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
PRIV(valid_utf)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