pcre_maketables.c

   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_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 #  ifdef HAVE_CONFIG_H
  49 #  include "config.h"
  50 #  endif
  51 #  include "pcre_internal.h"
  52 #endif
  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 PUBL(malloc)(), but when
  63 compiled inside dftables, use malloc().
  64
  65 Arguments:   none
  66 Returns:     pointer to the contiguous block of data
  67 */
  68
  69 #if defined COMPILE_PCRE8
  70 const unsigned char *
  71 pcre_maketables(void)
  72 #elif defined COMPILE_PCRE16
  73 const unsigned char *
  74 pcre16_maketables(void)
  75 #elif defined COMPILE_PCRE32
  76 const unsigned char *
  77 pcre32_maketables(void)
  78 #endif
  79 {
  80 unsigned char *yield, *p;
  81 int i;
  82
  83 #ifndef DFTABLES
  84 yield = (unsigned char*)(PUBL(malloc))(tables_length);
  85 #else
  86 yield = (unsigned char*)malloc(tables_length);
  87 #endif
  88
  89 if (yield == NULL) return NULL;
  90 p = yield;
  91
  92 /* First comes the lower casing table */
  93
  94 for (i = 0; i < 256; i++) *p++ = tolower(i);
  95
  96 /* Next the case-flipping table */
  97
  98 for (i = 0; i < 256; i++) *p++ = islower(i)? toupper(i) : tolower(i);
  99
 100 /* Then the character class tables. Don't try to be clever and save effort on
 101 exclusive ones - in some locales things may be different.
 102
 103 Note that the table for "space" includes everything "isspace" gives, including
 104 VT in the default locale. This makes it work for the POSIX class [:space:].
 105 From release 8.34 is is also correct for Perl space, because Perl added VT at
 106 release 5.18.
 107
 108 Note also that it is possible for a character to be alnum or alpha without
 109 being lower or upper, such as "male and female ordinals" (\xAA and \xBA) in the
 110 fr_FR locale (at least under Debian Linux's locales as of 12/2005). So we must
 111 test for alnum specially. */
 112
 113 memset(p, 0, cbit_length);
 114 for (i = 0; i < 256; i++)
 115   {
 116   if (isdigit(i)) p[cbit_digit  + i/8] |= 1 << (i&7);
 117   if (isupper(i)) p[cbit_upper  + i/8] |= 1 << (i&7);
 118   if (islower(i)) p[cbit_lower  + i/8] |= 1 << (i&7);
 119   if (isalnum(i)) p[cbit_word   + i/8] |= 1 << (i&7);
 120   if (i == '_')   p[cbit_word   + i/8] |= 1 << (i&7);
 121   if (isspace(i)) p[cbit_space  + i/8] |= 1 << (i&7);
 122   if (isxdigit(i))p[cbit_xdigit + i/8] |= 1 << (i&7);
 123   if (isgraph(i)) p[cbit_graph  + i/8] |= 1 << (i&7);
 124   if (isprint(i)) p[cbit_print  + i/8] |= 1 << (i&7);
 125   if (ispunct(i)) p[cbit_punct  + i/8] |= 1 << (i&7);
 126   if (iscntrl(i)) p[cbit_cntrl  + i/8] |= 1 << (i&7);
 127   }
 128 p += cbit_length;
 129
 130 /* Finally, the character type table. In this, we used to exclude VT from the
 131 white space chars, because Perl didn't recognize it as such for \s and for
 132 comments within regexes. However, Perl changed at release 5.18, so PCRE changed
 133 at release 8.34. */
 134
 135 for (i = 0; i < 256; i++)
 136   {
 137   int x = 0;
 138   if (isspace(i)) x += ctype_space;
 139   if (isalpha(i)) x += ctype_letter;
 140   if (isdigit(i)) x += ctype_digit;
 141   if (isxdigit(i)) x += ctype_xdigit;
 142   if (isalnum(i) || i == '_') x += ctype_word;
 143
 144   /* Note: strchr includes the terminating zero in the characters it considers.
 145   In this instance, that is ok because we want binary zero to be flagged as a
 146   meta-character, which in this sense is any character that terminates a run
 147   of data characters. */
 148
 149   if (strchr("\\*+?{^.$|()[", i) != 0) x += ctype_meta;
 150   *p++ = x;
 151   }
 152
 153 return yield;
 154 }
 155
 156 /* End of pcre_maketables.c */