src/src/pcre/pcre_maketables.c

   1 /* $Cambridge: exim/src/src/pcre/pcre_maketables.c,v 1.2 2005/08/08 10:22:14 ph10 Exp $ */
   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
  11            Copyright (c) 1997-2005 University of Cambridge
  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_maketables(), which builds
  44 character tables for PCRE in the current locale. The file is compiled on its
  45 own as part of the PCRE library. However, it is also included in the
  46 compilation of dftables.c, in which case the macro DFTABLES is defined. */
  47
  48
  49 #ifndef DFTABLES
  50 #include "pcre_internal.h"
  51 #endif
  52
  53
  54 /*************************************************
  55 *           Create PCRE character tables         *
  56 *************************************************/
  57
  58 /* This function builds a set of character tables for use by PCRE and returns
  59 a pointer to them. They are build using the ctype functions, and consequently
  60 their contents will depend upon the current locale setting. When compiled as
  61 part of the library, the store is obtained via pcre_malloc(), but when compiled
  62 inside dftables, use malloc().
  63
  64 Arguments:   none
  65 Returns:     pointer to the contiguous block of data
  66 */
  67
  68 const unsigned char *
  69 pcre_maketables(void)
  70 {
  71 unsigned char *yield, *p;
  72 int i;
  73
  74 #ifndef DFTABLES
  75 yield = (unsigned char*)(pcre_malloc)(tables_length);
  76 #else
  77 yield = (unsigned char*)malloc(tables_length);
  78 #endif
  79
  80 if (yield == NULL) return NULL;
  81 p = yield;
  82
  83 /* First comes the lower casing table */
  84
  85 for (i = 0; i < 256; i++) *p++ = tolower(i);
  86
  87 /* Next the case-flipping table */
  88
  89 for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
  90
  91 /* Then the character class tables. Don't try to be clever and save effort
  92 on exclusive ones - in some locales things may be different. Note that the
  93 table for "space" includes everything "isspace" gives, including VT in the
  94 default locale. This makes it work for the POSIX class [:space:]. */
  95
  96 memset(p, 0, cbit_length);
  97 for (i = 0; i < 256; i++)
  98   {
  99   if (isdigit(i))
 100     {
 101     p[cbit_digit  + i/8] |= 1 << (i&7);
 102     p[cbit_word   + i/8] |= 1 << (i&7);
 103     }
 104   if (isupper(i))
 105     {
 106     p[cbit_upper  + i/8] |= 1 << (i&7);
 107     p[cbit_word   + i/8] |= 1 << (i&7);
 108     }
 109   if (islower(i))
 110     {
 111     p[cbit_lower  + i/8] |= 1 << (i&7);
 112     p[cbit_word   + i/8] |= 1 << (i&7);
 113     }
 114   if (i == '_')   p[cbit_word   + i/8] |= 1 << (i&7);
 115   if (isspace(i)) p[cbit_space  + i/8] |= 1 << (i&7);
 116   if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
 117   if (isgraph(i)) p[cbit_graph  + i/8] |= 1 << (i&7);
 118   if (isprint(i)) p[cbit_print  + i/8] |= 1 << (i&7);
 119   if (ispunct(i)) p[cbit_punct  + i/8] |= 1 << (i&7);
 120   if (iscntrl(i)) p[cbit_cntrl  + i/8] |= 1 << (i&7);
 121   }
 122 p += cbit_length;
 123
 124 /* Finally, the character type table. In this, we exclude VT from the white
 125 space chars, because Perl doesn't recognize it as such for \s and for comments
 126 within regexes. */
 127
 128 for (i = 0; i < 256; i++)
 129   {
 130   int x = 0;
 131   if (i != 0x0b && isspace(i)) x += ctype_space;
 132   if (isalpha(i)) x += ctype_letter;
 133   if (isdigit(i)) x += ctype_digit;
 134   if (isxdigit(i)) x += ctype_xdigit;
 135   if (isalnum(i) || i == '_') x += ctype_word;
 136
 137   /* Note: strchr includes the terminating zero in the characters it considers.
 138   In this instance, that is ok because we want binary zero to be flagged as a
 139   meta-character, which in this sense is any character that terminates a run
 140   of data characters. */
 141
 142   if (strchr("*+?{^.$|()[", i) != 0) x += ctype_meta; *p++ = x; }
 143
 144 return yield;
 145 }
 146
 147 /* End of pcre_maketables.c */