src/src/pcre/maketables.c

   1 /* $Cambridge: exim/src/src/pcre/maketables.c,v 1.2 2005/06/15 08:57:10 ph10 Exp $ */
   2
   3 /*************************************************
   4 *      Perl-Compatible Regular Expressions       *
   5 *************************************************/
   6
   7 /*
   8 PCRE is a library of functions to support regular expressions whose syntax
   9 and semantics are as close as possible to those of the Perl 5 language.
  10
  11 Written by: Philip Hazel <ph10@cam.ac.uk>
  12
  13            Copyright (c) 1997-2003 University of Cambridge
  14
  15 -----------------------------------------------------------------------------
  16 Redistribution and use in source and binary forms, with or without
  17 modification, are permitted provided that the following conditions are met:
  18
  19     * Redistributions of source code must retain the above copyright notice,
  20       this list of conditions and the following disclaimer.
  21
  22     * Redistributions in binary form must reproduce the above copyright
  23       notice, this list of conditions and the following disclaimer in the
  24       documentation and/or other materials provided with the distribution.
  25
  26     * Neither the name of the University of Cambridge nor the names of its
  27       contributors may be used to endorse or promote products derived from
  28       this software without specific prior written permission.
  29
  30 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  31 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  32 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  33 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  34 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  35 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  36 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  37 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  38 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  39 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  40 POSSIBILITY OF SUCH DAMAGE.
  41 -----------------------------------------------------------------------------
  42 */
  43
  44
  45 /* This file is compiled on its own as part of the PCRE library. However,
  46 it is also included in the compilation of dftables.c, in which case the macro
  47 DFTABLES is defined. */
  48
  49 #ifndef DFTABLES
  50 #include "internal.h"
  51 #endif
  52
  53
  54
  55 /*************************************************
  56 *           Create PCRE character tables         *
  57 *************************************************/
  58
  59 /* This function builds a set of character tables for use by PCRE and returns
  60 a pointer to them. They are build using the ctype functions, and consequently
  61 their contents will depend upon the current locale setting. When compiled as
  62 part of the library, the store is obtained via pcre_malloc(), but when compiled
  63 inside dftables, use malloc().
  64
  65 Arguments:   none
  66 Returns:     pointer to the contiguous block of data
  67 */
  68
  69 const unsigned char *
  70 pcre_maketables(void)
  71 {
  72 unsigned char *yield, *p;
  73 int i;
  74
  75 #ifndef DFTABLES
  76 yield = (unsigned char*)(pcre_malloc)(tables_length);
  77 #else
  78 yield = (unsigned char*)malloc(tables_length);
  79 #endif
  80
  81 if (yield == NULL) return NULL;
  82 p = yield;
  83
  84 /* First comes the lower casing table */
  85
  86 for (i = 0; i < 256; i++) *p++ = tolower(i);
  87
  88 /* Next the case-flipping table */
  89
  90 for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
  91
  92 /* Then the character class tables. Don't try to be clever and save effort
  93 on exclusive ones - in some locales things may be different. Note that the
  94 table for "space" includes everything "isspace" gives, including VT in the
  95 default locale. This makes it work for the POSIX class [:space:]. */
  96
  97 memset(p, 0, cbit_length);
  98 for (i = 0; i < 256; i++)
  99   {
 100   if (isdigit(i))
 101     {
 102     p[cbit_digit  + i/8] |= 1 << (i&7);
 103     p[cbit_word   + i/8] |= 1 << (i&7);
 104     }
 105   if (isupper(i))
 106     {
 107     p[cbit_upper  + i/8] |= 1 << (i&7);
 108     p[cbit_word   + i/8] |= 1 << (i&7);
 109     }
 110   if (islower(i))
 111     {
 112     p[cbit_lower  + i/8] |= 1 << (i&7);
 113     p[cbit_word   + i/8] |= 1 << (i&7);
 114     }
 115   if (i == '_')   p[cbit_word   + i/8] |= 1 << (i&7);
 116   if (isspace(i)) p[cbit_space  + i/8] |= 1 << (i&7);
 117   if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
 118   if (isgraph(i)) p[cbit_graph  + i/8] |= 1 << (i&7);
 119   if (isprint(i)) p[cbit_print  + i/8] |= 1 << (i&7);
 120   if (ispunct(i)) p[cbit_punct  + i/8] |= 1 << (i&7);
 121   if (iscntrl(i)) p[cbit_cntrl  + i/8] |= 1 << (i&7);
 122   }
 123 p += cbit_length;
 124
 125 /* Finally, the character type table. In this, we exclude VT from the white
 126 space chars, because Perl doesn't recognize it as such for \s and for comments
 127 within regexes. */
 128
 129 for (i = 0; i < 256; i++)
 130   {
 131   int x = 0;
 132   if (i != 0x0b && isspace(i)) x += ctype_space;
 133   if (isalpha(i)) x += ctype_letter;
 134   if (isdigit(i)) x += ctype_digit;
 135   if (isxdigit(i)) x += ctype_xdigit;
 136   if (isalnum(i) || i == '_') x += ctype_word;
 137
 138   /* Note: strchr includes the terminating zero in the characters it considers.
 139   In this instance, that is ok because we want binary zero to be flagged as a
 140   meta-character, which in this sense is any character that terminates a run
 141   of data characters. */
 142
 143   if (strchr("*+?{^.$|()[", i) != 0) x += ctype_meta; *p++ = x; }
 144
 145 return yield;
 146 }
 147
 148 /* End of maketables.c */