Home | History | Annotate | Download | only in dist 
      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 */
    125