta-character, which in this sense is any character that terminates a run
135  of data characters. */
136 
137  if (strchr("\\*+?{^.$|()[", i) != 0) x += ctype_meta;
138  *p++ = x;
139  }
140 
141 return yield;
142 }
143 
144 /* End of pcre_maketables.c */