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) 1997-2012 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 a function for converting any UTF-32 character
42strings to host byte order. */
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#ifdef SUPPORT_UTF
55static pcre_uint32
56swap_uint32(pcre_uint32 value)
57{
58return ((value & 0x000000ff) << 24) |
59       ((value & 0x0000ff00) <<  8) |
60       ((value & 0x00ff0000) >>  8) |
61       (value >> 24);
62}
63#endif
64
65
66/*************************************************
67*  Convert any UTF-32 string to host byte order  *
68*************************************************/
69
70/* This function takes an UTF-32 string and converts
71it to host byte order. The length can be explicitly set,
72or automatically detected for zero terminated strings.
73BOMs can be kept or discarded during the conversion.
74Conversion can be done in place (output == input).
75
76Arguments:
77  output     the output buffer, its size must be greater
78             or equal than the input string
79  input      any UTF-32 string
80  length     the number of 32-bit units in the input string
81             can be less than zero for zero terminated strings
82  host_byte_order
83             A non-zero value means the input is in host byte
84             order, which can be dynamically changed by BOMs later.
85             Initially it contains the starting byte order and returns
86             with the last byte order so it can be used for stream
87             processing. It can be NULL, which set the host byte
88             order mode by default.
89  keep_boms  for a non-zero value, the BOM (0xfeff) characters
90             are copied as well
91
92Returns:     the number of 32-bit units placed into the output buffer,
93             including the zero-terminator
94*/
95
96int
97pcre32_utf32_to_host_byte_order(PCRE_UCHAR32 *output, PCRE_SPTR32 input,
98  int length, int *host_byte_order, int keep_boms)
99{
100#ifdef SUPPORT_UTF
101/* This function converts any UTF-32 string to host byte order and optionally
102removes any Byte Order Marks (BOMS). Returns with the remainig length. */
103int host_bo = host_byte_order != NULL ? *host_byte_order : 1;
104pcre_uchar *optr = (pcre_uchar *)output;
105const pcre_uchar *iptr = (const pcre_uchar *)input;
106const pcre_uchar *end;
107/* The c variable must be unsigned. */
108register pcre_uchar c;
109
110if (length < 0)
111  end = iptr + STRLEN_UC(iptr) + 1;
112else
113  end = iptr + length;
114
115while (iptr < end)
116  {
117  c = *iptr++;
118  if (c == 0x0000feffu || c == 0xfffe0000u)
119    {
120    /* Detecting the byte order of the machine is unnecessary, it is
121    enough to know that the UTF-32 string has the same byte order or not. */
122    host_bo = c == 0x0000feffu;
123    if (keep_boms != 0)
124      *optr++ = 0x0000feffu;
125    }
126  else
127    *optr++ = host_bo ? c : swap_uint32(c);
128  }
129if (host_byte_order != NULL)
130  *host_byte_order = host_bo;
131
132#else /* SUPPORT_UTF */
133(void)(output);  /* Keep picky compilers happy */
134(void)(input);
135(void)(keep_boms);
136(void)(host_byte_order);
137#endif /* SUPPORT_UTF */
138return length;
139}
140
141/* End of pcre32_utf32_utils.c */
142