release/src/router/pcre/pcre16_utf16_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-16 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 16 bit character support. */
  50 #define COMPILE_PCRE16
  51
  52 #include "pcre_internal.h"
  53
  54 /*************************************************
  55 *  Convert any UTF-16 string to host byte order  *
  56 *************************************************/
  57
  58 /* This function takes an UTF-16 string and converts
  59 it to host byte order. The length can be explicitly set,
  60 or automatically detected for zero terminated strings.
  61 BOMs can be kept or discarded during the conversion.
  62 Conversion can be done in place (output == input).
  63
  64 Arguments:
  65   output     the output buffer, its size must be greater
  66              or equal than the input string
  67   input      any UTF-16 string
  68   length     the number of 16-bit units in the input string
  69              can be less than zero for zero terminated strings
  70   host_byte_order
  71              A non-zero value means the input is in host byte
  72              order, which can be dynamically changed by BOMs later.
  73              Initially it contains the starting byte order and returns
  74              with the last byte order so it can be used for stream
  75              processing. It can be NULL, which set the host byte
  76              order mode by default.
  77   keep_boms  for a non-zero value, the BOM (0xfeff) characters
  78              are copied as well
  79
  80 Returns:     the number of 16-bit units placed into the output buffer,
  81              including the zero-terminator
  82 */
  83
  84 int
  85 pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *output, PCRE_SPTR16 input,
  86   int length, int *host_byte_order, int keep_boms)
  87 {
  88 #ifdef SUPPORT_UTF
  89 /* This function converts any UTF-16 string to host byte order and optionally
  90 removes any Byte Order Marks (BOMS). Returns with the remainig length. */
  91 int host_bo = host_byte_order != NULL ? *host_byte_order : 1;
  92 pcre_uchar *optr = (pcre_uchar *)output;
  93 const pcre_uchar *iptr = (const pcre_uchar *)input;
  94 const pcre_uchar *end;
  95 /* The c variable must be unsigned. */
  96 register pcre_uchar c;
  97
  98 if (length < 0)
  99   length = STRLEN_UC(iptr) + 1;
 100 end = iptr + length;
 101
 102 while (iptr < end)
 103   {
 104   c = *iptr++;
 105   if (c == 0xfeff || c == 0xfffe)
 106     {
 107     /* Detecting the byte order of the machine is unnecessary, it is
 108     enough to know that the UTF-16 string has the same byte order or not. */
 109     host_bo = c == 0xfeff;
 110     if (keep_boms != 0)
 111       *optr++ = 0xfeff;
 112     else
 113       length--;
 114     }
 115   else
 116     *optr++ = host_bo ? c : ((c >> 8) | (c << 8)); /* Flip bytes if needed. */
 117   }
 118 if (host_byte_order != NULL)
 119   *host_byte_order = host_bo;
 120
 121 #else /* Not SUPPORT_UTF */
 122 (void)(output);  /* Keep picky compilers happy */
 123 (void)(input);
 124 (void)(keep_boms);
 125 (void)(host_byte_order);
 126 #endif /* SUPPORT_UTF */
 127 return length;
 128 }
 129
 130 /* End of pcre16_utf16_utils.c */