release/src/router/pcre/pcre32_utf32_utils.c

   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) 1997-2012 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 a function for converting any UTF-32 character
  42 strings 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
  55 static pcre_uint32
  56 swap_uint32(pcre_uint32 value)
  57 {
  58 return ((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
  71 it to host byte order. The length can be explicitly set,
  72 or automatically detected for zero terminated strings.
  73 BOMs can be kept or discarded during the conversion.
  74 Conversion can be done in place (output == input).
  75
  76 Arguments:
  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
  92 Returns:     the number of 32-bit units placed into the output buffer,
  93              including the zero-terminator
  94 */
  95
  96 int
  97 pcre32_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
 102 removes any Byte Order Marks (BOMS). Returns with the remainig length. */
 103 int host_bo = host_byte_order != NULL ? *host_byte_order : 1;
 104 pcre_uchar *optr = (pcre_uchar *)output;
 105 const pcre_uchar *iptr = (const pcre_uchar *)input;
 106 const pcre_uchar *end;
 107 /* The c variable must be unsigned. */
 108 register pcre_uchar c;
 109
 110 if (length < 0)
 111   end = iptr + STRLEN_UC(iptr) + 1;
 112 else
 113   end = iptr + length;
 114
 115 while (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   }
 129 if (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 */
 138 return length;
 139 }
 140
 141 /* End of pcre32_utf32_utils.c */