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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) 1997-2012 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 */