root/maint/gnulib/lib/unistr/u8-uctomb.c

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DEFINITIONS

This source file includes following definitions.
  1. u8_uctomb

   1 /* Store a character in UTF-8 string.
   2    Copyright (C) 2002, 2005-2006, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2002.
   4 
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9 
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14 
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17 
  18 #include <config.h>
  19 
  20 #if defined IN_LIBUNISTRING
  21 /* Tell unistr.h to declare u8_uctomb as 'extern', not 'static inline'.  */
  22 # include "unistring-notinline.h"
  23 #endif
  24 
  25 /* Specification.  */
  26 #include "unistr.h"
  27 
  28 #include "attribute.h"
  29 
  30 #if !HAVE_INLINE
  31 
  32 int
  33 u8_uctomb (uint8_t *s, ucs4_t uc, ptrdiff_t n)
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  34 {
  35   if (uc < 0x80)
  36     {
  37       if (n > 0)
  38         {
  39           s[0] = uc;
  40           return 1;
  41         }
  42       /* else return -2, below.  */
  43     }
  44   else
  45     {
  46       int count;
  47 
  48       if (uc < 0x800)
  49         count = 2;
  50       else if (uc < 0x10000)
  51         {
  52           if (uc < 0xd800 || uc >= 0xe000)
  53             count = 3;
  54           else
  55             return -1;
  56         }
  57       else if (uc < 0x110000)
  58         count = 4;
  59       else
  60         return -1;
  61 
  62       if (n >= count)
  63         {
  64           switch (count) /* note: code falls through cases! */
  65             {
  66             case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
  67               FALLTHROUGH;
  68             case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
  69               FALLTHROUGH;
  70             case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
  71           /*case 1:*/ s[0] = uc;
  72             }
  73           return count;
  74         }
  75     }
  76   return -2;
  77 }
  78 
  79 #endif

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