/*************************************************

*      Perl-Compatible Regular Expressions       *

*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax

and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel

           Copyright (c) 1997-2013 University of Cambridge

-----------------------------------------------------------------------------

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,

      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright

      notice, this list of conditions and the following disclaimer in the

      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its

      contributors may be used to endorse or promote products derived from

      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.

-----------------------------------------------------------------------------

*/

/* This module contains an internal function for validating UTF-32 character

strings. */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

/* Generate code with 32 bit character support. */

#define COMPILE_PCRE32

#include "pcre_internal.h"

/*************************************************

*         Validate a UTF-32 string                *

*************************************************/

/* This function is called (optionally) at the start of compile or match, to

check that a supposed UTF-32 string is actually valid. The early check means

that subsequent code can assume it is dealing with a valid string. The check

can be turned off for maximum performance, but the consequences of supplying an

invalid string are then undefined.

More information about the details of the error are passed

back in the returned value:

PCRE_UTF32_ERR0  No error

PCRE_UTF32_ERR1  Surrogate character

PCRE_UTF32_ERR2  Unused (was non-character)

PCRE_UTF32_ERR3  Character > 0x10ffff

Arguments:

  string       points to the string

  length       length of string, or -1 if the string is zero-terminated

  errp         pointer to an error position offset variable

Returns:       = 0    if the string is a valid UTF-32 string

               > 0    otherwise, setting the offset of the bad character

*/

int

PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)

{

#ifdef SUPPORT_UTF

register PCRE_PUCHAR p;

register pcre_uchar c;

if (length < 0)

  {

  for (p = string; *p != 0; p++);

  length = p - string;

  }

for (p = string; length-- > 0; p++)

  {

  c = *p;

  if ((c & 0xfffff800u) != 0xd800u)

    {

    /* Normal UTF-32 code point. Neither high nor low surrogate. */

    if (c > 0x10ffffu)

      {

      *erroroffset = p - string;

      return PCRE_UTF32_ERR3;

      }

    }

  else

    {

    /* A surrogate */

    *erroroffset = p - string;

    return PCRE_UTF32_ERR1;

    }

  }

#else  /* SUPPORT_UTF */

(void)(string);  /* Keep picky compilers happy */

(void)(length);

(void)(erroroffset);

#endif /* SUPPORT_UTF */

return PCRE_UTF32_ERR0;   /* This indicates success */

}

/* End of pcre32_valid_utf32.c */