1/*************************************************
2*      Perl-Compatible Regular Expressions       *
3*************************************************/
4
5/* PCRE is a library of functions to support regular expressions whose syntax
6and 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-----------------------------------------------------------------------------
12Redistribution and use in source and binary forms, with or without
13modification, 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
26THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36POSSIBILITY OF SUCH DAMAGE.
37-----------------------------------------------------------------------------
38*/
39
40
41/* This module contains an internal function for validating UTF-32 character
42strings. */
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
59check that a supposed UTF-32 string is actually valid. The early check means
60that subsequent code can assume it is dealing with a valid string. The check
61can be turned off for maximum performance, but the consequences of supplying an
62invalid string are then undefined.
63
64More information about the details of the error are passed
65back in the returned value:
66
67PCRE_UTF32_ERR0  No error
68PCRE_UTF32_ERR1  Surrogate character
69PCRE_UTF32_ERR2  Unused (was non-character)
70PCRE_UTF32_ERR3  Character > 0x10ffff
71
72Arguments:
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
77Returns:       = 0    if the string is a valid UTF-32 string
78               > 0    otherwise, setting the offset of the bad character
79*/
80
81int
82PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
83{
84#ifdef SUPPORT_UTF
85register PCRE_PUCHAR p;
86register pcre_uchar c;
87
88if (length < 0)
89  {
90  for (p = string; *p != 0; p++);
91  length = p - string;
92  }
93
94for (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
121return PCRE_UTF32_ERR0;   /* This indicates success */
122}
123
124/* End of pcre32_valid_utf32.c */
125