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Member "pcre-8.42/pcre32_valid_utf32.c" (31 Jan 2014, 4168 Bytes) of package /linux/misc/pcre-8.42.tar.bz2:


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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) 1997-2013 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 an internal function for validating UTF-32 character
   42 strings. */
   43 
   44 
   45 #ifdef HAVE_CONFIG_H
   46 #include "config.h"
   47 #endif
   48 
   49 /* Generate code with 32 bit character support. */
   50 #define COMPILE_PCRE32
   51 
   52 #include "pcre_internal.h"
   53 
   54 /*************************************************
   55 *         Validate a UTF-32 string                *
   56 *************************************************/
   57 
   58 /* This function is called (optionally) at the start of compile or match, to
   59 check that a supposed UTF-32 string is actually valid. The early check means
   60 that subsequent code can assume it is dealing with a valid string. The check
   61 can be turned off for maximum performance, but the consequences of supplying an
   62 invalid string are then undefined.
   63 
   64 More information about the details of the error are passed
   65 back in the returned value:
   66 
   67 PCRE_UTF32_ERR0  No error
   68 PCRE_UTF32_ERR1  Surrogate character
   69 PCRE_UTF32_ERR2  Unused (was non-character)
   70 PCRE_UTF32_ERR3  Character > 0x10ffff
   71 
   72 Arguments:
   73   string       points to the string
   74   length       length of string, or -1 if the string is zero-terminated
   75   errp         pointer to an error position offset variable
   76 
   77 Returns:       = 0    if the string is a valid UTF-32 string
   78                > 0    otherwise, setting the offset of the bad character
   79 */
   80 
   81 int
   82 PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
   83 {
   84 #ifdef SUPPORT_UTF
   85 register PCRE_PUCHAR p;
   86 register pcre_uchar c;
   87 
   88 if (length < 0)
   89   {
   90   for (p = string; *p != 0; p++);
   91   length = p - string;
   92   }
   93 
   94 for (p = string; length-- > 0; p++)
   95   {
   96   c = *p;
   97 
   98   if ((c & 0xfffff800u) != 0xd800u)
   99     {
  100     /* Normal UTF-32 code point. Neither high nor low surrogate. */
  101     if (c > 0x10ffffu)
  102       {
  103       *erroroffset = p - string;
  104       return PCRE_UTF32_ERR3;
  105       }
  106     }
  107   else
  108     {
  109     /* A surrogate */
  110     *erroroffset = p - string;
  111     return PCRE_UTF32_ERR1;
  112     }
  113   }
  114 
  115 #else  /* SUPPORT_UTF */
  116 (void)(string);  /* Keep picky compilers happy */
  117 (void)(length);
  118 (void)(erroroffset);
  119 #endif /* SUPPORT_UTF */
  120 
  121 return PCRE_UTF32_ERR0;   /* This indicates success */
  122 }
  123 
  124 /* End of pcre32_valid_utf32.c */